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Práctica ProfesionalPRODUCCIÓN EDITORIALP. Profesional. Sofía Bustamante Leguia, Universidad de Tarapacá.

REVISTA DE CIENCIAS DE LA SALUD Y MEDICINA

ReCISAM

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Indice

• ReCISAM • Objetivos• Práctica• Etapa 1

• Anexos• Etapa 2




• Anexos

3 pag. 3 pag.4 pag.4 pag.

5-25 pag.26 pag.27 pag.26 pag.

28-29 pag.30 pag.

31-32 pag.30 pag.33 pag.


ReCISAM

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ReCISAM La Revista de Ciencias de la Salud y Medicina es un medio de difusión científica que nace el año 2014 al interior de la Facultad de Ciencias de la Salud de la Universidad de Tarapacá. Publicará trabajos originales sobre temas de interés en la Ciencias de la Salud, Medicina y Ciencias afines.

ObjetivosPromover la creación, divulgación e intercambio de información científica y técnica, entre profesionales, científicos y estudiantes que se desempeñan en las áreas de Ciencias de la Salud, Medicina y Ciencias afines.

Ser una revista científica internacional de reconocido

prestigio, calidad e impacto en las áreas de Ciencias de la Salud, Medicina y Ciencias afines.

Ser una revista que contribuya a la generación, promoción y transferencia científico-tecnológica de conocimientos a la comunidad científica regional, nacional e internacional.

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PrácticaLa practica profesional consistía en distintas actividades, como la edición y elaboración de el numero 3 de la Revista de Ciencias de la Salud “ReCISAM”, actualización de textos en HTML, creación de afiches publicitarios y elaboración de propuestas de diagramación para la aplicación futura de esta Revista de Ciencias de la Salud.

Etapa1La primera etapa consistía en la diagramación de los 15 artículos de la revista. Cada articulo debía estar correctamente editado, las imágenes debían encontrarse en una buena calidad, las tablas debían ser adaptadas al diseño de la revista y las referencias debían ser comprobadas.

A continuación 1 Artículo.

Rev. cienc. salud med. Volumen 3, Número 2, Mayo de 2016.

THE HALLMARK OF CD28, CD2, CD40L AND LFA.1 COSTIMULATORY MOLECULES IN THE MODULATION OF T LYMPHOCYTE RESPONSE

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ARTÍCULO DE REVISIÓN

THE HALLMARK OF CD28, CD2, CD40L AND LFA.1 COSTIMULATORY MOLECULES IN THE MODULATION OF T

LYMPHOCYTE RESPONSE

Eduardo Parra1

Luis Gutiérrez2

Andrea Larrazábal1

1.Escuela de Medicina, Facultad de Ciencias de la Salud, Universidad de Tarapacá, Avenida General Velásquez 1775, Arica, Chile.2.Universidad Arturo Prat, Avenida. Arturo Prat 2120, Iquique, Chile.

Correo autor: [email protected]

RESUMEN La activación de las células T es fundamental para la coordinación de las respuestas inmunes específicas contra patógenos invasores. La iniciación de estas respuestas requiere co-estimulación a través del receptor de las células T (TCR) y de otras moléculas co-estimuladoras ubicadas en la superficie de estas células. La participación de estas señales secundarias son cruciales, ya que la activación de las células T a través del TCR en ausencia de la señal 2 induce energía. A pesar del gran número de moléculas conocidas en la actualidad, cuatro tipos de interacción ligando receptor han sido ampliamente estudiados demostrando ser de mayor importancia en la activación de las células T: CD2/LFA-3, LFA-1/ICAM-1, CD28/B7-1/2, CD40L/CD40. Estas vías parecen inducir distintas funciones efectoras en los subgrupos de células T creando a partir de allí el perfil de la respuesta inmune. Es así, que la vía CD2/LFA-3 parece jugar un papel central en la expansión de las células vírgenes T ayudantes, caracterizándose por una función de adhesividad fuerte y por inducir la producción de TNF-α y IFN-g, pero es un mal inductor de la IL-2. Las células de memoria por otro lado parecen responder preferentemente a la vía LFA-1/ICAM-1, mientras que la interacción CD28/B7-1 es el inductor más eficaz de IL-2 y apoya la proliferación de células T por largos periodos de tiempo a través inducir la expresión de los factores nucleares AP-1, NF -kB, CD28RC y NF-AT. La interacción entre CD40L y CD40 proporciona una señal potente que regula la expresión de moléculas co-estimuladoras en las células presentadoras de antígenos (CPA) e induce la producción de la citoquina IL-12. En adición, la expresión de los tres miembros de la familia MAP quinasa (JNK-1, ERK-2 y p38) también requieren la presencia co-estimuladora de la vía CD28/B7-1 como una segunda señal para una óptima

CORRESPONDENCIA

ABSTRACTT-cell activation is critical for the coordination of specific immune responses against invading pathogens. Initiation of these T-cells responses requires costimulation through the T cells receptor (TCR) and costimulatory molecules expressed on T cells. The participation of these second signals are crucial, since activation of T cells by TCR in the absence of signal 2 induces anergy. Despite the actual number of molecules known, four main receptor/ligand pairs have been extensively studied and have been demonstrated to be of major importance in costimulation of T cells: CD2 / LFA-3, LFA-1/ICAM-1, CD28/B7-1/2, CD40L/CD40. These pathways seem to induce distinct effector functions in T cells subsets and thereby shape the profile of the immune response. The CD2/LFA-3 pathway seems to play a central role for expansion of naive T helper cells and is characterized by a strong adhesive function and production of TNF-α and IFN-g but is a poor inducer of IL-2. Memory cells seem to preferentially respond to LFA-1/ICAM-1 pathway, while CD28/B7-1 is the most efficient inducer of IL-2 and supports long-lasting T cell proliferation, by inducing the expression of AP-1, NF-kB, CD28RC and NF-AT nuclear factors. The CD40L-CD40 interaction delivers a potent signal that up regulates costimulatory molecules on the APC inducing the production of the cytokine IL-12. In addition, all three members of the MAP kinase family (JNK-1, ERK-2 and p38) also require the constimulatory presence of CD28/B7-1 as a second signal for an optimal activation. Interfamily redundancy of receptors/ligands offers an opportunity to regulate distinct T cell response profiles in various micro environments at separate time points of the immune response.Keywords: T-cells, T cells receptor, immune response.

INTRODUCTION

T lymphocyte activation and interleukin-2 (IL-2) production

require at least two signals, generated by the interaction

of antigen/MHC complexes with the T-cell receptor (TCR)

(signal 1) and costimulation provided by the antigen-

presenting cell (APC) through the CD28 receptor on the T

cells (signal 2) (1, 2). The participation of signal 2 is crucial,

since activation of T cells by signal 1 in the absence of signal

2 induces anergy (functional inactivation) (3, 4). All helper T

lymphocytes (CD4+) and most cytotoxic T lymphocytes

(CD8+) express the cell surface molecules CD28, CD2,

activación. La redundancia intrafamiliar de receptores/ligandos ofrece una oportunidad para regular distintos perfiles de respuesta de las células T en distintos micro-ambientes y en distintos tiempos de la respuesta inmune.Palabras Clave: Células T, receptor de las células T, respuesta inmune.


