Loss of CD103+ DCs and Mucosal IL-17+ and IL-22+ Lymphocytes is Associated with Mucosal Damage in SIV Infection

HIV/SIV disease progression is associated with multifocal damage to the GI tract epithelial barrier that correlates with microbial translocation and persistent pathological immune activation but the underlying mechanisms remain unclear. Investigating alterations in mucosal immunity during SIV infection, we found that damage to the colonic epithelial barrier was associated with loss of multiple lineages of IL-17-producing lymphocytes, cells that microarray analysis showed express genes important for enterocyte homeostasis, including IL-22. IL-22-producing lymphocytes were also lost after SIV infection. Potentially explaining coordinate loss of these distinct populations, we also observed loss of CD103+ DCs after SIV infection which associated with loss of IL-17 and IL-22-producing lymphocytes. CD103+ DCs expressed genes associated with promotion of IL-17/IL-22+ cells, and co-culture of CD103+ DCs and naïve T-cells led to increased IL17A and RORc expression in differentiating T-cells. These results reveal complex interactions between mucosal immune cell subsets providing potential mechanistic insights into mechanisms of mucosal immune dysregulation during HIV/SIV infection, and offer hints for development of novel therapeutic strategies to address this aspect of AIDS virus pathogenesis

Rate of AIDS progression is associated with gastrointestinal dysfunction in simian immunodeficiency virus-infected pigtail macaques

During HIV/SIV infection, mucosal immune system dysfunction and systemic immune activation are associated with progression to AIDS; however, it is unclear to what extent pre-existing gastrointestinal damage relates to disease progression postinfection. Pigtail macaques (PTM) are an excellent model in which to assess mucosal dysfunction in relation to HIV/SIV pathogenesis, as the majority of these animals have high levels of gastrointestinal damage, immune activation, and microbial translocation prior to infection, and rapidly progress to AIDS upon SIV infection. In this study, we characterized the mucosal immune environment prior to and throughout SIV infection in 13 uninfected PTM and 9 SIV-infected PTM, of which 3 were slow progressors. This small subset of slow progressors had limited innate immune activation in mucosal tissues in the periphery, which was associated with a more intact colonic epithelial barrier. Furthermore, we found that preinfection levels of microbial translocation, as measured by LPS-binding protein, in PTM correlated with the rate of progression to AIDS. These data suggest that pre-existing levels of microbial translocation and gastrointestinal tract dysfunction may influence the rate of HIV disease progression

Transitioning couple’s voluntary HIV counseling and testing (CVCT) from stand-alone weekend services into routine antenatal and VCT services in government clinics in Zambia’s two largest cities

Introduction: Most HIV infections in Africa are acquired by married/cohabiting adults and WHO recommends couple’s voluntary HIV counseling and testing (CVCT) for prevention. The handover from NGO-sponsored weekend CVCT to government-sponsored services in routine weekday antenatal care (ANC) and individual voluntary testing and counseling (VCT) services in Zambia’s two largest cities from 2009–2015 is described. Methods: Government clinic counselors were trained to provide CVCT, and along with community health workers they promoted CVCT services in their clinic and surrounding areas. When client volume exceeded the capacity of on-duty staff in ANC and VCT, non-governmental organization (NGO) subsidies were offered for overtime pay. Results: Implementation of routine CVCT services varied greatly by clinic and city. The 12 highest volume clinics were examined further, while 13 clinics had CVCT numbers that were too low to warrant further investigation. In Lusaka, the proportion of pregnant women whose partners were tested rose from 2.6% in 2009 to a peak of 26.2% in 2012 and 24.8% in 2015. Corresponding reports in Ndola were 2.0% in 2009, 17.0% in 2012 and 14.5% in 2015. Obstacles to CVCT included: limited space and staffing, competing priorities, record keeping not adapted for couples, and few resources for promotion and increasing male involvement. Conflicting training models for ‘partner testing’ with men and women separately vs. CVCT with joint post-test counseling led to confusion in reporting to district health authorities. Discussion: A focused and sustained effort will be required to reach a meaningful number of couples with CVCT to prevent heterosexual and perinatal HIV transmission. Establishing targets and timelines, funding for dedicated and appropriately trained staff, adoption of standardized data recording instruments with couple-level indicators, and expansion of community and clinic-based promotions using proven models are recommended

