Human Immunodeficiency Virus Immune Cell Receptors, Coreceptors, and Cofactors: Implications for Prevention and Treatment

Molecular Engineering of Virus Tropism

Engineered viral vectors designed to deliver genetic material to specific targets offer significant potential for disease treatment, safer vaccine development, and the creation of novel biochemical research tools. Viral tropism, the specificity of a virus for infecting a particular host, is often modified in recombinant viruses to achieve precise delivery, minimize off-target effects, enhance transduction efficiency, and improve safety. Key factors influencing tropism include surface protein interactions between the virus and host-cell, the availability of host-cell machinery for viral replication, and the host immune response. This review explores current strategies for modifying the tropism of recombinant viruses by altering their surface proteins. We provide an overview of recent advancements in targeting non-enveloped viruses (adenovirus and adeno-associated virus) and enveloped viruses (retro/lentivirus, Rabies, Vesicular Stomatitis Virus, and Herpesvirus) to specific cell types. Additionally, we discuss approaches, such as rational design, directed evolution, and in silico and machine learning-based methods, for generating novel AAV variants with the desired tropism and the use of chimeric envelope proteins for pseudotyping enveloped viruses. Finally, we highlight the applications of these advancements and discuss the challenges and future directions in engineering viral tropism.

Incidence of anaemia and its predictors among HIV-infected children receiving highly active antiretroviral treatment in North-West Ethiopia: a multicentre retrospective follow-up study

BACKGROUND

Anaemia is one of the most common problems in HIV-infected patients associated with increased HIV progression, decreased functional capacity, survival and quality of life. For better interventions, up-to-date information concerning anaemia among HIV-infected children less than 5 years of age on antiretroviral therapy (ART) is vital. Thus, this study aims to determine the predictors of anaemia among HIV-infected children less than 5 years of age receiving ART in North-West Ethiopia.

DESIGN

An institution-based retrospective follow-up study was conducted.

STUDY SETTING

Amhara region Comprehensive Specialized Hospitals, North-West Ethiopia.

PARTICIPANTS

In total, we examined 460 HIV-infected children less than 5 years of age who had followed highly active antiretroviral treatment from 2010 to 2020.

OUTCOME MEASURES

The outcome measures were median time to detection of anaemia, the incidence and the effects of cotrimoxazole preventive therapy (CPT), ART adherence, tuberculosis (TB), WHO clinical stage and wasting on anaemia.

RESULTS

The overall follow-up time was 9234 person-months of observation. The incidence density of anaemia was 8.34 per 1000 person-months of observation (95% CI 6.67 to 10.43). The cumulative survival probability of children after the last months of follow-up was 0.54. The independent predictors of anaemia were not receiving CPT (adjusted HR (AHR)=4.44; 95% CI 2.48 to 7.93), poor adherence to ART (AHR=2.46; 95% CI 1.37 to 4.42), TB (AHR=3.40; 95% CI 1.72 to 6.72), severe WHO clinical stage (AHR=3.03; 95% CI 1.40 to 6.58) and severe wasting (AHR=1.98; 95% CI 1.08 to 3.64).

CONCLUSION AND RECOMMENDATION

The incidence rate of anaemia was high and it was provoked by predictors like CPT, ART adherence, TB, WHO clinical stage and wasting. Therefore, it is necessary to emphasise for these predictors.

Prevalence of opportunistic intestinal coccidian parasites and associated factors in HIV/AIDS patients attending anti-retroviral therapy (ART) clinic at Debre Tabor Comprehensive Specialized Hospital, Northwest Ethiopia: A cross-sectional study

Background and Aims

A growing number of acquired immunodeficiency syndrome (AIDS) patients suffer from opportunistic intestinal coccidian infections. Instead of human immuno deficiency virus (HIV) infection itself, opportunistic infections like intestinal coccidian parasites cause death of over 80% AIDS patients. Factors like exposed drinking water sources and poverty aid the prevalence of opportunistic intestinal coccidian parasitic infections in HIV/AIDS patients. The goal of this study was to determine the prevalence of intestinal coccidian parasites and associated factors in HIV/AIDS patients.

Methods

A health facility based cross sectional study was conducted from 140 HIV/AIDS patients attending ART clinic in Debre Tabor Comprehensive Specialized Hospital, Northwest Ethiopia from September to December 2023. The sociodemographic characteristics were collected through face-to-face interviews. Stool samples were processed with Modified Acid Fast staining technique. Statistical Package for Social Sciences software version 20 was used to analyze the data. Logistic regression was used to assess factors associated with dependent variable and p < 0.05 was considered significantly associated.

Results

The total prevalence of opportunistic intestinal coccidian parasites (OICPs) in HIV/AIDS patients was 16.4% (23/140). Drinking surface water [p = 0.015, COR = 3.4] compared to tape water, drinking alcohol [p = 0.001, COR = 18] compared to not drinking alcohol, diarrhea [p = 0.005, COR = 1] compared to non-diarrheic, drug dropout [p = 0.01, COR = 11] compared to regular drug intake and low CD4 count [p = 0.042, COR = 9] compared to CD4 > 500/µL showed significant association with increased prevalence of OICPs in HIV/AIDS patients.