PARRA E. ET AL.

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CD40L and LFA-1. Binding of these molecules to their

respective ligands transduces signals that culminate in the

induction of several nuclear factors (i.e., AP-1. CD28RC,

NF-AT and NF-kB/Rel), which are required for the activation

of the genes necessary to deliver an immune response (5,

6). Most of these nuclear factors would normally act both as

transcriptional activators and repressors, depending on the

gene and the stimuli (7). However, despite the redundancy

in activation pathways, the CD28 receptor has been to

be essential for activation of helper T lymphocytes. It is

responsible for the delivery of the signals necessary to

strongly up-regulate the transcriptional activity of the IL-2

promoter, thus allowing its translation and the production of

IL-2 (1, 5, 6). This growth factor is mainly secreted by antigen

stimulated CD4+ (activated helper T cells).

The secreted IL-2 protein binds to its IL-2 receptor (IL-2R)

on T cells, although this interaction also plays a critical role

in the normal development, differentiation, and proliferation

of a number of immune cells, including B-cells, T cells and

NK cells. The frequency of T cells responding to a nominal

antigen is generally in the range of 1/10,000 or lower, while

the response to super antigens (SAg), which are a family

of bacterial and viral proteins, stimulate about 10 % of all T

cells (5, 6) (9 - 11). Bacterial SAg bind to MHC Class II proteins (1) and subsequently interact with T cells bearing particular

TCRV families. They bind as unprocessed proteins outside

the MHC class II peptide binding grove, and induce

activation of a large number of T cells to proliferate,

release cytokines and mediate cytotoxicity (1) ( 9 - 11). Several

molecules expressed on APC have both adhesive and

costimulatory functions (12, 13). These pathways appear to

be essential for the initiation and maintenance of a T cell

response, because blocking of one or more of the adhesion

receptor-ligand interaction prevents a primary immune

response.

Four main receptor/ligand pairs have been extensively

studied and have been demonstrated to be of major

importance in costimulation of T cells: CD2 / LFA-3, LFA-

1/ICAM-1, and CD28/B7-1/2, CD40L/CD40 (1, 11). These

adhesion/activation pathways seem to induce distinct

effector functions in T cells subsets and thereby shape the

profile of the immune response.

INDUCTION OF SIGNAL ONE AND TWO

The initial phase of T cell-APC interaction culminates with

the delivery of signal one and can be divided into at least

four stages: a) initial T cell target cell adhesion; b) ligation of

the TCR by an antigen/MHC complex; c) antigen dependent

strengthening of T cell-APC adhesion; and d) integration of

TCR costimulatory mediated signals (12 - 14). The induction

of signal 2 delivered by the interaction of costimulatory

molecules on APC such as B7-1/2, LFA-3 and ICAM-

1 with their respective receptors on T cells (CD28, CD2,

and LFA-1), will eventually activate T cells to proliferation

and cytokine production. The initiation of T cell signaling

through the TCR plus CD28, CD2 or LFA-1 induces a series

of biochemical events including kinase and phosphatase

activation and recruitment of scaffold proteins. TCR ligation

triggers the tyrosine phosphorylation of immune receptor

tyrosine-based activation motifs (ITAMs) on the TCR-

associated CD3 complex by the Src family kinases, Lck

and Fyn. This leads to the recruitment and subsequent

activation of the cytoplasmic tyrosine kinases, ZAP 70 and

Syk (15, 16).

These kinases have been shown to induce tyrosine

phosphorylation of linker for activation of T cells (LAT) (17).

LAT, a 36-38 kDa palmitoylated trans membrane protein,

becomes heavily tyrosine phosphorylated after TCR

ligation and associates with a number of effector proteins

including Grb2, Grap, PLCg, Cbl, Vav and p85 subunit

of phosphoinositide 3 kinase (PI3K) (17 - 19). Simultaneous

engagement of the CD28 receptor results in Tec kinase

association (20), p62 dok phosphorylation (21), and PI3K



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association (22 - 24). Initial costimulatory events induce a series of

biochemical events such as Ras activation, phosphoinositide

production, and calcium fluxes culminating in the induction of

genes such as IL-2, IL-2 a chain, and Bcl-XL (25). Two important

downstream pathways mediating these costimulatory events

are the ERK and JNK cascades. The ERK and JNK proteins

are members of the MAPK superfamily involved in proliferative,

apoptotic, and developmental processes. The simultaneous

delivery of these signals is crucial for T cell activation since T

cells that are exposed to APC capable of presenting antigen

but deficient costimulus become anergic (3, 4) (Figure 1).

ANTIGEN PRESENTING CELL

Costimulatory signals are delivered most efficiently by

dendritic cells, less effectively by monocytes and activated

B cells, poorly by resting B cells, and marginally by resting

T cells (26). The best studied dendritic cells in tissue are

the Langerhans´ cells, which differ from those found in

lymphoid tissue in several ways (27). Firstly, they can ingest

antigen and secondly, they lack costimulatory activity.

When the skin is infected, these cells take up antigen and

Figure 1: Two signals are required for optimal activation of T cells. A) Recognition of peptide/MHC in the absence of appropriate costimulatory signals induce functionally unresponsive or anergic T cells. B) Recognition of peptide/MHC in the presence of LFA-3 costimulatory signal induces T cells to be activated to clonal expansion and production of IL-2 in a autocrine manner. C) Recognition of peptide/MHC in the presence of the B7-1

costimulatory signal, activates T cells to proliferation and IL-2 production in a paracrine manner.


PARRA E. ET AL.

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are triggered to migrate through the lymph to the lymphoid

organs. There they differentiate into dendritic cells that

cannot ingest antigen but gain potent costimulatory

activity. Dendritic cells in the lymphoid tissues have a high

capacity to activate immunologically naive T cells and they

constitutively express high levels of MHC class II molecules

as well as a number of various adhesion ligands (28, 29). The

lymphoid dendritic cells are non-phagocytic and do not

readily take up antigen from the extracellular milieu. It has,

however, been suggested that they may be specialized

to present diff e rent viral peptides very efficiently on their

abundant MHC molecules (Figure 2).

Figure 2: In a, APC cell presented antigenic peptides (Ag) in the groove of MHC molecules to T cells. In b, the b-chain of the TCR recognizes SEA bound to the outside of the MHC class II molecule, away from the peptide binding groove. SEA contains two MHC class II binding sites, which bind to the a and b chains on two separate

HLA-DR4 molecules. V, variable region. C, constant region.

MEMBRANE-BOUND MOLECULES

The selectins are particularly important for leukocyte

homing to specific tissues and can be expressed either

on leukocytes (L-selectin) or on vascular endothelium

(P-selectin and E-selectin). L-selectin is expressed on naïve

T cells and binds to the carbohydrate moiety of mucin-like

molecules called vascular addressing, which are expressed

on vascular endothelium (30). The interaction between

L-selectin and the vascular addressing is responsible for

the specific homing of naive T cells to lymphoid organs. The

integrins comprise a large family of molecules that mediate

adhesion between cells and of cells to the extracellular

matrix in both immune and inflammatory reactions (31).

