Regulatory T cells and IL-10 as modulators of chikungunya disease outcome: a preliminary study.

Regulatory T (Treg) cells hold centre stage in regulating the immune responses in most viral infections. However, their involvement in chikungunya infection is unexplored. In the current study, the frequencies and functionality of peripheral Treg and T effector (Teff) cells were assessed during different phases of chikungunya by flow cytometry and in-vitro cytokine assays. Treg cells were also studied in rheumatoid arthritis (RA) patients, whose symptoms closely mimic chronic chikungunya arthritis patients. Frequency of Treg cells was lower in acute and chronic chikungunya arthritis patients than in recovered individuals and controls, and comparable among recovered individuals and controls. Treg/Teff ratio was lower in acute than in chronic chikungunya arthritis patients, recovered individuals and controls. Higher secretion of CHIKV specific IL-10 was observed in recovered individuals than in acute, chronic chikungunya arthritis patients and controls. Frequencies of Treg and Teff cells were higher and Treg/Teff ratio was lower in RA patients than in chronic chikungunya arthritis patients. The results indicate that reduction of Treg cells was associated with ongoing CHIKV infection and normalization of Treg cells with resolution of disease. Contrasting phenotypic data in RA and chronic chikungunya arthritis suggest an altogether different mechanism of Treg-mediated pathology in both arthritis conditions. Overall, our preliminary study, suggesting an association of peripheral Treg cells and IL-10 with recovery from chikungunya, may provide insight into chikungunya disease prognosis and warrants further study.

Altered profile of regulatory T cells and associated cytokines in mild and moderate dengue.

The pathogenesis of dengue is immune-mediated. Regulatory T cells suppress immune response and may contribute to better prognosis. The present study evaluates Tregs and cytokines in dengue patients in the context of disease severity, time of sampling and immune status. The cohort included 90 patients (51 mild, 39 moderate) and 27 healthy controls. Frequencies of Tregs, CD4(+)CD25(-)Foxp3(+) T cells and CD3(+), CD3(+)CD4(+) and CD3(+)CD8(+) T cells were enumerated by flow cytometry. Circulating levels of 15 cytokines/chemokines were measured using Luminex technology and mRNA levels of Foxp3, IL-10 and TGF-ß were assessed by real-time polymerase chain reaction (PCR). Significantly higher frequencies of Tregs were observed in mild cases, especially during post-defervescence. The difference between mild and moderate cases was more evident in secondary infections. Frequencies of T cells were higher in mild cases but during pre-defervescence. On the other hand, the levels of IL-6, IL-7, IL-8, TNF-α and IL-10 were significantly higher in moderate cases. IL-6 and IL-8 levels correlated negatively with Treg frequencies during post-defervescence and in secondary infections. Higher levels of IL-10 and TGF-ß in moderate cases were not reflected by their corresponding mRNA levels. Platelet counts correlated positively with Treg frequencies and TGF-ß levels, and negatively with IL-10 levels. Higher Treg frequencies may favour a beneficial outcome in dengue. Higher cytokine levels may indirectly contribute to disease severity by exerting an inhibitory influence on Tregs. The dichotomy between mRNA and proteins levels for IL-10 and TGF-ß is suggestive of increased translational efficiency.

Suppressive activity and altered conventional phenotype markers/mediators of regulatory T cells in patients with self-limiting hepatitis E.

Hepatitis E virus (HEV) is a major cause of self-limiting acute viral hepatitis in several developing countries. Elevated levels of peripheral CD4(+) CD25(+) Foxp3(+) , CD4(+) CD25(-) Foxp3(+) and rise in IL-10 in hepatitis E have been associated with the involvement of regulatory T cells (Treg). The functional role of the same is yet elusive. In the current study, we have assessed (i) Foxp3 expression by real-time PCR and by flow cytometry, (ii) the levels of antigen-specific IL-10 and TGF-ß by ELISA, (iii) functional analysis of Treg cells and (iv) expression of Treg-associated conventional phenotypes by flow cytometry in 54 acute patients, 44 recovered individuals from hepatitis E and in 33 healthy controls. Foxp3 mRNA elevation in the acute compared with recovered group and elevation in Foxp3(+) cells in both patient groups were significantly elevated. The levels of IL-10 and TGF-ß in the acute patients and TGF-ß in the recovered individuals were elevated. Significantly higher expression of CTLA-4, PD1, GITR, CD95, CD103 and CD73 on Treg and T effector (Teff) cells was detected in the patient groups. Treg cells of acute patients and recovered individuals exhibited suppressive activity indicating that the Treg cells of hepatitis E patients are functional. The suppressive capacity of Treg cells in acute hepatitis E patients was significantly higher compared with the recovered individuals. Based on our findings, the suppressive functionality of these key markers associated with hepatitis E Treg function need further exploration to get a better understanding of the mechanisms of Treg-mediated suppression.

Peripheral T regulatory cells and cytokines in hepatitis E infection.

