The Hitchhiker Guide to CD4+ T-Cell Depletion in Lentiviral Infection. A Critical Review of the Dynamics of the CD4+ T Cells in SIV and HIV Infection

It's all in the gut: the central role of the gut and microbiome in preventing disease progression in simian immunodeficiency viruses infected African nonhuman primates

PURPOSE OF REVIEW

Typically, both HIV-infected humans and simian immunodeficiency virus (SIV)-infected Asian nonhuman primates (NHPs) eventually progress to AIDS, while African NHPs that are natural hosts of SIV do not, in spite of life-long, high levels of viral replication. Lack of disease progression in African NHPs is not due to some adaptation by the virus, but rather to host adaptations to the virus. Central to these adaptations is maintenance of the gut integrity during acute viral replication and inflammation, which allows natural hosts to avoid the chronic inflammation characteristic to pathogenic HIV/SIV infection.

RECENT FINDINGS

It has been recently shown that natural hosts of SIVs, such as the African green monkey (AGM), avoid damage to the mucosal epithelium through wound healing mechanisms, possibly with the contribution of a unique anti-inflammatory microbiome. Furthermore, these mechanisms are independent of viral replication, and CD4 + T-cell activation or depletion.

SUMMARY

Future SIV research on natural hosts should focus on further elucidating the anti-inflammatory state of their gut, and the role of microbiome/dysbiosis in the pathogenesis of SIV infection, with the goal of development new regiments or treatments to reduce or even halt the vicious cycle of gut damage and inflammation triggered by pathogenic HIV/SIV infection.

Study on the prediction performance of AIDS monthly incidence in Xinjiang based on time series and deep learning models

OBJECTIVE

AIDS is a highly fatal infectious disease of Class B, and Xinjiang is a high-incidence region for AIDS in China. The core of prevention and control lies in early monitoring and early warning. This study aims to identify the best model for predicting the monthly AIDS incidence in Xinjiang, providing scientific evidence for AIDS prevention and control.

METHODS

Monthly AIDS incidence data from January 2004 to December 2020 in Xinjiang were collected. Six different models, including the ARIMA (2,1,2) model, ARIMA (2,1,2)-EGARCH (2,2) combined model, ARIMA (2,1,2)-TGARCH (1,1) combined model, ETS (A, A, A) model, XGBoost model, and LSTM model, were used for fitting and forecasting.

RESULTS

All models were able to capture the overall trend of the monthly AIDS incidence in Xinjiang. In terms of RMSE and MAE, the ETS (A, A, A) model performed the best, achieving the smallest values. For the MAPE metric, the ARIMA (2,1,2)-TGARCH (1,1) model performed the best. Considering RMSE, MAE, and MAPE together, the ETS (A, A, A) model was the best-performing model in this study. The LSTM model also showed good predictive performance, while the XGBoost model and ARIMA (2,1,2) model performed relatively poorly.

CONCLUSION

The ETS (A, A, A) model is the best model for predicting the monthly AIDS incidence in Xinjiang. Deep learning models (such as LSTM) have significant potential in time series forecasting. The XGBoost model and ARIMA (2,1,2) model may have limitations when handling time series data, and future improvements or combinations could enhance prediction performance.

Comparative Analysis of Virology and Pathogenesis of SARS-CoV-2 and HIV Infections: Implications for Public Health and Treatment Strategies

Introduction

Coronavirus Disease 19 (COVID-19), caused by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), and Human Immunodeficiency Virus (HIV) are significant 21st-century pandemics with distinct virological and clinical characteristics. COVID-19 primarily presents as an acute respiratory illness, while HIV leads to chronic immune suppression. Understanding their differences can enhance public health strategies and treatment approaches.

Purpose

This narrative review compares the virology, transmission, immune responses, and clinical outcomes of SARS-CoV-2 and HIV to inform treatment strategies and public health interventions.

Methods

A narrative review was conducted, synthesizing data from peer-reviewed literature and expert commentary from 2010 to 2024. Databases such as PubMed, Cochrane Library, and Google Scholar were searched for relevant studies.