Integrins are made up of a large a chain that has several

cation-binding sites, which are usually occupied by calcium

ions, paired non-covalently with a smaller b chain. Most

integrins expressed on leukocytes have a common b 2

chain, but different a chains.

All T cells express the integrin LFA-1 (CD11a/CD18),

whereas macrophages express both the Mac-1 (CD11b/

CD18) and the gp 150, 95 (CD11c/CD18) molecules (11, 32).

The Ig superfamily includes the Igs, TCR, the CD4 and CD8

co-receptors, the VCAM-1, CD2, LFA-3 (CD58), CD28,

CTLA-4, B7-1 (CD80), B7-2 (CD86), CD40/CD40L and the

ICAMs, 1, 2 and 3. The CD2 /LFA-3, LFA-1/ICAM-1 and

CD28/B7 receptor/ligand pairs have both adhesive and

costimulatory functions and they seem to induce distinct

effector functions in T cell subsets and there by shape

the profile of the immune response. LFA- 3 represents

one of the most broadly expressed adhesion molecules,

whilst B7 is restricted to professional APC (33, 34). The ICAM

family of proteins is distinctly expressed in various tissues;

ICAM-1 is inducible on a wide variety of cells (11), ICAM-

2 is associated with endothelial cells (35), and ICAM-3 is

expressed constitutively on leucocytes (36). B7-1 and B7-2

are costimulatory molecules, which are mainly expressed

on professional APCs (37). CD28 is the only ligand for B7

on naive T cells, whereas activated T cells also express

the B7 ligand CTLA-4. It have been demonstrate that

CTLA-4 functions as a down regulatory molecule for T cells

when ligated to B7 (38, 39). Thus the regulation of an immune

response by costimulatory signals is governed by the tissue

distribution of various adhesion molecule ligands as well as

by the ability of these to transduce distinct signals into the

responding T cell subsets (Fig. 3).



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Figure 3: Some receptor/ligand pairs expressed by T and APC cells, with stimulatory/costimulatory activities. CD28/B7, CD2/LFA-3, LFA-1/ICAM-1, and CD40L/CD40 are the major adhesion/activation pathways for T cell activation. The growth factor IL-2 is produced by activated T lymphocytes in an autocrine and paracrine manner.

CD2/LFA-3 THE MOST IMPORTANT ADHESION PATHWAY OF RESTING T CELLS

CD2 is expressed on all T cells and interacts with LFA-3

(CD58), CD59 and CD48 ligands (40, 41). A role for CD48

has so far been only demonstrated in the murine system,

whereas LFA-3 seems to be the major ligand for CD2 in the

human. The LFA-3 binding site on CD2 has been localized

to the adhesion domain of CD2, which is the amino-terminal

domain 1 (42, 43). It is clear that the CD2/LFA-3 interaction

functions to promote T cell activation and T cell adhesion

(Fig. 4 A). The CD2 molecule on resting T cells expresses

two different epitopes, which have been identified by several

monoclonal antibodies (mAbs) including T11.1 and T11.2 (44, 45). Adhesion to LFA-3 transfected cells has been shown

to be similar by CD45RA+ naive and CD45RO+memory T

helper cells. However, the naïve T cells proliferated more

vigorously compare d to the memory T cells when activated

by SAg and HLA - DR/LFA-3 transfected cells. This

suggests that naive T cells utilize the CD2/LFA-3 pathway

for signal transduction more efficiently than memory cells.

The favorable costimulation of naïve T cells by LFA-3

expressing APC may allow rapid cell expansion during an

early phase of an immune response. A recent study has

demonstrated that mAbs directed at either the adhesion

domain of CD2 or LFA-3 specifically inhibit IL-12-induced

proliferation and IFN-g production by activated T cells

(46). Furthermore, by using activating pairs of CD2 mAb,

CD2 stimulation strongly synergized with IL-12 in inducing

proliferation and IFN-g production.

These data suggest that CD2 is a critical functional link

between T cells and APC by mediating an IL-12/IFN-g

positive feedback loop (46). Moreover, mice lacking the

functional CD2 gene generate specific CTL responses

in vivo, with no CD2 requirement for the maintenance

or activation of memory CTL (47). Taken together, the

adhesive properties of LFA-3 (Fig. 4 A), the potent effect

on proliferation of naive T helper cells (Fig. 4 B, C) and the

ability to induce strong IFN-g production in memory cells,

suggest that LFA-3 may play a central role during the early

immune response of both naive and memory T helper cells

(11). The release of IFN-g would result in up-regulation of

ICAM-1 and B7 and thereby indirectly facilitate amplification

of a secondary immune response.

Figure 4. A) LFA-3 is the major adhesion molecule for resting CD4 + T cells. The adhesion of resting CD4 T cells to untransfected CHO cells and HLA-DR transfected CHO cells co-expressing the adhe-sion molecule B7-1, ICAM-1, L FA-3 and B7-1/LFA-3, was analyzed in a cell adhesion assay of Cr uptake by the labelled T cells. Prolifer-ation of purified naive CD4 CD45RA. B) and memory CD4 CD45R0. C) T cells subsets (0.5x10 /ml) after 3 days of incubation with irra-diated CHO-DR4, CHO-DR4/B7, CHO-DR 4/LFA-3, and CHO-DR4/B7/LFA-3 (1:10 ratio to T cells) in the presence of various doses of SEA. Cultures were pulsed with [36+H] TdR on day 3 and harvested

6 h later.


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LFA-1/ICAM-1, THE MOST VERSATILE AND DYNAMIC PATHWAY

The integrin are a large family of versatile cell surface

heterodimers expressed on resting lymphocytes in a

low-avidity state. LFA-1 is the best characterized integrin

expressed by T cells and is composed of a heterodimer of

the CD11a and CD18 molecules (13, 48). The gross structure

of the first described LFA-1 ligand, ICAM-1, was initially

examined by electron microscopy and showed that the

molecule consisted of five Ig-like domains oriented ”head-

to-tail” (49). ICAM-2 contains two Ig-like domains having 36%

amino acid identity with the first two domains (D1 and D2) of

ICAM-1 (50). Cloning of ICAM-3 demonstrated the existence

of five Ig-like domains that are highly homologous to the

corresponding domains in ICAM-1 and ICAM-2 (51). ICAM-

1 can be induced on a wide variety of cells in response to

inflammatory mediators such as IFN-g, IL-1 and TNF (52).

ICAM-1 seems to be able to regulate cell trafficking during

inflammatory responses and facilitate T cell recognition of

specific antigens (53). ICAM-2 is the major ligand for LFA-

1 on resting endothelial cells, and it has been assumed

that ICAM-2 has important effects on normal recirculation

of lymphocytes (54). ICAM-3 is strongly expressed on

APCs and resting T cells (55). LFA-1 is transiently induced

to a high avidity state by ligation of the TCR or CD2 (56).