Dynamics of simian immunodeficiency virus SIVmac239 infection in pigtail macaques

Pigtail macaques (PTM) are an excellent model for HIV research; however, the dynamics of simian immunodeficiency virus (SIV) SIVmac239 infection in PTM have not been fully evaluated. We studied nine PTM prior to infection, during acute and chronic SIVmac239 infections, until progression to AIDS. We found PTM manifest clinical AIDS more rapidly than rhesus macaques (RM), as AIDS-defining events occurred at an average of 42.17 weeks after infection in PTM compared to 69.56 weeks in RM (P = 0.0018). However, increased SIV progression was not associated with increased viremia, as both peak and set-point plasma viremias were similar between PTM and RM (P = 0.7953 and P = 0.1006, respectively). Moreover, this increased disease progression was not associated with rapid CD4(+) T cell depletion, as CD4(+) T cell decline resembled other SIV/human immunodeficiency virus (HIV) models. Since immune activation is the best predictor of disease progression during HIV infection, we analyzed immune activation by turnover of T cells by BrdU decay and Ki67 expression. We found increased levels of turnover prior to SIV infection of PTM compared to that observed with RM, which may contribute to their increased disease progression rate. These data evaluate the kinetics of SIVmac239-induced disease progression and highlight PTM as a model for HIV infection and the importance of immune activation in SIV disease progression

Lusaka: Average number of couples per month that received weekday couples voluntary counseling and testing in clinics with a monthly average of ≥40 couples in at least one year.

<p>Blue bar represents CVCT provided by on-duty government counselors in the ANC clinics; orange bars represent CVCT provided by on duty government counselors in the VCT department; grey bar represents weekday CVCT provided by a ZEHRP-sponsored counselor. Grey stars indicate clinic-years when no ZEHRP-sponsored staff provided CVCT services. Blue and orange stars indicate clinics in which logbooks for data extraction were not available for that year.</p

Ndola: Average number of couples per month that received weekday couples voluntary counseling and testing in clinics with at least two years of data.

<p>Blue bar represents CVCT provided by on-duty government counselors in the ANC clinics; orange bars represent CVCT provided by on duty government counselors in the VCT department; grey bar represents weekday CVCT provided by a ZEHRP-sponsored counselor. Grey stars indicate clinic-years when no ZEHRP-sponsored staff provided CVCT services. Blue stars indicate clinics in which logbooks for data extraction were not available for that year.</p

Number and percent of first time ANC clients and partners tested 2009–2015, from HMIS reports to DHMT in Ndola.

<p>Blue represents women whose partners were not tested, orange represents women whose partners were tested. Percentage of ANC clients with male partner tested is shown above each bar.</p

Probiotic/prebiotic supplementation of antiretrovirals improves gastrointestinal immunity in SIV-infected macaques

HIV infection results in gastrointestinal (GI) tract damage, microbial translocation, and immune activation, which are not completely ameliorated with suppression of viremia by antiretroviral (ARV) therapy. Furthermore, increased morbidity and mortality of ARV-treated HIV-infected individuals is associated with these dysfunctions. Thus, to enhance GI tract physiology, we treated SIV-infected pigtail macaques with ARVs, probiotics, and prebiotics or with ARVs alone. This synbiotic treatment resulted in increased frequency and functionality of GI tract APCs, enhanced reconstitution and functionality of CD4 + T cells, and reduced fibrosis of lymphoid follicles in the colon. Thus, ARV synbiotic supplementation in HIV-infected individuals may improve GI tract immunity and thereby mitigate inflammatory sequelae, ultimately improving prognosis