Results

SARS-CoV-2 primarily spreads through airborne droplets and contaminated surfaces, while HIV transmits through direct contact with infected bodily fluids. The immune response to SARS-CoV-2 involves both innate and adaptive systems, potentially leading to a cytokine storm in severe cases. In contrast, HIV evades the immune system by integrating into host cells, resulting in chronic infection and progressive immune deterioration. Treatment for SARS-CoV-2 focuses on symptom management and prevention, with antiviral medications and vaccines playing crucial roles. Conversely, HIV treatment relies on antiretroviral therapy (ART) to suppress viral replication and maintain immune function.

Conclusion

The review highlights the acute nature of SARS-CoV-2 versus the chronic progression of HIV. Tailored prevention and treatment strategies are essential for effective disease management.

Recommendations

Public health strategies should address the unique transmission routes and progression of both viruses. Further research into vaccine development and therapeutic interventions is critical for improving disease management.

Thyroid disorders in patients with human immunodeficiency virus infection: a meta-analysis

BACKGROUND

Thyroid disorders have significant clinical sequelae, including impaired growth in children, metabolic abnormalities, and impaired cognitive function. However, available studies on burden of thyroid diseases in people with human immunodeficiency virus (HIV), particularly its prevalence and its interaction with HIV related factors (like CD4 count), are controversial. This review aimed to provide a comprehensive summary and analysis on the extent of thyroid dysfunctions in this population.

METHODS

Following Preferred reporting items for systematic review and meta-analysis (PRISMA) guidelines, a comprehensive search was done through Medline/PubMed, Web of Science, Science Direct, and World Health Organization Virtual Health Library Regional Portal. Using Comprehensive Meta-Analysis Software version 3.3, we calculated the pooled prevalence and standardized mean difference (SMD) estimates with 95% confidence intervals (CIs).

RESULTS

A total of 30 studies met the eligibility criteria and were further included for the analyses. The most common types of thyroid dysfunction identified among HIV patients were subclinical hypothyroidism (7.7%), overt hypothyroidism (2.7%), sick euthyroid syndrome (2.47%), isolated low FT4 (1.80%), and overt hyperthyroidism (0.7%). Hypothyroidism among HIV patients was significantly associated with lower CD4 count (p < 0.001). The analysis revealed that only FT4 levels had significant differences between patients with HIV and healthy people (p = 0.013).

CONCLUSION

Individuals with HIV are at risk of developing variable manifestations of thyroid abnormalities. While being not abundant in the HIV population, monitoring of thyroid dysfunction is essential due to the potential for progression to overt hypothyroidism and associated adverse health outcomes.

Artificial antigen-presenting cell system reveals CD28's role in modulating T cell functions during human immunodeficiency virus infection

T cell immune dysfunction is a prominent feature of chronic HIV infection. To evaluate non-specific dysfunction, a method involving both generic activation and T cell receptor (TCR) stimulation is necessary. We created a tunable artificial antigen-presenting cell (aAPC) system. This system consists of lipid bilayers on cytometry-compatible silica microbeads (5 μm). When only anti-CD3 is incorporated, T cell activation is limited. Introducing anti-CD28 agonists significantly elevates the cytokine expression and upregulation of activation-induced markers. CD28 co-stimulation modulates the response profile, preferentially promoting IL-2 expression relative to other cytokines. aAPCs-stimulated CD4+ and CD8+ T cells from untreated HIV-infected individuals exhibit altered effector functions and diminished CD28 dependence. These functions are skewed toward TNFα, IFNγ and CD107a, with reduced IL-2. Antiretroviral therapy partially normalizes this distorted profile in CD4+ T cells, but not in CD8+ T cells. Our findings show T cell intrinsic biases that may contribute to persistent systemic T cell dysfunction associated with HIV pathogenesis.