Memory T helper cells strongly bind to ICAM-1 expressing

cells in an antigen- independent manner, while naive T

helper cells fail to adhere. Upon pre-treatment with the

mAb NKI-L16, a dramatic increase in adhesion of naive

cells is seen, comparable to that of memory T cells (Fig.

5). Naive and memory T helper cells are characterized by

low and high surface levels of LFA-1, respectively (57) (Fig.

5). NKI-L16-activated naive T cells display an increased

binding without any change in the total number of LFA – 1

molecule expressed, and this argues for changes in LFA-

1 conformation rather than an altered surface level. This

suggests that memory cells express a substantial number

of activated LFA-1 molecules, whilst naive cells express

mainly the inactive form. The inactive form may play a

physiological role in keeping naive cells in the resting state,

thus avoiding irrelevant antigen triggering. Therefore, the

L FA-1/ICAM-1 pathway seems to have a unique dynamic

function in the regulation of T cell adhesion during distinct

differentiation stages.

Figure 5: The NKI-L16 mAb has the ability to increase the adhe-sion of the LFA-1/ICAM-1 pathway in both CD4+45RA+ naive and CD4+45RO memory T cells. Naive A) and memory B) T cells were pre incubated with NKI-L16 mAb for 15 min at 37ºC, before being

added to the transfected CHO cells.

CD28 IS THE PRIMARY CO-STIMULATORY SIGNAL RECEPTOR FOR T CELLS ACTIVATION, PROLIFERATION AND IL-2 PRODUCTION.

The first indication that the CD28 receptor acts as a

costimulatory T cell receptor was the demonstration that

mAb 9.3 (anti-CD28 mAb) combined with phytohemaglutinin

or PMA induced a marked increase of cell growth in human

T cells (57).

The CD28 receptor is a potent costimulators of T cells,

inducing IL-2 production, IL-2 receptor expression and

clonal expansion of T cells (Fig. 6 A). No detectable effect

on resting T cells after stimulation with anti-CD28 mAb

alone can be demonstrated (58). In addition, CD28 activation

induces production of survival factors. This is also true for



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CD152, as expression of the anti-apoptotic gene BclxL is

induced by CD152 ligation at similar levels as by CD28 (59).

The common belief is that CD152 is a negative modulator

of T cell activation, yet Liu et al. claim that CD152 is in

fact a positive costimulator y receptor (60). They have used

tumors expressing wild type and mutant CD80 to address

the role of CD152 in anti-tumor immune responses. The

expression of mutant CD80 that binds to CD152 but not

CD28 on tumor increases their immunogenicity while

reducing their tumorigenicity. In contrast, a mutant that

binds neither CD28 nor CD152 on the same tumor fails to

elicit the same effect. The two major B7 family members,

B7-1 (CD80) and B7-2 (CD86) are only distantly related

based on the amino acid sequence which shows 26%

identity (61). B7-2 is constitutively expressed at low levels

on DCs, resting monocytes and B cells. A variety of factors

regulate B7 expression, including MHC class II ligation,

cross-linking of B cell Ig receptors, CD40 ligation, mitogens

and cytokines such as IL-4 and IFN-g (62). Upon activation,

B7-2 is rapidly up regulated on DCs, monocytes and B cells (63, 64). B7-1, which shows low-level constitutive expression,

is up regulated in response to activation more slowly and to

a lower extent than B7-2 on DCs, monocytes and B cells.

Figure 6: LFA-3 and B7-1 cooperate to induce long lasting T cell proliferation. A) CD4 T cells were activated with SEA and CHO cells expressing HLA-DR4, HLADR4/LFA-3, HLA-DR4/B7, and HLA-DR4/B7-1/LFA-3. Cell proliferation was analyzed at day 3. B) CD4+ T cells were activated with SEA (10 ng/ml) and APC as indicated in

A. Cell proliferation was analyzed at days 3, 5, 7, and 10.

Overlapping and distinct functions of B7-1 and B7-2

costimulatory molecules have been proposed (65, 66).

Transfectants expressing B7-1 or B7-2 were shown to

provide similar costimulatory signals for T cell expansion,

cytokine production and generation of cytotoxic T cells

as determined by the magnitude and kinetics of the

response (66). In another study with mAbs and transfectants

expressing B7-1 or B7-2 it was demonstrated that B7-2

induced higher levels of the Th2 cytokine IL-4 than

that induced by B7-2 (67). They suggested that B7s can

differently influence the Th1/Th2 cytokine profile and that

B7-2 may be more important for the humoral response

than B7-1. It has been hypothesized that B7-2 is more

important in the initiation of T cell activation, whereas

B7-1 is more important for amplification and prolongation

of the immune response (68, 69).In experimental allergic

encephalomyelitis (EAE) (a model for multiple sclerosis

in the mouse) the effect of CTLA-4-Ig and blocking mAbs

towards B7-1 and B7-2 were demonstrated to differently

affect disease (67, 70). Treatment with blocking anti-B7-1

mAb reduced the incidence of disease, while treatment

with blocking anti-B7-2 mAbs enhanced disease severity.

This supported the idea that inflammatory cytokines play a

role in the pathogenesis of the disease. Moreover, detailed

analyses have suggested that the binding affinity of B7-1

for its receptor is somewhat higher than B7-2, whilst B7-2

appears to have a slower dissociation rate than B7-1 (71).

This implies subtle differences in binding characteristics of

the B7 family members (72). Another study confirmed these

data by showing that B7-1 and B7-2 are not equivalent in

the way that repetitive costimulation of CD4+ naive T cells

with B7-2 resulted in production of both IL-2 and IL-4. On

the contrary, the same activation with B7-1 gave high levels

of IL-2 but only low levels of IL-4 (73, 74). In our model, CHO

transfectants expressing either B7-1 or B7-2 were efficient

costimulators for T cell proliferation, cytokine production,

and generation of CTL (1, 74, 75). In addition, B7 and LFA-3

costimulation supported proliferation of T cells stimulated

with nanomolar concentration of the SAg SEA (Fig. 6 A).


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Exposing T helper cells to B7 costimulation resulted in

long-lasting proliferation (Fig. 6 B) and release of high

amount of IL-2. B7 costimulation of naive and memory T

helper cells resulted in high of IL-2 and TNF-a secretion in

both subsets, but only memory cells were able to produce

high amounts of IFN-g (Figure 7).

Figure 7: Differences in IL-2, IFN-g and TNF-b production between CD4+ 45RA (naive) and CD4+45RO (memory) T cell subsets. IL-2 production was measured from the supernatant of freshly purified naive (A, C, E) and memory (B, D,F) helper T cells (0.5 x 106/ml) cultured for 24 and 48 h with the indicated number of irradiated CHO

transfectants (0.5 x 106/ml).

However, analyzing the role of B7-1 and B7-2 costimulation

on IL-2 transcriptional activity, we found that B7-1

costimulation induced 2 times as high IL-2 transcriptional

activity and IL-2 production as CD86 (75). A further dissection

of IL-2 gene transcription demonstrated that B7-1 more

strongly induced NF-kB, AP-1 and CD28RE transcriptional

activity compared with B7-2 (77). Thus, higher levels of

transcriptional activity induced by B7-1 than B7-2 may

explain the higher induction of IL-2 protein induced by B7-1

compared with B7-2.

