RESUMO
OBJECTIVES: We evaluate the frequency and functional response of innate immune cells in peripheral blood (PB) from patients with common variable immunodeficiency (CVID) and healthy controls upon activation with agonists of the Toll-like receptors (TLR) TLR2, TLR4, and TLR9. In addition, several nonsynonymous single nucleotide polymorphisms (SNPs) within these TLR genes were examined. METHODS: Flow cytometry was used to perform immunophenotyping and evaluate the expression of cell surface markers. Levels of cytokines in the culture supernatants were evaluated using cytometric bead array technology. SNPs in the TLR genes were evaluated from genomic DNA using different sequencing techniques. RESULTS: Our results demonstrate that the frequency of CD1d-restricted TCR invariant natural killer T cells in PB was significantly reduced in the patients with CVID. A marked, though not significant, reduction in absolute numbers of plasmacytoid dendritic cells and natural killer cells was also observed in these patients. Interestingly, CD80 and CD86 expression on innate cells upon stimulation with TLR ligands was not altered in the patients although 3 of them exhibited low baseline levels of these surface molecules on monocytes compared to healthy controls. We also observed a significant increase in TNF-alpha levels in supernatants of PB mononuclear cells from CVID patients after stimulation with lipopolysaccharide. Finally, no association was found between the presence of nonsynonymous SNPs within the TLR genes and the clinical presentation of CVID. CONCLUSIONS: Taken together, our study demonstrates than innate immune responses are disturbed in some CVID patients and prompts the evaluation of innate immunity genes as candidates to explain the CVID clinical phenotype.
Assuntos
Imunodeficiência de Variável Comum/imunologia , Imunidade Inata/imunologia , Receptores Toll-Like/imunologia , Adulto , Antígenos CD/genética , Antígenos CD/imunologia , Antígenos CD/metabolismo , Antígenos de Superfície/imunologia , Imunodeficiência de Variável Comum/genética , Citocinas/biossíntese , Citocinas/imunologia , Citocinas/metabolismo , Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Feminino , Humanos , Células Matadoras Naturais/imunologia , Células Matadoras Naturais/metabolismo , Lipopolissacarídeos/imunologia , Masculino , Pessoa de Meia-Idade , Monócitos/imunologia , Monócitos/metabolismo , Polimorfismo de Nucleotídeo Único , Receptores Toll-Like/agonistas , Receptores Toll-Like/genética , Fator de Necrose Tumoral alfa/biossíntese , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/imunologia , Regulação para Cima/genética , Adulto JovemRESUMO
In Colombia, most cases of human cutaneous leishmaniasis are caused by Leishmania (Viannia) panamensis. Interestingly, up to 30% of the exposed population do not suffer from clinical leishmaniasis although it is likely that they are continuously infected with Leishmania parasites. Since it is believed that the induction of efficient Th1 immune responses protects against Leishmania infections both in humans and in animal models, we determined if endemically exposed asymptomatics showed stronger Leishmania-specific Th1 immune responses than patients with active localized cutaneous leishmaniasis (LCL). We found that Montenegro skin test responses were slightly higher among asymptomatic individuals compared to patients suffering from LCL. However, PBMC from patients with LCL showed similar Leishmania-specific proliferative responses compared to PBMC from asymptomatic individuals. Furthermore, PBMC from both groups also secreted similar amounts of IFN-gamma, IL-12p40 and IL-10 after in vitro exposure to L. panamensis. No IL-4 was detected in the supernatants. Taken together our results suggest that lack of LCL development in endemically exposed asymptomatics cannot be explained by stronger systemic anti-Leishmania Th1 immune responses or decreased Th2 responses in these individuals in comparison to individuals who develop LCL. It may be possible that other mechanisms are responsible for resistance to cutaneous leishmaniasis in Colombia in endemically exposed asymptomatics.