In addition, PBMCs collected from treated and untreated mucosal leishmaniasis (ML) and visceral leishmaniasis (VL) patients, as well as in healthy subjects living in endemic region of disease, were in vitro stimulated, when IFN-γ, IL-4 and IL-10 levels were evaluated in the cell supernatant.
In contrast, the pathophysiological mechanism of VL has received ample support by the promotion of Th2 cytokines (IL-4 and IL-10) in the presence of arsenic-exposed Leishmania parasites (LdAS).
Furthermore, stimulation of PBMC isolated from VL patients with rLdcTXN resulted in up-regulation of IL-4 and IL-10 production whereas IL-12 and IFN-γ was significantly down-regulated suggesting a pivotal role of cTXN in provoking the immune suppression during VL.
Combined neutralization of interferon gamma and tumor necrosis factor alpha induces IL-4 production but has no direct additive impact on parasite burden in splenic cultures of human visceral leishmaniasis.
Our study signifies no possible association of functional IL-4 polymorphisms with Indian VL and postulate other vital genes involved in the IL-4 pathway may provide genetic clues to elucidate of IL-4 regulation and immune-pathogenesis during VL.
Immunization with rLdp45 exerted considerable prophylactic efficacy (∼85%) supported by an increase in mRNA expression of iNOS, IFN-γ, TNF-α and IL-12 and decrease in TGF-β and IL-4, indicating its potential as a vaccine candidate against VL.
Twenty-three single nucleotide polymorphisms (SNPs) were genotyped in the cytokine 5q23.3-q31.1 region IRF1-IL5-IL13-IL4-IL9-LECT2-TGFBI in 102 families (323 DTH+; 190 DTH-; 123 VL individuals) from a VL endemic region in northeast Brazil.
Kinetoplastid membrane protein-11 DNA vaccination induces complete protection against both pentavalent antimonial-sensitive and -resistant strains of Leishmania donovani that correlates with inducible nitric oxide synthase activity and IL-4 generation: evidence for mixed Th1- and Th2-like responses in visceral leishmaniasis.
Transmission disequilibrium testing with robust variance estimates confirmed association in the presence of linkage between VL per se and IL4 (P=0.008) but not IL9.
Further studies are indicated to determine whether the immunologic detection of IL-4 produced in human visceral leishmaniasis is obscured because of sequestration by soluble receptor and whether the production of sIL-4R is relevant to the pathogenesis of visceral leishmaniasis.