Elevation and persistence of CD8 T-cells in HIV infection: the Achilles heel in the ART era

Dynamics of pulmonary mucosal cytotoxic CD8 T-cells in people living with HIV under suppressive antiretroviral therapy

BACKGROUND

Despite the success of antiretroviral therapy (ART), people living with HIV (PLWH) suffer from a high burden of pulmonary diseases, even after accounting for their smoking status. Cytotoxic CD8 T-cells are likely implicated in this phenomenon and may act as a double-edged sword. While being essential in viral infection control, their hyperactivation can also contribute to lung mucosal tissue damage. The effects of HIV and smoking on pulmonary mucosal CD8 T-cell dynamics has been a neglected area of research, which we address herein.

METHODS

Bronchoalveolar lavage (BAL) fluid were obtained from ART-treated PLWH (median duration of supressed viral load: 9 years; smokers: n = 14; non-smokers: n = 21) and HIV-uninfected controls (smokers: n = 11; non-smokers: n = 20) without any respiratory symptoms or active infection. Lymphocytes were isolated and CD8 T-cell subsets and homing markers were characterized by multiparametric flow cytometry.

RESULTS

Both smoking and HIV infection were independently associated with a significant increase in frequencies of total pulmonary mucosal CD8 T-cell. BAL CD8 T-cells were primarily CD69 + expressing CD103 and/or CD49a, at least one of the two granzymes (GzmA/GzmB), and little Perforin. Higher expression levels of CD103, CD69, and GzmB were observed in smokers versus non-smokers. The ex vivo phenotype of GzmA + and GzmB + cells revealed increased expression of CD103 and CXCR6 in smokers, while PLWH displayed elevated levels of CX3CR1 compared to controls.

CONCLUSION

Smoking and HIV could promote cytotoxic CD8 T-cell retention in small airways through different mechanisms. Smoking likely increases recruitment and retention of GzmB + CD8 Trm via CXCR6 and CD103. Heightened CX3CR1 expression could be associated with CD8 non-Trm recruitment from the periphery in PLWH.

Multiple treatment interruptions and protecting HIV-specific CD4 T cells enable durable CD8 T cell response and viral control

Human Immunodeficiency Virus (HIV) remains a global health challenge, and novel approaches to improve HIV control are significantly important. The cell and gene therapy product AGT103-T was previously evaluated (NCT04561258) for safety, immunogenicity, and persistence in seven patients for up to 180 days post infusion. In this study, we sought to investigate the impact of AGT103-T treatment upon analytical treatment interruptions (ATIs). Six patients previously infused with AGT103-T were enrolled into an ATI study (NCT05540964), wherein they suspended their antiretroviral therapy (ART) until their viral load reached 100,000 copies/mL in two successive visits, or their CD4 count was reduced to below 300 cells/μL. During the ATI, all patients experienced viral rebound followed by a notable expansion in HIV specific immune responses. The participants demonstrated up to a five-fold increase in total CD8 counts over baseline approximately 1-2 weeks followed by the peak viremia. This coincided with a rise in HIV-specific CD8 T cells, which was attributed to the increase in antigen availability and memory recall. Thus, the protocol was amended to include a second ATI with the first ATI serving as an "auto-vaccination." Four patients participated in a second ATI. During the second ATI, the Gag-specific CD8 T cells were either maintained or rose in response to viral rebound and the peak viremia was substantially decreased. The patients reached a viral set point ranging from 7,000 copies/mL to 25,000 copies/mL. Upon resuming ART, all participants achieved viral control more rapidly than during the first ATI, with CD4 counts remaining within 10% of baseline measurements and without any serious adverse events or evidence of drug resistance. In summary, the rise in CD8 counts and the viral suppression observed in 100% of the study participants are novel observations demonstrating that AGT103-T gene therapy when combined with multiple ATIs, is a safe and effective approach for achieving viral control, with viral setpoints consistently below 25,000 copies/mL and relatively stable CD4 T cell counts. We conclude that HIV cure-oriented cell and gene therapy trials should include ATI and may benefit from designs that include multiple ATIs when induction of CD8 T cells is required to establish viral control.

Advanced in immunological monitoring of HIV infection: profile of immune cells and cytokines in people living with HIV-1 in Benin

BACKGROUND

Immune cells and cytokines have been linked to viremia dynamic and immune status during HIV infection. They may serve as useful biomarkers in the monitoring of people living with HIV-1 (PLHIV-1). The present work was aimed to assess whether cytokines and immune cell profiles may help in the therapeutic follow-up of PLHIV-1.

METHODS

Forty PLHIV-1 in treatment success (PLHIV-1s) and fifty PLHIV-1 in treatment failure (PLHIV-1f) followed at the University Hospital of Abomey-Calavi/Sô-Ava in Benin were enrolled. Twenty healthy persons were also recruited as control group. Circulating cytokines and immune cells were quantified respectively by ELISA and flow cytometry.

RESULTS

PLHIV-1 exhibited low proportions of CD4 + T cells, NK, NKT, granulocytes, classical and non-classical monocytes, and high proportions of CD8 + T cells, particularly in the PLHIV-1f group, compared to control subjects. Eosinophils, neutrophils and B cell frequencies did not change between the study groups. Circulating IFN-γ decreased whereas IL-4 significantly increased in PLHIV-1s compared to PLHIV-1f and control subjects even though the HIV infection in PLHIV-1s downregulated the high Th1 phenotype observed in control subjects. However, Th1/Th2 ratio remained biased to a Th1 phenotype in PLHIV-1f, suggesting that high viral load may have maintained a potential pro-inflammatory status in these patients. Data on inflammatory cytokines showed that IL-6 and TNF-α concentrations were significantly higher in PLHIV-1s and PLHIV-1f groups than in control subjects. Significant high levels of IL-5 and IL-7 were observed in PLHIV-1f compared to controls whereas PLHIV-1s presented only a high level of IL-5. No change was observed in IL-13 levels between the study groups.

CONCLUSION

Our study shows that, in addition to CD4/CD8 T cell ratio, NK and NKT cells along with IL-6, TNF-α, IL-5 and IL-7 cytokines could serve as valuable immunological biomarkers in the therapeutic monitoring of PLHIV-1 although a larger number of patients would be necessary to confirm these results.

Exploring the association between erythema multiforme and HIV infection: some mechanisms and implications

Erythema multiforme (EM) is an immune-mediated mucocutaneous condition characterized by hypersensitivity reactions to antigenic stimuli from infectious agents and certain drugs. The most commonly implicated infectious agents associated with EM include herpes simplex virus (HSV) and Mycoplasma pneumoniae. Other infectious diseases reported to trigger EM include human immunodeficiency virus (HIV) infection and several opportunistic infections. However, studies focusing on EM and human immunodeficiency virus (HIV) infection are scarce. even though the incidence of EM among HIV-infected individuals have increased, the direct and indirect mechanisms that predispose HIV-infected individuals to EM are not well understood. In turn, this makes diagnosing and managing EM in HIV-infected individuals an overwhelming task. Individuals with HIV infection are prone to acquiring microorganisms known to trigger EM, such as HSV, Mycobacterium tuberculosis, Treponema pallidum, histoplasmosis, and many other infectious organisms. Although HIV is known to infect CD4 + T cells, it can also directly bind to the epithelial cells of the oral and genital mucosa, leading to a dysregulated response by CD8 + T cells against epithelial cells. HIV infection may also trigger EM directly when CD8 + T cells recognize viral particles on epithelial cells due to the hyperactivation of CD8 + T-cells. The hyperactivation of CD8 + T cells was similar to that observed in drug hypersensitivity reactions. Hence, the relationship between antiretroviral drugs and EM has been well established. This includes the administration of other drugs to HIV-infected individuals to manage opportunistic infections. Thus, multiple triggers may be present simultaneously in HIV-infected individuals. This article highlights the potential direct and indirect role that HIV infection may play in the development of EM and the clinical dilemma that arises in the management of HIV-infected patients with this condition. These patients may require additional medications to manage opportunistic infections, many of which can also trigger hypersensitivity reactions leading to EM.

Differences in the Course of CD4 and CD8 Cells After Chemoradiotherapy in People Living with HIV with Anal Cancer

Incidence of anal carcinoma (AC) in people living with HIV (PLWH) is increased compared to the general population. Adverse effects of chemoradiotherapy (CRT) on the immune system are associated with a significant detrimental prognosis on overall survival in patients receiving CRT for solid tumors. The aim of this study was to evaluate immunological factors, in particular the differences in recovery of CD4+ and CD8+ cell counts before and after CRT for AC in PLWH. Retrospective single-center chart review extraction to analyze immunological data collected from PLWH with AC; descriptive statistics were used. Thirty-six PLWH with histologically proven AC were included in the analysis. Absolute CD4 cell count 60 months after CRT was 67.2% of the value at the beginning of CRT, whereas the CD8 cell count reached 82.3%. These differences were statistically significant (p = .048), whereas CD4/CD8-ratio remained stable. The findings of the presented study regarding CD4+ and CD8+ cell recovery after CRT are congruent with results from prior studies in non-HIV infected patients. Although not reaching the level of prior CRT T cell numbers, the ability to generate CD8+ cells seems to be better recovered, while CD4+ regeneration is more impaired. These observations are best explained by faster recovery of CD8+ cells via thymic-independent pathways, which are not available for regeneration of CD4+ cells. Further studies with larger numbers of patients are required to analyze the specific CD4+ and CD8+ cell subsets.

A Case of Kaposi's Sarcoma Associated with Disseminated AIDS: The Management Challenges

Background

As a malignant tumor derived from vascular endothelial cells, Kaposi's sarcoma (KS) is quite common in AIDS patients. Nonspecific clinical symptoms often lead to timely diagnosis or wrong treatment, leading to recurrent disease and poor prognosis. Anti-retroviral therapy (ART) could significantly reduce its morbidity and aggressiveness. As one of the ARTs, liposome anthracyclines are the preferred chemotherapy regimen for disseminated KS with multiple organs or tissue invasion. The curative effect is highly related to the degree of immunosuppression. This is the first case of AIDS with Kaposi's sarcoma, who was cured after ART and two consecutive chemotherapy with doxorubicin liposome without recurrence. This case may provide new ideas and methods for the clinical management of AIDS with Kaposi's sarcoma.

