Sex differences in HIV-1-mediated immunopathology

Cannabinoid receptor 1 positive allosteric modulator ZCZ011 shows differential effects on behavior and the endocannabinoid system in HIV-1 Tat transgenic female and male mice

The cannabinoid receptor type 1 (CB1R) is a promising therapeutic target for various neurodegenerative diseases, including HIV-1-associated neurocognitive disorder (HAND). However, the therapeutic potential of CB1R by direct activation is limited due to its psychoactive side effects. Therefore, research has focused on indirectly activating the CB1R by utilizing positive allosteric modulators (PAMs). Studies have shown that CB1R PAMs (ZCZ011 and GAT211) are effective in mouse models of Huntington's disease and neuropathic pain, and hence, we assess the therapeutic potential of ZCZ011 in a well-established mouse model of neuroHIV. The current study investigates the effect of chronic ZCZ011 treatment (14 days) on various behavioral paradigms and the endocannabinoid system in HIV-1 Tat transgenic female and male mice. Chronic ZCZ011 treatment (10 mg/kg) did not alter body mass, locomotor activity, or anxiety-like behavior regardless of sex or genotype. However, differential effects were noted in hot plate latency, motor coordination, and recognition memory in female mice only, with ZCZ011 treatment increasing hot plate latency and improving motor coordination and recognition memory. Only minor effects or no alterations were seen in the endocannabinoid system and related lipids except in the cerebellum, where the effect of ZCZ011 was more pronounced in female mice. Moreover, AEA and PEA levels in the cerebellum were positively correlated with improved motor coordination in female mice. In summary, these findings indicate that chronic ZCZ011 treatment has differential effects on antinociception, motor coordination, and memory, based on sex and HIV-1 Tat expression, making CB1R PAMs potential treatment options for HAND without the psychoactive side effects.

Effects of acute cannabidiol on behavior and the endocannabinoid system in HIV-1 Tat transgenic female and male mice

Background

Some evidence suggests that cannabidiol (CBD) has potential to help alleviate HIV symptoms due to its antioxidant and anti-inflammatory properties. Here we examined acute CBD effects on various behaviors and the endocannabinoid system in HIV Tat transgenic mice.

Methods

Tat transgenic mice (female/male) were injected with CBD (3, 10, 30 mg/kg) and assessed for antinociception, activity, coordination, anxiety-like behavior, and recognition memory. Brains were taken to quantify endocannabinoids, cannabinoid receptors, and cannabinoid catabolic enzymes. Additionally, CBD and metabolite 7-hydroxy-CBD were quantified in the plasma and cortex.

Results

Tat decreased supraspinal-related nociception and locomotion. CBD and sex had little to no effects on any of the behavioral measures. For the endocannabinoid system male sex was associated with elevated concentration of the proinflammatory metabolite arachidonic acid in various CNS regions, including the cerebellum that also showed higher FAAH expression levels for Tat(+) males. GPR55 expression levels in the striatum and cerebellum were higher for females compared to males. CBD metabolism was altered by sex and Tat expression.

Conclusion

Findings indicate that acute CBD effects are not altered by HIV Tat, and acute CBD has no to minimal effects on behavior and the endocannabinoid system.

Longitudinal patterns of inflammatory mediators after acute HIV infection correlate to intact and total reservoir

Background

Despite the beneficial effects of antiretroviral therapy (ART) initiation during acute HIV infection (AHI), residual immune activation remains a hallmark of treated HIV infection.

Methods

Plasma concentrations of 40 mediators were measured longitudinally in 39 early treated participants of a Belgian AHI cohort (HIV+) and in 21 HIV-negative controls (HIV-). We investigated the association of the inflammatory profile with clinical presentation, plasma viral load, immunological parameters, and in-depth characterization of the HIV reservoir.

Results

While levels of most soluble mediators normalized with suppressive ART, we demonstrated the persistence of a pro-inflammatory signature in early treated HIV+ participants in comparison to HIV- controls. Examination of these mediators demonstrated a correlation with their levels during AHI, which seemed to be viremia-driven, and suggested involvement of an activated myeloid compartment, IFN-γ-signaling, and inflammasome-related pathways. Interestingly, some of these pro-inflammatory mediators correlated with a larger reservoir size and slower reservoir decay. In contrast, we also identified soluble mediators which were associated with favorable effects on immunovirological outcomes and reservoir, both during and after AHI.

Conclusion

These data highlight how the persistent pro-inflammatory profile observed in early ART treated individuals is shaped during AHI and is intertwined with viral dynamics.