Conclusions

OICPs are still the common causes of morbidity and mortality in HIV/AIDS patients. Surface water consumption, alcoholism, interruption of treatment drugs, diarrhea, and reduced CD4+ T-cells significantly contribute to acquisition and prevalence of OICPs in HIV/AIDS patients. Routine screening of OICPs with sensitive diagnostic techniques in HIV/AIDS patients regardless of symptoms is crucial and has to be practiced in health settings.

Evaluating HIV-1 Infectivity and Virion Maturation across Varied Producer Cells with a Novel FRET-Based Detection and Quantification Assay

The maturation of HIV-1 virions is a crucial process in viral replication. Although T-cells are a primary source of virus production, much of our understanding of virion maturation comes from studies using the HEK293T human embryonic kidney cell line. Notably, there is a lack of comparative analyses between T-cells and HEK293T cells in terms of virion maturation efficiency in existing literature. We previously developed an advanced virion visualization system based on the FRET principle, enabling the effective distinction between immature and mature virions via fluorescence microscopy. In this study, we utilized pseudotyped, single-round infectious viruses tagged with FRET labels (HIV-1 Gag-iFRET∆Env) derived from Jurkat (a human T-lymphocyte cell line) and HEK293T cells to evaluate their virion maturation rates. HEK293T-derived virions demonstrated a maturity rate of 81.79%, consistent with other studies and our previous findings. However, virions originating from Jurkat cells demonstrated a significantly reduced maturation rate of 68.67% (p < 0.0001). Correspondingly, viruses produced from Jurkat cells exhibited significantly reduced infectivity compared to those derived from HEK293T cells, with the relative infectivity measured at 65.3%. This finding is consistent with the observed relative maturation rate of viruses produced by Jurkat cells. These findings suggest that initiation of virion maturation directly correlates with viral infectivity. Our observation highlights the dynamic nature of virus-host interactions and their implications for virion production and infectivity.

HIV-TB Coinfection: Current Therapeutic Approaches and Drug Interactions

The co-occurrence of human immunodeficiency virus (HIV) and tuberculosis (TB) infection poses a significant global health challenge. Treatment of HIV and TB co-infection often necessitates combination therapy involving antiretroviral therapy (ART) for HIV and anti-TB medications, which introduces the potential for drug-drug interactions (DDIs). These interactions can significantly impact treatment outcomes, the efficacy of treatment, safety, and overall patient well-being. This review aims to provide a comprehensive analysis of the DDIs between anti-HIV and anti-TB drugs as well as potential adverse effects resulting from the concomitant use of these medications. Furthermore, such findings may be used to develop personalized therapeutic strategies, dose adjustments, or alternative drug choices to minimize the risk of adverse outcomes and ensure the effective management of HIV and TB co-infection.

Modeling HIV-1 Infection in CNS via Infected Monocytes Using Immunocompetent Brain Organoids

The development of 3D-organoid models has revolutionized the way diseases are studied. Recently, our brain organoid model has been shown to recapitulate in in vitro the human brain cytoarchitecture originally encountered in HIV-1 neuropathogenesis, allowing downstream applications. Infected monocytes, macrophages, and microglia are critically important immune cells for infection and dissemination of HIV-1 throughout brain during acute and chronic phase of the disease. Once in the brain parenchyma, long-lived infected monocytes/macrophages along with resident microglia contribute to the establishment of CNS latency in people with HIV (PWH). Hence, it is important to better understand how HIV-1 enters and establishes infection and latency in CNS to further develop cure strategies. Here we detailed an accessible protocol to incorporate monocytes (infected and/or labeled) as a model of transmigration of peripheral monocytes into brain organoids that can be applied to characterize HIV-1 neuroinvasion and virus dissemination.

Consequences of HIV infection in the bone marrow niche

Dysregulation of the bone marrow niche resulting from the direct and indirect effects of HIV infection contributes to haematological abnormalities observed in HIV patients. The bone marrow niche is a complex, multicellular environment which functions primarily in the maintenance of haematopoietic stem/progenitor cells (HSPCs). These adult stem cells are responsible for replacing blood and immune cells over the course of a lifetime. Cells of the bone marrow niche support HSPCs and help to orchestrate the quiescence, self-renewal and differentiation of HSPCs through chemical and molecular signals and cell-cell interactions. This narrative review discusses the HIV-associated dysregulation of the bone marrow niche, as well as the susceptibility of HSPCs to infection by HIV.

The prenatal environment and its influence on maternal and child mitochondrial DNA copy number and methylation: A review of the literature

Mitochondrial DNA (mtDNA) is sensitive to environmental stressors and associated with human health. We reviewed epidemiological literature examining associations between prenatal environmental, dietary, and social exposures and alterations in maternal/child mtDNA copy number (mtDNAcn) and mtDNA methylation. Evidence exists that prenatal maternal exposures are associated with alterations in mtDNAcn for air pollution, chemicals (e.g. metals), cigarette smoke, human immunodeficiency virus (HIV) infection and treatment. Evidence for their associations with mtDNA methylation was limited. Given its potential implications as a disease pathway biomarker, studies with sufficient biological specificity should examine the long-term implications of prenatal and early-life mtDNA alterations in response to prenatal exposures.

