Current HIV Research - Volume 17, Issue 1, 2019

The advent of highly active antiretroviral therapy (HAART) has significantly reduced the incidence of AIDS events, including AIDS-defining malignancies. Nevertheless, several cohort studies conducted in the post-HAART period have reported an increasing risk of non-AIDS-defining cancers (NADC). Overall, the potential mechanisms leading to an increased risk of developing NADCs probably involve multiple known and unknown factors. In addition to ageing, chronic inflammation and ongoing immune system dysregulation, other contributing factors are co-infection with potentially oncogenic viruses (HBV, HCV, HPV, EBV) and high-risk behaviours such as tobacco smoking. As a consequence of these risk factors, high standardized incidence ratios have been consistently reported, mainly in cohort studies regarding smoking-related cancers (lung cancer, but also pharyngeal and kidney cancer), due to the far more common cigarette smoking habit in the HIV-population. Also in the setting of infection-related malignancies, the high frequency of liver cancer, as a consequence of HBV and HCV co-infection is well known. Similarly, HPV infection accounts for the higher risk of anal cancer. On the same line, Hodgkin lymphoma is more frequent in the HIV population, due to the dysregulation and proliferation of EBV-infected lymphocytes. Several studies addressed the direct relationship between immunosuppression and cancer progression, showing that subjects with HIV infection experience higher cancer-specific mortality, as compared to the general population, independently of cancer stage or cancer treatment. In the HIV population, for many NADCs, the prognosis is still worse as compared to the general population. However, an improvement has been reported over the last decades, mainly thanks to more available and adequate treatment chances.

During HIV infection, massive destruction of CD4+ T cells ensues, preferentially depleting the Th17 subset at the gut-associated lymphoid tissue (GALT), leading to a loss of mucosal integrity and an increase in cell permeability. This process favors microbial translocation between the intestinal lumen and the circulatory system, contributing to persistent immune activation and chronic inflammation characteristic of HIV infection. Thus, the gut microbiota plays an integral role in maintaining the structure and function of the mucosal barrier, a critical factor for immune homeostasis. However, in the context of HIV infection, changes in the gut microbiota have been reported and have been linked to disease progression. Here, we review evidence for the role of the gut microbiota in intestinal homeostasis, its contribution to HIV pathogenesis, as well as its use in the development of therapeutic strategies.

It has been found that human immunodeficiency virus (HIV)-1 RNA or antigens can be detected in the intraocular tissues of HIV-1 patients even under effective highly active anti-retroviral therapy (HAART). In vivo, blood-retinal barrier (BRB) establishes a critical, physiological guardian against microbial invasion of the eye, but may be compromised in the presence of HIV-1. The envelope glycoprotein gp120 is exposed on the surface of the HIV envelope, essential for virus entry into cells by the attachment to specific cell surface receptors. The BRB disruption by glycoprotein gp120 has been widely recognized, which is toxic to human retinal epithelial cells (RPE) and umbilical vein endothelial cells (HUVEC). The present review elaborates on various mechanisms of BRB disruption induced by HIV gp120, which may represent potential targets for the prevention of ocular HIV complications in the future.

Background: Several approaches have not been successful to suppress HIV (Human immunodeficiency virus) infection among infected individuals or to prevent it yet. In order to expand strong HIV specific humoral and cellular responses, Virus-like particles (VLPs) as potential vaccines show significant increase in neutralizing antibodies secretion, T-cell count and also secretion of cytokines. Objective: This study aimed at immunological evaluation of VLPs harboring high copy of MPERV3 in BALB/c mice. Methods: Female BALB/c mice were immunized with homologous and heterologous primeboosting regimens of HIV-1 VLPMPER-V3. Their immune responses were evaluated for humoral responses (Total IgG and IgG isotyping) and cellular responses (IFN-γ, IL-5 secretion, in vitro CTL assay and T cell proliferation) and compared in immunized mice. Results: The data showed robust induction of humoral response in mice groups which received different regimens of VLP. Furthermore, analysis of cytokine profile indicated that the highest IL-5 secretion was related to VLP+M50 group and confirmed the dominance of Th2 immunity in this group. Conclusion: This study showed that VLP MPER-V3 as a potential vaccine candidate has the potency as an effective prophylactic vaccine and this finding guarantees further investigations to achieve a promising HIV-1 vaccine candidate.