Effects of acute Δ9-tetrahydrocannabinol on behavior and the endocannabinoid system in HIV-1 Tat transgenic female and male mice

Cannabis use is highly prevalent especially among people living with HIV (PLWH). Activation of the anti-inflammatory and neuroprotective endocannabinoid system by phytocannabinoids, i.e. Δ9-tetrahydrocannabinol (THC), has been proposed to reduce HIV symptoms. However, THC's effects on HIV-related memory deficits are unclear. Using HIV-1 Tat transgenic mice, the current study investigates acute THC effects on various behavioral outcomes and the endocannabinoid system. For the rodent tetrad model, THC doses (1, 3, 10 mg/kg) induced known antinociceptive effects, with Tat induction increasing antinociceptive THC effects at 3 and 10 mg/kg doses. Only minor or no effects were noted for acute THC on body temperature, locomotor activity, and coordination. Increased anxiety-like behavior was found for females compared to males, but acute THC had no effect on anxiety. Object recognition memory was diminished by acute THC in Tat(-) females but not Tat(+) females, without affecting males. The endocannabinoid system and related lipids were not affected by acute THC, except for THC-induced decreases in CB1R protein expression levels in the spinal cord of Tat(-) mice. Female sex and Tat induction was associated with elevated 2-AG, AEA, AA, CB1R, CB2R, FAAH and/or MAGL expression in various brain regions. Further, AEA levels in the prefrontal cortex of Tat(+) females were negatively associated with object recognition memory. Overall, findings indicate that acute THC exerts differential effects on antinociception and memory, dependent on sex and HIV Tat expression, potentially in relation to an altered endocannabinoid system, which may be of relevance in view of potential cannabis-based treatment options for PLWH.

Impact of early antiretroviral therapy, early life immunity and immune sex differences on HIV disease and posttreatment control in children

PURPOSE OF REVIEW

To review recent insights into the factors affecting HIV disease progression in children living with HIV, contrasting outcomes: following early ART initiation with those in natural, antiretroviral therapy (ART)-naive infection; in children versus adults; and in female individuals versus male individuals.

RECENT FINDINGS

Early life immune polarization and several factors associated with mother-to-child transmission of HIV result in an ineffective HIV-specific CD8+ T-cell response and rapid disease progression in most children living with HIV. However, the same factors result in low immune activation and antiviral efficacy mediated mainly through natural killer cell responses in children and are central features of posttreatment control. By contrast, rapid activation of the immune system and generation of a broad HIV-specific CD8+ T-cell response in adults, especially in the context of 'protective' HLA class I molecules, are associated with superior disease outcomes in ART-naive infection but not with posttreatment control. The higher levels of immune activation in female individuals versus male individuals from intrauterine life onwards increase HIV infection susceptibility in females in utero and may favour ART-naive disease outcomes rather than posttreatment control.

SUMMARY

Early-life immunity and factors associated with mother-to-child transmission typically result in rapid HIV disease progression in ART-naive infection but favour posttreatment control in children following early ART initiation.

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 Many Faces of Immune Activation in HIV-1 Infection: A Multifactorial Interconnection

Chronic immune activation has a significant role in HIV-1 disease pathogenesis and CD4+ T-cell depletion. The causes of chronic inflammation and immune activation are incompletely understood, but they are likely multifactorial in nature, involving both direct and indirect stimuli. Possible explanations include microbial translocation, coinfection, and continued presence of competent replicating virus. In fact, long-term viral suppression treatments are unable to normalize elevated markers of systemic immune activation. Furthermore, high levels of pro-inflammatory cytokines increase susceptibility to premature aging of the immune system. The phenomenon of "inflammaging" has begun to be evident in the last decades, as a consequence of increased life expectancy due to the introduction of cART. Quality of life and survival have improved substantially; however, PLWH are predisposed to chronic inflammatory conditions leading to age-associated diseases, such as inflammatory bowel disease, neurocognitive disorders, cardiovascular diseases, metabolic syndrome, bone abnormalities, and non-HIV-associated cancers. Several approaches have been studied in numerous uncontrolled and/or randomized clinical trials with the aim of reducing immune activation/inflammatory status in PLWH, none of which have achieved consistent results.

Associations between female birth sex and risk of chronic kidney disease development among people with HIV in the USA: A longitudinal, multicentre, cohort study

Background

Women represent a meaningful proportion of new HIV diagnoses, with Black women comprising 58% of new diagnoses among women. As HIV infection also increases risk of chronic kidney disease (CKD), understanding CKD risk among women with HIV (WWH), particularly Black women, is critical.

Methods

In this longitudinal cohort study of people with HIV (PWH) enrolled in CFAR Network of Integrated Clinical Systems (CNICS), a multicentre study comprised of eight academic medical centres across the United States from Jan 01, 1996 and Nov 01, 2019, adult PWH were excluded if they had ≤2 serum creatinine measurements, developed CKD prior to enrollment, or identified as intersex or transgendered, leaving a final cohort of 33,998 PWH. The outcome was CKD development, defined as estimated glomerular filtration rate (eGFR) <60 mL/min/1·73 m2 calculated using the CKD-EPI equation, for ≥90 days with no intervening higher values.

Findings

Adjusting for demographic and clinical characteristics, WWH were 61% more likely to develop CKD than men (adjusted hazard ratio [aHR]: 1·61, 95% CI: 1·46-1·78, p<0·001). This difference persisted after further adjustment for APOL1 risk variants (aHR female sex: 1·92, 95% CI: 1·63-2·26, p<0·001) and substance abuse (aHR female sex: 1·70, 95% CI: 1·54-1·87, p<0·001).