Case Description

The patient, a male aged 60 years, was hospitalized on 21/11/2018 following having a cough, expectoration, and difficulty breathing. He was infected with HIV eight years ago and presented symptoms of blood-stained sputum. The patient complained that he had not received ART before. After admission, he was diagnosed as KS with disseminated AIDS after multiple biopsies and histopathological examinations. The patient was treated with ten months of ART (lamivudine+tenofovir+dolutegravir) and 14 times of chemotherapy with doxorubicin liposome (20 mg/m2, three times per week, seven times per course of treatment). The patient's disease was finally alleviated, and there was no recurrence during the follow-up.

Conclusion

The reconstitution of immune function and consecutive chemotherapy with doxorubicin liposome play a vital role in treating KS. In addition, for the early general symptoms of AIDS patients, such as thrombocytopenia and hemorrhagic purple papules, it is necessary to increase vigilance and obtain the results of histopathological verification as soon as possible to diagnose KS patients at an earlier stage and realize clinical intervention in time.

COVID-19 severity and in-hospital mortality in an area with high HIV prevalence

Background

HIV infection causes immune dysregulation affecting T-cell and monocyte function, which may alter coronavirus disease 2019 (COVID-19) pathophysiology.

Objectives

We investigated the associations among clinical phenotypes, laboratory biomarkers, and hospitalisation outcomes in a cohort of people hospitalised with COVID-19 in a high HIV prevalence area.

Method

We conducted a prospective observational cohort study in Tshwane, South Africa. Respiratory disease severity was quantified using the respiratory oxygenation score. Analysed biomarkers included inflammatory and coagulation biomarkers, CD4 T-cell counts, and HIV-1 viral loads (HIVVL).

Results

The analysis included 558 patients, of whom 21.7% died during admission. The mean age was 54 years. A total of 82 participants were HIV-positive. People living with HIV (PLWH) were younger (mean age 46 years) than HIV-negative people; most were on antiretroviral treatment with a suppressed HIVVL (72%) and the median CD4 count was 159 (interquartile range: 66-397) cells/µL. After adjusting for age, HIV was not associated with increased risk of mortality during hospitalisation (age-adjusted hazard ratio = 1.1, 95% confidence interval: 0.6-2.0). Inflammatory biomarker levels were similar in PLWH and HIV-negative patients. Detectable HIVVL was associated with less severe respiratory disease. In PLWH, mortality was associated with higher levels of inflammatory biomarkers. Opportunistic infections, and other risk factors for severe COVID-19, were common in PLWH who died.

Conclusion

PLWH were not at increased risk of mortality and those with detectable HIVVL had less severe respiratory disease than those with suppressed HIVVL.

What this study adds

This study advances our understanding of severe COVID-19 in PLWH.

Cellular and molecular insights into incomplete immune recovery in HIV/AIDS patients

Highly active antiretroviral therapy (ART) can effectively inhibit virus replication and restore immune function in most people living with human immunodeficiency virus (HIV). However, an important proportion of patients fail to achieve a satisfactory increase in CD4⁺ T cell counts. This state is called incomplete immune reconstitution or immunological nonresponse (INR). Patients with INR have an increased risk of clinical progression and higher rates of mortality. Despite widespread attention to INR, the precise mechanisms remain unclear. In this review, we will discuss the alterations in the quantity and quality of CD4⁺ T as well as multiple immunocytes, changes in soluble molecules and cytokines, and their relationship with INR, aimed to provide cellular and molecular insights into incomplete immune reconstitution.

CD4:CD8 Ratio and CD8 Cell Count and Their Prognostic Relevance for Coronary Heart Disease Events and Stroke in Antiretroviral Treated Individuals: The Swiss HIV Cohort Study

INTRODUCTION

HIV infection leads to a persistent expansion of terminally CD8 T cells and CD8 T suppressor cells, a marker of chronic immune activation leading to a low CD4:CD8 ratio that may persist in the presence of potent antiretroviral therapy and regained CD4 helper cells. It remains unclear whether a low CD4:CD8 ratio is associated with cardiovascular diseases.

METHODS

We conducted an observational cohort study to investigate the association of immune depression and activation as characterized by the proxy of the CD4:CD8 ratio on the hazard of coronary heart disease (CHD) and stroke among treated individuals living with HIV, while accounting for viral load and known risk factors for cardiovascular diseases and exposure to abacavir or protease inhibitors. We used Cox proportional hazard models with time-dependent cumulative and lagged exposures to account for time-evolving risk factors and avoid reverse causality.

RESULTS

CD4, CD8, and CD4:CD8 immunological markers were not associated with an increased hazard for CHD. CD8 cell count lagged at 12 months above 1000 cells per μL increased the hazard of stroke, after adjusting for sociodemographics, cardiovascular risk factors, and exposure to specific types of antiretroviral drugs.

CONCLUSIONS

This analysis of treated HIV-positive individuals within a large cohort with long-term follow-up does not provide evidence for a prognostic role of immune dysregulation regarding CHD. However, increased CD8 cell count may be a moderate risk factor for stroke. Early detection and treatment of HIV-positive individuals are crucial for an optimal immune restoration and a limited CD8 cells expansion.

Increased Macrophage-Specific Arterial Infiltration Relates to Noncalcified Plaque and Systemic Immune Activation in People With Human Immunodeficiency Virus

BACKGROUND

Persistent immune activation is thought to contribute to heightened atherosclerotic cardiovascular disease (ASCVD) risk among people with human immunodeficiency virus (PWH).

METHODS

Participants (≥18 years) with or without human immunodeficiency virus (HIV) and without history of clinical ASCVD were enrolled. We hypothesized that increased macrophage-specific arterial infiltration would relate to plaque composition and systemic immune activation among PWH. We applied a novel targeted molecular imaging approach (technetium-99m [99mTc]-tilmanocept single photon emission computed tomography [SPECT]/CT) and comprehensive immune phenotyping.

RESULTS

Aortic 99mTc-tilmanocept uptake was significantly higher among PWH (n = 20) than participants without HIV (n = 10) with similar 10-year ASCVD risk (P = .02). Among PWH, but not among participants without HIV, noncalcified aortic plaque volume related directly to aortic 99mTc-tilmanocept uptake at different uptake thresholds. An interaction (P = .001) was seen between HIV status and noncalcified plaque volume, but not calcified plaque (P = .83). Systemic levels of caspase-1 (P = .004), CD14-CD16+ (nonclassical/patrolling/homing) monocytes (P = .0004) and CD8+ T cells (P = .005) related positively and CD4+/CD8+ T-cell ratio (P = .02) inversely to aortic 99mTc-tilmanocept uptake volume.

CONCLUSIONS

Macrophage-specific arterial infiltration was higher among PWH and related to noncalcified aortic plaque volume only among PWH. Key systemic markers of immune activation relating to macrophage-specific arterial infiltration may contribute to heightened ASCVD risk among PWH.

CLINICAL TRIALS REGISTRATION

NCT02542371.

Cellular Senescence in Immunity against Infections

Cellular senescence is characterized by irreversible cell cycle arrest in response to different triggers and an inflammatory secretome. Although originally described in fibroblasts and cell types of solid organs, cellular senescence affects most tissues with advancing age, including the lymphoid tissue, causing chronic inflammation and dysregulation of both innate and adaptive immune functions. Besides its normal occurrence, persistent microbial challenge or pathogenic microorganisms might also accelerate the activation of cellular aging, inducing the premature senescence of immune cells. Therapeutic strategies counteracting the detrimental effects of cellular senescence are being developed. Their application to target immune cells might have the potential to improve immune dysfunctions during aging and reduce the age-dependent susceptibility to infections. In this review, we discuss how immune senescence influences the host's ability to resolve more common infections in the elderly and detail the different markers proposed to identify such senescent cells; the mechanisms by which infectious agents increase the extent of immune senescence are also reviewed. Finally, available senescence therapeutics are discussed in the context of their effects on immunity and against infections.

Identification of CD8+ T cell subsets that normalize in early-treated people living with HIV receiving antiretroviral therapy

Background

Although combined antiretroviral therapy (cART) has decreased the mortality associated with HIV infection, complete immune reconstitution is not achieved despite viral suppression. Alterations of CD8⁺ T cells and some of their subpopulations, such as interleukin (IL)-17-producing cells, are evidenced in treated individuals and are associated with systemic inflammation and adverse disease outcomes. We sought to evaluate if different CD8⁺ T cell subsets are differentially normalized during a clinical follow-up of people living with HIV (PLWH) receiving suppressive cART.

Methods

We explored the changes in the frequencies, activation/exhaustion phenotypes (HLA-DR, CD38, PD-1, and TIM-3), and function (total and HIV-specific cells expressing CD107a, perforin, granzyme B, interferon [IFN]-γ and IL-17) of CD8⁺ T cells from early-treated PLWH receiving cART in a 1-year follow-up, using a multidimensional flow cytometry approach.

Results

Despite continuous cART-induced viral suppression and recovery of CD4⁺ T cells, after a 1-year follow-up, the CD8⁺ T cell counts, CD4:CD8 ratio, PD-1 expression, and IL-17 production by CD8⁺ T cells exhibited incomplete normalization compared with seronegative controls. However, the proportion of CD8⁺ T cells with an exhausted phenotype (co-expressing PD-1 andTIM-3), and cells co-expressing cytotoxic molecules (Perforin and Granzyme B), reached normalization.

Conclusions

Although suppressive cART achieves normalization of CD4⁺ T cell counts, only particular subsets of CD8⁺ T cells are more rapidly normalized in PLWH receiving cART, which could be routinely used as biomarkers for therapy efficiency in these patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12981-022-00465-0.