Background: Due to the persistence of latent HIV-infected cellular reservoirs, HIV virus can not be eradicated completely. Objective: To identify proteins related to HIV latency, we performed a subcellular proteomic study in HIV latent cell lines. Methods: An established HIV-1 latent cell model (J-Lat Tat-GFP Clone A7 cells, A7 cells) and its parental cell line (Jurkat cells) were used. The plasma membrane (PM) fraction from cultured cells was enriched through aqueous two-phase partition. PM proteins were extracted and then separated using two-dimensional electrophoresis (2DE). Differentially expressed proteins were identified by mass spectrometry, and verified by western blotting. Results: Thirteen non-redundant proteins were identified to be differentially expressed in the A7 PM fraction compared to those in the Jurkat PM. Eight had a PM location through Gene Ontology (GO) analysis. A differential protein network of CAPG-ACTR3-CD3D was detected to have interactions with HIV Vpr, Tat, gp160, etc. through STRING software analysis. One of the differential proteins (Macrophage-capping protein (CAPG)) was verified by western blotting to be down- regulated in two cell lines and HIV resting CD4+ T cells negatively selected from patients. Conclusion: We identified 13 proteins in A7 compared to Jurkat cells. CAPG may be a potential biomarker related to HIV latency.

Background: Over the past years, an increasing trend was noticed for non-B and non- CRF01_AE HIV-1 strains prevalence in Hong Kong. Objective: In this study, we aimed at using the available HIV-1 pol sequences collected from 1994 to 2013 through our local antiretroviral resistance surveillance program to investigate the molecular epidemiology and evolution of HIV-1 minority subtypes in Hong Kong. We also aimed at investigating their potential association and impact of those transmission risk groups. Methods: A total of 2,315 HIV-1 partial pol sequences were included. HIV-1 genotypes were determined by REGA Genotyping Tool and phylogenetic analysis with reference sequences. The viral evolutionary rates and time of the most common ancestor (tMRCA) were estimated by Bayesian Markov Chain Monte Carlo (MCMC) interference. Results: Apart from the two prevalent HIV-1 genotypes in Hong Kong (subtype B,41.6%, CRF01_AE,40.5%), phylogenetic analysis revealed a broad viral diversity including CRF07_BC(5.1%), subtype C(4.5%), CRF02_AG(1.1%), CRF08_BC(0.8%), subtype A1(0.8%), subtype G(0.4%), subtype D(0.4%), CRF06_cpx(0.4%), subtype F(0.1%), CRF12_BF(0·04%) and other recombinants(4.5%). The top five minority subtypes were further analyzed which demonstrated distinct epidemiological and phylogenetic patterns. Over 70% of subtypes A1, C and CRF02_AG infections were circulated among non-Chinese Asians or African community in Hong Kong and were mainly transmitted between heterosexual regular partners. Instead, over 90% of CRF07_BC and CRF08_BC patients were Chinese. An epidemic cluster was identified in CRF07_BC and estimated to expand from 2002 onwards based on skyline plot and molecular clock analysis. Conclusion: Our results highlighted the emergence of CRF07_BC epidemic in local MSM community, public health interventions targeting the community should be further enhanced to tackle the epidemic.

Background: Indonesia lags behind its peers with regard to ART coverage of PLHIV. Insufficient HIV testing among MSM and other key affected populations remains a barrier to increasing ART coverage. Objective: This report presents the results of the first government-endorsed implementation research study of a community screening approach to increasing the rate of HIV testing among MSM in three cities. Methods: All new MSM outreach contacts meeting eligibility criteria during March-June 2017 were included in the study. HIV testing at a government health facility, which is required to qualify for government-supported ART, was advised for all new contacts. Men refusing formal testing were offered an HIV screening test in a community setting using a saliva-based rapid test and advised to get a confirmatory test at a health facility. All outreach contacts and testing activities were recorded on individual client records. Results: Of 1,149 eligible MSM, 27% were willing to be referred to receive HIV testing at a health facility, among which 83% were confirmed to have been tested. Of the 838 study subjects refusing health facility testing, 38% accepted community screening. The screening positivity rate was 14.8%. Only 38% of men with reactive screening tests received a confirmatory test at a health facility, along with 8% of those with non-reactive tests. Conclusion: While community screening resulted in more MSM knowing their HIV status, reluctance to avail government health facility-based services, or indeed to be tested at all, must be addressed if community screening is to accelerate progress in getting HIV-positive MSM onto treatment.