RESUMO
Humanized NOD/SCID/IL-2 receptor γ-chainnull (huNSG) mice recapitulate some features of human T-cell populations that can be exploited in basic and pre-clinical research. CXCR5+ T CD8+ T-cells play an important role in the control of viral infections and tumors. Indeed, they have been associated with low-level HIV replication, making them a possible novel correlate of protection, and potentially useful in the eradication of HIV reservoirs. Here, by flow cytometry, we evaluated the reconstitution of CXCR5+ CD8+ T-cells in huNSG mice engrafted with CD34+ hematopoietic stem cells. This population was readily generated in huNSG mice, and where particularly confined to spleen and lymph nodes. These cells exhibited a follicular-like phenotype, with expression of Programmed Death (PD)-1, Inducible T-cell costimulatory (ICOS), and absence of CCR7. Moreover, CXCR5+ CD8+ T-cells had a higher expression of interleukin (IL)-21 and a higher cytotoxic potential compared with CXCR5- cells. HIV infection did not affect the frequencies of CXCR5+ CD8+ T-cells in secondary lymphoid organs. Finally, taking advantage of the high proportion of naïve T-cells in huNSG mice, we evaluated the in vitro response of splenic T-cells to the follicular profile-polarizing cytokines Transforming Growth Factor (TGF)-ß1 and IL-23. After in vitro treatment, there was an increase in CXCR5+ CD8+ T-cells, which exhibited high levels of PD-1, CD40 L and low expression of CCR7. Thus, there is a reconstitution of CXCR5+ CD8+ T-cells in huNSG mice, supporting the use of this model for exploring the biology and role of this cell population in healthy and diseased conditions.
Assuntos
Linfócitos T CD8-Positivos/imunologia , Receptores CXCR5/imunologia , Animais , Células Cultivadas , Citometria de Fluxo , Infecções por HIV/imunologia , Células-Tronco Hematopoéticas/imunologia , Humanos , Proteína Coestimuladora de Linfócitos T Induzíveis/imunologia , Interleucinas/imunologia , Linfonodos/imunologia , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Receptor de Morte Celular Programada 1/imunologia , Baço/imunologia , Linfócitos T Auxiliares-Indutores/imunologiaRESUMO
CD4+ T follicular helper cells (TFH) were assessed in adult patients with common variable immune deficiency (CVID) classified according to the presence of granulomatous disease (GD), autoimmunity (AI), or both GD and AI (Group I) or the absence of AI and GD (Group II). TFH lymphocytes were characterized by expression of CXCR5 and PD-1. TFH were higher (in both absolute number and percentage) in Group I than in Group II CVID patients and normal controls (N). Within CXCR5+CD4+ T cells, the percentage of PD-1 (+) was higher and that of CCR7 (+) was lower in Group I than in Group II and N. The percentages of Treg and TFH reg were similar in both CVID groups and in N. TFH responded to stimulation increasing the expression of the costimulatory molecules CD40L and ICOS as did N. After submitogenic PHA+IL-2 stimulation, intracellular expression of TFH cytokines (IL-10, IL-21) was higher than N in Group I, and IL-4 was higher than N in Group II. These results suggest that TFH are functional in CVID and highlight the association of increased circulating TFH with AI and GD manifestations.