A likelihood approach to incorporating self-report data in HIV recency classification

Estimating new HIV infections is significant yet challenging due to the difficulty in distinguishing between recent and long-term infections. We demonstrate that HIV recency status (recent versus long-term) could be determined from self-report testing history and biomarkers, which are increasingly available in bio-behavioral surveys. HIV recency status is partially observed, given the self-report testing history. For example, people who tested positive for HIV over 1 year ago should have a long-term infection. Based on the nationally representative samples collected by the Population-based HIV Impact Assessment (PHIA) Project, we propose a likelihood-based probabilistic model for HIV recency classification. The model incorporates individuals with known recency status based on testing histories and individuals whose recency status could not be determined and integrates the mechanism of how HIV recency status depends on biomarkers and the mechanism of how HIV recency status, together with the self-report time of the most recent HIV test, impacts the test results. We compare our method to logistic regression and the binary classification tree (current practice) on Malawi PHIA data, as well as on simulated data. Our model obtains more efficient and less biased parameter estimates and is relatively robust to potential reporting error and model misspecification.

Seroprevalence and Associated Outcomes of Parvovirus B19 Infection in Human Immunodeficiency Virus Patients: A Systematic Review

Several case reports have highlighted the presence of serious clinical outcomes in patients with human immunodeficiency virus (HIV) related to parvovirus B19 (PVB19). However, epidemiological studies have produced inconsistent and varying results regarding the prevalence of PVB19 and its associated clinical outcomes in this population. These inconsistencies highlight the need for a thorough summary and analysis of present data to better understand burden and impact of PVB19 on HIV patients. This review aims to provide an overview of current evidence and identify areas for further research. Following the Meta-analyses of Observational Studies in Epidemiology (MOOSE) guidelines, a comprehensive search was conducted across Medline/PubMed, Google Scholar, and World Health Organization Virtual Health Library Regional Portal. The pooled prevalence with the corresponding 95% confidence interval (CI) was measured using Comprehensive Meta-Analysis Software version 3.3. Publication bias was estimated based on Begg's test, Egger's test, and examination of the funnel plots. A total of 16 studies, with 2,122 HIV patients, were included in the meta-analysis. The pooled prevalence of detecting anti-PVB19 immunoglobulin G, anti-PVB19 immunoglobulin M, and PVB19 DNA particles among HIV patients was 43.6% (95% CI: 23.5-66.1%), 5.10% (95% CI: 2.10-12.10%), and 6.40% (95% CI: 4.10-9.90%), respectively. In the overall population of HIV patients, most of the included studies did not establish a statistically significant association between PVB19 infection and the occurrence of anemia. PVB19 infection is commonly detected in individuals with HIV. However, anemia due to PVB19 is not common in this population. Findings from a few studies suggest that PVB19 infection may contribute to anemia in individuals with advanced HIV disease or significant immunosuppression. Additional research is needed to confirm and clarify these relationships in individuals with HIV, particularly those with compromised immune systems.

Making a Monkey out of Human Immunodeficiency Virus/Simian Immunodeficiency Virus Pathogenesis: Immune Cell Depletion Experiments as a Tool to Understand the Immune Correlates of Protection and Pathogenicity in HIV Infection

Understanding the underlying mechanisms of HIV pathogenesis is critical for designing successful HIV vaccines and cure strategies. However, achieving this goal is complicated by the virus's direct interactions with immune cells, the induction of persistent reservoirs in the immune system cells, and multiple strategies developed by the virus for immune evasion. Meanwhile, HIV and SIV infections induce a pandysfunction of the immune cell populations, making it difficult to untangle the various concurrent mechanisms of HIV pathogenesis. Over the years, one of the most successful approaches for dissecting the immune correlates of protection in HIV/SIV infection has been the in vivo depletion of various immune cell populations and assessment of the impact of these depletions on the outcome of infection in non-human primate models. Here, we present a detailed analysis of the strategies and results of manipulating SIV pathogenesis through in vivo depletions of key immune cells populations. Although each of these methods has its limitations, they have all contributed to our understanding of key pathogenic pathways in HIV/SIV infection.