THE EFFECTS OF COSTIMULATORY SIGNALS ON THE ACTIVITY OF AP-1, NF-AT, NF-kB AND CD28RC TRANSCRIPTION FACTORS

Production of IL-2 is considered to reflect a checkpoint in

commitment to T cell expansion. The regulation of the IL-2

enhancer/promoter region has been studied intensively

as a key target for control of T cell growth. The minimal

inducible IL-2 enhancer region has been identified as

a region located within 300 bp from 5’-end of the IL-2

transcription start site (7, 28, 76). Located within this region is

a number of target DNA-motifs for ubiquitous as well as

T-cell specific transcriptional factors. These include binding

sites for AP-1, the octamer- binding (Oct) protein 1 and

2, nuclear factor of activated T cells (NF-AT), the NF-

kB, and the CD28-responsive complex (CD28RC) (7, 28,

76). The simultaneous presence of these trans activating

factors is required to obtain optimal activation of IL-2 gene

transcription and emphasizes the role of these transcription

factors as a point of signal integration.

Among the transcription factors binding to the IL-2 enhancer,

AP-1 and NF-kB appear to be of central importance for

the immune response. They are involved in the induction

of several different cytokine gene promoters and also

participate as partners in combinatorial interactions between

the NFAT, Oct, and CD28RC-transactivating function (77, 78).

The AP-1 family of transcription factors include Jun, Fos,

ATF-2, and their relatives. This family induces transcription

of numerous genes through tumor promoting agent (TPA)

response elements (TREs) and cAMP response elements

(CREs). Structurally, AP-1 members contain a basic region

leucine zipper (bZIP) motif mediating both dimerization

among family members and DNA binding.

Transcriptional activity of c-Jun and ATF-2 is mediated by

JNK phosphorylation on serine/threonine residues at their

transcriptional activation domains. The NF-AT family of

transcription factors contains a conserved domain distantly



13


related to RHD. NF-AT activity is induced by calcium

signals. Calcium influxes activate the calcium/calmodulin

regulated serine/threonine phosphatase calcineurin, which

dephosphorylates NF-AT and contribute to its nuclear

translocation (79, 80). The kB-DNA motif is recognized by

proteins of the NF-kB/Rel family of transcription factors.

The cRel/ NF-kB transcription factors and IkB proteins are

an evolutionarily conserved family which modulates gene

induction during immune, inflammatory, and acute phase

responses.

The cRel/ NF-kB transcription factors include cRel, p65,

p50, p52 and Rel B, which contain an amino-terminal

Rel-homology domain (RHD). This conserved, 300

amino acid domain contains subdomains mediating DNA

binding, dimerization, nuclear localization, and IkB protein

interactions. Responses to stimuli such as TNFa, IL-1, UV

light, and T-cell costimulation cause IkB phosphorylation,

ubiquitination and proteasome-mediated degradation (81, 82).

In our system, gel shift analysis revealed that stimulation

with antigen alone induced NF-kB binding whereas

induction of AP-1 binding proteins required costimulation.

LFA-3 induces moderate levels of AP-1 and does not

influence levels of NF-kB. Stimulation with B7-1 induces

strongly AP-1 and enhances NF-kB binding (5, 6). Supershift

analysis of the NF-kB complex revealed the presence of

p50, p65, and small amounts of c-Rel proteins while the

AP-1 binding complex contained c-Jun, Jun-D and Fra-1.

The sum of these results suggests distinct effects of B7-1

and LFA-3 costimulation on the activity of AP-1 and NF-kB.

These may partly account for the differential effects of B7-1

and LFA-3 costimulation on IL-2 expression. Luciferase

reporter constructs containing the IL-2 promoter region

(-500 to +60) and multimers of NF-AT, NF-kB, AP- 1 and

CD28RE, showed that DNA binding of NFAT, NF-kB, AP-

1, CD28RE and Oct-1 and transcription of the luciferase

gene driven by multimerized binding sites for these nuclear

factors are differentially induced when SAg is presented by

CHO cells transfected with B7-1 and/or LFA-3. It was shown

that CD2 and CD28 activation induced differing patterns of

NF-AT complexes and NF-AT associated proteins (6). CD28,

but not LFA-3 costimulation led to the induction of factors

binding to the CD28RE in the IL-2 promoter. Mutation of the

CD28RE in the IL-2 promoter reduced the CD28 induced

IL-2 transcription significantly (Figure 8).

Figure 8: Functional demonstration of the specificity of the CD28RE on the transcriptional activity of a wild type and a mutated version of the IL-2 promoter. Leukemia Jurkat T cells were transfected with the wild type IL-2 luciferase reporter gene or with the mutant version. Af-ter 24 h incubation the cells were stimulated with SEE and the CHO-DR, CHO-DR/LFA-3, and CHO-DR/B7-1 transfectants. Eight hours later, samples were harvested and analyzed for luciferase activity. The native CD28RE sequence of the IL-2 promoter 5´-AAATTC-3´ was mutated to 5´-CCTCGA-3´. Luciferase activity is expressed as

arbitrary light units minus background units of buffer alone.

In general, CD28/B7 interaction led to a greater induction of

the IL-2 promoter activity, NF-kB and AP-1 expression. The

combination of overexpression of p65 and c-Jun was very

effective in activating the IL-2 promoter and was dependent

on the CD28RE (83). Overexpression of p65 and c-Jun was

able to hyper induce LFA-3 expression and synergize with

signal 1 to induce similar levels of transcriptional activity to

that observed by the wild type IL-2 promoter after HLA-DR/

B7-1 costimulation.

This led us to propose that transition of IL-2 expression

from an LFA-3 autocrine response to a B7-1 paracrine

response involves the activation of p65 and c-Jun and the

CD28RE in the IL-2 promoter effecting diverse cellular


PARRA E. ET AL.

14


programs such as activation, proliferation, differentiation,

and apoptosis (84, 85). B7-1 costimulation induced strong

activation of all three MAPK members (JNK-1, ERK-

2 and p38), compared with the CD2/LFA-3 pathway that

induce ERK-2 expression but only moderately p38 (Fig. 9).

Contrary to what has been previously proposed, we show

that SEE (signal 1)-induced activation of the ERK pathway

is further increased by costimulation with either B7-1 or

LFA-3. These observations suggest that the integration of

signals that lead to T cell activation and IL-2 induction may

occur in the JNK pathway. It is tempting to suggest that

the differential signaling between CD28 and CD2 in these

events may be explained by the differential effect on the

MAPK observed in our results (Figure 9).

Figure 9: Activation of the JNK-1 (A), ERK-2 (B) and p38 (C) MAPKs by SEE (100 ng/ml) and the CHO-DR, CHO-DR/B7-1 and CHO-DR/LFA-3. Jurkat cells were incubated in medium containing 10% FBS. The cells were stimulated with and without SEE and the various CHO transfectants for the indicated periods of time. Whole cell ex-tracts were pre p a red and assayed using and immune complex kinase assay with GST-c-Jun, MBP, and GSTATF-2 as substrates for JNK, ERK2, and p38, respectively. The cpm activity with respect

to untreated cells is shown.