Plasma vesicular miR-155 as a biomarker of immune activation in antiretroviral treated people living with HIV

People living with HIV (PLWH), despite suppression of viral replication with antiretroviral therapy (ART), have high morbidity and mortality due to immune activation and chronic inflammation. Discovering new biomarkers of immune activation status under ART will be pertinent to improve PLWH quality of life when the majority will be treated. We stipulate that plasma large and small extracellular vesicle (EVs) and their microRNA content could be easily measured biomarkers to monitor immune activation in PLWH. Venous blood samples from n = 128 ART-treated PLWH with suppressed viral load (≤ 20 copies/mL) and n = 60 HIV-uninfected participants were collected at five testing or treatment centers of PLWH in Burkina Faso. Large and small plasma EVs were purified, counted, and the mature miRNAs miR-29a, miR-146a, and miR-155 were quantified by RT-qPCR. Diagnostic performances of large and small EVs miRNAs level were evaluated by receiver operating characteristic (ROC) curve analysis and principal component analysis (PCA). Among the EVs microRNA measured, only large EVs miR-155 copies distinguished PLWH with immune activation, with AUC of 0.75 for CD4/CD8 < 1 (95% CI: 0.58–0.91, P = 0.0212), and 0.77 for CD8 T cells ≥ 500/µL (95% CI: 0.63–0.92, P = 0.0096). In addition, PCA results suggest that large EVs miR-155 copies may be a biomarker of immune activation. Since miR-155 may influence immune cell function, its enrichment in large EV subpopulations could be a functional biomarker of immune activation in PLWH on ART. This measure could help to monitor and diagnose the immune activation with more accuracy.

HIV but Not CMV Replication Alters the Blood Cytokine Network during Early HIV Infection in Men

OBJECTIVE

CMV coinfection contributes to sustained immune activation in people with chronic HIV. In particular, asymptomatic CMV shedding in semen has been associated with increased local and systemic immune activation, even during suppressive antiretroviral therapy (ART). However, the effect of seminal CMV shedding in people with HIV in the earliest phase of HIV infection is not known.

METHODS

Using Luminex, we measured the concentration of 34 cytokines in the blood plasma of sixty-nine men who had sex with men with or without HIV and in subgroups of CMV shedders vs. non-shedders. Differences in blood plasma cytokines between groups were investigated using the multivariate supervised partial least squares discriminant analysis method.

RESULTS

Independently of CMV, we found that concentrations of IP-10, MIG, MCP-1, I-TAC 10, IL-16, and MIP-1β were modulated in the earliest phase of HIV infection compared with control individuals without HIV. In people with HIV, there was no difference in blood cytokines among CMV shedders vs. non-shedders.

CONCLUSION

In early/acute HIV infection, asymptomatic CMV shedding in semen does not drive additional cytokine changes in blood. Early ART initiation should remain the priority, while the added benefit of CMV suppression during the various stages of HIV infection needs to be further investigated.

Effects of Erectile Dysfunction Drugs Use on T-cells and Immune Markers on Men Who Have Sex with Men

Objective

Examine prospective relationships between erectile dysfunction (ED) drugs EDand CD4 and CD8 T-cells, and immune markers among men who have sex with men (MSM).

Methods

Data from Multicenter AIDS Cohort Study, an observational prospective cohort study, with semi-annual follow-ups conducted in four U.S. centers from 1998 onwards was used. Marginal structural models using g-computation was fitted to estimate the mean differences for the effects of self-reported ED drug use on CD4 and CD8 T-cell outcomes and immune biomarkers.

Results

Total of 1,391 men with HIV (MWH) and 307 men without HIV (MWOH) was included. Baseline mean CD4 cell count among MWH and MWOH was 499.9 cells/μL and 966.7 cells/μL, respectively. At baseline, 41.8% of MWH were virally suppressed. ED drug users reported a mean of 44.4 months of exposure to ED drugs. ED drug use was associated with increased CD4 cell outcomes among MWH but not MWOH. Mean differences in CD4 cell counts after 1 year of ED drug use was 57.6 cells/μL and increased to 117.7 after 10 years among MWH. CD8 counts were higher in ED drug users among MWH over 10 years than non-users; no consistent differences were found among MWOH. ED drug use appeared to reduce immune marker levels, such as IL-6 and increase markers, such as IL-10. We observed similar effects of ED drug use on biomarker levels among MWOH.

Conclusion

Long-term use of ED drugs do not adversely affect immune function among MWH or MWOH. Future studies on the relationships between different types of ED drugs and effects on T-cell subtypes are warranted.

Predictive value of CD8+ T cell and CD4/CD8 ratio at two years of successful ART in the risk of AIDS and non-AIDS events

BACKGROUND

While increased CD8 counts and low CD4/CD8 ratio during treated HIV correlate with immunosenescence, their additional predictive values to identify individuals with HIV at higher risk of clinical events remain controversial.

METHODS

We selected treatment-naive individuals initiating ART from ACTG studies 384, 388, A5095, A5142, A5202, and A5257 who had achieved viral suppression at year 2. We examined the effect of CD8+ T cell counts and CD4/CD8 at year 2 on the probability of AIDS and serious non-AIDS events in years 3-7. We used inverse probability weighting methods to address informative censoring, combined with multivariable logistic regression models.

FINDINGS

We analyzed 5133 participants with a median age of 38 years; 959 (19%) were female, pre-ART median CD4 counts were 249 (Q1-Q3 91-372) cell/µL. Compared to participants with CD8 counts between 500/µL and 1499/µL, those with >1500/µL had a higher risk of clinical events during years 3-7 (aOR 1.75; 95%CI 1.33-2.32). CD4/CD8 ratio was not predictive of greater risk of events through year 7. Additional analyses revealed consistent CD8 count effect sizes for the risk of AIDS events and noninfectious non-AIDS events, but opposite effects for the risk of severe infections, which were more frequent among individuals with CD8 counts <500/µL (aOR 1.70; 95%CI 1.09-2.65).

INTERPRETATION

The results of this analysis with pooled data from clinical trials support the value of the CD8 count as a predictor of clinical progression. People with very high CD8 counts during suppressive ART might benefit from closer monitoring and may be a target population for novel interventions.

FUNDING

This research was supported by NIH/NIAID awards UM1 AI068634, UM1 AI068636, and UM1 AI106701 and Carlos III Health Institute and FEDER funds (BA21/00017 and BA21/00022).

Transcription Factor ZNF683 Inhibits SIV/HIV Replication through Regulating IFNγ Secretion of CD8+ T Cells

Pulmonary microbial invasion frequently occurs during AIDS progression in HIV patients. Inflammatory cytokines and other immunoregulatory factors play important roles in this process. We previously established an AIDS model of SIVmac239 infection in northern pig-tailed macaques (NPMs), which were divided into rapid progressor (RP) and slow progressor (SP) groups according to their AIDS progression rates. In this study, we performed 16S rDNA and transcriptome sequencing of the lungs to reveal the molecular mechanism underlying the difference in progression rate between the RPs and SPs. We found that microbial invasion in the RP group was distinct from that in the SP group, showing marker flora of the Family XI, Enterococcus and Ezakiella, and more Lactobacilli. Through pulmonary transcriptome analysis, we found that the transcription factor ZNF683 had higher expression in the SP group than in the RP group. In subsequent functional experiments, we found that ZNF683 increased the proliferation and IFNγ secretion ability of CD8+ T cells, thus decreasing SIV or HIV replication, which may be related to AIDS progression in SIVmac239-infected NPMs. This study helps elucidate the various complexities of disease progression in HIV-1-infected individuals.

Persistence of High Peripheral Activated CD8+ T-cells and Not a Low CD4:CD8 Ratio Predict cytologic HPV-Related Dysplasia in cART-Treated, HIV-Positive Subjects

Background

People with HIV are at increased risk of HPV-disease progression, given the persistence of immune activation and residual inflammation despite effective cART. Whether a low CD4:CD8 T-cell ratio, known to mirror peripheral immune dysfunction, associates with Squamous Intraepithelial Lesions (SIL) is unknown.

Methods

Retrospective cohort study on cART-treated HIV-positive subjects undergoing screening for HPV-related dysplasia (anal/cervical cytology and HPV genotyping). SIL was defined as the presence of either atypical squamous cells of undetermined significance (ASCUS), Low-grade SIL or High-grade SIL. Demographic and viro-immunological parameters (T-cell count, CD4:CD8 T-cell ratio, CD8+CD38+ T-cells percentage) at the time of screening were analyzed by Chi square, Mann Whitney test and multivariate logistic regression analysis.

Results

419 cART-treated subjects were included. Half of the patients had cervical/anal SIL. Individuals with SIL were more commonly males, MSM, co-infected with Treponema pallidum, treated with Integrase Inhibitors (INSTI)-based cART regimens and with a shorter time since HIV diagnosis and cART initiation than subjects with normal cytology. CD38+CD8+ T-cells percentage, but not the CD4:CD8 T-cell ratio, correlated with SIL. HPV infection, especially with multiple and high-risk genotypes, was confirmed associated with SIL. In multivariate analysis, the only factors independently associated with cervical/anal dysplasia were HPV infection and harbouring higher percentages of peripheral activated CD38+CD8+ T-cells.

Conclusions

HPV infection is the major driver of dysplasia in the setting of HIV infection. CD8+CD38+ T-cells also resulted an independent predictor of dysplasia in cART-treated subjects, while the CD4:CD8 T-cell ratio did not. In the setting of HIV-HPV co-infection, the CD4:CD8 T-cell ratio may not fully capture the alterations of HPV-specific immunity.

Pulmonary Immune Dysregulation and Viral Persistence During HIV Infection

Despite the success of antiretroviral therapy (ART), people living with HIV continue to suffer from high burdens of respiratory infections, lung cancers and chronic lung disease at a higher rate than the general population. The lung mucosa, a previously neglected HIV reservoir site, is of particular importance in this phenomenon. Because ART does not eliminate the virus, residual levels of HIV that remain in deep tissues lead to chronic immune activation and pulmonary inflammatory pathologies. In turn, continuous pulmonary and systemic inflammation cause immune cell exhaustion and pulmonary immune dysregulation, creating a pro-inflammatory environment ideal for HIV reservoir persistence. Moreover, smoking, gut and lung dysbiosis and co-infections further fuel the vicious cycle of residual viral replication which, in turn, contributes to inflammation and immune cell proliferation, further maintaining the HIV reservoir. Herein, we discuss the recent evidence supporting the notion that the lungs serve as an HIV viral reservoir. We will explore how smoking, changes in the microbiome, and common co-infections seen in PLWH contribute to HIV persistence, pulmonary immune dysregulation, and high rates of infectious and non-infectious lung disease among these individuals.

CCR5 antagonist reduces HIV-induced amyloidogenesis, tau pathology, neurodegeneration, and blood-brain barrier alterations in HIV-infected hu-PBL-NSG mice

BACKGROUND

Neurocognitive impairment is present in 50% of HIV-infected individuals and is often associated with Alzheimer's Disease (AD)-like brain pathologies, including increased amyloid-beta (Aβ) and Tau hyperphosphorylation. Here, we aimed to determine whether HIV-1 infection causes AD-like pathologies in an HIV/AIDS humanized mouse model, and whether the CCR5 antagonist maraviroc alters HIV-induced pathologies.