HIV-Host Cell Interactions

The development of antiretroviral drugs (ARVs) was a great milestone in the management of HIV infection. ARVs suppress viral activity in the host cell, thus minimizing injury to the cells and prolonging life. However, an effective treatment has remained elusive for four decades due to the successful immune evasion mechanisms of the virus. A thorough understanding of the molecular interaction of HIV with the host cell is essential in the development of both preventive and curative therapies for HIV infection. This review highlights several inherent mechanisms of HIV that promote its survival and propagation, such as the targeting of CD4⁺ lymphocytes, the downregulation of MHC class I and II, antigenic variation and an envelope complex that minimizes antibody access, and how they collaboratively render the immune system unable to mount an effective response.

The Pathological Activation of Microglia Is Modulated by Sexually Dimorphic Pathways

Microglia are the primary immunocompetent cells of the central nervous system (CNS). Their ability to survey, assess and respond to perturbations in their local environment is critical in their role of maintaining CNS homeostasis in health and disease. Microglia also have the capability of functioning in a heterogeneous manner depending on the nature of their local cues, as they can become activated on a spectrum from pro-inflammatory neurotoxic responses to anti-inflammatory protective responses. This review seeks to define the developmental and environmental cues that support microglial polarization towards these phenotypes, as well as discuss sexually dimorphic factors that can influence this process. Further, we describe a variety of CNS disorders including autoimmune disease, infection, and cancer that demonstrate disparities in disease severity or diagnosis rates between males and females, and posit that microglial sexual dimorphism underlies these differences. Understanding the mechanism behind differential CNS disease outcomes between men and women is crucial in the development of more effective targeted therapies.

Potential long-term effects of SARS-CoV-2 infection on the pulmonary vasculature: Multilayered cross-talks in the setting of coinfections and comorbidities

The Coronavirus Disease 2019 (COVID-19) caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) and its sublineages pose a new challenge to healthcare systems worldwide due to its ability to efficiently spread in immunized populations and its resistance to currently available therapies. COVID-19, although targeting primarily the respiratory system, is also now well established that later affects every organ in the body. Most importantly, despite the available therapy and vaccine-elicited protection, the long-term consequences of viral infection in breakthrough and asymptomatic individuals are areas of concern. In the past two years, investigators accumulated evidence on how the virus triggers our immune system and the molecular signals involved in the cross-talk between immune cells and structural cells in the pulmonary vasculature to drive pathological lung complications such as endothelial dysfunction and thrombosis. In the review, we emphasize recent updates on the pathophysiological inflammatory and immune responses associated with SARS-CoV-2 infection and their potential long-term consequences that may consequently lead to the development of pulmonary vascular diseases.

Anaemia and Nutritional Status during HIV and Helminth Coinfection among Adults in South Africa

Sub-Saharan Africa is burdened with helminthiasis and HIV/AIDS, and there is a significant overlap between these infections. However, little is known about the extent of anaemia and malnutrition in HIV/AIDS and helminth coinfected adults. The study investigated the anaemia profiles and nutritional status of HIV and helminth coinfected adult South Africans. Stool samples were collected from participants (N = 414) for parasite detection using the Kato−Katz and Mini Parasep® SF techniques. Blood was collected to determine participants’ HIV status, micro- and macronutrients, haematological parameters, and Ascaris lumbricoides-specific IgE and IgG4 levels. Thereafter, participants were stratified into single infection (HIV or helminths), coinfection, and uninfected controls (no HIV and helminth) groups. The majority (74.9%) of participants had CD4 counts of >500 cells/μL, indicating no significant immunosupression. The coinfected group had an overall anaemia prevalence of 16.9%, which was lower than that of the HIV-infected group (44.6%) and higher than helminth infected group (15.4%). Overall helminth prevalence was 33%, with Ascaris lumbricoides being the most prevalent. The coinfected group also had lower vitamin A (p = 0.0107), calcium (p = 0.0002), and albumin (p < 0.0001) levels compared to HIV/helminth uninfected controls. Unexpectedly, the coinfected group had the highest serum iron levels, followed by the helminth-infected and control groups, both of which had similar iron levels, and finally, the HIV-infected group, which had the lowest iron levels (p = 0.04). Coinfected adults may be prone to micronutrient deficiency and anaemia. Further research and intervention programmes are required in this neglected field.

Identification and Implications of HIV-1 CRF01_AE Subtype in Hawai'i

Human Immunodeficiency Virus has a high propensity for genetic variation, demonstrated by its complex phylogeny and multiplicity of subtypes. Subtype B is predominant in North America as well as in Hawai'i while CRF01_AE is found in over 50% of cases in the Philippines and Southeast Asia. In a small collaborative study between the Hawai'i Center for AIDS and Philippines General Hospital, molecular phylogenetic subtyping was conducted on HIV+ participants. Two of 15 (13%) participants from the Hawai'i cohort and 12 of 21 (57%) participants from the Philippines cohort were identified as having CRF01_AE subtype of HIV-1, with remaining participants identified as subtype B. While one individual in Hawai'i with CRF01_AE had emigrated from the Philippines, the other participant from Hawai'i with CRF01_AE subtype was a local individual, born and raised in Hawai'i. The authors report that HIV subtype diversity may be increased in Hawai'i and discuss its potential clinical and public health implications.