The Role of Glutathione in the Management of Cell-Mediated Immune Responses in Individuals with HIV

Human immunodeficiency virus (HIV) is a major cause of death worldwide. Without appropriate antiretroviral therapy, the infection can develop into acquired immunodeficiency syndrome (AIDS). AIDS leads to the dysregulation of cell-mediated immunity resulting in increased susceptibility to opportunistic infections and excessive amounts of inflammatory cytokines. HIV-positive individuals also demonstrate diminished glutathione (GSH) levels which allows for increased viral replication and increased pro-inflammatory cytokine release, further contributing to the high rates of mortality seen in patients with HIV. Adequate GSH supplementation has reduced inflammation and slowed the decline of CD4+ T cell counts in HIV-positive individuals. We aim to review the current literature regarding the role of GSH in cell-mediated immune responses in individuals with HIV- and AIDS-defining illnesses.

The Potential of Clostridium butyricum to Preserve Gut Health, and to Mitigate Non-AIDS Comorbidities in People Living with HIV

A dramatic reduction in mortality among people living with HIV (PLWH) has been achieved during the modern antiretroviral therapy (ART) era. However, ART does not restore gut barrier function even after long-term viral suppression, allowing microbial products to enter the systemic blood circulation and induce chronic immune activation. In PLWH, a chronic state of systemic inflammation exists and persists, which increases the risk of development of inflammation-associated non-AIDS comorbidities such as metabolic disorders, cardiovascular diseases, and cancer. Clostridium butyricum is a human butyrate-producing symbiont present in the gut microbiome. Convergent evidence has demonstrated favorable effects of C. butyricum for gastrointestinal health, including maintenance of the structural and functional integrity of the gut barrier, inhibition of pathogenic bacteria within the intestine, and reduction of microbial translocation. Moreover, C. butyricum supplementation has been observed to have a positive effect on various inflammation-related diseases such as diabetes, ulcerative colitis, and cancer, which are also recognized as non-AIDS comorbidities associated with epithelial gut damage. There is currently scant published research in the literature, focusing on the influence of C. butyricum in the gut of PLWH. In this hypothesis review, we speculate the use of C. butyricum as a probiotic oral supplementation may well emerge as a potential future synergistic adjunctive strategy in PLWH, in tandem with ART, to restore and consolidate intestinal barrier integrity, repair the leaky gut, prevent microbial translocation from the gut, and reduce both gut and systemic inflammation, with the ultimate objective of decreasing the risk for development of non-AIDS comorbidities in PLWH.

Influence of HIV infection on cognition and overall intelligence in HIV-infected individuals: advances and perspectives

It is now well understood that HIV-positive individuals, even those under effective ART, tend to develop a spectrum of cognitive, motor, and/or mood conditions which are contemporarily referred to as HIV-associated neurocognitive disorder (HAND), and which is directly related to HIV-1 infection and HIV-1 replication in the central nervous system (CNS). As HAND is known to induce difficulties associated with attention, concentration, and memory, it is thus legitimate and pertinent to speculate upon the possibility that HIV infection may well influence human cognition and intelligence. We therefore propose herein to review the concept of intelligence, the concept of cells of intelligence, the influence of HIV on these particular cells, and the evidence pointing to differences in observed intelligence quotient (IQ) scores between HIV-positive and HIV-negative individuals. Additionally, cumulative research evidence continues to draw attention to the influence of the gut on human intelligence. Up to now, although it is known that HIV infection profoundly alters both the composition and diversity of the gut microbiota and the structural integrity of the gut, the influence of the gut on intelligence in the context of HIV infection remains poorly described. As such, we also provide herein a review of the different ways in which HIV may influence human intelligence via the gut-brain axis. Finally, we provide a discourse on perspectives related to HIV and human intelligence which may assist in generating more robust evidence with respect to this issue in future studies. Our aim is to provide insightful knowledge for the identification of novel areas of investigation, in order to reveal and explain some of the enigmas related to HIV infection.

Recent advances in poor HIV immune reconstitution: what will the future look like?