METHODS

NOD/scid-IL-2Rγcnull mice engrafted with human blood leukocytes were infected with HIV-1, left untreated or treated with maraviroc (120 mg/kg twice/day). Human cells in animal's blood were quantified weekly by flow cytometry. Animals were sacrificed at week-3 post-infection; blood and tissues viral loads were quantified using p24 antigen ELISA, RNAscope, and qPCR. Human (HLA-DR+) cells, Aβ-42, phospho-Tau, neuronal markers (MAP 2, NeuN, neurofilament-L), gamma-secretase activating protein (GSAP), and blood-brain barrier (BBB) tight junction (TJ) proteins expression and transcription were quantified in brain tissues by immunohistochemistry, immunofluorescence, immunoblotting, and qPCR. Plasma Aβ-42, Aβ-42 cellular uptake, release and transendothelial transport were quantified by ELISA.

RESULTS

HIV-1 significantly decreased human (h)CD4+ T-cells and hCD4/hCD8 ratios; decreased the expression of BBB TJ proteins claudin-5, ZO-1, ZO-2; and increased HLA-DR+ cells in brain tissues. Significantly, HIV-infected animals showed increased plasma and brain Aβ-42 and phospho-Tau (threonine181, threonine231, serine396, serine199), associated with transcriptional upregulation of GSAP, an enzyme that catalyzes Aβ formation, and loss of MAP 2, NeuN, and neurofilament-L. Maraviroc treatment significantly reduced blood and brain viral loads, prevented HIV-induced loss of neuronal markers and TJ proteins; decreased HLA-DR+ cells infiltration in brain tissues, significantly reduced HIV-induced increase in Aβ-42, GSAP, and phospho-Tau. Maraviroc also reduced Aβ retention and increased Aβ release in human macrophages; decreased the receptor for advanced glycation end products (RAGE) and increased low-density lipoprotein receptor-related protein-1 (LRP1) expression in human brain endothelial cells. Maraviroc induced Aβ transendothelial transport, which was blocked by LRP1 antagonist but not RAGE antagonist.

CONCLUSIONS

Maraviroc significantly reduced HIV-induced amyloidogenesis, GSAP, phospho-Tau, neurodegeneration, BBB alterations, and leukocytes infiltration into the CNS. Maraviroc increased cellular Aβ efflux and transendothelial Aβ transport via LRP1 pathways. Thus, therapeutically targeting CCR5 could reduce viremia, preserve the BBB and neurons, increased brain Aβ efflux, and reduce AD-like neuropathologies.

Concurrent HIV viral blips during two episodes of multicentric Castleman disease in an adult on antiretroviral therapy: Implication for HIV persistence

Human herpesvirus-8 (HHV8)-associated multicentric Castleman disease (HHV8-MCD) is a rare nonmalignant lymphoproliferative disorder most commonly observed in PLWH. Herein, we describe an HIV-infected adult male from Cameroon with relapsing HHV8-MCD (HIV+MCD). The patient developed constitutional symptoms, diffuse lymphadenopathy, thrombocytopenia and autoimmune hemolytic anemia. Excisional lymph node biopsy findings were consistent with HHV8-MCD. He was successfully treated with corticosteroids and rituximab. One year later, he developed relapsing disease and was successfully treated again with rituximab. Interestingly, HIV viral load blips correlate with MCD flares, suggesting that low-level viremia is linked with T-cell clonal expansion and/or inflammation, rather than a lack of effective antiretroviral therapy. Rituximab either alone or in combination with chemotherapy for aggressive disease is the standard of care, with approximately 95% of treated patients achieving complete remission. Despite highly effective therapy, HIV+MCD often presents with a relapsing and remitting disease course and carries an increased risk for the development of HHV8-associated lymphoma.

Cytomegalovirus viremia is associated with poor outcomes in AIDS patients with disseminated nontuberculous mycobacterial disease

Both cytomegalovirus (CMV) viremia and disseminated nontuberculous mycobacterial (NTM) disease are common opportunistic infections in AIDS patients. Whether concurrent CMV viremia is associated with mortality in patients with AIDS and disseminated NTM disease is unknown. Subjects were patients with AIDS and disseminated NTM disease seen at a single center from January 2015 to April 2021. Data were retrospectively collected. Differences in demographics and clinical characteristics and hospitalization survival rates were compared between patients with disseminated NTM and with CMV viremia or not. Subjects were 113 AIDS patients with disseminated NTM who were seen at this Hospital from January 2015 to April 2021. Twenty-six of the patients had CMV viremia and 87 did not. The median age was 36 years (interquartile range [IQR] 29-42) and 108 patients were male (96%). The median CD4 count was 7 cells/µL (IQR 3-17). The median plasma CMV viral load was 9,245 IU/mL (IQR 3147-45725). The serum albumin of patients with CMV viremia was significantly lower than that of patients without CMV viremia (P = 0.03). Compared to patients without CMV viremia (81.6%), patients with CMV viremia had a significantly poorer prognosis (P = 0.01). Cox regression analysis indicated that the risk of a poor prognosis in patients with CMV viremia was 4.7 times higher than that in patients without CMV viremia (P = 0.003), and patients with CD8 more than 250/μL had a better prognosis (P = 0.02). CMV viremia increases the risk of a poor prognosis in patients with AIDS and a disseminated NTM infection. A routine CMV DNA test should be performed on patients with AIDS and disseminated NTM disease in order to reduce the risk of death.

Mathematical modeling of impact of eCD4-Ig molecule in control and management of HIV within a host

Eradication and eventually cure of the HIV virus from the infected individual should be the primary goal in all HIV therapy. This has yet to be achieved, however development of broadly neutralizing antibodies (bNabs) and eCD4-Ig and its related particles are promising therapeutic alternatives to eliminate the HIV virus from the host. Past studies have found superior protectivity and efficacy eradicating the HIV virus with the use of eCD4-Igs over bNabs, which has proposed the antibody-dependent cell-mediated cytotoxicity (ADCC) effect as one of the key-factors for antibody design. In this study, we evaluated the dynamics of the HIV virus, CD4 T-cells, and eCD4-Ig in humans using a gene-therapy approach which has been evaluated in primates previously. We utilized a mathematical model to investigate the relationship between eCD4-Ig levels, ADCC effects, and the neutralization effect on HIV elimination. In addition, a balance between ADCC and viral neutralization effect of eCD4-Ig has been investigated in order to understand the condition of which HIV eliminating antibodies needs to satisfy. Our analysis indicated some level of ADCC effect, which was missing from ART, was required for viral elimination. The results will be helpful in designing future drugs or therapeutic strategies.

Impact of switching to raltegravir and/or adding losartan in lymphoid tissue fibrosis and inflammation in people living with HIV. A randomized clinical trial

BACKGROUND

Persistent inflammation and immune activation are associated with lymph node fibrosis and end-organ diseases in treatment-suppressed people living with HIV (PLWH). We investigated the effect of switching to raltegravir and/or adding losartan on lymphoid tissue fibrosis and on the inflammatory/immune-activation mediators in treated HIV patients.

METHODS

Chronic HIV-infected patients treated with two nucleoside reverse transcriptase inhibitors (2NRTI) and one non-NRTI (NNRTI) or protease inhibitor (PI) during at least 48 weeks were randomized to four groups (n = 48): 2NRTI + efavirenz (EFV), 2NRTI + EFV + losartan, 2NRTI + raltegravir and 2NRTI + raltegravir + losartan for 48 weeks. Tonsillar biopsy and peripheral blood markers of CD4 and CD8 T-lymphocyte activation and senescence, monocyte activation and soluble markers of inflammation were determined at baseline and at week 48 and compared between groups.

RESULTS

No changes in lymphoid tissue architecture were observed. Adding losartan had no impact on lymphocyte subsets. Conversely, patients who switched to raltegravir showed a higher decrease in all activated [CD4+CD38+HLA-DR+, -0.3 vs. 0.48 (P = 0.033); CD8+CD38+ HLA-DR+, -1.6 vs. 1.3 (P = 0.02)] and senescent [CD4+CD28-CD57+, -0.3 vs. 0.26 (P = 0.04); CD8+CD28-CD57+, -6.1 vs. 3.8 (P = 0.002)] T lymphocytes. In addition, the median CD4/CD8 ratio increased by 0.35 in patients in the raltegravir group vs. 0.03 in the other arms (P = 0.002). Differences between groups in monocyte subpopulations or soluble inflammation markers were not observed.

CONCLUSIONS

Losartan had no effect on lymphoid fibrosis or immune activation/inflammation. Conversely, switching to a regimen with raltegravir significantly decreased activated and senescent T-lymphocyte subpopulations and increased CD4/CD8 ratio in successfully treated PLWH.

Stage-Dependent Within-Individual Comparison Reveals SIV-Specific Activation/Exhaustion Shift in Rhesus Macaques

It is challenging to trace the complicated individual-based variations of HIV-specific immunocompetence shift during the successful antiretroviral therapy (ART) era. Using eight rhesus monkeys simulating a longitudinal stage-dependent cohort (baseline-SIV acute infection-SIV suppression by ART-ART withdrawal), baseline immunocompetence monitoring for 28 days (SIV-negative stage, SN) was compared with host immunocompetence undergoing 90-day ART treatment (SIV-suppressed stage, SS) to reveal the SIV-specific immunity shift aroused by undetectable individual viral replication. During acute SIV infection for 98 days (SIV-emerged stage, SE), immune activation was compared with re-immune activation post ART for 49-day follow-up (SIV-rebounded stage, SR) to reveal the SIV-specific immune activation variation aroused by detectable individual viral replication. Individual immunocompetence was measured by co-expression of CD4, CD8, CD38, HLA-DR, CCR7, CD45RA, and PD-1 on T cells and a cytokine panel. Compared with SN, mild immune activation/exhaustion was characterized by increased CD38⁺ HLA-DR^– CD4⁺/CD8⁺ T-cell subsets and PD-1⁺ memory CD4⁺/CD8⁺ T-cell subsets with three elevated cytokines (MIP-1β, IL-8, and IL-10) significantly emerged in SS. Compared with SE, SR produced more exhaustion characterized by increased PD-1⁺ CD4⁺ T_CM cells and decreased PD-1⁺ CD4⁺ T_EM cells with four elevated pro-inflammatory cytokines (IFN-γ, IL-1β, IL-6, and TNF-α). By such individualized stage-dependent comparison, the sustainable immune activation was found from activation/exhaustion shifted into exhaustion during the longitudinal viral persistence. Further, validated SIV accelerates host immunosenescence continuously independent of viral replication.