Therapeutic Potential of Marine Bioactive Peptides against Human Immunodeficiency Virus: Recent Evidence, Challenges, and Future Trends

Acquired immunodeficiency syndrome (AIDS) is a chronic and potentially fatal ailment caused by the human immunodeficiency virus (HIV) and remains a major health problem worldwide. In recent years, the research focus has shifted to a greater emphasis on complementing treatment regimens involving conventional antiretroviral (ARV) drug therapies with novel lead structures isolated from various marine organisms that have the potential to be utilized as therapeutics for the management of HIV-AIDS. The present review summarizes the recent developments regarding bioactive peptides sourced from various marine organisms. This includes a discussion encompassing the potential of these novel marine bioactive peptides with regard to antiretroviral activities against HIV, preparation, purification, and processing techniques, in addition to insight into the future trends with an emphasis on the potential of exploration and evaluation of novel peptides to be developed into effective antiretroviral drugs.

Impact of HIV Infection on the Course of Inflammatory Bowel Disease and Drug Safety Profile: A Multicenter GETAID Study

BACKGROUND AND AIMS

Inflammatory bowel diseases (IBD), including Crohn's disease (CD) and ulcerative colitis (UC), and human immunodeficiency virus (HIV) both impact innate and adaptive immunity in the intestinal mucosa. As it is a rare situation, the intersection between HIV and IBD remains unclear, especially the impact of HIV infection on the course of IBD, and the drug safety profile is unknown.

METHODS

We conducted a multicenter retrospective cohort study between January 2019 and August 2020. All adult patients with IBD and concomitant HIV infection were included. Each IBD patient with HIV was matched to two HIV-uninfected IBD patients.

RESULTS

Overall, 195 patients with IBD were included, including 65 HIV-infected patients and 130 without HIV infection. Of the 65 infected patients, 22 (33.8%) required immunosuppressants and 31 (47.7%) biologics. In the HIV-infected group, the need for immunosuppressants (p = 0.034 for CD and p = 0.012 for UC) and biologics (p = 0.004 for CD and p = 0.008 for UC) was significantly lower. The disease course, using a severity composite criterion, was not significantly different between the two groups for CD (hazard ration (HR) = 1.3 [0.7; 2.4], p = 0.45) and UC (HR, 1.1 [0.5; 2.7], p = 0.767). The overall drug safety profile was statistically similar between the two groups.

CONCLUSION

Although HIV-infected patients receive less treatments, the course of their IBD did not differ than uninfected, suggesting that HIV infection might attenuate IBD. The drug safety profile is reassuring, allowing physician to treat these patients according to current recommendations.

Developing an Effective Peptide-Based Vaccine for COVID-19: Preliminary Studies in Mice Models

Coronavirus disease 2019 (COVID-19) has caused massive health and economic disasters worldwide. Although several vaccines have effectively slowed the spread of the virus, their long-term protection and effectiveness against viral variants are still uncertain. To address these potential shortcomings, this study proposes a peptide-based vaccine to prevent COVID-19. A total of 15 B cell epitopes of the wild-type severe acute respiratory coronavirus 2 (SARS-CoV-2) spike (S) protein were selected, and their HLA affinities predicted in silico. Peptides were divided into two groups and tested in C57BL/6 mice with either QS21 or Al(OH)₃ as the adjuvant. Our results demonstrated that the peptide-based vaccine stimulated high and durable antibody responses in mice, with the T and B cell responses differing based on the type of adjuvant employed. Using epitope mapping, we showed that our peptide-based vaccine produced antibody patterns similar to those in COVID-19 convalescent individuals. Moreover, plasma from vaccinated mice and recovered COVID-19 humans had the same neutralizing activity when tested with a pseudo particle assay. Our data indicate that this adjuvant peptide-based vaccine can generate sustainable and effective B and T cell responses. Thus, we believe that our peptide-based vaccine can be a safe and effective vaccine against COVID-19, particularly because of the flexibility of including new peptides to prevent emerging SARS-CoV-2 variants and avoiding unwanted autoimmune responses.

Complement Receptor 3 Mediates HIV-1 Transcytosis across an Intact Cervical Epithelial Cell Barrier: New Insight into HIV Transmission in Women