Interpretation

WWH experienced increased risk of CKD. Given disparities in care among patients with end-stage kidney disease, efforts to engage WWH in nephrology care to improve chronic disease management are critical.

Funding

US National Institutes of Health.

The immune response to COVID-19: Does sex matter?

The coronavirus disease 2019 (COVID-19) pandemic has created unprecedented challenges worldwide. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes COVID-19 and has a complex interaction with the immune system, including growing evidence of sex-specific differences in the immune response. Sex-disaggregated analyses of epidemiological data indicate that males experience more severe symptoms and suffer higher mortality from COVID-19 than females. Many behavioural risk factors and biological factors may contribute to the different immune response. This review examines the immune response to SARS-CoV-2 infection in the context of sex, with emphasis on potential biological mechanisms explaining differences in clinical outcomes. Understanding sex differences in the pathophysiology of SARS-CoV-2 infection will help promote the development of specific strategies to manage the disease.

Fish female-biased gene cyp19a1a leads to female antiviral response attenuation between sexes by autophagic degradation of MITA

From insects to mammals, both innate and adaptive immune response are usually higher in females than in males, with the sex chromosome and hormonal differences considered the main reasons. Here, we report that zebrafish cyp19a1a (cytochrome P450, family 19, subfamily A, polypeptide 1a), an autosomal gene with female-biased expression, causes female fish to exhibit a lower antiviral response. First, we successfully constructed an infection model by intraperitoneal injection of spring viremia of carp virus (SVCV) into zebrafish (Danio rerio) and Carassius auratus herpesvirus (CaHV) in gibel carp (Carassius gibelio). Specifically, female fish were more vulnerable to viral infection than males, accompanied by a significantly weaker interferon (IFN) expression. After screening several candidates, cyp19a1a, which was highly expressed in female fish tissues, was selected for further analysis. The IFN expression and antiviral response were significantly higher in cyp19a1a-/- than in cyp19a1a+/+. Further investigation of the molecular mechanism revealed that Cyp19a1a targets mediator of IRF3 activation (MITA) for autophagic degradation. Interestingly, in the absence of MITA, Cyp19a1a alone could not elicit an autophagic response. Furthermore, the autophagy factor ATG14 (autophagy-related 14) was found interacted with Cyp19a1a to either promote or attenuate Cyp19a1a-mediated MITA degradation by either being overexpressed or knocked down, respectively. At the cellular level, both the normal and MITA-enhanced cellular antiviral responses were diminished by Cyp19a1a. These findings demonstrated a sex difference in the antiviral response based on a regulation mechanism controlled by a female-biased gene besides sex chromosome and hormonal differences, supplying the current understanding of sex differences in fish.

Sex stratification of the trends and risk of mortality among individuals living with HIV under different transmission categories

We retrospectively examined 33,142 persons living with HIV (PLWH) in Taiwan from a nationwide database to assess sex-stratified trends and risk of all-cause mortality under different transmission categories from 1984 to 2016. Overall, 61.25% were men who have sex with men (MSM), 14.37% were men who have sex with women (MSW), 18.32% were male persons who inject drugs (M-PWID), 3.30% were women who have sex with men (WSM), and 2.74% were female PWID (F-PWID). All-cause mortality (per 100 person-years) among heterosexual people and PWID was higher in men (4.04 and 3.39, respectively) than in women (2.93 and 2.18, respectively). In each sex-stratified transmission category, the all-cause mortality reduced substantially from 1984–1996 to 2012–2016, but evolved distinctly from 2007–2011 to 2012–2016. Since 2007–2011, the decline in all-cause mortality has slowed notably in the groups with sexually transmitted HIV, but has increased in PWID, surpassing even that among groups with sexually transmitted HIV in 2012–2016. PLWH with sexually transmitted HIV had lower risks of all-cause mortality than PWID, regardless of sex. Sex and transmission category did not interact significantly on all-cause mortality. Understanding the reasons for the distinct evolving trends of all-cause mortality in each transmission category serves as a reference for developing strategies to reduce mortality in PLWH in Taiwan further.

Cardiovascular Implications of Immune Disorders in Women

Immune responses differ between men and women, with women at higher risk of developing chronic autoimmune diseases and having more robust immune responses to many viruses, including HIV and hepatitis C virus. Although immune dysregulation plays a prominent role in chronic systemic inflammation, a key driver in the development of atherosclerotic cardiovascular disease (ASCVD), standard ASCVD risk prediction scores underestimate risk in populations with immune disorders, particularly women. This review focuses on the ASCVD implications of immune dysregulation due to disorders with varying global prevalence by sex: autoimmune disorders (female predominant), HIV (male-female equivalent), and hepatitis C virus (male predominant). Factors contributing to ASCVD in women with immune disorders, including traditional risk factors, dysregulated innate and adaptive immunity, sex hormones, and treatment modalities, are discussed. Finally, the need to develop new ASCVD risk stratification tools that incorporate variables specific to populations with chronic immune disorders, particularly in women, is emphasized.