CONCLUDING REMARKS

During the last decade, the number of members of the

adhesion molecule family has continued to increase. Until

the middle of 90s, the only known ligands to the CD2 and

LFA-1 receptors were LFA -3 and ICAM-1, respectively.

CD48 and CD59 have thereafter been found to serve as

supplementary ligands for CD2 and ICAM-2/ICAM-3 for

LFA - 1.

Moreover, when the receptor-ligand pairs CD28/B7-1 and

CTLA-4/B7-1 were first described, it was anticipated that

other ligands might exist; these have now been identified as

B7-2. At least two different ligands to each receptor seem

to exist within these families of adhesive and costimulatory

molecules. Most likely, the immune system has evolved this

redundancy to fine-tune the immune response.

The need for T cell costimulation has been shown to be

extremely important in the generation of potent T cell

responses, especially when the antigen in question is

weakly immunogenic. It has now been demonstrated that

T cells actually acquire T cell costimulatory molecules from

APC upon activation. Depending on the level of signal 1

and the level of expression of costimulatory molecules,

this phenomenon can have either immune stimulatory or

immune regulatory consequences.

REFERENCES

1. Fontana F, Vance R. Two signal models in immunity. Immunological Reviews. 2011; 243: 26-39.

2. Samelson L. Lymphocyte activation. Current opinion in Immunology. 1989; 2: 210-214.

3. Schwartz R. T cell anergy. Annu Rev Immunol. 2003; 21: 305-334.

4. Fathman G, Lineberry N. Molecular mechanisms of CD4+ T-cell anergy. Nature Reviews Immunology.



15


2007; 7: 599-609.5. Parra E, Varga M, Sigvardsson M, Hedlund G, Kalland

T, Leanderson T, et al. Costimulation of CD4+ T cells with B7 and LFA-3 induce distinct effect on AP-1 and NF-kB. J Immunol. 1995; 155: 1132-1141.

6. Parra E, Varga M, Hedlund G, Kalland T, Dohlsten M. Costimulation of B7-1 and LFA-3 targets distinct nuclear factors that bind to the Interleukin-2 promoter: B7-1 negatively regulates LFA-3-induced NF-AT binding. Mol Cell Biol. 1997; 17: 1314-1325.

7. Cheng J, Montecalvo A, Kane L. Regulation of NF-kB induction by TCR/CD28. Immunol Res. 2011; 50: 113-117.

8. Li T, Zhu J, Wang F, Leng X. Down regulation of Donor Kupffer Cell Expression reduced recipient lymphocyte activation and secretion of interleukin-2 in vitro. Transplant Proc. 2015; 47: 2985-2990.

9. Herman A, Kappler J, Marrack P, Pullen A. Superantigens: mechanism of T-cell stimulation and role in immune response. Ann Rev Immunol. 1991; 9: 745-772.

10. Fischer H, Gjörloff A, Hedlund G, Hedman H, Lundgren E, Kalland T, et al. Stimulation of human naïve and memory T helper Cells with bacterial superantigen. J Immunology. 1992; 148: 1993-1998.

11. Parra E, Wingren A, Hedlund G, Kalland T, Dohlsten M. The role of B7-1 and LFA-3 in costimulation of CD8+ T cells. J Immunol. 1997; 158: 637-47.

12. Parra E, Wingren A, Hedlund G, Sjögren H, Kalland T, Dohlsten M. Human Naive and Memory T- helper cells display distinct adhesion properties to ICAM-1, LFA-3 and B7 molecules. Scand J Immunol; 1993; 38: 508-16.

13. Fontana M, Vance R. Two signal models in innate immunity. Immunological Reviews. 2011;243(1):26-39.

14. Baxter A, Hodgkin P. Activation rules: the two-signal theories of immune activation. Nat Rev Immunol. 2002; 2: 439-446.

15. Walk S, March M, Ravichandran K. Roles of Lck,

Syk and ZAP-70 tyrosine kinases in TCR-mediated phosphorylation of the adapter protein Shc. Eur J Immunol. 1998; 28: 2265-2275.

16. Alberola J, Takaki S, Kerner J, Perlmutter R. Differential signaling by lymphocyte antigen receptors. Annu Rev Immunol. 1997; 15: 125-154.

17. Wonerow P, Watson S. The transmembrane adapter LAT plays a central role in immune receptor signaling. Oncogene. 2011; 44: 6273-6283.

18. Finco T, Kadlecek T, Zhang W, Samelson L, Weiss A. LAT is required for TCR-mediated activation of PLC gamma and the ras pathway. Immunity. 1998; 9: 617-626.

19. Zhang W, Trible R, Samelson L. LAT palmitoylation: its essential role in membrane microdomain targeting and tyrosine phosphorylation during T cell activation. Immunity. 1998; 9: 239-246.

20. Yang W, Ghiotto M, Barbarat B, Olive D. The role of Tec protein - tyrosine kinase in T cell signaling. J Biol Chem. 1999; 274: 607-617.

21. Nunes J, Truneh A, Olive D, Cantrell D. Signaling transduction by CD28 costimulatory receptor on T cells. B7-1 and B7-2 regulation of tyrosine kinase adaptor molecules. J Biol Chem. 1996; 271:1591-1598.

22. August A, Dupont B. CD28 of T lymphocytes associates with phosphatidylinositol 3-kinase. Int Immunol. 1994; 6: 769-774.

23. Cai Y, Cefai D, Schneider H, Raab M, Nabavi N, Rudd C. Selective CD28pYMNM mutations implicate phosphatylinositol 3-kinasein CD86-CD28-mediated costimulation. Immunity. 1995; 3: 417-426.

24. Truitt K, Hicks C, Imboden J. Stimulation of CD28 triggers an association between CD28 and phosphatidylinositol 3-kinase in Jurkat T cells. J Exp Med. 1994; 179: 1071-1076.

25. Boise L, Noel P, Thompson C. CD28 and apoptosis. Curr Opin Immunol. 1995; 7: 620-625.

26. Jenkins M, Johnson J. Molecules involved in T-cell costimulation. Curr Op Immunol. 1993; 5: 361-382.


PARRA E. ET AL.

16


27. Steinman RM. The dendritic cell system and its role in immunogenicity. Ann. Rev. Immunol. 1991; 9: 271-296.

28. Croft M. Activation of naive, memory and effector T cells. Curr Op Immunol. 1994; 6: 431-442.

29. Stingl G, Bergstreser P. Dendritic cells: a major story unfolds. Immunol Today. 1995; 16: 330-333.

30. McEver R. Role of selectins in leukocyte adhesion to platelets and endothelium. Ann NY Acad Sci. 1994; 714: 1859.

31. Hogg N, Berlin C. Structure and function of adhesion receptors in leukocyte trafficking. Immunol Today. 1995; 16: 327-330.

