METHODS: Anti-retroviral therapy (ART) naïve HIV-seropositive individuals (progressors, n=16) and long-term non-progressors (LTNPs, n=10) were recruited for this study. We employed multi-color flow cytometry on frozen peripheral blood mononuclear cells (PBMCs) to determine iNKT subset frequencies, the levels of co-inhibitory 2B4 expression, and intracellular IFN-γ production. CD1d tetramer was used to characterize iNKT cells.
RESULTS: We report significantly lower level of 2B4 expression on bulk LTNPs iNKT cells as well as on their CD4 subsets compared to HIV progressors. Furthermore, the iNKT cells from LTNPs produced higher amount of IFN-γ than HIV progressors as detected by intracellular cytokine staining. Interestingly, the frequency of 2B4iNKT cells of progressors but not LTNPs significantly correlates with CD4 T cell count, HIV viral load and IFNγ production by iNKT cells.
CONCLUSION: Our results suggest that in addition to suppressed HIV replication, diminished 2B4 expression and associated co-inhibitory signaling, and substantial production of IFN-γ could contribute to preserved iNKT cell phenotype in LTNPs.
MATERIALS AND METHODS: The extracts were obtained sequentially with petroleum ether, ethyl acetate and water using Soxhlet apparatus. The anti-inflammatory property of the identified compounds using GC- MS spectroscopy was evaluated in silico. The antioxidant activity was performed by DPPH and H2O2 method whereas anti-inflammatory study was carried out by HRBC membrane stabilization method. Terpenoids were found to be a major constituents in petroleum ether extract while, phenols and flavonoids were predominantly found in ethyl acetate extract.
RESULTS AND DISCUSSION: The GC-MS analysis of the extract revealed six major molecules including Squalene, 19β, 28-epoxyleanan-3-ol and 2-tu-Butyl-5-chloromethyl-3-methyl-4-oxoimidazolidine- 1-carboxylic acid. The ethyl acetate extract showed a significant antioxidant activity (P<0.01) in both DPPH method (70.87%) and H2O2 method (73.58%) at 200 μg mL-1. Increased membrane stabilization of petroleum ether extract was observed in the in vitro anti-inflammatory activity study. A strong relationship between the terpenoid content and anti-inflammatory activity was obtained from the correlation (0.971) and docking study.
CONCLUSION: These results justify T. involucrata to be a rich source of terpenoids with potent anti- inflammatory property.
METHODS: Cytokines were measured using a commercial Bio-plex Pro Human Cytokine Grp I Panel 17-plex kit (BioRad, Hercules, CA, USA). Inflammation was assessed by measuring an array of plasma cytokines, and phenotypic alterations in CD4+ T cells including circulating Tfh cells, CD8+ T cells, and TCR iVα7.2+ MAIT cells in chronic HBV, HCV, and HIV-infected patients and healthy controls. The cells were characterized based on markers pertaining to immune activation (CD69, ICOS, and CD27) proliferation (Ki67), cytokine production (TNF-α, IFN-γ) and exhaustion (PD-1). The cytokine levels and T cell phenotypes together with cell markers were correlated with surrogate markers of disease progression.
RESULTS: The activation marker CD69 was significantly increased in CD4+hi T cells, while CD8+ MAIT cells producing IFN-γ were significantly increased in chronic HBV, HCV and HIV infections. Six cell phenotypes, viz., TNF-α+CD4+lo T cells, CD69+CD8+ T cells, CD69+CD4+ MAIT cells, PD-1+CD4+hi T cells, PD-1+CD8+ T cells, and Ki67+CD4+ MAIT cells, were independently associated with decelerating the plasma viral load (PVL). TNF-α levels showed a positive correlation with increase in cytokine levels and decrease in PVL.
CONCLUSION: Chronic viral infection negatively impacts the quality of peripheral MAIT cells and Tfh cells via differential expression of both activating and inhibitory receptors.