Sex Differences in Non-AIDS Comorbidities Among People With Human Immunodeficiency Virus

Women are grossly underrepresented in human immunodeficiency virus (HIV) clinical and translational research. This is concerning given that people with HIV (PWH) are living longer, and thus accumulating aging-related non-AIDS comorbidities (NACMs); emerging evidence suggests that women are at higher risk of NACM development and progression compared with men. It is widely recognized that women vs men have greater immune activation in response to many viruses, including HIV-1; this likely influences sex-differential NACM development related to differences in HIV-associated chronic inflammation. Furthermore, many sociobehavioral factors that contribute to aging-related NACMs are known to differ by sex. The objectives of this review were to (1) synthesize sex-stratified data on 4 NACMs among PWH: bone disease, cardiovascular disease, metabolic dysfunction, and neurocognitive impairment; (2) evaluate the characteristics of key studies assessing sex differences in NACMs; and (3) introduce potential biological and psychosocial mechanisms contributing to emerging trends in sex-differential NACM risk and outcomes among PWH.

Differences in Heart Graft Survival by Recipient Sex

Supplemental Digital Content is available in the text.

We aimed to characterize patterns of differences in heart graft failure rates by recipient sex, accounting for modifying effects of donor sex and recipient age.

Interactions with Commensal and Pathogenic Bacteria Induce HIV-1 Latency in Macrophages through Altered Transcription Factor Recruitment to the LTR

Macrophages are infected by HIV-1 in vivo and contribute to both viral spread and pathogenesis. Recent human and animal studies suggest that HIV-1-infected macrophages serve as a reservoir that contributes to HIV-1 persistence during anti-retroviral therapy. The ability of macrophages to serve as persistent viral reservoirs is likely influenced by the local tissue microenvironment, including interactions with pathogenic and commensal microbes. Here we show that the sexually transmitted pathogen Neisseria gonorrhoeae (GC) and the gut-associated microbe Escherichia coli (E. coli), which encode ligands for both Toll-like receptor 2 (TLR2) and TLR4, repressed HIV-1 replication in macrophages and thereby induced a state reminiscent of viral latency. This repression was mediated by signaling through TLR4 and the adaptor protein TRIF and was associated with increased production of type I interferons. Inhibiting TLR4 signaling, blocking type 1 interferon, or knocking-down TRIF reversed LPS- and GC-mediated repression of HIV-1. Finally, the repression of HIV-1 in macrophages was associated with the recruitment of interferon regulatory factor 8 (IRF8) to the interferon stimulated response element (ISRE) downstream of the 5' HIV-1 long terminal repeat (LTR). Our data indicate that IRF8 is responsible for repression of HIV-1 replication in macrophages in response to TRIF-dependent signaling during GC and E. coli co-infection. These findings highlight the potential role of macrophages as HIV-1 reservoirs as well as the role of the tissue microenvironment and co-infections as modulators of HIV-1 persistence.IMPORTANCE The major barrier toward the eradication of HIV-1 infection is the presence of a small reservoir of latently infected cells, which include CD4+ T cells and macrophages that escape immune-mediated clearance and the effects of anti-retroviral therapy. There remain crucial gaps in our understanding of the molecular mechanisms that lead to transcriptionally silent or latent HIV-1 infection of macrophages. The significance of our research is in identifying microenvironmental factors, such as commensal and pathogenic microbes, that can contribute to the establishment and maintenance of latent HIV-1 infection in macrophages. It is hoped that identifying key processes contributing to HIV-1 persistence in macrophages may ultimately lead to novel therapeutics to eliminate latent HIV-1 reservoirs in vivo.

Enhanced immunovirological response in women compared to men after antiretroviral therapy initiation during acute and early HIV-1 infection: results from a longitudinal study in the French ANRS Primo cohort

Introduction

Previous studies have reported better immunovirological characteristics in women compared with men after HIV seroconversion. We investigated whether differences persisted under long‐term antiretroviral therapy (ART) in individuals treated since acute and early HIV‐1 infection (AHI).

Methods

Data were obtained for 262 women and 1783 men enrolled between 1996 and 2017 in the French multicentre ANRS PRIMO cohort. We modelled the viral response, long‐term immune recovery and HIV DNA decay in the 143 women and 1126 men who initiated ART within the first three months of infection.

Results

The participants were mostly white. The mean age was 37 years at AHI diagnosis. Pre‐ART viral loads were lower in women than men, 5.2 and 5.6 log₁₀ copies/mL (p = 0.001). After ART initiation, women more rapidly achieved viral suppression than men (adjusted hazard ratio: 1.33, 95% confidence interval 1.09 to 1.69). They also experienced a faster increase in CD4⁺ T‐cell count and CD4:CD8 ratio during the first months of treatment. Sex‐related differences in CD4⁺ T‐cell counts were more pronounced with increasing age. This led to a sustained mean difference of 99 to 168 CD4⁺ T‐cells/µL depending on age between women and men at 150 months of ART. Moreover, CD4:CD8 ratio of women was higher than that of men by 0.31, at 150 months of ART. There was no statistically significant difference between sexes for the levels of HIV DNA over time (mean estimate at the last modelling point: 1.9 log₁₀ copies/10⁶ PBMCs after 70 months of ART for both sexes).