32. Hemler M. VLA proteins in the integrin family: structures, functions, and their role on leukocytes. Ann Rev Immunol. 1990; 8: 365-400.

33. Moingeon P, Chang H, Sayre P, Clayton L, Alcover A, Gardner P, Reinherz E. The structural biology of CD2. Immunol Rev. 1989; 111: 111-132.

34. Hahn W, Menu E, Bierer B. In Lymphocyte Adhesion Molecules, Ed Y Shimizu, RG. Landes Company. 1993: 105.

35. Fawcett J, Holness C, Needham L, Turley H, Gatter K, Simmons D. Molecular cloning of ICAM-3, a third ligand for LFA-1, constitutively expressed on resting leukocytes. Nature. 1992; 360: 481-484.

36. Vazeux R, Hoffman P, Tomita J, Dickinson E, Jasman R, John T, et al. Cloning and characterization of a new intercellular adhesion molecule ICAM-R. Nature. 1992; 360: 485-488.

37. Linsley P, Ledbetter J. The role of the CD28 receptor during T cell responses to antigen. Ann Rev Immunol. 1993; 11: 191-212.

38. Krummel M, Allison J. CD28 and CTLA-4 have opposing effects on the response of T cells to stimulation. J Exp Med. 1995; 182: 459-465.

39. Gribben J, Freeman G, Boussiotis V, Rennert P, Jellis C, et al. CTLA-4 mediates antigen-specific apoptosis of human T cells. Proc Natl Acad Sci USA. 1995; 92: 811-823.

40. Hahn W, Rosenstein Y, Calvo V, Burakoff S, Bierer B. A distinct domain of CD2 regulates ligand avidity and T cell responsiveness to antigen. Proc. Natl. Acad. Sci. 1992; 89: 7179-7183.

41. Kato K, Koyanagi M, Okada H, Takanashi T, Wong Y, Williams A, et al. CD48 is a counter- receptor for mouse CD2 and is involved in T cell activation. J Exp Med. 1992; 176: 1241-1252.

42. Selvaraj P, Plunkett M, Dustin M, Sanders M, Shaw S, Springer T. The T lymphocyte glycoprotein CD2 binds the cell surface ligand LFA-3. Nature. 1987; 326: 400-407.

43. Arulanandam A, Withka J, Wyss D, Wagner G, Kister A, Pallai P, et al. The CD58 (LFA-3) binding site is a localized and highly charged surface area on the AGFCCC face of the human CD2 adhesion domain. Proc Natl Acad Sci. 1993; 90: 11613-11617.

44. Meuer S, Hussey R, Fabbi M, Fox D, Acuto O, Fitzgerald K, et al. An alternative pathway of T cell activation: a functional role for the 50 Kd T11 sheep erythrocyte receptor protein. An alternative Pathway of T cell activation: a functional role for the 50 Kd T11 Sheep erythrocyte receptor protein. Cell. 1984; 36: 397-406.

45. Bierer B, Sleckman B, Ratnofsky S, Burakoff S. The biologic roles of CD2, CD4 and CD8 in T cell activation. Ann Rev Immunol. 1989; 7: 579-599.

46. Gollob J, Li J, Reinherz E, Ritz J. CD2 regulates responsiveness of activated T cells to interleukin 12. J. Exp Med. 1995; 182: 721-731.

47. Evans C, Rall G, Killeen N, Littman D, Oldstone MBA. CD2-deficient mice generate virus-specific cytotoxic T lymphocytes upon infection with lymphocytic choriomeningitis. J. Immunol 1993; 151: 6259-6264.

48. Hynes R. Integrins: versatility, modulation and signaling in cell adhesion. Cell. 1992; 69: 11-25.

49. Staunton D, Dustin M, Erickson H, Springer T. The arrangement of the immunoglobulin-like domain of ICAM-1 and the binding sites for LFA-1 and rhinovirus. Cell. 1990; 61: 243-254.



17


50. Staunton D, Dustin M, Springer T. Functional cloning of ICAM-2, a cell adhesion ligand for LFA-1 homologous to ICAM-1. Nature. 1989; 339: 61-63.

51. De Fougerolles A, Qin X, Springer T. Characterization of the function of intercellular adhesion molecule (ICAM)-3 and comparison with ICAM-1 and ICAM-2 in immune responses. J Exp Med. 1994; 179: 619-629.

52. Dustin M, Rothlein R, Bhan A, Dinarello C, Springer T. T cell receptor crosslinking transiently stimulates adhesiveness through LFA-1. Nature. 1988; 341: 619-622.

53. Altmann D, Hogg N, Trowsdale J, Wilkinson D. Cotransfection of ICAM-1 and HLA-DR reconstitutes human antigen-presenting cell function in mouse L cells. Nature. 1989; 338: 512-514.

54. De Fougerolles A, Stacker S, Schwarting R, Springer T. Characterization of ICAM-2 and evidence for a third counter receptor for LFA-1. J Exp Med. 1991; 174: 253-267.

55. De Fougerolles A, Springer T. Intercellular adhesion molecule 3, a third adhesion counter-receptor for lymphocyte function-associated molecule 1 on resting lymphocytes. J Exp Med. 1992; 175:185-90.

56. Van Kooyk Y, Figdor C. Lymphocyte adhesion mediated by integrins. Res Immunol. 1993; 144: 709-722.

57. Valmu L, Autero M, Siljander P, Patarroyo M, Gahmberg CG. Phosphorylation of the beta-subunit of CD11/CD18 integrins by protein kinase C correlates with leukocyte adhesion. Eur J Immunol. 1991; 21: 2857-2862.

58. Springer T. Traffic signals for lymphocyte re circulation and leukocyte emigration: The multistep paradigm. Cell. 1994; 76: 301-314.

59. June C, Ledbetter J, Gillespie M, Lindsten T, Thompson C. T-cell proliferation involving the CD28 pathway is associated with cyclosporine-resistant interleukin 2 gene expression. Mol Cell Biol. 1987; 7: 4472-4481.

60. Blair P, Riley J, Levine B, Lee K, Craighead N, et al. CTLA-4 ligation delivers a unique signal to resting human CD4 T cells that inhibits interleukin-2 secretion

but allows Bcl-X(L) induction. J Immuno. 1998; 160: 12-21.

61. Zheng P, Wu Y, Guo Y, Lee C, Liu Y. B7-CTLA4 interaction Enhances both production of antitumor cytotoxic T Lymphocytes and resistance to tumor challenge. Proc Natl Acad Sci USA. 1998; 95: 6284-6296.

62. Expression of costimulatory molecules B7-1 (CD80) and B7-2 (CD86) on human hepatocellular carcinoma. Hepatology. 1997; 25(5): 1108-1114

63. Hathcock K, Laszlo G, Pucillo C, Linsley P, Hodes R. Comparative analysis of B71 and B7-2 costimulatory ligands: expression and function. J Exp Med. 1994; 180: 631-639.

64. Caux C, Vanbervliet B, Massacrier C, Azuma M, Okumura K, Lanier L, et al. B70/B7-2 is identical to CD86 and is the major functional ligand for CD28 expressed on human dendritic cells. J Exp Med. 1994; 180: 1841-1848.