Immune restoration in HIV-1-infected patients after 12 years of antiretroviral therapy: a real-world observational study

Using normalization of CD4 counts as the main evaluation parameter of complete immune restoration for HIV-1 patients under antiretroviral therapy (ART) might be not enough. A comprehensive evaluation system more accurately reflecting immune restoration are urgently needed. Totally, 91,805 HIV-1 patients from 17 tertiary hospitals in China during 2005–2018 were included in this study. Immune restoration and mortality were assessed. Patients initiated ART with baseline CD4 counts <50, 50–199, 200–349, 350–499, and ≥500 cells/μL, and results showed an increase in the median CD4 counts to 445 (12-year), 467 (12-year), 581 (11-year), 644 (7-year), and 768 cells/µL (5-year), as well as the CD4/CD8 ratio to 0.59 (12-year), 0.65 (12-year), 0.79 (11-year), 0.82 (7-year), 0.9 (5-year), respectively. The median CD8 count was relatively high (median range 732–845 cells/μL), regardless of the baseline CD4 counts. Furthermore, the probabilities of death in patients achieving CD4 counts ≥500 cells/μL and CD4/CD8 ratio ≥0.8 simultaneously were significantly lower than those in patients achieving either CD4 counts ≥500 cells/μL (2.77% vs 3.50%, p=0.02) or CD4/CD8 ≥ 0.8 (2.77% vs 4.28%, p<0.001) after 12-year of ART. In this study, a new binary-indicator would accurately assess immune restoration in the era of “treat all.”

Clinical characteristics and risk factors for poor prognosis among HIV patients with Talaromyces marneffei bloodstream infection

Background

Talaromyces marneffei (TM) bloodstream infection is common in Acquired Immunodeficiency Syndrome (AIDS) patients with extreme immunodeficiency in Southeast Asia and South China, however, clinical case study on TM bloodstream infection is scarce. We retrospectively analyzed the clinical characteristics of TM bloodstream infection in hospitalized AIDS patients and determined the outcomes of hospitalization after diagnosis in our hospital over the past 5 years.

Methods

From January 2015 to July 2020, 87 cases of TM detected by blood culture in patients admitted to our center were collected. The admission complaints, blood cells, biochemistry, CD4 and CD8 cell counts and 1,3-β-D-glucan (BDG), procalcitonin (PCT), CRP level on the day of blood culture test, and outcomes during hospitalization were analyzed. Logistic regression analysis was performed for the risk factors for poor prognosis (60 cases). Spearman correlation analysis was used to analyze the correlation between peripheral blood cells, albumin and the time required for TM turnaround in blood culture. The difference was statistically significant when the P value was < 0.05.

Results

A total of 87 patients were collected, with a median age of 34 years, a median hemoglobin of 94 g/L and CD4 count of 7/μl. The rate of TM bloodstream infection among all in-hospital patients increased from 0.99% in 2015 to 2.09% in 2020(half year). Patients with TM bloodstream infection with CD8 count < 200/μl had a 12.6-fold higher risk of poor prognosis than those with CD8 count > 200/μl (p = 0.04), and those with BDG < 100 pg/mL had a 34.9-fold higher risk of poor prognosis than those with BDG > 100 pg/mL (p = 0.01).

Conclusions

TM bloodstream infection is becoming more common in advanced AIDS patients in endemic areas. For those patients with extremely low CD4 and CD8 cell counts below 200/μl is with an increased risk of poor prognosis.

Cytomegalovirus Seropositivity Is Associated With Increased Microbial Translocation in People Living With Human Immunodeficiency Virus and Uninfected Controls

Background

Cytomegalovirus (CMV) seropositivity and anti-CMV immunoglobulin G (IgG) levels are associated with adverse health outcomes in elderly populations. Among people living with human immunodeficiency virus (PLWH), CMV seropositivity has been associated with persistent CD8 T-cell elevation and increased risk of developing non-AIDS comorbidities despite long-term antiretroviral therapy (ART). Herein, we investigated whether CMV seropositivity and elevation of anti-CMV IgG levels were associated with increased epithelial gut damage, microbial translocation, and systemic inflammation.

Methods

A total of 150 PLWH (79 ART-naive and 71 ART-treated) were compared to 26 without human immunodeficiency virus (HIV) infection (uninfected controls). Plasma markers of HIV disease progression, epithelial gut damage, microbial translocation, nonspecific B-cell activation, anti-CMV and anti–Epstein-Barr virus (EBV) IgG levels, and proinflammatory cytokines were measured.

Results

CMV seropositivity and elevated anti-CMV IgG levels were associated with markers of epithelial gut damage, microbial translocation, and inflammation in PLWH and participants without HIV infection. In contrast, total nonspecific IgG, immunoglobulin M, immunoglobulin A, and anti-EBV IgG levels were not associated with these markers. CMV seropositivity was associated with markers of epithelial gut damage, microbial translocation, and inflammation independent of sociodemographic and behavioral characteristics of the study population.

Conclusions

CMV-seropositive people with and without HIV had increased epithelial gut damage, microbial translocation, and inflammation. Furthermore, anti-CMV IgG levels were independently associated with increased epithelial gut damage and microbial translocation. CMV coinfection may partially explain persistent gut damage, microbial translocation, and inflammation in ART-treated PLWH.

The Impact of Markers of HIV Infection on Change in Liver Stiffness in People With HIV and Hepatitis C Virus Co-infection After Treatment and Cure of Hepatitis C

BACKGROUND

Markers of HIV disease severity are associated with increased liver fibrosis in HIV/Hepatitis C virus (HCV) co-infected individuals. HCV treatment may reverse liver fibrosis, but evidence among HIV/HCV-co-infected populations and the impact of HIV parameters on fibrosis regression is limited. We aimed to assess the influence of surrogate markers of HIV-infection and other determinants of liver stiffness before HCV treatment and changes after HCV cure in people living with HIV.

METHODS

We used data from an HCV treatment implementation study aiming for HCV micro-elimination among gay and bisexual men with HIV in Melbourne, Australia (co-EC Study). We obtained liver stiffness measurements (LSM) before and after direct-acting antiviral treatment using transient elastography (FibroScan). Linear mixed models were used to evaluate determinants of pretreatment LSM and changes in LSM following cure with duration in years between pre- and post-LSM assessment as main exposure variable.

RESULTS

At least one LSM was available in 173 participants, and 98 participants had 2 LSMs. Median pre- and post-treatment LSMs were 5.7 and 5.1 kPa, respectively. Median time between transient elastography measurements was 1.3 years (interquartile range = 0.9-2.1). In multivariable analysis, longer duration of known HIV infection, a lower CD4 and CD8 T-cell count and hazardous alcohol consumption were associated with higher LSM values before treatment initiation. Successfully treated patients had a 6% (95% confidence interval = -10% to -2%) annual decrease (0.34 kPa predicted decrease) in LSM following cure. Changes in LSM values did not depend on any of the pretreatment HIV markers or other factors.

CONCLUSION

Low levels of liver stiffness were observed before treatment initiation and a small decrease (6%) in LSM following HCV cure in people living with HIV. No clear predictors affecting change in LSM following cure were found in this study, including markers of HIV infection. However, markers of advanced HIV immunodeficiency and hazardous alcohol consumption remained associated with higher LSM values even after HCV cure.

Frequency of Effector Memory Cells Expressing Integrin α4β7 Is Associated With TGF-β1 Levels in Therapy Naïve HIV Infected Women With Low CD4+ T Cell Count

Integrin α₄β₇ expressing CD4⁺ T cells are preferred targets for HIV infection and are thought to be predictors of disease progression. Concurrent analysis of integrin α₄β₇ expressing innate and adaptive immune cells was carried out in antiretroviral (ART) therapy naïve HIV infected women in order to determine its contribution to HIV induced immune dysfunction. Our results demonstrate a HIV infection associated decrease in the frequency of integrin α₄β₇ expressing endocervical T cells along with an increase in the frequency of integrin α₄β₇ expressing peripheral monocytes and central memory CD4⁺ T cells, which are considered to be viral reservoirs. We report for the first time an increase in levels of soluble MAdCAM-1 (sMAdCAM-1) in HIV infected individuals as well as an increased frequency and count of integrin β7Hi CD8⁺ memory T cells. Correlation analysis indicates that the frequency of effector memory CD8⁺ T cells expressing integrin α₄β₇ is associated with levels of both sMAdCAM-1 and TGF-β1. The results of this study also suggest HIV induced alterations in T cell homeostasis to be on account of disparate actions of sMAdCAM-1 and TGF-β1 on integrin α₄β₇ expressing T cells. The immune correlates identified in this study warrant further investigation to determine their utility in monitoring disease progression.

Adjunct Therapy for CD4+ T-Cell Recovery, Inflammation and Immune Activation in People Living With HIV: A Systematic Review and Meta-Analysis

Background: HIV infection results in immune homeostasis perturbations, which is characterized by CD4⁺ T-cell depletion, immune activation, and inflammation. Effective antiretroviral therapy (ART) does not fully restore immunologic and clinical health in people living with HIV (PLWH). Various drugs have been used to improve their immune status and CD4⁺ T-cell counts, but no measures have been tested effective. Here we conduct a systematic review and meta-analysis of existing clinical studies on improving CD4⁺ T-cell count while decreasing inflammation and immune activation.

Methods: We retrieved possible relevant publications from a total of five electronic databases and selected eligible studies, which dealt with outcomes of medical therapy for CD4⁺ T-cell count recovery, inflammation, and immune activation with or without ART. We paid particular attention to immunologic non-responders with a favorable treatment regimen.

Results: Thirty-three articles were included in the systematic review and meta-analysis. However, there were no safe and effective medications specific for improving CD4⁺ T-cell reconstitution. The immunological benefits or adverse events mainly depend on the safety, dosage, and duration of the candidate medication use, as well as whether it is combined with ART.