Conclusions

The high level of immune recovery and decrease in total HIV DNA levels achieved after ART initiation during AHI reinforce the importance of early diagnosis of HIV infection and immediate ART initiation. The immunological benefit of being female increased throughout prolonged ART duration, which may give women additional protection from adverse clinical events and premature ageing.

Sex-derived attributes contributing to SARS-CoV-2 mortality

Epidemiological data in COVID-19 mortality indicate that men are more prone to die of SARS-CoV-2 infection than women, but biological causes for this sexual dimorphism are unknown. We discuss the prospective behavioral and biological differences between the sexes that could be attributed to this sex-based differentiation. The female sex hormones and the immune stimulatory genes, including Toll-like receptors, interleukins, and micro-RNAs present on X-chromosome, may impart lesser infectivity and mortality of the SARS-CoV-2 in females over males. The sex hormone estrogen interacts with the renin-angiotensin-aldosterone system, one of the most critical pathways in COVID-19 infectivity, and modulates the vasomotor homeostasis. Testosterone on the contrary enhances the levels of the two most critical molecules, angiotensin-converting enzyme 2 (ACE2) and the transmembrane protease serine-type 2 (TMPRSS2), transcriptionally and posttranslationally, thereby increasing viral load and delaying viral clearance in men as compared with women. We propose that modulating sex hormones, either by increasing estrogen or antiandrogen, may be a therapeutic option to reduce mortality from SARS-CoV-2.

Sex differences in HIV treatment outcomes and adherence by exposure groups among adults in Guangdong, China: A retrospective observational cohort study

INTRODUCTION

We aimed to assess sex differences in treatment outcomes and adherence comparing men who have sex with women (MSW), men who have sex with men (MSM), and women who have sex with men (WSM), as well as men and women who inject drugs living with HIV on combination antiretroviral therapy (ART) in Guangdong, China.

METHODS

We performed a retrospective observational cohort study with data from the National Free Antiretroviral Treatment Program database. We included ART-naive patients aged 18 to 80 years who had contracted HIV through sex or injecting drugs, initiated first-line ART between January 2004 and December 2016, and had at least 60 days of follow-up. Participants were followed for five years. Kaplan-Meier analysis and Cox proportional hazard models were used to evaluate all-cause mortality. Cumulative incidence function and Cox proportional hazards models accounting for competing risks were used to evaluate disease progression to AIDS. Modified Poisson regression models were used to evaluate immunological and virological responses and loss to follow-up. Repeated measures analysis was used to evaluate regular CD4+ cell count, HIV viral load monitoring, ART adherence, side effects, and interruption of ART.

FINDINGS

We included 26,409 persons living with HIV. 21,779 (82·5%) people acquired HIV through sex (5118 WSM [23·5%], 8506 MSW [39·0%], 8175 MSM [37·5%]), and 4610 people (17·5%) through injection drug use (249 women [5·4%], 4361 men [94·6%]). Among those infected through sex, MSW had increased risks of all-cause mortality (adjusted hazard ratio [aHR] 1·48, 95% CI 1·20-1·83), progression to AIDS (1·27, 1·09-1·47), virological failure (adjusted incidence rates ratio [aIRR] 1·27, 95% CI 1·09-1·48), and loss to follow-up (1·22, 1·10-1·35) compared to WSM. In contrast, MSM had lower risk of all-cause mortality (aHR 0·49, 95%CI 0·32-0·76), disease progression to AIDS (0·83, 0·68-1·00), and virological failure (aIRR 0·78, 95%CI 0·65-0·94), were more likely to receive regular CD4+ cell count (1·08, 1·07-1·10) and HIV viral load monitoring (1·13, 1·12-1·15), were less likely to report missing ART doses (0·54, 0·49-0·61), interrupt ART (0·34, 0·26-0·44), or be lost to follow-up (0·56, 0·49-0·65) compared to WSM. Men who inject drugs were almost twice as likely as women who inject drugs to die (aHR 1·72, 95%CI 1·03-2·85), experience disease progression to AIDS (2·05, 1·18-3·57), virological failure (aIRR 1·81, 95%CI 1·19-2·76), report ART side effects (1·78, 1·43-2·22), and interruptions in ART (2·29, 1·50-3·50).

INTERPRETATION

Our findings highlight the importance of identifying potentially at-risk MSW and promoting HIV education and testing among them. Particular attention is warranted among men who inject drugs to improve timely HIV diagnosis, drug interaction management, and retention in treatment. Additional research from rural settings is needed to assess the long-term treatment outcomes and adherence in MSM with HIV.