Transmission of HIV across the mucosal surface of the female reproductive tract to engage subepithelial CD4-positive T cells is not fully understood. Cervical epithelial cells express complement receptor 3 (CR3) (integrin αMβ2 or CD11b/CD18). In women, the bacterium Neisseria gonorrhoeae uses CR3 to invade the cervical epithelia to cause cervicitis. We hypothesized that HIV may also use CR3 to transcytose across the cervical epithelia. Here, we show that HIV-1 strains bound with high affinity to recombinant CR3 in biophysical assays. HIV-1 bound CR3 via the I-domain region of the CR3 alpha subunit, CD11b, and binding was dependent on HIV-1 N-linked glycans. Mannosylated glycans on the HIV surface were a high-affinity ligand for the I-domain. Man5 pentasaccharide, representative of HIV N-glycans, could compete with HIV-1 for CR3 binding. Using cellular assays, we show that HIV bound to CHO cells by a CR3-dependent mechanism. Antibodies to the CR3 I-domain or to the HIV-1 envelope glycoprotein blocked the binding of HIV-1 to primary human cervical epithelial (Pex) cells, indicating that CR3 was necessary and sufficient for HIV-1 adherence to Pex cells. Using Pex cells in a Transwell model system, we show that, following transcytosis across an intact Pex cell monolayer, HIV-1 is able to infect TZM-bl reporter cells. Targeting the HIV-CR3 interaction using antibodies, mannose-binding lectins, or CR3-binding small-molecule drugs blocked HIV transcytosis. These studies indicate that CR3/Pex may constitute an efficient pathway for HIV-1 transmission in women and also demonstrate strategies that may prevent transmission via this pathway. IMPORTANCE In women, the lower female reproductive tract is the primary site for HIV infection. How HIV traverses the epithelium to infect CD4 T cells in the submucosa is ill-defined. Cervical epithelial cells have a protein called CR3 on their surface. We show that HIV-1 binds to CR3 with high affinity and that this interaction is necessary and sufficient for HIV adherence to, and transcytosis across, polarized, human primary cervical epithelial cells. This suggests a unique role for CR3 on epithelial cells in dually facilitating HIV-1 attachment and entry. The HIV-CR3 interaction may constitute an efficient pathway for HIV delivery to subepithelial lymphocytes following virus transmission across an intact cervical epithelial barrier. Strategies with potential to prevent transmission via this pathway are presented.

Sympathetic Nerves and Innate Immune System in the Spleen: Implications of Impairment in HIV-1 and Relevant Models

The immune and sympathetic nervous systems are major targets of human, murine and simian immunodeficiency viruses (HIV-1, MAIDS, and SIV, respectively). The spleen is a major reservoir for these retroviruses, providing a sanctuary for persistent infection of myeloid cells in the white and red pulps. This is despite the fact that circulating HIV-1 levels remain undetectable in infected patients receiving combined antiretroviral therapy. These viruses sequester in immune organs, preventing effective cures. The spleen remains understudied in its role in HIV-1 pathogenesis, despite it hosting a quarter of the body’s lymphocytes and diverse macrophage populations targeted by HIV-1. HIV-1 infection reduces the white pulp, and induces perivascular hyalinization, vascular dysfunction, tissue infarction, and chronic inflammation characterized by activated epithelial-like macrophages. LP-BM5, the retrovirus that induces MAIDS, is a well-established model of AIDS. Immune pathology in MAIDs is similar to SIV and HIV-1 infection. As in SIV and HIV, MAIDS markedly changes splenic architecture, and causes sympathetic dysfunction, contributing to inflammation and immune dysfunction. In MAIDs, SIV, and HIV, the viruses commandeer splenic macrophages for their replication, and shift macrophages to an M2 phenotype. Additionally, in plasmacytoid dendritic cells, HIV-1 blocks sympathetic augmentation of interferon-β (IFN-β) transcription, which promotes viral replication. Here, we review viral–sympathetic interactions in innate immunity and pathophysiology in the spleen in HIV-1 and relevant models. The situation remains that research in this area is still sparse and original hypotheses proposed largely remain unanswered.

Why the HIV Reservoir Never Runs Dry: Clonal Expansion and the Characteristics of HIV-Infected Cells Challenge Strategies to Cure and Control HIV Infection

Antiretroviral therapy (ART) effectively reduces cycles of viral replication but does not target proviral populations in cells that persist for prolonged periods and that can undergo clonal expansion. Consequently, chronic human immunodeficiency virus (HIV) infection is sustained during ART by a reservoir of long-lived latently infected cells and their progeny. This proviral landscape undergoes change over time on ART. One of the forces driving change in the landscape is the clonal expansion of infected CD4 T cells, which presents a key obstacle to HIV eradication. Potential mechanisms of clonal expansion include general immune activation, antigenic stimulation, homeostatic proliferation, and provirus-driven clonal expansion, each of which likely contributes in varying, and largely unmeasured, amounts to maintaining the reservoir. The role of clinical events, such as infections or neoplasms, in driving these mechanisms remains uncertain, but characterizing these forces may shed light on approaches to effectively eradicate HIV. A limited number of individuals have been cured of HIV infection in the setting of bone marrow transplant; information from these and other studies may identify the means to eradicate or control the virus without ART. In this review, we describe the mechanisms of HIV-1 persistence and clonal expansion, along with the attempts to modify these factors as part of reservoir reduction and cure strategies.

