Target cell availability, rather than breast milk factors, dictates mother-to-infant transmission of SIV in sooty mangabeys and rhesus macaques.

Mother-to-infant transmission (MTIT) of HIV is a serious global health concern, with over 300,000 children newly infected in 2011. SIV infection of rhesus macaques (RMs) results in similar rates of MTIT to that of HIV in humans. In contrast, SIV infection of sooty mangabeys (SMs) rarely results in MTIT. The mechanisms underlying protection from MTIT in SMs are unknown. In this study we tested the hypotheses that breast milk factors and/or target cell availability dictate the rate of MTIT in RMs (transmitters) and SMs (non-transmitters). We measured viral loads (cell-free and cell-associated), levels of immune mediators, and the ability to inhibit SIV infection in vitro in milk obtained from lactating RMs and SMs. In addition, we assessed the levels of target cells (CD4+CCR5+ T cells) in gastrointestinal and lymphoid tissues, including those relevant to breastfeeding transmission, as well as peripheral blood from uninfected RM and SM infants. We found that frequently-transmitting RMs did not have higher levels of cell-free or cell-associated viral loads in milk compared to rarely-transmitting SMs. Milk from both RMs and SMs moderately inhibited in vitro SIV infection, and presence of the examined immune mediators in these two species did not readily explain the differential rates of transmission. Importantly, we found that the percentage of CD4+CCR5+ T cells was significantly lower in all tissues in infant SMs as compared to infant RMs despite robust levels of CD4+ T cell proliferation in both species. The difference between the frequently-transmitting RMs and rarely-transmitting SMs was most pronounced in CD4+ memory T cells in the spleen, jejunum, and colon as well as in central and effector memory CD4+ T cells in the peripheral blood. We propose that limited availability of SIV target cells in infant SMs represents a key evolutionary adaptation to reduce the risk of MTIT in SIV-infected SMs.

Insights into the role of HCV Plus-/Minus strand RNA, IFN-γ and IL-29 in relapse outcome in patients infected with HCV.

BACKGROUND AND OBJECTIVES: Approximately one-third of hepatitis C virus (HCV) infected patients who complete antiviral therapy with undetectable serum HCV RNA at the end of therapy (ETR), will experience relapse. The reasons for the failure of treatment have not been elucidated. It was showed that HCV RNA can persist and replicate in extra hepatic sites, e.g. in peripheral blood mononuclear cells (PBMCs), but the relevance of its presence with relapse over time is still unknown. Moreover, interferon-gamma (IFN-γ) and IFN-lambdas [IFN-λ1, interleukin-29 (IL-29)], possess potent antiviral activity. We studied if the presence of plus-/minus strand RNA in PBMCs of patients and the serum level of IFN-γ and IL-29, which is the most abundant IFN-lambdas in serum, can be considered as predictive factors in relapse outcomes. METHODS: Patients were screened for plus-/minus strand RNA at ETR and after 6 months. Also, we measured the serum level of IFN-γ and IL-29 and compared the result with those who developed a sustained virological response (SVR). RESULTS: Levels of IL-29 and IFN-? serum were significantly higher in SVR at ETR and 6 months later compared to those of the relapsed patients, but there was no difference between the two groups regarding the presence or absence of plus-/minus HCV strand in PBMCs. CONCLUSIONS: Our novel findings showed that the serum level of IL-29 and IFN-γ are predictive of relapse outcomes to HCV treatment, but there was no association between the presence of plus-γminus HCV RNA in PBMCs of patients with an outcome of therapy at ETR and later.

Molecular Epidemiology of Enteric Adenovirus Gastroenteritis in under-Five-Year-Old Children in Iran.

Background. Acute gastroenteritis is one of the major sources of morbidity and mortality among young children in developed and developing countries. The aim of this study was to determine the prevalence of human adenovirus- (HAdV-) 40 and HAdV-41 in children hospitalized with gastroenteritis in five different health centers of Iran. Methods. In a cross-sectional epidemiological study, we studied 2682 fecal specimens that were collected from children under the age of 5 years in five educational and therapeutic pediatric centers in Iran from February 2012 to February 2013. Samples were tested for HAdV-40 and HAdV-41, using a specific pair of primers in polymerase chain reaction (PCR) method. Results. HAdV-40 and HAdV-41 were detected in 132 (5.18%) of the patients with diarrhea. A significantly higher prevalence of HAdV-40 and HAdV-41 (58.3%) was observed in children under 12 months of age, compared to other age groups. The male to female ratio was 1.7. Conclusion. The results of this study demonstrated that HAdV-40 and HAdV-41 could be considered etiological agents for acute gastroenteritis among children in Iran. The PCR as a rapid test may increase the chance for a relatively mild course of the disease followed by a complete recovery and avoiding administration of unnecessary antibiotics.

Expansion of CD4+ CD25+ FoxP3+ regulatory T cells in chronic hepatitis C virus infection.

BACKGROUND: Regulatory T cells (Tregs) have been involved in impaired immunity and may have a pivotal role in persistence of viral infections. OBJECTIVE: To develop a simple and reliable in-house three color flow cytometery of peripheral blood to understand the role of HCV infection in the increase of Tregs. METHODS: The level of naturally occurring CD4+ CD25+ FoxP3+ regulatory T cells (nTregs) in 20 chronically infected with hepatitis C virus (HCV) patients was compared to those of 15 healthy individuals by flowcytometry. In a different approach we performed permeabilization and intracellular staining before surface staining which allows the preservation of the surface molecules in the combined detection process and results in the normal frequency of nTregs in blood. RESULTS: Using the optimized method, it was shown that a significantly higher proportion of nTregs in the total CD4+ T cell population was seen in the peripheral blood of chronic HCV patients (0.83 ± 0.21%, p=0.05) as compared to controls (0.26 ± 0.1, p=0.05). CONCLUSIONS: In accordance with other studies, we showed that HCV infection induces a dramatic increase in Tregs, which might contribute to the immune response failure during HCV infection.