65. Inaba K, Wi t m e r-Pack M, Inaba M, Hathcock KS, Sakuta H, Azuma M, et al. The tissue distribution of the B7-2 costimulator in mice: abundant expression on dendritic cells in situ and during maturation in vitro. J Exp Med. 1994; 180: 1849-1857.

66. Fleischer J, Soeth E, Reiling N, Grage-Griebenow E, Flad HD and Ernst M. Differential expression and function of CD80 (B7-1) and CD86 (B7-2) on human peripheral blood monocytes. Immunology. 1996; 89: 592-599.

67. Slavik J, Hutchcroft J, Bierer B. CD80 and CD86 are not equivalent in their ability to induce the tyrosine phosphorylation of CD28. J Biol Chem. 1999; 274: 3116-3123.

68. Freeman G, Boussiotis V, Anumanthan A, Bernstein G, Ke X, Rennert P, et al. B7-1 and B7-2 do not deliver identical costimulatory signals, since B7-2 but not B7-1 preferentially costimulates the initial production of IL-4. Immunity 1995; 2: 523-529.

69. Freeman G, Borrielo F, Hodes R, Reiser H, Hathcock


PARRA E. ET AL.

18


K, Laszlo G, et al. Uncovering of functional alternative CTLA4 counter-receptor in B7 deficient mice. Science. 1993; 262: 907-910.

70. Lenschow D, Su G, Zuckerman L, Nabavi N, Jellis C, Gray G, et al. Expression and functional significance of an additional ligand for CTLA-4. Proc Natl Acad Sci USA. 1993; 90: 11054-11063.

71. C ross A, Girard T, Giacoletto K, Evans R, Keeling R, Lin R, et al. Long-term inhibition of murine experimental autoimmune encephalomyelitis using CTLA-4-Fc supports a key role for CD28 costimulation. J Clin Invest. 1996; 95: 2783-2792.

72. Linsley P, Greene J, Brady W, Bajorath J, Ledbetter J, Peach R. Human B7-1 (CD80) and B7-2 (CD86) bind with similar avidities but distinct kinetic to CD28 and CTLA-4 receptors. Immunity. 1994; 1: 793-805.

73. Robey E, Allison J. T-cell integration of signals from the antigen receptor and costimulatory molecules. Immunol Today. 1995; 16: 306-310.

74. Kuchroo V, Prabhu Das M, Brown J, Ranger A, Zamvil S, Sobel R et al. B7-1 and B7-2 costimulatory molecules activate differentially the Th1/Th2 developmental pathways: Application to autoimmune disease therapy. Cell. 1995; 80(5): 707-718.

75. Freeman G, Boussiotis V, Anumanthan A, Bernstein G, Ke X, Nadler L, et al. B7-1 and B7-2 do not deliver identical costimulatory signal, since B7-2 but not B7-1 preferentially costimulates the initial production of IL-4. Immunity. 1995; 2: 523-532.

76. Surest M, Whitmire J, Harrington L, Larsen C, Pearson T, Altman J, Ahmed R. Role of CD28-B7 interaction in generation and maintenance of CD8 T cell memory. The Journal of Immunology. 2001; 167(10): 5565-5578.

77. Lanier L, O´Fallon S, Somoza C, Linsley P, Okumura K, Azuma M, et al. CD80 (B7) and CD86 (B70) provide similar Costimulatory signals for T cell proliferation, cytokine production, and generation of CTL. J Immunol. 1995; 154: 97-108.

78. Pan F, Ye Z, Cheng L, Liu J. Myocyte enhancer

factior 2 mediates calcium- dependent transcription of the interleukin-2 gene in T lymphocytes: a calcium signaling module that is distinct from but collaborates with the nuclear factor of activated T cells (NFAT). J Biol Chem. 2004; 279(15): 14477-14780.

79. Ghosh P, Tan T, Rice N, Sica A, Young H. The interleukin 2 CD28-responsive complex contain at least three members of the kB family: c-rel, p50, and p65. Proc natl Acad Sci USA. 1993; 90: 1696-1705.

80. Andreucci J, Grant D, Cox D, Tomc L, Prywes R, Goldhamer D et al. Composition and Function of AP-1 Transcription Complexes during Muscle Cell Differentiation. Journal of Biological Chemistry. 2002; 277(19): 16426-16432.

81. Salowe S, Hermes J. Competitive and slow-binding inhibition of calcineurin by drug x immunophilin complexes. Arch Biochem Biophys. 1998; 355(2): 165-174.

82. Rao A. NF-ATp: a transcription factor required for the coordinate induction of several cytokine genes. Immunol Today. 1994; 15: 274-281.

83. Baldwin A. The NF-kappa B and I kappa B proteins: new discoveries and insights. Annu Rev Immunol. 1996; 14: 649-683.

84. Zandi E, Chen Y, Karin M. Direct phosphorylation of IkappaB by IKK alpha and IKK beta: discrimination between free and NF-kappaB-bound substrate. Science. 1998; 281: 1360-1363.

85. Parra E, Mcguire K, Hedlund G, Dohlsten M. Overexpression of RelA and c-Jun substitutes for B7-1 costimulation by targeting the CD28RE within the IL-2 promoter. J Immunol. 1998; 160: 5374-5386.

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Etapa 2 En la segunda etapa se debía confeccionar la portada de la revista, para ello se debía tomar una fotografía propia y editarla. Este numero al contar con mas artículos de radiología, se confeccionó una portada acorde a un tema radiológico.

A continuación portada de la revista.

Etapa 3Realizar distintas propuestas de afiches publicitarios insertos en la revista. Estos afiches si bien son de eventos o instituciones prestigiosas no contaban con su propio afiche o en algunos casos una buena publicidad. Estos afiches solo estarán dentro de la revista como anexos.

A continuación 2 publicidades.

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ReCISAMR

eCISA

M VO

L3, Nº 2, M

AYO D

E 2016 ISSN 0719-6008

Ponemos a disposición de toda la comunidad científica los artículos correspondientes al número de Mayo, publicados en la Revista de Ciencias de la Salud y Medicina.


ReCISAM

EDITORIALART. DE INVESTIGACIÓN

ART. DE REVISIÓN Y DOCUMENTO

21

Publicidades

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Etapa 4En esta etapa se debían adaptar los distintos artículos de los 3 números de la revista a una versión Html, en la pagina web: “www.rcienciasdelasaludymedicina.cl”, que aun se encuentra en proceso de actualización.

A continuación se presentan las siguientes capturas del sitio web:www.rcienciasdelasaludymedicina.cl/new

Etapa 5Se debían realizar posibles propuestas de diseño para una aplicación movil, donde el cliente podría leer la revista de manera sencilla, lograr una mayor accesibilidad y popularidad entre los interesados.

A continuación se presentan la propuesta.

24

Articulos en HTML

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Diseño para aplicación móvil

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PRÁCTICA PROFESIONALPRODUCCIÓN EDITORIAL

P. Profesional. Sofía Bustamante Leguia, Universidad de Tarapacá.


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