Regulation of ABC Drug Efflux Transporters in Human T-Cells Exposed to an HIV Pseudotype

ATP-binding cassette (ABC) drug efflux transporters could contribute to low intracellular concentrations of antiretroviral drugs in HIV-1 cell reservoirs and sanctuary sites. Furthermore, the functional expression of these transporters could be induced in activated T-cells. Therefore, we investigated the expression of ABC drug efflux transporters in human T-cells exposed to an HIV pseudotype virus (pHIV_NL4-3), and further examined the potential involvement of the mammalian target of rapamycin (mTOR) signaling pathway in regulating their expression following exposure to pHIV_NL4-3. Additionally, we investigated the contribution of the drug efflux transporters to the inflammatory response following pHIV_NL4-3-induced T-cell activation. Human peripheral blood mononuclear cells (PBMCs) were exposed to HIV-1 envelope glycoprotein gp120_IIIB, pHIV_NL4-3 and/or mTOR inhibitors. The expression of ABC transporters, T-cell activation marker CD69, mTOR and pHIV_NL4-3 was assessed in CD4⁺ T-cells by Flow cytometry. mRNA and protein levels of proinflammatory cytokines (IL6, TNFα and INFγ) were examined in PBMCs by qPCR and ELISA analyses, respectively, following exposure to pHIV_NL4-3 with or without inhibitors of mTOR or ABC transporters. The expression of ABC transporters (P-glycoprotein, breast cancer resistance protein and multi-drug resistance associated protein-1) was significantly increased in CD4⁺ T-cells exposed to pHIV_NL4-3. Treatment with mTOR inhibitors attenuated pHIV_NL4-3-induced transporter expression, as well as mRNA and protein levels of IL6, TNFα and INFγ. Additionally, inhibition of P-gp or MRP1 activity resulted in lower concentrations of proinflammatory cytokines in supernatants of PBMC exposed to pHIV_NL4-3. Herein we present novel data demonstrating that upregulation of ABC drug efflux transporters could involve the mTOR signaling pathway in CD4⁺ T-cells exposed to an HIV pseudotype. These transporters could limit antiretroviral drug penetration in HIV target T-cells. Furthermore, ABC transporters could potentially contribute to HIV-associated proinflammatory cytokine secretion.

G2-S16 Polyanionic Carbosilane Dendrimer Can Reduce HIV-1 Reservoir Formation by Inhibiting Macrophage Cell to Cell Transmission

Human immunodeficiency virus (HIV-1) is still a major problem, not only in developing countries but is also re-emerging in several developed countries, thus the development of new compounds able to inhibit the virus, either for prophylaxis or treatment, is still needed. Nanotechnology has provided the science community with several new tools for biomedical applications. G2-S16 is a polyanionic carbosilane dendrimer capable of inhibiting HIV-1 in vitro and in vivo by interacting directly with viral particles. One of the main barriers for HIV-1 eradication is the reservoirs created in primoinfection. These reservoirs, mainly in T cells, are untargetable by actual drugs or immune system. Thus, one approach is inhibiting HIV-1 from reaching these reservoir cells. In this context, macrophages play a main role as they can deliver viral particles to T cells establishing reservoirs. We showed that G2-S16 dendrimer is capable of inhibiting the infection from infected macrophages to healthy T CD4/CD8 lymphocytes by eliminating HIV-1 infectivity inside macrophages, so they are not able to carry infectious particles to other body locations, thus preventing the reservoirs from forming.

Genome-Wide Variation in Betacoronaviruses

The Severe acute respiratory syndrome coronavirus (SARS-CoV) and SARS-CoV-2 originated in bats and adapted to infect humans. Several SARS-CoV-2 strains have been identified. Genetic variation is fundamental to virus evolution and, in response to selection pressure, is manifested as the emergence of new strains and species adapted to different hosts or with novel pathogenicity. The combination of variation and selection forms a genetic footprint on the genome, consisting of the preferential accumulation of mutations in particular areas. Properties of betacoronaviruses contributing to variation and the emergence of new strains and species are beginning to be elucidated. To better understand their variation, we profiled the accumulation of mutations in all species in the genus Betacoronavirus, including SARS-CoV-2 and two other species that infect humans: SARS-CoV and Middle East respiratory syndrome coronavirus (MERS-CoV). Variation profiles identified both genetically stable and variable areas at homologous locations across species within the genus Betacoronavirus. The S glycoprotein is the most variable part of the genome and is structurally disordered. Other variable parts include proteins 3 and 7 and ORF8, which participate in replication and suppression of antiviral defense. In contrast, replication proteins in ORF1b are the least variable. Collectively, our results show that variation and structural disorder in the S glycoprotein is a general feature of all members of the genus Betacoronavirus, including SARS-CoV-2. These findings highlight the potential for the continual emergence of new species and strains with novel biological properties and indicate that the S glycoprotein has a critical role in host adaptation.

IMPORTANCE Natural infection with SARS-CoV-2 and vaccines triggers the formation of antibodies against the S glycoprotein, which are detected by antibody-based diagnostic tests. Our analysis showed that variation in the S glycoprotein is a general feature of all species in the genus Betacoronavirus, including three species that infect humans: SARS-CoV, SARS-CoV-2, and MERS-CoV. The variable nature of the S glycoprotein provides an explanation for the emergence of SARS-CoV-2, the differentiation of SARS-CoV-2 into strains, and the probability of SARS-CoV-2 repeated infections in people. Variation of the S glycoprotein also has important implications for the reliability of SARS-CoV-2 antibody-based diagnostic tests and the design and deployment of vaccines and antiviral drugs. These findings indicate that adjustments to vaccine design and deployment and to antibody-based diagnostic tests are necessary to account for S glycoprotein variation.