Conclusion: Under the “safe, combined, adequate and long (SCAL)” principles, alternative approaches are needed to accelerate the recovery of CD4⁺ T-cells, and to prevent adverse long-term outcomes in PLWH with standard ART treatment.

Poor CD4/CD8 ratio recovery in HBcAb-positive HIV patients with worse immune status is associated with significantly higher CD8 cell numbers

Low CD4+ cell count in patients with human immunodeficiency virus (HIV) and hepatitis B virus (HBV) coinfection during combination antiretroviral therapy (cART) has been described; however, notably few studies have investigated coinfected patients positive for antibodies to the HBV c antigen (HBcAb). An observational retrospective study enrolling 190 patients was conducted by grouping patients with respect to HBV status and recording CD4+ T cell counts and percentages (CD4%), CD8+ T cell counts and percentages (CD8%), and the CD4+ to CD8+ T cell ratio (CD4/CD8) at the time of HIV diagnosis, at the start of treatment and at months 1, 2, 3, 4, 5, 6, 12, and 24 after beginning cART. One hundred and twenty patients (63.2%) were negative for previous HBV infection, while 70 (36.8%) were HBcAb-positive. A significant increase in the CD4/CD8 ratio was recorded in HIV monoinfected subjects compared to HBV coinfected patients from months 4 to 12 from the beginning of cART (p value = 0.02 at month 4, p value = 0.005 at month 5, p value = 0.006 at month 6, and p value = 0.008 at month 12). A significant increase in the absolute count of CD8+ T lymphocytes was described from months 2 to 24 from the start of cART in the subgroup of HBV coinfected patients with an AIDS event at the onset of HIV infection. The presence of HBcAb was observed to be associated with reduced CD4/CD8 ratio growth and a significantly higher proportion of subjects with CD4/CD8 < 0.45 in the HIV/HBV coinfected group. A significant increase in the CD8 T cell count was shown up to 24 months after the initiation of effective cART in the subgroup of patients with the worst immune status.

Failure of CD4 T Cell-Deficient Hosts To Control Chronic Nontyphoidal Salmonella Infection Leads to Exacerbated Inflammation, Chronic Anemia, and Altered Myelopoiesis

Immunocompromised patients are more susceptible to recurrent nontyphoidal Salmonella (NTS) bacteremia. A key manifestation of HIV infection is the loss of CD4 T cells, which are crucial for immunity to Salmonella infection. We characterized the consequences of CD4 T cell depletion in mice where virulent Salmonella establish chronic infection, similar to chronic NTS disease in humans. Salmonella-infected, CD4-depleted 129X1/SvJ mice remained chronically colonized for at least 5 weeks, displaying increased splenomegaly and more severe splenitis than infected mice with CD4 T cells. Mature erythrocytes, immature erythroid cells, and phagocytes accounted for the largest increase in splenic cellularity. Anemia, which is associated with increased mortality in Salmonella-infected humans, was exacerbated by CD4 depletion in infected mice and was accompanied by increased splenic sequestration of erythrocytes and fewer erythropoietic elements in the bone marrow, despite significantly elevated levels of circulating erythropoietin. Splenic sequestration of red blood cells, the appearance of circulating poikilocytes, and elevated proinflammatory cytokines suggest inflammation-induced damage to erythrocytes contributes to anemia and splenic retention of damaged cells in infected animals. Depleting CD4 T cells led to increased myeloid cells in peripheral blood, spleen, and bone marrow, as well as expansion of CD8 T cells, which has been observed in CD4-depleted humans. This work describes a mouse model of Salmonella infection that recapitulates several aspects of human disease and will allow us to investigate the interplay of innate and adaptive immune functions with chronic inflammation, anemia, and susceptibility to Salmonella infection.

CD4/CD8 ratio, comorbidities, and aging in treated HIV infected individuals on viral suppression

The progression of the human immunodeficiency virus (HIV) infection to acquired immunodeficiency syndrome (AIDS) can be efficiently interrupted by antiretroviral therapy (ART). However, even successfully treated HIV-infected individuals are prone to develop non-AIDS-related diseases that affect the metabolism and several organs and systems. Biomarkers that predict the occurrence of comorbidities may help develop preventive measures. Current research shows that CD4+ T cell counts and viral load do not predict the development of non-AIDS-related diseases. The CD4/CD8 ratio has been indicated as a suitable marker of persistent immune dysfunction and the occurrence of non-AIDS-related events in treated HIV-positive patients. In this study, we explored the relationship between CD4/CD8 ratios, comorbidities, and aging in ART-treated HIV patients on viral suppression. We collected and evaluated data from 352 HIV-positive adults who were virologically suppressed (<40 copies/mL) on ART and with CD4 counts above 350 cells/mm3 . The median age for participants was 46 years, 218 individuals had at least one comorbidity, and 239 had inverted CD4/CD8 ratios (<1). Current CD4/CD8 ratios were predicted by baseline CD4/CD8 ratios and nadir CD4 counts. Despite the high rates of inverted CD4/CD8 ratios and prevalence of comorbidities, no association between them was observed. The prevalence of comorbidities was significantly higher in older individuals, though aging alone did not explain the rate of all individual comorbidities. Low CD4/CD8 ratios were linked to neurocognitive disorders, suggesting that persistent T cell dysfunction contributes to neurocognitive decline.

The DARC-null trait is associated with moderate modulation of NK cell profiles and unaltered cytolytic T cell profiles in black South Africans

The Duffy Antigen Receptor for Chemokines (DARC)-null trait, common among persons of African descent and associated with lower absolute neutrophil counts (ANCs), may be linked to increased risk to certain infections including HIV-1 but the underlying causes are poorly understood. We hypothesized that DARC-null-linked neutropenia may negatively impact neutrophil immunoregulatory modulation of other immune cells such as natural killer (NK) and CD8+ T cells leading to altered phenotype, functionality and homeostatic activity of these immune cells. HIV-1 uninfected (n = 20) and HIV-1 chronically infected (n = 19) participants were assessed using multi-parametric flow cytometry to determine NK and CD8+ T cell counts, phenotypic profiles, and cytokine production and degranulation. Annexin V and carboxyfluorescein succinimidyl ester (CFSE) staining were used to examine NK cell survival and NK cell and CD8+ T cell proliferation respectively. Participants were genotyped for the DARC-null polymorphism using allelic discrimination assays and ANCs were measured by full blood count. In HIV uninfected individuals, a reduction of total NK cell counts was noted in the absence of DARC and this correlated with lower ANCs. HIV uninfected DARC-null subjects displayed a less mature NK cell phenotype. However, this did not translate to differences in NK cell activation or effector functionality by DARC state. Whilst HIV-1 infected subjects displayed NK cell profiling that is typical of HIV infection, no differences were noted upon DARC stratification. Similarly, CD8+ T cells from HIV infected individuals displayed phenotypic and functional modulation that is characteristic of HIV infection, but profiling was unaffected by the DARC-null variant irrespective of HIV status. Overall, the data suggests that the DARC-null polymorphism and lower ANCs does not impede downstream cytolytic cell priming and functionality.

CD4+:CD8+ T Cell Ratio Normalization and the Development of AIDS Events in People with HIV Starting Antiretroviral Therapy

We identify factors associated with the normalization of the CD4+:CD8+ T cell ratio among UK Collaborative HIV Cohort study participants, and describe the association of the CD4+ and CD8+ T cell counts and the CD4+:CD8+ T cell ratio, with the risk of new AIDS events among individuals who achieve a suppressed viral load. Participants initiating combination antiretroviral therapy (cART) after 2006 with a CD4+:CD8+ T cell ratio <1, and viral suppression within 6 months were included. Cox proportional hazard models were used to examine associations with ratio normalization (ratio ≥1). Poisson regression models were used to investigate factors associated with the development of AIDS after viral load suppression. A total of 13,178 participants [median age: 37 (interquartile range: 31–44)] were followed for 75,336 person-years. Of the 4,042 (32.9%) who experienced ratio normalization, individuals with a high CD4+ T cell count [>500 vs. ≤200 cells/mm³, adjusted hazard ratio (95% confidence interval): 7.93 (6.97–9.01)], low CD8+ T cell count [>1,150 vs. ≤500 cells/mm³: 0.18 (0.16–0.21)], and low CD4+:CD8+ T cell ratio [>0.8 vs. <0.2: 12.36 (10.41–14.68)] at cART initiation were more likely to experience ratio normalization. Four hundred and nineteen people developed a new AIDS event. Most recent CD4+ T cell count [>500 vs. ≤200 cells/mm³: adjusted rate ratio 0.24 (0.16–0.34)] and CD4+:CD8+ T cell ratio [>0.8 vs. <0.2: 0.33 (0.21–0.52)] were independently associated with a new AIDS event. One third of study participants experienced ratio normalization after starting cART. CD4+ T cell count and CD4+:CD8+ T cell ratio are both individually associated with ratio normalization and the development of new AIDS events after cART.

Safety and Impact of Low-dose Methotrexate on Endothelial Function and Inflammation in Individuals With Treated Human Immunodeficiency Virus: AIDS Clinical Trials Group Study A5314

BACKGROUND

Chronic inflammation in treated HIV infection is associated with mortality and atherosclerotic cardiovascular disease (ASCVD). We evaluated the safety and potential efficacy of low-dose methotrexate (LDMTX) in treated HIV.

METHODS

This was a phase 2 randomized, double-blind, multicenter trial in adults ≥40 years old with treated HIV, with CD4+ T-cell count ≥400 cells/μL and with/at increased risk for ASCVD. Participants received LDMTX (5-15 mg/week) or placebo (plus folic acid) for 24 weeks and were followed for an additional 12 weeks. Primary endpoints were safety and brachial artery flow-mediated dilation (FMD).

RESULTS

The 176 participants (90% male) had a median (Q1, Q3) age of 54 (49, 59) years. LDMTX was associated with decreases in CD4+ T cells at week 24 and CD8+ T cells at weeks 8, 12, and 24. Eleven participants (12.8%) experienced safety events in the LDMTX group vs 5 (5.6%) in placebo (Δ = 7.2%, upper 1-sided 90% CI, 13.4%; Pnoninferiority = .037). Week 24 change in FMD was 0.47% with LDMTX and 0.09% with placebo (P = .55). No inflammatory markers changed differentially with LDMTX compared to placebo.