Assuntos
Imunodeficiência de Variável Comum/imunologia , Regulação da Expressão Gênica/imunologia , Doença Granulomatosa Crônica/imunologia , Linfócitos T Auxiliares-Indutores/imunologia , Linfócitos T Reguladores/imunologia , Adulto , Idoso , Autoimunidade , Ligante de CD40/genética , Ligante de CD40/imunologia , Estudos de Casos e Controles , Imunodeficiência de Variável Comum/complicações , Imunodeficiência de Variável Comum/genética , Imunodeficiência de Variável Comum/patologia , Feminino , Doença Granulomatosa Crônica/complicações , Doença Granulomatosa Crônica/genética , Doença Granulomatosa Crônica/patologia , Humanos , Proteína Coestimuladora de Linfócitos T Induzíveis/genética , Proteína Coestimuladora de Linfócitos T Induzíveis/imunologia , Interleucina-10/genética , Interleucina-10/imunologia , Interleucina-2/farmacologia , Interleucina-4/genética , Interleucina-4/imunologia , Interleucinas/genética , Interleucinas/imunologia , Contagem de Linfócitos , Masculino , Pessoa de Meia-Idade , Fito-Hemaglutininas/farmacologia , Cultura Primária de Células , Receptor de Morte Celular Programada 1/genética , Receptor de Morte Celular Programada 1/imunologia , Receptores CCR7/genética , Receptores CCR7/imunologia , Receptores CXCR5/genética , Receptores CXCR5/imunologia , Transdução de Sinais , Linfócitos T Auxiliares-Indutores/efeitos dos fármacos , Linfócitos T Auxiliares-Indutores/patologia , Linfócitos T Reguladores/efeitos dos fármacos , Linfócitos T Reguladores/patologiaRESUMO
Dendritic cells (DCs) are essential for the maintenance of homeostasis in the organism, and they do that by modulating lymphocyte priming, expansion, and response patterns according to signals they receive from the environment. The induction of suppressive lymphocytes by DCs is essential to hinder the development of autoimmune diseases but can be reverted against homeostasis when in the context of neoplasia. In this setting, the induction of suppressive or regulatory T cells contributes to the establishment of a state of tolerance towards the tumor, allowing it to grow unchecked by an otherwise functional immune system. Besides affecting its local environment, tumor also has been described as potent sources of anti-inflammatory/suppressive factors, which may act systemically, generating defects in the differentiation and maturation of immune cells, far beyond the immediate vicinity of the tumor mass. Cytokines, as IL-10 and TGF-beta, as well as cell surface molecules like PD-L1 and ICOS seem to be significantly involved in the redirection of DCs towards tolerance induction, and recent data suggest that tumor cells may, indeed, modulate distinct DCs subpopulations through the involvement of these molecules. It is to be expected that the identification of such molecules should provide molecular targets for more effective immunotherapeutic approaches to cancer.
Assuntos
Antígeno B7-H1/imunologia , Células Dendríticas/imunologia , Proteína Coestimuladora de Linfócitos T Induzíveis/imunologia , Interleucina-10/imunologia , Neoplasias/imunologia , Linfócitos T Reguladores/imunologia , Fator de Crescimento Transformador beta/imunologia , Antígeno B7-H1/genética , Comunicação Celular , Células Dendríticas/patologia , Regulação da Expressão Gênica , Humanos , Tolerância Imunológica , Proteína Coestimuladora de Linfócitos T Induzíveis/genética , Interleucina-10/genética , Ativação Linfocitária , Neoplasias/patologia , Transdução de Sinais , Linfócitos T Reguladores/patologia , Fator de Crescimento Transformador beta/genética , Microambiente Tumoral/imunologiaRESUMO
Peripheral blood mononuclear cells with T(FH) phenotype from two asymptomatic XLP patients were studied. Normal/high numbers of CXCR5+, CD4+ T cells coexpressing PD-1 were demonstrated. Peripheral blood mononuclear cells (PBMC) from these patients responded to sub-optimal PHA/IL-2 stimulation upregulating ICOS and CD40L and increasing intracellular expression of IL-10, IL-21 and IL-4 by CD4+ T(FH) cells. However when compared to N, the time profile of activation and cytokine synthesis was different in XLP and N. While ICOS and CD40L expression in N decreased after 6-8 days, it continued to increase or was maintained in XLP cultures. Intracellular IL-10, IL-21 and IL-4 reached higher values in XLP than N after 8 days. Rather than the absence of T(FH) cells or their intrinsic inability to respond to stimuli, differences in the time profile of their response could contribute to impair their role as helpers of B lymphocytes.