SARS-CoV-2 and Human Immunodeficiency Virus: Pathogen Pincer Attack

Paramount efforts worldwide are seeking to increase understanding of the basic virology of SARS-CoV-2, characterize the spectrum of complications associated with COVID-19, and develop vaccines that can protect from new and recurrent infections with SARS-CoV-2. While we continue learning about this new virus, it is clear that 1) the virus is spread via the respiratory route, primarily by droplets and contact with contaminated surfaces and fomites, as well as by aerosol formation during invasive respiratory procedures; 2) the airborne route is still controversial; and 3) that those infected can spread the virus without necessarily developing COVID-19 (ie, asymptomatic). With the number of SARS-CoV-2 infections increasing globally, the possibility of co-infections and/or co-morbidities is becoming more concerning. Co-infection with Human Immunodeficiency Virus (HIV) is one such example of polyparasitism of interest. This military-themed comparative review of SARS-CoV-2 and HIV details their virology and describes them figuratively as separate enemy armies. HIV, an old enemy dug into trenches in individuals already infected, and SARS-CoV-2 the new army, attempting to attack and capture territories, tissues and organs, in order to provide resources for their expansion. This analogy serves to aid in discussion of three main areas of focus and draw attention to how these viruses may cooperate to gain the upper hand in securing a host. Here we compare their target, the key receptors found on those tissues, viral lifecycles and tactics for immune response surveillance. The last focus is on the immune response to infection, addressing similarities in cytokines released. While the majority of HIV cases can be successfully managed with antiretroviral therapy nowadays, treatments for SARS-CoV-2 are still undergoing research given the novelty of this army.

Antiviral Properties of Human Milk

Humans have always coexisted with viruses, with both positive and negative consequences. Evolutionary pressure on mammals has selected intrinsic properties of lactation and milk to support the relatively immunocompromised neonate from environmental pathogens, as well as support the normal development of diverse immune responses. Human milk supports both adaptive and innate immunity, with specific constituents that drive immune learning and maturation, and direct protection against microorganisms. Viruses constitute one of the most ancient pressures on human evolution, and yet there is a lack of awareness by both public and healthcare professionals of the complexity of human milk as an adaptive response beyond the production of maternal antibodies. This review identifies and describes the specific antiviral properties of human milk and describes how maternal support of infants through lactation is protective beyond antibodies.

A Review of Current Strategies Towards the Elimination of Latent HIV-1 and Subsequent HIV-1 Cure

Background

During the past 35 years, highly effective ART has saved the lives of millions of people worldwide by suppressing viruses to undetectable levels. However, this does not translate to the absence of viruses in the body as HIV persists in latent reservoirs. Indeed, rebounded HIV has been recently observed in the Mississippi and California infants previously thought to have been cured. Hence, much remains to be learned about HIV latency, and the search for the best strategy to eliminate the reservoir is the direction current research is taking. A systems-level approach that fully recapitulates the dynamics and complexity of HIV-1 latency In vivo and is applicable in human therapy is prudent for HIV eradication to be more feasible.

Objectives

The main barriers preventing the cure of HIV with antiretroviral therapy have been identified, progress has been made in the understanding of the therapeutic targets to which potentially eradicating drugs could be directed, integrative strategies have been proposed, and clinical trials with various alternatives are underway. The aim of this review is to provide an update on the main advances in HIV eradication, with particular emphasis on the obstacles and the different strategies proposed. The core challenges of each strategy are highlighted and the most promising strategy and new research avenues in HIV eradication strategies are proposed.

Methods

A systematic literature search of all English-language articles published between 2015 and 2019, was conducted using MEDLINE (PubMed) and Google scholar. Where available, medical subject headings (MeSH) were used as search terms and included: HIV, HIV latency, HIV reservoir, latency reactivation, and HIV cure. Additional search terms consisted of suppression, persistence, establishment, generation, and formation. A total of 250 articles were found using the above search terms. Out of these, 89 relevant articles related to HIV-1 latency establishment and eradication strategies were collected and reviewed, with no limitation of study design. Additional studies (commonly referenced and/or older and more recent articles of significance) were selected from bibliographies and references listed in the primary resources.

Results

In general, when exploring the literature, there are four main strategies heavily researched that provide promising strategies to the elimination of latent HIV: Haematopoietic Stem-Cell Transplantation, Shock and Kill Strategy, Gene-specific transcriptional activation using RNA-guided CRISPR-Cas9 system, and Block and Lock strategy. Most of the studies of these strategies are applicable in vitro, leaving many questions about the extent to which, or if any, these strategies are applicable to complex picture In vivo. However, the success of these strategies at least shows, in part, that HIV-1 can be cured, though some strategies are too invasive and expensive to become a standard of care for all HIV-infected patients.

Conclusion

Recent advances hold promise for the ultimate cure of HIV infection. A systems-level approach that fully recapitulates the dynamics and complexity of HIV-1 latency In vivo and applicable in human therapy is prudent for HIV eradication to be more feasible. Future studies aimed at achieving a prolonged HIV remission state are more likely to be successful if they focus on a combination strategy, including the block and kill, and stem cell approaches. These strategies propose a functional cure with minimal toxicity for patients. It is believed that the cure of HIV infection will be attained in the short term if a strategy based on purging the reservoirs is complemented with an aggressive HAART strategy.