Sex-related differences in markers of immune activation in virologically suppressed HIV-infected patients

OBJECTIVES

Gender-specific studies remain a neglected area of biomedical research. Recent reports have emphasized that sex-related biological factors may affect disease progression during HIV-1 infection. The aim of this study was to investigate the influence of sex on the levels of immune activation in the gut and in peripheral blood of individuals with HIV treated with fully suppressive antiretroviral therapy (ART).

METHODS

Thirty individuals with HIV undergoing long-term fully suppressive ART were enrolled in this study. Lamina propria lymphocytes (LPL) and peripheral blood mononuclear cells (PBMCs) were isolated from gut biopsies collected by pancolonoscopy and peripheral blood samples. The expression of markers of immune activation was evaluated by multi-parametric flow cytometry. This is a sub analysis of ClinicalTrials.gov Identifier: NCT02276326 RESULTS: We observed differences in the levels of immune activation in the gut and in PBMCs, with values higher in the gut compartment compared to PBMCs. In addition, we found that the mean value of the levels of immune activation was higher in the women than in the men. Finally, we measured the markers of immune activation by mean relative difference (MRD) and confirmed the higher value in the women.

CONCLUSION

A significant sex-related difference in the level of immune activation was observed in a population of individuals with HIV on long-term ART. A more complete characterization of these differences may support the introduction of sex-specific approaches in the clinical management of individuals with HIV.

Association between the cytokine storm, immune cell dynamics, and viral replicative capacity in hyperacute HIV infection

INTRODUCTION

Immunological damage in acute HIV infection (AHI) may predispose to detrimental clinical sequela. However, studies on the earliest HIV-induced immunological changes are limited, particularly in sub-Saharan Africa. We assessed the plasma cytokines kinetics, and their associations with virological and immunological parameters, in a well-characterized AHI cohort where participants were diagnosed before peak viremia.

METHODS

Blood cytokine levels were measured using Luminex and ELISA assays pre-infection, during the hyperacute infection phase (before or at peak viremia, 1-11 days after the first detection of viremia), after peak viremia (24-32 days), and during the early chronic phase (77-263 days). Gag-protease-driven replicative capacities of the transmitted/founder viruses were determined using a green fluorescent reporter T cell assay. Complete blood counts were determined before and immediately following AHI detection before ART initiation.

RESULTS

Untreated AHI was associated with a cytokine storm of 12 out of the 33 cytokines analyzed. Initiation of ART during Fiebig stages I-II abrogated the cytokine storm. In untreated AHI, virus replicative capacity correlated positively with IP-10 (rho = 0.84, P < 0.001) and IFN-alpha (rho = 0.59, P = 0.045) and inversely with nadir CD4⁺ T cell counts (rho = - 0.58, P = 0.048). Hyperacute HIV infection before the initiation of ART was associated with a transient increase in monocytes (P < 0.001), decreased lymphocytes (P = 0.011) and eosinophils (P = 0.003) at Fiebig stages I-II, and decreased eosinophils (P < 0.001) and basophils (P = 0.007) at Fiebig stages III-V. Levels of CXCL13 during the untreated hyperacute phase correlated inversely with blood eosinophils (rho = - 0.89, P < 0.001), basophils (rho = - 0.87, P = 0.001) and lymphocytes (rho = - 0.81, P = 0.005), suggesting their trafficking into tissues. In early treated individuals, time to viral load suppression correlated positively with plasma CXCL13 at the early chronic phase (rho = 0.83, P = 0.042).

CONCLUSION

While commencement of ART during Fiebig stages I-II of AHI abrogated the HIV-induced cytokine storm, significant depletions of eosinophils, basophils, and lymphocytes, as well as transient expansions of monocytes, were still observed in these individuals in the hyperacute phase before the initiation of ART, suggesting that even ART initiated during the onset of viremia does not abrogate all HIV-induced immune changes.

Gender differences in innate responses and gene expression profiles in memory CD4 T cells are apparent very early during acute simian immunodeficiency virus infection

Gender differences in Human immunodeficiency virus (HIV) disease progression and comorbidities have been extensively reported. Using the simian immunodeficiency virus (SIV) infected rhesus macaque model, we show that these differences are apparent very early during the course of infection. Though there were no major changes in the proportions of CD4 T cells or its subsets, central memory CD4 T cells from female macaques were found to differentially regulate a significantly larger number of genes at day 4 post-infection (PI) as compared to males. Pathway analysis revealed divergence of both canonical and biological pathways that persisted at day 10 PI. Changes in gene expression profiles were accompanied by a significant increase in plasma levels of pro-inflammatory mediators such as MCP-1/CCL2, I-TAC/CXCL11, and MIF. Though plasma levels of IFNα did not differ between male and female macaques, the expression levels of IFNα subtype-14, 16, IFNβ, and IFNω were significantly upregulated in the lymph nodes of female macaques at day 10 PI as compared to male macaques. Our results suggest that the pathogenic sequelae seen during chronic infection may be shaped by gender differences in immune responses induced very early during the course of HIV infection.

