Immunological recovery failure in cART-treated HIV-positive patients is associated with reduced thymic output and RTE CD4+ T cell death by pyroptosis

Higher proportions of circulating CXCR3+ CCR6- Tfh cells as a hallmark of impaired CD4+ T-cell recovery in HIV-1-infected immunological non-responders

Despite long-term suppressive antiretroviral therapy (ART), immune dysregulation due to impaired reconstitution of CD4+ T cells is a major hurdle for reducing morbidity and mortality in HIV-1-infected immunological non-responders (INRs, CD4+ T cells ≤350 cells/µL). To evaluate potential immunological factors associated with impaired CD4+ T-cell reconstitution, we performed comprehensive immunophenotyping of multiple subsets of CD4+ T cells among HIV-1-infected individuals with high (>350 cells/µL) and low (≤350 cells/µL) CD4+ T cells, either ART-naïve or ART-exposed (median, 10 years). In comparison to other groups, INRs showed exclusively elevated proportions of CXCR3+ CCR6- Th1-like circulatory T follicular helper (cTfh1) CD4+ T cells, correlating negatively with CD4+ T cells (r = -0.6769, P < 0.0001), suggesting a strong association with incomplete CD4+ T-cell recovery. In contrast, compared to INRs, higher proportions of CXCR3- CCR6+ Th17-like cTfh cells (cTfh17) in immunological responders (IRs, CD4+ T cells >350 cells/µL) showed no correlation with CD4+ T-cell counts, suggesting a lack of association with CD4+ T-cell recovery. Additionally, proportions of activated (CD4+ CD38+ HLA-DR+) and regulatory (CD4+ CD25+/hi CD127-/lo) CD4+ T cells were increased in INRs compared to IRs, as previously known. A negative correlation was also observed between the CD4+ T-cell counts and activated (r = -0.6726, P < 0.0001) or regulatory (r = -0.5627, P < 0.0001) CD4+ T-cell proportions among IRs and INRs. Our study highlights that immune dysregulation associated with skewing of cTfh cells toward CXCR3+ CCR6- Th1-like phenotype may be the leading cause of inefficient CD4+ T-cell recovery in INRs and can serve as a hallmark of impaired CD4+ T-cell reconstitution.IMPORTANCEThe altered proportions of CD4+ T-cell subsets in immunological non-responders (INRs) indicate their involvement in poor CD4+ T-cell reconstitution. Reversing these alterations may help prevent the loss of CD4+ T cells. Particularly, blocking cTfh-cell polarization toward CXCR3+ CCR6- cTfh-cell subset may help restore CD4+ T-cell counts in INRs, thereby preventing increased risk of morbidity and mortality.

How to properly define immunological nonresponse to antiretroviral therapy in people living with HIV? an integrative review

In recent decades, significant progress has been made in understanding the mechanisms underlying human immunodeficiency virus (HIV) infection and its treatment. Antiretroviral therapy (ART) has notable improved the life expectancy and quality of life for people living with HIV (PLHIV) by suppressing viral replication and promoting CD4+ T-cell recovery. However, despite its efficacy, approximately 10-40% of ART-treated PLHIV with virological suppression (<50 RNA copies/mL) do not achieve adequate immunological reconstitution. These PLHIV, classified as immunological non-responders (INR), experience higher morbidity and mortality rates compared to those with satisfactory immune reconstitution, known as immunological responders (IR). Various studies have explored the mechanisms contributing to immunological nonresponse, yet a major challenge remains: the lack of a standardized definition of immunological response and nonresponse across studies. Currently, definitions are inconsistent, limiting comparability between studies. This review proposes a clear and adequate classification for IR and INR PLHIV to support future advancements in understanding immunological recovery and improving the quality of life for ART-treated PLHIV.

Impaired immune reconstitution in HIV infection: the role of CD4+ T-cell-associated NKG2D ligands, CD4+ T-cell subsets imbalance, and immune function deficiency

Objective

The role of natural killer (NK) cells, which mediate innate immunity, in the immune reconstitution of people living with HIV (PLWH) remains unclear. Our previous research indicated that early activation of CD56dimCD16dim/- NK cells plays an important role in the recovery of CD4+ T cells in immunological non-responders (INRs) after ART. This study mainly focuses on the profiles of cell receptors and their relative ligands for NK cells and CD4+ T cells exhibited on INRs and immunological responders (IRs) in order to analyze the impact of differential immune status on immune reconstitution in PLWH receiving ART.

Methods

This study included 66 PLWH who had been on ART for 4 years, comprising 32 INRs and 34 IRs. Using flow cytometry, we examined the expression of cell receptors and ligands for NK cells and CD4+ T cells in PBMCs, as well as the differentiation of CD4+ T cells.