Combination antiretroviral therapy has demonstrated proved effectiveness in suppressing viral replication and significantly recovering CD4+ T cell count in HIV type-1 (HIV-1)-infected patients, contributing to a dramatic reduction in AIDS morbidity and mortality. However, the factors affecting immune reconstitution are extremely complex. Demographic factors, co-infection, baseline CD4 cell level, abnormal immune activation, and cytokine dysregulation may all affect immune reconstitution. According to report, 10-40% of HIV-1-infected patients fail to restore the normalization of CD4+ T cell count and function. They are referred to as immunological non-responders (INRs) who fail to achieve complete immune reconstitution and have a higher mortality rate and higher risk of developing other non-AIDS diseases compared with those who achieve complete immune reconstitution. Heretofore, the mechanisms underlying incomplete immune reconstitution in HIV remain elusive, and INRs are not effectively treated or mitigated. This review discusses the recent progress of mechanisms and factors responsible for incomplete immune reconstitution in AIDS and summarizes the corresponding therapeutic strategies according to different mechanisms to improve the individual therapy.

MAdCAM-1 costimulation in the presence of retinoic acid and TGF-β promotes HIV infection and differentiation of CD4+ T cells into CCR5+ TRM-like cells

CD4+ tissue resident memory T cells (TRMs) are implicated in the formation of persistent HIV reservoirs that are established during the very early stages of infection. The tissue-specific factors that direct T cells to establish tissue residency are not well defined, nor are the factors that establish viral latency. We report that costimulation via MAdCAM-1 and retinoic acid (RA), two constituents of gut tissues, together with TGF-β, promote the differentiation of CD4+ T cells into a distinct subset α4β7+CD69+CD103+ TRM-like cells. Among the costimulatory ligands we evaluated, MAdCAM-1 was unique in its capacity to upregulate both CCR5 and CCR9. MAdCAM-1 costimulation rendered cells susceptible to HIV infection. Differentiation of TRM-like cells was reduced by MAdCAM-1 antagonists developed to treat inflammatory bowel diseases. These finding provide a framework to better understand the contribution of CD4+ TRMs to persistent viral reservoirs and HIV pathogenesis.

Prolonged experimental CD4+ T-cell depletion does not cause disease progression in SIV-infected African green monkeys

CD4⁺ T-cell depletion is a hallmark of HIV infection, leading to impairment of cellular immunity and opportunistic infections, but its contribution to SIV/HIV-associated gut dysfunction is unknown. Chronically SIV-infected African Green Monkeys (AGMs) partially recover mucosal CD4⁺ T-cells, maintain gut integrity and do not progress to AIDS. Here we assess the impact of prolonged, antibody-mediated CD4 + T-cell depletion on gut integrity and natural history of SIV infection in AGMs. All circulating CD4⁺ T-cells and >90% of mucosal CD4⁺ T-cells are depleted. Plasma viral loads and cell-associated viral RNA in tissues are lower in CD4⁺-cell-depleted animals. CD4⁺-cell-depleted AGMs maintain gut integrity, control immune activation and do not progress to AIDS. We thus conclude that CD4⁺ T-cell depletion is not a determinant of SIV-related gut dysfunction, when gastrointestinal tract epithelial damage and inflammation are absent, suggesting that disease progression and resistance to AIDS are independent of CD4⁺ T-cell restoration in SIVagm-infected AGMs.

Inflammasomes as mediators of inflammation in HIV-1 infection

Human immunodeficiency virus type 1 (HIV-1) infection is a chronic disease without a known cure. The advent of effective antiretroviral therapy (ART) has enabled people with HIV (PWH) to have significantly prolonged life expectancies. As a result, morbidity and mortality associated with HIV-1 infection have declined considerably. However, these individuals experience chronic systemic inflammation whose multifaceted etiology is associated with other numerous comorbidities. Inflammasomes are vital mediators that contribute to inflammatory signaling in HIV-1 infection. Here, we provide an overview of the inflammatory pathway that underlies HIV-1 infection, explicitly highlighting the role of the NLRP3 inflammasome. We also delineate the current literature on inflammasomes and the therapeutic targeting strategies aimed at the NLRP3 inflammasome to moderate HIV-1 infection-associated inflammation. Here we describe the NLRP3 inflammasome as a key pathway in developing novel therapeutic targets to block HIV-1 replication and HIV-1-associated inflammatory signaling. Controlling the inflammatory pathways is critical in alleviating the morbidities and mortality associated with chronic HIV-1 infection in PWH.