CONCLUSIONS

Adults with HIV and increased ASCVD risk treated with LDMTX had more safety events than with placebo, but the prespecified noninferiority margin of 15% was not exceeded. LDMTX had no significant effect on endothelial function or inflammatory biomarkers but was associated with a significant decrease in CD8+ T cells. The balance of risks and potential benefits of LDMTX in this population will require additional investigation.

CLINICAL TRIALS REGISTRATION

NCT01949116.

HIV Reservoir Decay and CD4 Recovery Associated With High CD8 Counts in Immune Restored Patients on Long-Term ART

Background: Whether varying CD8 counts influence the human immunodeficiency virus (HIV) reservoir and CD4 restoration in patients with CD4 counts ≥ 500 cells/μL after long-term antiretroviral therapy (ART) remains unknown. In this study, we analyzed relationships between CD8 levels and viral reservoir decay or CD4 recovery in immune restored patients on long-term ART.

Methods: Chronic HIV-infected patients who received 5 years of ART with CD4 counts ≥ 500 cells/μL were grouped according to CD8 counts: CD8 <500 (Group 1), 500–1,000 (Group 2), and ≥1,000 cells/μL (Group 3). CD4 recovery, viral decay, CD8 T-cell function, and their correlations were analyzed during ART among the three groups.

Results: Dynamics of viral decay and CD4 recovery were different among the three groups. Both viral decay and CD4 recovery were higher in Group 3 than the other two groups after 5 years of ART, mainly during years 3–5 of ART. Higher expression levels of Ki67 while PD-1 levels were lower on CD8 T-cells in Group 3 compared with the other groups, and Group 3 showed stronger CD8 T-cells functional capacity after 3 years of ART. Reduced HIV DNA levels and increased CD4 counts between years 3 and 5 of ART were positively correlated with CD8 counts and function.

Conclusions: High CD8 counts are beneficial for persistent viral decay and CD4 recovery in immune restored patients during long-term ART.

The activation of bystander CD8+ T cells and their roles in viral infection

During viral infections, significant numbers of T cells are activated in a T cell receptor-independent and cytokine-dependent manner, a phenomenon referred to as "bystander activation." Cytokines, including type I interferons, interleukin-18, and interleukin-15, are the most important factors that induce bystander activation of T cells, each of which plays a somewhat different role. Bystander T cells lack specificity for the pathogen, but can nevertheless impact the course of the immune response to the infection. For example, bystander-activated CD8⁺ T cells can participate in protective immunity by secreting cytokines, such as interferon-γ. They also mediate host injury by exerting cytotoxicity that is facilitated by natural killer cell-activating receptors, such as NKG2D, and cytolytic molecules, such as granzyme B. Interestingly, it has been recently reported that there is a strong association between the cytolytic function of bystander-activated CD8⁺ T cells and host tissue injury in patients with acute hepatitis A virus infection. The current review addresses the induction of bystander CD8⁺ T cells, their effector functions, and their potential roles in immunity to infection, immunopathology, and autoimmunity.

Compromised CD4:CD8 ratio recovery in people living with HIV aged over 50 years: an observational study

OBJECTIVES

Persistent CD4:CD8 ratio inversion (< 1) is associated with mortality in older people. We investigated the interaction of the effects of baseline CD8 count and age at HIV diagnosis on CD4:CD8 ratio recovery with antiretroviral therapy (ART).

METHODS

An observational study (1 January 2007 to 31 December 2016) was carried out using routinely collected data from the HIV outpatient services at Imperial College Healthcare NHS Trust, London, UK. CD4 and CD8 counts, prior to and during ART, treatment during primary HIV infection (PHI) and HIV-1 viral load were included in univariate and multivariate analyses using Cox proportional hazard regression.

RESULTS

Data were included for 876 patients starting ART, where HIV suppression was achieved. Of these patients, 741 of 876 (84.6%) were male and 507 of 876 (57.9%) were Caucasian. The median time on ART was 38 [interquartile range (IQR) 17-66] months. CD8 count change on ART was bidirectional; low CD8 counts (≤ 600 cells/μL) increased and high CD8 counts (> 900 cells/μL) decreased. The median pre-ART CD4:CD8 ratio was 0.41 (IQR 0.24-0.63), and recovery (≥ 1) occurred in 274 of 876 patients (31.3%). Pre- and post-ART CD4:CD8 ratios were lower in those aged > 50 years compared with young adults aged 18-30 years (P < 0.001 and P = 0.002, respectively). After adjustment, younger age at HIV diagnosis (P < 0.001) and treatment during PHI (P < 0.001) were favourable for CD4:CD8 ratio normalization.

CONCLUSIONS

Older age (> 50 years) at HIV diagnosis was associated with persistent CD4:CD8 ratio inversion, whereas treatment of PHI was protective. These findings confirm the need for testing and early treatment of people aged > 50 years, and could be used in a risk management algorithm for enhanced surveillance.

Simian-Human Immunodeficiency Virus SHIV.CH505 Infection of Rhesus Macaques Results in Persistent Viral Replication and Induces Intestinal Immunopathology

Simian-human immunodeficiency viruses (SHIVs) have been utilized to test vaccine efficacy and characterize mechanisms of viral transmission and pathogenesis. However, the majority of SHIVs currently available have significant limitations in that they were developed using sequences from chronically HIV-infected individuals or uncommon HIV subtypes or were optimized for the macaque model by serially passaging the engineered virus in vitro or in vivo Recently, a newly developed SHIV, SHIV.C.CH505.375H.dCT (SHIV.CH505), which incorporates vpu-env (gp140) sequences from a transmitted/founder HIV-1 subtype C strain, was shown to retain attributes of primary HIV-1 strains. However, a comprehensive analysis of the immunopathology that results from infection with this virus, especially in critical tissue compartments like the intestinal mucosa, has not been completed. In this study, we evaluated the viral dynamics and immunopathology of SHIV.CH505 in rhesus macaques. In line with previous findings, we found that SHIV.CH505 is capable of infecting and replicating efficiently in rhesus macaques, resulting in peripheral viral kinetics similar to that seen in pathogenic SIV and HIV infection. Furthermore, we observed significant and persistent depletions of CCR5⁺ and CCR6⁺ CD4⁺ T cells in mucosal tissues, decreases in CD4⁺ T cells producing Th17 cell-associated cytokines, CD8⁺ T cell dysfunction, and alterations of B cell and innate immune cell function, indicating that SHIV.CH505 elicits intestinal immunopathology typical of SIV/HIV infection. These findings suggest that SHIV.CH505 recapitulates the early viral replication dynamics and immunopathogenesis of HIV-1 infection of humans and thus can serve as a new model for HIV-1 pathogenesis, treatment, and prevention research.IMPORTANCE The development of chimeric SHIVs has been instrumental in advancing our understanding of HIV-host interactions and allowing for in vivo testing of novel treatments. However, many of the currently available SHIVs have distinct drawbacks and are unable to fully reflect the features characteristic of primary SIV and HIV strains. Here, we utilize rhesus macaques to define the immunopathogenesis of the recently developed SHIV.CH505, which was designed without many of the limitations of previous SHIVs. We observed that infection with SHIV.CH505 leads to peripheral viral kinetics and mucosal immunopathogenesis comparable with those caused by pathogenic SIV and HIV. Overall, these data provide evidence of the value of SHIV.CH505 as an effective model of SIV/HIV infection and an important tool that can be used in future studies, including preclinical testing of new therapies or prevention strategies.

Standard-Dose Intradermal Influenza Vaccine Elicits Cellular Immune Responses Similar to Those of Intramuscular Vaccine in Men With and Those Without HIV Infection

BACKGROUND

Human immunodeficiency virus (HIV)-infected persons are at a higher risk of severe influenza. Although we have shown that a standard-dose intradermal influenza vaccine versus a standard-dose intramuscular influenza vaccine does not result in differences in hemagglutination-inhibition titers in this population, a comprehensive examination of cell-mediated immune responses remains lacking.

METHODS

Serological, antigen-specific B-cell, and interleukin 2-, interferon γ-, and tumor necrosis factor α-secreting T-cell responses were assessed in 79 HIV-infected men and 79 HIV-uninfected men.

RESULTS

The route of vaccination did not affect the immunoglobulin A and immunoglobulin G (IgG) plasmablast or memory B-cell response, although these were severely impaired in the group with a CD4+ T-cell count of <200 cells/μL. The frequencies of IgG memory B cells measured on day 28 after vaccination were highest in the HIV-uninfected group, followed by the group with a CD4+ T-cell count of ≥200 cells/μL and the group with a CD4+ T-cell count of <200 cells/μL. The route of vaccination did not affect the CD4+ or CD8+ T-cell responses measured at various times after vaccination.

CONCLUSIONS

The route of vaccination had no effect on antibody responses, antibody avidity, T-cell responses, or B-cell responses in HIV-infected or HIV-uninfected subjects. With the serological and cellular immune responses to influenza vaccination being impaired in HIV-infected individuals with a CD4+ T-cell count of <200 cells/μL, passive immunization strategies need to be explored to protect this population.

CLINICAL TRIALS REGISTRATION

NCT01538940.

Short Communication: A Quantitative System for Monitoring Blood-Circulating Viral Protein R of Human Immunodeficiency Virus-1 Detected a Possible Link with Pathogenic Indices

We developed a detergent-free enzyme-linked immunosorbent assay (ELISA) for HIV-1 viral protein R (Vpr), an accessory protein of human immunodeficiency virus type-1 (HIV), and detected soluble Vpr in ∼22% of HIV patients who were receiving combination antiretroviral therapy and were free of plasma HIV RNA. Notably, the levels of CD8-positive cell count, soluble intercellular adhesion molecule-1 (sICAM-1), and C-C motif chemokine ligand 2 (CCL2), all of which are markers of chronic inflammation in HIV patients, were higher in Vpr-positive patients than in Vpr-negative patients. Because sICAM1 and CCL2 are associated with an increased risk of HIV-associated neurocognitive disorder, we propose that an established Vpr-ELISA would be useful for monitoring the risk of HIV complications during latent HIV infection.

Immunological profiles of HIV-positive recipients of liver transplant

BACKGROUND

Scarce data are available about immune cell frequencies in HIV-positive recipients of liver transplant. Alterations in immune subsets can lead to persistent immune activation and disease progression or reduced HIV-specific responses. In liver transplantation, impaired immune tolerance can lead to organ rejection.