This study addresses the involvement of regulatory T cells in hepatitis E (HE) infection. The study population comprised 77 acute viral HE patients, 52 recovered individuals (overall, 129 individuals with HE) and 53 healthy controls. Peripheral CD4(+)CD25(+)Foxp3(+) and CD4(+)CD25(-)Foxp3(+) frequencies by flow cytometry and HE-specific cytokines/chemokines quantitation were carried out. The median percentage of CD4(+)CD25(+)Foxp3(+) and CD4(+)CD25(-)Foxp3(+) T cells in acute patients were significantly higher compared to controls and recovered individuals. Both of the T regulatory (Treg) subset populations in overall HE were significantly elevated compared to controls. Comparisons of cytokines/chemokines revealed that the levels of IL-10 were elevated in: (a) acute viral hepatitis E (AVH-E) versus recovered individuals and controls, and (b) HE versus controls. Overall, the elevation of CD4(+)CD25(+)Foxp3(+) and CD4(+)CD25(-)Foxp3(+) frequencies and the rise in IL-10 suggest that Treg cells might be playing a pivotal role in hepatitis E virus (HEV) infection.

Epidemic of hepatitis B with high mortality in India: association of fulminant disease with lack of CCL4 and natural killer T cells.

An explosive outbreak of Hepatitis B with high mortality was reported in 2009, in Modasa, Gujarat, India. Mortality was associated with basal core promoter and precore mutant hepatitis B virus (HBV). The current study addresses the role of immunological parameters in the progression to fulminant hepatitis. The study population comprised of 22 acute HBV patients, 13 fulminant HBV liver failure patients and 54 healthy controls. Hepatitis B surface antigen-induced CTL responses by enzyme-linked immunosorbent spot (ELISPOT), cytokine and chemokine quantitation by Bioplex assay, peripheral NK, natural killer T (NKT), CD4 and CD8 T-cell frequencies by flow cytometry were carried out. The median percentage of NK cells in the lymphocytes of the acute and fulminant liver failure patients were significantly lower compared to controls. Acute and fulminant liver failure patients had significantly high and comparable NKT cells compared to controls, respectively. Importantly, NKT cells were significantly lower in fulminant HBV liver failure than acute HBV patients. Circulating peripheral CD4/CD8 T-cell subsets among the patient categories and controls were comparable. In acute HBV patients, a significant increase in IFN-γ release was recorded (ELISPOT) by the unstimulated, antigen-stimulated and mitogen-stimulated cells when compared to controls. Comparisons of cytokines and chemokines among the disease categories revealed significantly lower levels of CCL4 in fulminant liver failure patients. NKT cells and CCL4 might be playing a pivotal role in limiting HBV infection among the patients investigated.

Viral load, antibody titers and recombinant open reading frame 2 protein-induced TH1/TH2 cytokines and cellular immune responses in self-limiting and fulminant hepatitis e.

OBJECTIVES: Hepatitis E virus (HEV) is the predominant cause of water-borne epidemics, sporadic acute viral hepatitis (AVH) in adults and fulminant hepatic failure (FHF) among pregnant women and other adults in India. This preliminary study was designed to examine the association of viral load and certain host immune responses with uneventful recovery or progression to FHF. METHODS: Viral load, anti-HEV antibody titers, rORF2p-induced Th1/Th2 cytokines levels and cellular immune responses were assessed in 47 patients with self-limiting hepatitis E and 14 FHF-E cases. The controls included 16 anti-HEV-IgM and IgG-negative healthy individuals. RESULTS: In AVH category, the viral load was 2.4 x 10(4) +/- 1.92 x 10(4) copies/ml while except for one, all FHF patients were negative for HEV RNA; anti-HEV-IgM and IgG titers were higher in the FHF group. Lymphocyte proliferative response to rORF2p was comparable in both groups. As compared to AVH, significantly higher levels of both Th1 (IFN-gamma, IL-2 and TNF-alpha) and Th2 (IL-10) cytokines were recorded in FHF patients. Analysis of sequential samples differentiated FHF recovered and fatal patients with respect to IFN-gamma and IL-12. CONCLUSION: The results document increased Th1/Th2 responses and anti-HEV titers in FHF patients that warrant in-depth immunological studies.

Effect of retrotestosterone on accessory sex organs & spermatogenesis of rat.

PIP: Retrotestosterone (17beta-hydroxy 9beta 10alpha androst 4-en 3 one) (RT), testosterone propionate (TP), and a combination of TP and RT were administered to adult male rats in order to study the effects of such treatment on male sex organs and spermatogenesis. Although TP treatment did not produce significant reduction in testis weight, RT and RT+TP did. Seminal vesicle (SV) weight was increased by TP treatment and TP+RT treatment, but it was decreased with the RT treatment. Ventral prostate (VP) weight was increased significantly by TP and TP+RT treatment, whereas RT did not alter VP weight. The The pituitary weight of RT- and RT+TP-treated rats was significantly reduced but that of the TP rats was unaltered. Resting spermatocytes, pachytene spermatocytes, Stage 7 spermatids, and spermatogonia were increased in all treatment groups. In castrated rats, the increase in VP and SV weight was significant in the group treated with TP, but in the RT-treated group, S V and VP weights were significantly reduced. Simultaneous administration of TP and RT in 1:1, 1:4, and 1:8 ratios failed to produce statistically significant increases in SV and VP weight. The group treated with 1:20 ratio of RT:TP produced highly significant incre ases in SV and VP weights. In the spermatodynamic study, results showed that RT is comparatively more potent than TP in stimulating spermatogenesis. RT+TP treatment produced maximum increase in the count of resting and pachytene spermatocytes, whereas spermatogonia and Stage 7 spermatids were more than in the TP-treated group but less than in the RT-treated group. The findings indicate that RT is weakly androgenic and unable to stimulate accessory organs but that it is able to block the effect of endogenous androgen on the target tissue.^ieng