RESUMO
Antibody-mediated responses play a critical role in vaccine-mediated immunity. However, for reasons that are poorly understood, these responses are highly variable between individuals. Using a mouse model, we report that antibiotic-driven intestinal dysbiosis, specifically in early life, leads to significantly impaired antibody responses to five different adjuvanted and live vaccines. Restoration of the commensal microbiota following antibiotic exposure rescues these impaired responses. In contrast, antibiotic-treated adult mice do not exhibit impaired antibody responses to vaccination. Interestingly, in contrast to impaired antibody responses, immunized mice exposed to early-life antibiotics display significantly enhanced T cell cytokine recall responses upon ex vivo restimulation with the vaccine antigen. Our results demonstrate that, in mice, antibiotic-driven dysregulation of the gut microbiota in early life can modulate immune responses to vaccines that are routinely administered to infants worldwide.
Assuntos
Antibacterianos/efeitos adversos , Antibacterianos/imunologia , Formação de Anticorpos/imunologia , Disbiose/imunologia , Vacinas/imunologia , Animais , Antibacterianos/uso terapêutico , Linfócitos T CD4-Positivos/imunologia , Citocinas/metabolismo , DNA Bacteriano , Fezes/microbiologia , Feminino , Microbioma Gastrointestinal/efeitos dos fármacos , Microbioma Gastrointestinal/genética , Microbioma Gastrointestinal/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Modelos Animais , Gravidez , RNA Ribossômico 16S/genética , VacinaçãoRESUMO
Gata3 acts as a master regulator for T helper 2 (Th2) cell differentiation by inducing chromatin remodeling of the Th2 cytokine loci, accelerating Th2 cell proliferation, and repressing Th1 cell differentiation. Gata3 also directly transactivates the interleukin-5 (Il5) gene via additional mechanisms that have not been fully elucidated. We herein identified a mechanism whereby the methylation of Gata3 at Arg-261 regulates the transcriptional activation of the Il5 gene in Th2 cells. Although the methylation-mimicking Gata3 mutant retained the ability to induce IL-4 and repress IFNγ production, the IL-5 production was selectively impaired. We also demonstrated that heat shock protein (Hsp) 60 strongly associates with the methylation-mimicking Gata3 mutant and negatively regulates elongation of the Il5 transcript by RNA polymerase II. Thus, arginine methylation appears to play a pivotal role in the organization of Gata3 complexes and the target gene specificity of Gata3.
Assuntos
Arginina/genética , Metilação de DNA , Fator de Transcrição GATA3/genética , Interleucina-5/genética , Células Th2/metabolismo , Ativação Transcricional , Sequência de Aminoácidos , Animais , Arginina/metabolismo , Western Blotting , Diferenciação Celular , Proliferação de Células , Células Cultivadas , Chaperonina 60/antagonistas & inibidores , Chaperonina 60/genética , Chaperonina 60/metabolismo , Montagem e Desmontagem da Cromatina , Imunoprecipitação da Cromatina , Citocinas/genética , Citocinas/metabolismo , Citometria de Fluxo , Imunofluorescência , Fator de Transcrição GATA3/metabolismo , Imunoprecipitação , Interleucina-5/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Proteínas Mitocondriais/antagonistas & inibidores , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo , Dados de Sequência Molecular , Regiões Promotoras Genéticas/genética , RNA Mensageiro/genética , RNA Interferente Pequeno/genética , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Homologia de Sequência de Aminoácidos , Células Th1/imunologia , Células Th1/metabolismo , Células Th2/imunologiaRESUMO
GATA binding protein 3 (Gata3) is a GATA family transcription factor that controls differentiation of naïve CD4 T cells into T helper 2 (Th2) cells. However, it is unknown how Gata3 simultaneously activates Th2-specific genes while repressing those of other Th lineages. Here we show that chromodomain helicase DNA-binding protein 4 (Chd4) forms a complex with Gata3 in Th2 cells that both activates Th2 cytokine transcription and represses the Th1 cytokine IFN-γ. We define a Gata3/Chd4/p300 transcriptional activation complex at the Th2 cytokine loci and a Gata3/Chd4-nucleosome remodeling histone deacetylase repression complex at the Tbx21 locus in Th2 cells. We also demonstrate a physiological role for Chd4 in Th2-dependent inflammation in an in vivo model of asthmatic inflammation. Thus, Gata3/Chd4 forms functionally distinct complexes, which mediate both positive and negative gene regulation to facilitate Th2 cell differentiation.
Assuntos
Diferenciação Celular/imunologia , DNA Helicases/metabolismo , Fator de Transcrição GATA3/imunologia , Complexos Multiproteicos/imunologia , Células Th2/imunologia , Transcrição Gênica/imunologia , Animais , Asma/genética , Asma/imunologia , Asma/patologia , DNA Helicases/genética , Modelos Animais de Doenças , Fator de Transcrição GATA3/genética , Loci Gênicos/imunologia , Inflamação/genética , Inflamação/imunologia , Inflamação/patologia , Interferon gama/genética , Interferon gama/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Complexos Multiproteicos/genética , Nucleossomos/genética , Nucleossomos/imunologia , Proteínas com Domínio T/genética , Proteínas com Domínio T/imunologia , Células Th2/patologia , Transcrição Gênica/genéticaRESUMO
To develop more effective vaccines and strategies to regulate chronic inflammatory diseases, it is important to understand the mechanisms of immunological memory. Factors regulating memory CD4(+) T helper (Th)-cell pool size and function remain unclear, however. We show that activation of type I invariant natural killer T (iNKT) cells with glycolipid ligands and activation of type II natural killer T (NKT) cells with the endogenous ligand sulfatide induced dramatic proliferation and expansion of memory, but not naïve, CD4 T cells. NKT cell-induced proliferation of memory Th1 and Th2 cells was dependent largely on the production of IL-2, with Th2-cell proliferation also affected by loss of IL-4. Type II NKT cells were also required for efficient maintenance of memory CD4 T cells in vivo. Activation of iNKT cells resulted in up-regulation of IFN-γ expression by memory Th2 cells. These IFN-γ-producing memory Th2 cells showed a decreased capability to induce Th2 cytokines and eosinophilic airway inflammation. Thus, activated NKT cells directly regulate memory CD4 T-cell pool size and function via the production of cytokines in vivo.