Walk on the wild side: SIV infection in African non-human primate hosts-from the field to the laboratory

HIV emerged following cross-species transmissions of simian immunodeficiency viruses (SIVs) that naturally infect non-human primates (NHPs) from Africa. While HIV replication and CD4+ T-cell depletion lead to increased gut permeability, microbial translocation, chronic immune activation, and systemic inflammation, the natural hosts of SIVs generally avoid these deleterious consequences when infected with their species-specific SIVs and do not progress to AIDS despite persistent lifelong high viremia due to long-term coevolution with their SIV pathogens. The benign course of natural SIV infection in the natural hosts is in stark contrast to the experimental SIV infection of Asian macaques, which progresses to simian AIDS. The mechanisms of non-pathogenic SIV infections are studied mainly in African green monkeys, sooty mangabeys, and mandrills, while progressing SIV infection is experimentally modeled in macaques: rhesus macaques, pigtailed macaques, and cynomolgus macaques. Here, we focus on the distinctive features of SIV infection in natural hosts, particularly (1): the superior healing properties of the intestinal mucosa, which enable them to maintain the integrity of the gut barrier and prevent microbial translocation, thus avoiding excessive/pathologic immune activation and inflammation usually perpetrated by the leaking of the microbial products into the circulation; (2) the gut microbiome, the disruption of which is an important factor in some inflammatory diseases, yet not completely understood in the course of lentiviral infection; (3) cell population shifts resulting in target cell restriction (downregulation of CD4 or CCR5 surface molecules that bind to SIV), control of viral replication in the lymph nodes (expansion of natural killer cells), and anti-inflammatory effects in the gut (NKG2a/c+ CD8+ T cells); and (4) the genes and biological pathways that can shape genetic adaptations to viral pathogens and are associated with the non-pathogenic outcome of the natural SIV infection. Deciphering the protective mechanisms against SIV disease progression to immunodeficiency, which have been established through long-term coevolution between the natural hosts and their species-specific SIVs, may prompt the development of novel therapeutic interventions, such as drugs that can control gut inflammation, enhance gut healing capacities, or modulate the gut microbiome. These developments can go beyond HIV infection and open up large avenues for correcting gut damage, which is common in many diseases.

I've looked at gut from both sides now: Gastrointestinal tract involvement in the pathogenesis of SARS-CoV-2 and HIV/SIV infections

The lumen of the gastrointestinal (GI) tract contains an incredibly diverse and extensive collection of microorganisms that can directly stimulate the immune system. There are significant data to demonstrate that the spatial localization of the microbiome can impact viral disease pathogenesis. Here we discuss recent studies that have investigated causes and consequences of GI tract pathologies in HIV, SIV, and SARS-CoV-2 infections with HIV and SIV initiating GI pathology from the basal side and SARS-CoV-2 from the luminal side. Both these infections result in alterations of the intestinal barrier, leading to microbial translocation, persistent inflammation, and T-cell immune activation. GI tract damage is one of the major contributors to multisystem inflammatory syndrome in SARS-CoV-2-infected individuals and to the incomplete immune restoration in HIV-infected subjects, even in those with robust viral control with antiretroviral therapy. While the causes of GI tract pathologies differ between these virus families, therapeutic interventions to reduce microbial translocation-induced inflammation and improve the integrity of the GI tract may improve the prognoses of infected individuals.

