MicroRNA 155 (miR155) promotes CD4<sup>+</sup> Th1 responses and IFN-γ production by targeting suppressor of cytokine signaling-1 (SOCS1) and Src homology-2 domain-containing inositol 5-phosphatase 1 (SHIP-1) and therefore could play a role in the resolution of VL.
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.
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.
The protection against VL was associated with increased production of nitric oxide (NO), interferon gamma (IFN-γ), IL-17A, and tumor necrosis factor alpha by splenic cells restimulated <i>ex vivo</i> with <i>L. infantum</i> antigens.
The in vitro peptide stimulation of peripheral blood mononuclear cells (PBMC) from cured HLA-A02<sup>+</sup> visceral leishmaniasis (VL) subjects produced significantly higher IFN-γ, IL-2 and IL-12 compared to no peptide control healthy subjects.
This paper examines the IL-2, IFN-γ, IFN-γ-induced protein 10 (IP-10), and monokine-induced-by-IFN-γ (MIG) levels in whole blood-stimulated <i>in vitro</i> with soluble <i>Leishmania</i> antigen (SLA)-taken from asymptomatic individuals and patients treated for VL living in a post-outbreak (<i>Leishmania infantum</i>) area in Spain, and in an endemic (<i>Leishmania donovani</i>) area of Bangladesh.
Results indicated that the administration of live recombinant Leishmania produced a significant high level of IFN-γ accompanied by reduced levels of IL-10 as compared to wild-type parasites as live vaccine control, thus suggesting the induction of a Th1-type immune response in a mouse model of visceral leishmaniasis.
The stimulation of peripheral blood mononuclear cells with r-LdODC up-regulated IL-10 production but not IFN-γ production from CD4(+) T cells in active as well as cured visceral leishmaniasis cases, indicating a pivotal role for r-LdODC in causing strong immune suppression in a susceptible host.
This study aimed to identify putative functional polymorphisms in the IFNGR1 gene, and to determine whether differences in expression of interferon-γ (IFNG) and IFNGR1 at the RNA level are associated with pathogenesis of VL and/or PKDL in Sudan.
Most importantly, blockade of IFNγ in ex-vivo splenic aspirate cultures demonstrated that despite the progressive nature of their disease, the endogenous IFNγ produced in patients with active VL serves to limit parasite growth.
In the primary domestic reservoir of VL, dogs, we define occurrence of both CD4(+) and CD8(+) T cell exhaustion as a significant stepwise loss of Ag-specific proliferation and IFN-γ production, corresponding to increasing VL symptoms.
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.