Human Pannexin 1 channel: Insight in structure-function mechanism and its potential physiological roles

Pannexins, large non-gap junction super family exists in vertebrates, play multiple roles in different cellular functions through their ATP release. Panx1-mediated adenosine 5'-triphosphate (ATP) release plays a vital role in physiological and pathophysiological conditions and is known major extracellular molecule in purinergic signaling. To modulate their function in vivo, a proper regulation of channel is necessary. Post-translational modifications are considered to be some regulating mechanisms for PANX1, while PANX2, PANX3 have been uncharacterized to date. Through their significant evidences, PANXs exclude from gap junction and conduits ATP release and other cellular molecules from cells by various mechanisms. PANX1 is most extensive characterized and implicated in ATP signaling and inflammatory processes. Despite the constant advances, much significance of PANX1 in physiological processes remains elusive. Recently, various research groups along with our group have reported the Cryo-EM structure of Panx1 channel and uncovered the hidden functions in structure-function mechanism as well as to provide the clear understanding in physiological and pathophysiological roles. These research groups reported the novel heptameric structure with contains 4 transmembrane helices (TM), two extracellular loops and one intracellular loop with N and C terminus located at the intracellular side. In addition, the structure contains a large pore of which an inhibitor CBX act as a plug that blocking the passage of substrate. In this context, this review will present current mechanistic understanding in structure and function together with significant physiological roles particularly ATP release in health and disease. As such, this review emphasizes on recent functional properties associated with novel heptameric channel and demystifies channel-mediated ATP release function.

CD300a identifies a CD4+ memory T cell subset with a higher susceptibility to HIV-1 infection

: Human CD300a is known to promote the infection by dengue and other enveloped viruses and is overexpressed on CD4 T cells from HIV-1-infected patients. We found that infected CD4+RA- T cells from untreated HIV-1-infected patients were mostly CD300a+. Furthermore, CD300a expressing CD4+RA- T cells from healthy donors were significantly more infected by HIV-1 in vitro than CD300a- cells. CD300a might represent a biomarker of susceptibility to HIV-1 infection on memory CD4 T lymphocytes.

Current and Future Therapeutic Strategies for Lentiviral Eradication from Macrophage Reservoirs

Macrophages, one of the most abundant populations of leukocytes in the body, function as the first line of defense against pathogen invaders. Human Immunodeficiency virus 1 (HIV-1) remains to date one of the most extensively studied viral infections. Naturally occurring lentiviruses in domestic and primate species serve as valuable models to investigate lentiviral pathogenesis and novel therapeutics. Better understanding of the role macrophages play in HIV pathogenesis will aid in the advancement towards a cure. Even with current efficacy of first- and second-line Antiretroviral Therapy (ART) guidelines and future efficacy of Long Acting Slow Effective Release-ART (LASER-ART); ART alone does not lead to a cure. The major challenge of HIV eradication is viral latency. Latency Reversal Agents (LRAs) show promise as a possible means to eradicate HIV-1 from the body. It has become evident that complete eradication will need to include combinations of various effective therapeutic strategies such as LASER-ART, LRAs, and gene editing. Review of the current literature indicates the most promising HIV eradication strategy appears to be LASER-ART in conjunction with viral and receptor gene modifications via the CRISPR/Cas9 system. Graphical abstract A multimodal approach to HIV treatment including gene editing, LASER-ART, and latency reversal agents may provide a means to achieve HIV eradication.

Syndemic synergy of HPV and other sexually transmitted pathogens in the development of high-grade anal squamous intraepithelial lesions

Background

Anal intraepithelial neoplasia is associated with high-risk human papillomavirus (hrHPV) as a precursor to anal cancer. However, factors other than hrHPV are likely to be involved and further study of cofactors is required because of the possibility of syndemic interactions.

Methods

Three hundred and fourteen patients underwent 457 operations. Histopathology and hrHPV testing using the Digene Hybrid Capture 2 (HC 2) method were performed. Demographic factors and sexually transmissible infections (STIs) were recorded.

Results

Results showed that hrHPV alone was associated with HSIL (OR = 4.65, p < 0.001). None of the other STIs were alone associated with HSIL but amplification of risk was found when hrHPV infection occurred with HIV (OR = 11.1); syphilis (OR = 5.58); HSV 2 (OR = 7.85); gonorrhoea (OR = 6.45) and some other infections.

Conclusions

These results suggest that hrHPV is a sufficient cause of anal HSIL. Seropositivity for HIV, HSV 2, T. pallidum, HBV and HCV and a history of gonorrhoea or chlamydia exert a powerful amplifying factor increasing the risk of HSIL above the risk with hrHPV alone. Other co-factors which are associated with an increased risk of HSIL are increased age, male gender, MSM behaviour and self-reported history of more than 50 sexual partners. This pattern of disease in patients with warts is characteristic of a syndemic with potential serious increased risk of anal carcinoma.

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High-risk HPV is a necessary and sufficient cause of progression from LSIL to HSIL.

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HIV, HSV 2, HBV and HCV are associated with an amplified risk of hrHPV induced HSIL.

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Gonorrhoea, chlamydia, and syphilis are associated with increased odds HSIL.

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HSIL shows syndemic interaction patterns with STIs and behavioural/social factors.