Sex-specific neurogenic deficits and neurocognitive disorders in middle-aged HIV-1 Tg26 transgenic mice

Varying degrees of cognitive deficits affect over half of all HIV-1 infected patients. Because of antiretroviral treatment (ART) regimens, the HIV-1 patient population is increasing in age. Very few epidemiological studies have focused on sex-specific differences in HIV-1-associated neurocognitive disorders (HAND). The purpose of this study is to examine any possible differences between male and female mice in the progression of cognitive dementia during persistent low-level HIV-1 protein exposure, mimicking the typical clinical setting in the post-ART era. Eight to ten-month old HIV-1 Tg26(+/-) transgenic mice were utilized to assess for specific learning and memory modalities. Initial physiological screening and fear conditioning assessments revealed that Tg26 mice exhibited no significant differences in general behavioral function, contextual fear conditioning, or cued fear conditioning responses when compared to their wild-type (WT) littermates, regardless of sex. However, Barnes maze testing revealed significantly impaired short and long-term spatial memory in males, while females had impaired spatial learning abilities and short-term spatial memory. The potential cellular mechanism underlying these sex-specific neurocognitive deficits was explored with hippocampal neurogenic analysis. Compared to WT mice, both male and female Tg26(+/-) mice had fewer quiescent neural stem cells and neuroblasts in their hippocampi. Male Tg26(+/-) mice had a more robust reduction of the quiescent neural stem cell pool than female Tg26(+/-) mice. While female WT mice had a higher number of neural progenitor cells than male WT mice, only female Tg26(+/-) mice exhibited a robust reduction in the number of neural progenitor cells. Altogether, these results suggest that middle-aged male and female Tg26(+/-) mice manifest differing impairments in cognitive functioning and hippocampal neurogenesis. This study emphasizes the importance of understanding sex related differences in HAND pathology, which would aid in designing more optimized therapeutic regimens for the treatment of HAND.

Increased IL-17 and/or IFN-γ producing T-cell subsets in gut mucosa of long-term-treated HIV-1-infected women

OBJECTIVE

The influence of sex on gut mucosal T-cell response in HIV-1 infection remains largely unknown. We explored whether the frequencies of interferon-γ and/or IL-17 producing naive, T central memory and T effector memory (TEM) CD4+ (Th1, Th17) and CD8+ T (Tc1, Tc17) cells measured in gut and peripheral districts differed between female and male HIV-1-infected patients.

METHODS

Thirty long-term-treated HIV-1-infected individuals were enrolled. The frequencies of Th1, Th17, Tc1, Tc17-cell subsets (single and double) were evaluated by multiparametric flow cytometry in lamina propria lymphocytes and peripheral blood mononuclear cells (PBMC).

RESULTS

A sex-based pattern was recorded in the differences of Th1, Th17, Tc1, Tc17-cell subset (single and double) frequencies between gut and peripheral blood. Female patients had stronger alterations in the gut mucosal T-cell repertoire, especially increased Th1, Th17, and Th1/Th17-cell subset frequencies, compared with the blood district than their male counterparts. Higher naive Tc1, Tc17, Tc1/Tc17, TEM Tc17, and TEM Tc1/Tc17 levels were also recorded in the gut mucosa than in the PBMC of HIV-1-infected women. Males and females also differed in their gut T-cell response, with women being characterized by higher Th1, Th17, Tc1, Tc17, and Th1/Th17 cells subset levels than men. By contrast, only TEM Th1/Th17 and TEM Tc17 in PBMC differed between males and females.

CONCLUSION

Sex-based differences observed in the gut T-cell response of HIV-1-infected patients might contribute to the disease dimorphism.

Longitudinal evaluation of markers of inflammation in HIV-positive and HIV-negative Rwandan women

OBJECTIVES

African women are disproportionately affected by HIV infection and may experience non-AIDS-related complications associated with inflammation. High-sensitivity C-reactive protein (hsCRP), d-dimer and transthyretin have been examined as inflammatory markers elsewhere, but it is unclear how they change over time in HIV-negative or HIV-positive African women with or without antiretroviral therapy (ART) initiation.

METHODS

We examined hsCRP, d-dimer and transthyretin levels at baseline and at follow-up of ≥2 years in 185 HIV-negative and 510 HIV-positive Rwandan women who were ART naïve at study entry. Generalized estimating equations for each marker were used to investigate the association with HIV infection/CD4 count, ART and follow-up time.

RESULTS

Compared with HIV-negative women, HIV-positive women had higher hsCRP and d-dimer and lower transthyretin concentrations, with greater differences at lower CD4 counts. After adjusting for CD4 count and other factors, ART was not significantly associated with log hsCRP (P = 0.36) at follow-up, but was independently associated with lower log d-dimer (P = 0.03) and higher transthyretin (P = 0.0008) concentrations. At ≥ 2 years of follow-up, hsCRP had not significantly changed in any group but log d-dimer had decreased significantly in all groups. Transthyretin declined significantly over time in HIV-negative women and HIV-positive non-ART initiators, but increased significantly in HIV-positive ART initiators.