HIV Infection and Spread between Th17 Cells

HIV mainly targets CD4+ T cells, from which Th17 cells represent a major cell type, permissive, and are capable of supporting intracellular replication at mucosal sites. Th17 cells possess well-described dual roles, while being central to maintaining gut integrity, these may induce inflammation and contribute to autoimmune disorders; however, Th17 cells’ antiviral function in HIV infection is not completely understood. Th17 cells are star players to HIV-1 pathogenesis and a potential target to prevent or decrease HIV transmission. HIV-1 can be spread among permissive cells via direct cell-to-cell and/or cell-free infection. The debate on which mode of transmission is more efficient is still ongoing without a concrete conclusion yet. Most assessments of virus transmission analyzing either cell-to-cell or cell-free modes use in vitro systems; however, the actual interactions and conditions in vivo are not fully understood. The fact that infected breast milk, semen, and vaginal secretions contain a mix of both cell-free viral particles and infected cells presents an argument for the probability of HIV taking advantage of both modes of transmission to spread. Here, we review important insights and recent findings about the role of Th17 cells during HIV pathogenesis in mucosal surfaces, and the mechanisms of HIV-1 infection spread among T cells in tissues.

The Youngbloods. Get Together. Hypercoagulation, Complement, and NET Formation in HIV/SIV Pathogenesis

Chronic, systemic T-cell immune activation and inflammation (IA/INFL) have been reported to be associated with disease progression in persons with HIV (PWH) since the inception of the AIDS pandemic. IA/INFL persist in PWH on antiretroviral therapy (ART), despite complete viral suppression and increases their susceptibility to serious non-AIDS events (SNAEs). Increased IA/INFL also occur during pathogenic SIV infections of macaques, while natural hosts of SIVs that control chronic IA/INFL do not progress to AIDS, despite having persistent high viral replication and severe acute CD4+ T-cell loss. Moreover, natural hosts of SIVs do not present with SNAEs. Multiple mechanisms drive HIV-associated IA/INFL, including the virus itself, persistent gut dysfunction, coinfections (CMV, HCV, HBV), proinflammatory lipids, ART toxicity, comorbidities, and behavioral factors (diet, smoking, and alcohol). Other mechanisms could also significantly contribute to IA/INFL during HIV/SIV infection, notably, a hypercoagulable state, characterized by elevated coagulation biomarkers, including D-dimer and tissue factor, which can accurately identify patients at risk for thromboembolic events and death. Coagulation biomarkers strongly correlate with INFL and predict the risk of SNAE-induced end-organ damage. Meanwhile, the complement system is also involved in the pathogenesis of HIV comorbidities. Despite prolonged viral suppression, PWH on ART have high plasma levels of C3a. HIV/SIV infections also trigger neutrophil extracellular traps (NETs) formation that contribute to the elimination of viral particles and infected CD4+ T-cells. However, as SIV infection progresses, generation of NETs can become excessive, fueling IA/INFL, destruction of multiple immune cells subsets, and microthrombotic events, contributing to further tissue damages and SNAEs. Tackling residual IA/INFL has the potential to improve the clinical course of HIV infection. Therefore, therapeutics targeting new pathways that can fuel IA/INFL such as hypercoagulation, complement activation and excessive formation of NETs might be beneficial for PWH and should be considered and evaluated.

So Pathogenic or So What?-A Brief Overview of SIV Pathogenesis with an Emphasis on Cure Research

HIV infection requires lifelong antiretroviral therapy (ART) to control disease progression. Although ART has greatly extended the life expectancy of persons living with HIV (PWH), PWH nonetheless suffer from an increase in AIDS-related and non-AIDS related comorbidities resulting from HIV pathogenesis. Thus, an HIV cure is imperative to improve the quality of life of PWH. In this review, we discuss the origins of various SIV strains utilized in cure and comorbidity research as well as their respective animal species used. We briefly detail the life cycle of HIV and describe the pathogenesis of HIV/SIV and the integral role of chronic immune activation and inflammation on disease progression and comorbidities, with comparisons between pathogenic infections and nonpathogenic infections that occur in natural hosts of SIVs. We further discuss the various HIV cure strategies being explored with an emphasis on immunological therapies and "shock and kill".