Results

The expression of NKG2D ligands, including MICA/B and ULBP2-5, on CD4+ T cells in INRs is elevated prior to ART. Further research found that the expression of CD95 on MICA/B+CD4+ T cells and ULBP2-5+CD4+ T cells was higher in INRs before ART compared to IRs. Simultaneously, the percentages of death receptor CD95 expression on MICA/B+CD4+ T cells and on ULBP2-5+CD4+ T cells before ART were negatively correlated with CD4+ T-cell counts and ΔCD4. Among the CD4+ T-cell subsets, an imbalance persists in the CD4+ Tcm and CD4+ Temra subsets in both INRs and IRs, before or after ART. CD4+ T cells exhibit elevated levels of activation, proliferation, exhaustion, and apoptosis prior to ART initiation. However, CD4+ T-cell activation and proliferation normalize post-ART, while apoptosis and exhaustion levels remain significantly elevated. Regardless of ART, the anti-apoptotic capacity of CD4+ T cells in INRs is still lower than that of IRs and healthy controls (HCs). Before ART, the frequency of CD31 expression on naive CD4+ T cells in INRs is lower than that in IRs and HCs. Following ART, the amounts of CD31+ Tn from CD4+ T cells remain impaired in both INRs and IRs compared to HCs.

Conclusion

The upregulation of related ligands for the NKG2D receptor on CD4+ T cells in INRs is associated with increased susceptibility of CD4+ T cells to NK cell-mediated killing. CD95 may plays an important role in poor recovery of CD4+ T cells co-expressing NKG2D-related ligands. The imbalance in CD4+ Tcm and CD4+ Temra subset homeostasis and impaired CD31 expression on naive CD4+ T cells in INRs are associated with poor immune reconstitution outcomes.

Sociobehavioral Risk Factors and Clinical Implications of Late Presentation Among People Living with HIV in the Brazilian Amazon Region

This study aimed to analyze the prevalence, sociobehavioral factors and clinical-laboratory consequences of late presentation among people living with HIV (PLHIV) in the Brazilian Amazon region. In total, 402 HIV + individuals treated at reference units in Belém city (Pará, Brazil) between 2018 and 2019 were evaluated. Late presentation was defined as a first-collection LTCD4+ count below 350 cells/µL. Sociodemographic, behavioral and clinical data were obtained from questionnaires or medical records. Th1, Th2 and Th17 cytokine profiles were evaluated by flow cytometry. Longitudinal data on viral load, T lymphocytes, and antiretroviral therapy administration were obtained from control and logistic databases. Approximately 52.73% of the participants were late presenters and sought medical care 7-12 + months after their primary HIV diagnosis. Sociobehavioral factors associated with late presentation included illicit drug use for more than 5 years, polyamory, no alcohol consumption, homosexuality, and sexual inactiveness after HIV diagnosis. Clinically, late presentation was associated with coinfection rate; polysymptomatology; high IFN-ɣ, IL-6 and IL-10 levels; nonresponse to antiretroviral therapy; and virological failure- and tuberculosis coinfection-motivated changes to therapy. In summary, the prevalence of late presentation in Pará in the Brazilian Amazon region is high. Delays in seeking specialized care after a primary HIV diagnosis cause medium/long-term changes in the life expectancy and health of PLHIV.

Brief Report: In cART-Treated HIV-Infected Patients, Immunologic Failure Is Associated With a High Myeloid-Derived Suppressor Cell Frequency

BACKGROUND

During HIV infection, effective combined antiretroviral therapy suppresses viral replication and restores the number of circulating CD4+ T cells. However, 15%-30% of treated patients show a discordant response to combined antiretroviral therapy. Myeloid-derived suppressor cells (MDSC) are expanded in HIV+ patients; to better understand the role of MDSC on CD4 T-cell recovery, we evaluated the frequency of MDSC in HIV+ patients under combined antiretroviral therapy and its association with immunologic response.

METHODS

We enrolled 60 HIV+ patients, including complete responders (R, n = 44), virologic nonresponders (VNR, n = 5), and immunologic nonresponders (INR, n = 11). The frequency of circulating MDSC and the percentage of activated and naïve CD4 T cells were evaluated by flow cytometry. Plasmatic cytokine levels were analyzed by automated ELISA.

RESULTS

As previously observed, polymorphonuclear MDSC (PMN-MDSC) frequency was higher in HIV+ patients compared with healthy donors. Furthermore, PMN-MDSC percentage was higher in INR than R patients, and a significant association between MDSC frequency and immunologic failure was confirmed by a receiver operator characteristic analysis. Accordingly, an inverse correlation was found between the percentages of PMN-MDSC and naïve CD4 T cells. A positive correlation was observed between PMN-MDSC frequency and the percentage of human leucocyte antigen locus DR + CD4 T cells and the plasmatic level of IL-1β and IL-8.

CONCLUSION

Our results show that a high frequency of PMN-MDSC persists in INR, possibly because of immune activation, contributing to CD4 T-cell recovery failure. These findings further highlight the detrimental role of MDSC during HIV infection, suggesting these cells as a possible new therapeutic target.