CONCLUSIONS

HIV infection and advanced immune suppression were associated with higher hsCRP and d-dimer and lower transthyretin concentrations. ART (independently of CD4 changes) was significantly associated with decreases in d-dimer and increases in transthyretin, but, in contrast to other studies, was not associated with decreases in hsCRP. We found no change in hsCRP over time in any group.

Human Immunodeficiency Virus 1 and Type I Interferons-Where Sex Makes a Difference

The human immunodeficiency virus (HIV)-1 epidemic continues to represent a global health problem that is over-proportionally affecting women from sub-Saharan Africa. Besides social and environmental factors, the modulation of immunological pathways by sex hormones and gene dosage effects of X chromosomal-encoded genes have been suggested to lead to differential outcomes in HIV-1 disease. Women present with lower HIV-1 loads early in infection. However, the progression to AIDS for the same level of viremia is faster in women than in men. Type I interferons (IFNs) play a prominent role in the control of HIV-1 transmission and replication. Continuous stimulation of type I IFNs in chronic viral infections can lead to increased levels of immune activation, which can be higher in HIV-1-infected women than in men. A role of steroid hormone signaling in regulating viral replication has been postulated, which might further account for sex differences observed in HIV-1 infections. Here, we review recent findings and current knowledge on sex-specific differences in HIV-1 infections.

Sex Drives Dimorphic Immune Responses to Viral Infections

New attention to sexual dimorphism in normal mammalian physiology and disease has uncovered a previously unappreciated breadth of mechanisms by which females and males differentially exhibit quantitative phenotypes. Thus, in addition to the established modifying effects of hormones, which prenatally and postpubertally pattern cells and tissues in a sexually dimorphic fashion, sex differences are caused by extragonadal and dosage effects of genes encoded on sex chromosomes. Sex differences in immune responses, especially during autoimmunity, have been studied predominantly within the context of sex hormone effects. More recently, immune response genes have been localized to sex chromosomes themselves or found to be regulated by sex chromosome genes. Thus, understanding how sex impacts immunity requires the elucidation of complex interactions among sex hormones, sex chromosomes, and immune response genes. In this Brief Review, we discuss current knowledge and new insights into these intricate relationships in the context of viral infections.

Pharmacologic Considerations for Preexposure Prophylaxis in Transgender Women

Studies of tenofovir disoproxil fumarate (TDF)-emtricitabine (FTC)-based preexposure prophylaxis (PrEP) have not focused on transgendered women who are at disproportionate risk of HIV acquisition. Concerns exist for drug interactions between cross-sex therapy (estradiol, progestins, and spironolactone) with tenofovir disoproxil fumarate-emtricitabine. This review assessed the experimental and theoretical risk for such drug interactions. It was found that none of these medications are implicated as major perpetrators of drug interactions, and the classes use different metabolic pathways for clearance, suggesting a low likelihood for interactions in either direction. Subanalyses of transgender women in Preexposure Prophylaxis Initiative suggested PrEP efficacy if adherence was high. Nevertheless, several research gaps were identified, particularly the need for controlled interaction studies in transgendered women, including effects on renal clearance, intracellular tenofovir diphosphate and emtricitabine triphosphate in target cells, as well as hormone effects on HIV susceptibility and immunity. PrEP should continue to be offered to transgender women while additional research is planned or pending.

Sex-specific regulation of immune responses by PPARs

The prevalence of autoimmune, infectious and metabolic diseases is different for men and women owing to the respective ability of their immune systems to respond to self and foreign antigens. Although several factors, including hormones and the X-chromosome, have been suggested to contribute to such sex-specific immune responses, the underlying factors remain poorly defined. Recent studies using peroxisome proliferator-activated receptor (PPAR) ligands and knockout mice have identified sex-dimorphic expression of PPARs, and have shown that the inhibitory functions of PPAR in T cells are substantially affected by the sex hormones. In this review, we consider the sex-specific differences in PPARs and summarize the diverse PPAR-mediated, sex-specific properties of effector T-cell responses, such as T-cell activation, survival and differentiation, as well as their involvement in T-cell-related autoimmune diseases, including colitis, graft-versus-host disease and experimental autoimmune encephalomyelitis. Understanding PPAR-mediated sex differences in immune responses will provide more precise insights into the roles of PPARs in effector T cells.

The X awakens: multifactorial ramifications of sex-specific differences in HIV-1 infection

Sex-specific differences have been described for a variety of infectious and autoimmune diseases. In HIV-1 infection women present with significantly lower viral loads during early infection, but during chronic infection women progress faster to AIDS for the same amount of viral replication. Recent studies have shown that sex differences during HIV-1 infection might also include the size of the latent viral reservoir, which represents a major obstacle towards a cure for HIV-1. Here we review different immunological and virological aspects that can be influenced by sex hormones and sex-specific genetic factors and their contribution to viral replication, as well as the creation and maintenance of the HIV-1 reservoir.