METHODS

HIV-positive subjects with undetectable HIVRNA and CD4 > 100/mm³ were included. Control groups were non-transplanted HIV-positive patients with similar immunovirological parameters and healthy subjects. B cells (memory, transitional, and mature subsets), T cells (effector TH1, nonclassic TH1, TH17, TH1/17; T regulatory naïve and effector subsets and CD8⁺ T regulatory cells), and NK cells (CD56^dim and CD56^bright subsets) were analyzed by flow cytometry.

RESULTS

A total of 56 patients, including 14 HIV-positive transplant recipients (HIV-LT), 14 HIV-positive controls, and 28 healthy controls were included. Median age of HIV-LT patients was 54.9 years with median time from transplant of 7.6 years. Eleven (79%) were HIV/HCV coinfected. Compared to nontransplanted patients, HIV-LT displayed significantly increased frequency of T CD8⁺ cells, lower percentage of T CD4+ cell, and lower number of nonclassic TH1, TH1/17 cells and naïve T CD4⁺ regulatory cells (Tregs). Healthy controls showed increased numbers of B cell subsets and decreased percentage of T effector subpopulations compared to HIV-LT. Compared to HIV-positive patients, healthy controls had higher B cells, NK cells, CD4⁺ T cells, naïve CD4+ Tregs but lower CD8⁺ T cells, effector Tregs, CD8⁺ Tregs, and all T effector cell subsets.

CONCLUSIONS

Immune cell subpopulations potentially associated with HIV progression and organ rejection were detected in HIV-positive transplant recipients. We confirmed altered frequencies of B, T, and NK cell populations in HIV-positive liver transplant recipients compared to healthy controls. The imbalance among immune cell subsets deserves further studies to identify markers of transplant outcome and potential therapeutic targets.

Experimental and computational analyses reveal that environmental restrictions shape HIV-1 spread in 3D cultures

Pathogens face varying microenvironments in vivo, but suitable experimental systems and analysis tools to dissect how three-dimensional (3D) tissue environments impact pathogen spread are lacking. Here we develop an Integrative method to Study Pathogen spread by Experiment and Computation within Tissue-like 3D cultures (INSPECT-3D), combining quantification of pathogen replication with imaging to study single-cell and cell population dynamics. We apply INSPECT-3D to analyze HIV-1 spread between primary human CD4 T-lymphocytes using collagen as tissue-like 3D-scaffold. Measurements of virus replication, infectivity, diffusion, cellular motility and interactions are combined by mathematical analyses into an integrated spatial infection model to estimate parameters governing HIV-1 spread. This reveals that environmental restrictions limit infection by cell-free virions but promote cell-associated HIV-1 transmission. Experimental validation identifies cell motility and density as essential determinants of efficacy and mode of HIV-1 spread in 3D. INSPECT-3D represents an adaptable method for quantitative time-resolved analyses of 3D pathogen spread.

Here, using an integrative experimental and computational approach, Imle et al. show how cell motility and density affect HIV cell-associated transmission in a three-dimensional tissue-like culture system of CD4⁺ T cells and collagen, and how different collagen matrices restrict infection by cell-free virions.

AIDS prevention and control in the Yunnan region by T cell subset assessment

Background

Prior to being spread throughout broader China, multiple human immunodeficiency virus (HIV)-1 genotypes were originally discovered in the Yunnan Province. As the HIV-1 epidemic continues its spread in Yunnan, knowledge of the influence of gender, age, and ethnicity to instances of HIV reservoirs will benefit monitoring the spread of HIV.

Methods

The degree to which T cells are depleted during an HIV infection depends on the levels of immune activation. T-cell subsets were assessed in newly-diagnosed HIV/AIDS patients in Yunnan, and the influence of age, gender, and ethnicity were investigated. Patients that were newly diagnosed with the HIV-infection between the years 2015 and 2018 at the First Affiliated Hospital of Kunming Medical College were selected for this study (N = 408). The lymphocyte levels and T cell subsets were retrospectively measured in whole blood samples by FACS analysis.

Results

The median CD4 count was 224 ± 191 cells/μl. Significantly higher mean frequencies and absolute numbers were observed in CD3⁺, CD3⁺CD4⁺, CD3⁺CD8⁺, CD45⁺, and CD3⁺CD4⁺/CD45⁺ in females compared to males. Han patients showed a higher total number of CD3+T cells and the ratio of CD3⁺ /CD45⁺ cells compared to any other ethnic minority (P < 0.001). The numbers of CD3+ T-cells, CD3+CD8+ T cells, and CD45+ T cells were highest in the age group ≥ 60. Significant differences were observed in the counts of CD3+, CD3+CD8+, and CD45⁺ cells and the ratio of CD3⁺/CD45⁺ and CD3⁺CD4⁺/CD45⁺ cells between the ≤ 29 and 30–59 age groups.

Conclusion

This study has revealed that low levels of CD4⁺ T cells can be observed in newly-diagnosed HIV/AIDS patients in the Yunnan province. It has also been demonstrated that gender, age, and ethnicity have a significant association with the ratio of T-cell subsets that may contribute to virus progression and disease prognosis in individuals belonging to certain subsets of the population. This study has highlighted the importance of HIV/AIDS screening in at-risk populations to ensure timely and adequate clinical management in Yunnan.

Altered Immunity and Microbial Dysbiosis in Aged Individuals With Long-Term Controlled HIV Infection

The introduction of highly active antiretroviral therapy (HAART) resulted in a significant increase in life expectancy for HIV patients. Indeed, in 2015, 45% of the HIV+ individuals in the United States were ≥55 years of age. Despite improvements in diagnosis and treatment of HIV infection, geriatric HIV+ patients suffer from higher incidence of comorbidities compared to age-matched HIV- individuals. Both chronic inflammation and dysbiosis of the gut microbiome are believed to be major contributors to this phenomenon, however carefully controlled studies investigating the impact of long-term (>10 years) controlled HIV (LTC-HIV) infection are lacking. To address this question, we profiled circulating immune cells, immune mediators, and the gut microbiome from elderly (≥55 years old) LTC-HIV+ and HIV- gay men living in the Palm Springs area. LTC-HIV+ individuals had lower frequency of circulating monocytes and CD4+ T-cells, and increased frequency CD8+ T-cells. Moreover, levels of systemic INFγ and several growth factors were increased while levels of IL-2 and several chemokines were reduced. Upon stimulation, immune cells from LTC-HIV+ individuals produced higher levels of pro-inflammatory cytokines. Last but not least, the gut microbiome of LTC-HIV+ individuals was enriched in bacterial taxa typically found in the oral cavity suggestive of loss of compartmentalization, while levels of beneficial butyrate producing taxa were reduced. Additionally, prevalence of Prevotella negatively correlated with CD4+ T-cells numbers in LTC-HIV+ individuals. These results indicate that despite long-term adherence and undetectable viral loads, LTC-HIV infection results in significant shifts in immune cell frequencies and gut microbial communities.

HIV-1 coreceptor tropism: A syllogistic connection with The Veterans Aging Cohort Study Index and the CD4/CD8 ratio

BACKGROUND

The association between X4 virus and an increased risk of non-AIDS-events has been reported. Morbidity/mortality due to non-AIDS events, which are properly predicted by the CD4/CD8 ratio and VACS index, have become particularly remarkable in HIV-infected patients receiving effective combined antiretroviral therapy (cART).

METHODS

We verified the validity of the syllogism: as HIV-tropism (CRT) contributes to the onset of non-AIDS events which are successfully predicted by the CD4/CD8 ratio and VACS index, then CRT correlates with these two variables. The CD4/CD8 ratio and VACS index at baseline and overtime were analyzed according to CRT tested before the first successful cART regimen in newly-diagnosed patients.

RESULTS

Patients with R5 variants had a significantly lower baseline VACS percentage risk [mean (95%CI):18.2%(16.1-20.3) vs 24.3%(18.2-22.5), p = 0.002] and higher baseline CD4/CD8 ratio [mean (95%CI):0.43 (0.38-0.47) vs 0.28 (0.19-0.36), p = 0.002] than non-R5 patients. After an initial drop, VACS increased again in R5 and non-R5 patients and the two trend curves almost overlapped. The CD4/CD8 ratio had an increasing trend in both R5 and non-R5 patients; however, even though non-R5 patients had a greater gain of CD4+, they maintained a lower CD4/CD8 ratio at any time point.

CONCLUSION

Our study confirms an association between pre-therapy CRT, CD4/CD8 ratio and VACS. A successful cART regimen positively affects the CD4/CD8 ratio; however, the disadvantage conferred by a non-R5 CRT is maintained overtime. The restoration of VACS in all patients could be directly due to variables included in the VACS calculation and to factors that adversely influence these variables.

Harnessing CD8+ T Cells Under HIV Antiretroviral Therapy

Antiretroviral therapy (ART) has transformed HIV from a fatal disease to a chronic condition. In recent years there has been considerable interest in strategies to enable HIV-infected individuals to cease ART without viral rebound, either by purging all cells infected harboring replication-competent virus (HIV eradication), or by boosting immune responses to allow durable suppression of virus without rebound (HIV remission). Both of these approaches may need to harness HIV-specific CD8⁺ T cells to eliminate infected cells and/or prevent viral spread. In untreated infection, both HIV-specific and total CD8⁺ T cells are dysfunctional. Here, we review our current understanding of both global and HIV-specific CD8⁺ T cell immunity in HIV-infected individuals with durably suppressed viral load under ART, and its implications for HIV cure, eradication or remission. Overall, the literature indicates significant normalization of global T cell parameters, including CD4/8 ratio, activation status, and telomere length. Global characteristics of CD8⁺ T cells from HIV⁺ART⁺ individuals align more closely with those of HIV-seronegative individuals than of viremic HIV-infected individuals. However, markers of senescence remain elevated, leading to the hypothesis that immune aging is accelerated in HIV-infected individuals on ART. This phenomenon could have implications for attempts to prime de novo, or boost existing HIV-specific CD8⁺ T cell responses. A major challenge for both HIV cure and remission strategies is to elicit HIV-specific CD8⁺ T cell responses superior to that elicited by natural infection in terms of response kinetics, magnitude, breadth, viral suppressive capacity, and tissue localization. Addressing these issues will be critical to the success of HIV cure and remission attempts.