Role of thymosin α1 in restoring immune response in immunological nonresponders living with HIV

BACKGROUND

Immunological nonresponders (INRs) living with HIV are at increased risk of co-infection and multiple tumors, with no effective strategy currently available to restore their T-cell immune response. This study aimed to explore the safety and efficacy of thymosin α1 in reconstituting the immune response in INRs.

METHODS

INRs with CD4 + T cell counts between 100 and 350 cells/μL were enrolled and received two-staged 1.6 mg thymosin α1 subcutaneous injections for 24 weeks (daily in the first 2 weeks and biweekly in the subsequent 22 weeks) while continuing antiretroviral therapy. T cell counts and subsets, the expression of PD-1 and TIM-3 on T cells, and signal joint T cell receptor excision circles (sjTREC) at week 24 were evaluated as endpoints.

RESULTS

Twenty three INRs were screened for eligibility, and 20 received treatment. The majority were male (19/20), with a median age of 48.1 years (interquartile range: 40.5-57.0) and had received antiretroviral therapy for 5.0 (3.0, 7.3) years. Multiple comparisons indicated that CD4 + T cell count and sjTREC increased after initiation of treatment, although no significant differences were observed at week 24 compared to baseline. Greatly, levels of CD4 + T cell proportion (17.2% vs. 29.1%, P < 0.001), naïve CD4 + and CD8 + T cell proportion (17.2% vs. 41.1%, P < 0.001; 13.8% vs. 26.6%, P = 0.008) significantly increased. Meanwhile, the proportion of CD4 + central memory T cells of HIV latent hosts (42.7% vs. 10.3%, P < 0.001) significantly decreased. Moreover, the expression of PD-1 on CD4 + T cells (14.1% vs. 6.5%, P < 0.001) and CD8 + T cells (8.5% vs. 4.1%, P < 0.001) decreased, but the expression of TIM-3 on T cellsremained unaltered at week 24. No severe adverse events were reported and HIV viral loads kept stable throughout the study.

CONCLUSIONS

Thymosin α1 enhance CD4 + T cell count and thymic output albeit as a trend rather than an endpoint. Importantly, it improves immunosenescence and decreases immune exhaustion, warranting further investigation.

TRIAL REGISTRATION

This single-arm prospective study was registered with ClinicalTrials.gov (NCT04963712) on July 15, 2021.

Distinct inflammation-related proteins associated with T cell immune recovery during chronic HIV-1 infection

Chronic inflammation and T cell dysregulation persist in individuals infected with human immunodeficiency virus type 1 (HIV-1), even after successful antiretroviral treatment. The mechanism involved is not fully understood. Here, we used Olink proteomics to comprehensively analyze the aberrant inflammation-related proteins (IRPs) in chronic HIV-1-infected individuals, including in 24 treatment-naïve individuals, 33 immunological responders, and 38 immunological non-responders. T cell dysfunction was evaluated as T cell exhaustion, activation, and differentiation using flow cytometry. We identified a cluster of IRPs (cluster 7), including CXCL11, CXCL9, TNF, CXCL10, and IL18, which was closely associated with T cell dysregulation during chronic HIV-1 infection. Interestingly, IRPs in cluster 5, including ST1A1, CASP8, SIRT2, AXIN1, STAMBP, CD40, and IL7, were negatively correlated with the HIV-1 reservoir size. We also identified a combination of CDCP1, CXCL11, CST5, SLAMF1, TRANCE, and CD5, which may be useful for distinguishing immunological responders and immunological non-responders. In conclusion, the distinct inflammatory milieu is closely associated with immune restoration of T cells, and our results provide insight into immune dysregulation during chronic HIV-1 infection.

The role of pyroptosis in incomplete immune reconstitution among people living with HIV：Potential therapeutic targets

Globally, HIV infection causes significant morbidity and mortality, and is a major public health problem. Despite the fact that widespread use of antiretroviral therapy (ART) has substantially altered the natural history of HIV infection from originally being a universally lethal disease to now being a chronic medical condition for those taking appropriate treatment, approximately 10-40% of people living with HIV (PLWH) who take effective ART and maintain long-term viral suppression fail to achieve normalization of CD4 + T-cell counts. This phenomenon is referred to as incomplete immune reconstitution or immunological non-response. Although the precise mechanisms underlying this outcome have not been elucidated, recent evidence indicates that excessive pyroptosis may play a crucial role in the development of incomplete immune reconstitution. Pyroptosis is characterized by the formation of pores in the cell membrane, cell rupture, and secretion of intracellular contents and pro-inflammatory cytokines, including IL-1β and IL-18. This excessive inflammation-induced programmed cell death leads to a massive loss of CD4 + T-cells, and inflammatory consequences that may promote and sustain incomplete immune reconstitution. Herein, we review the possible pathways activated in HIV infection by inflammasomes that act as switches of pyroptosis, and the role of pyroptosis in HIV, as well as the relevance of CD4 + T-cells in incomplete immune reconstitution. We also highlight the possible mechanisms of pyroptosis involved in incomplete immune reconstitution, thus paving the way for the development of potential targets for the treatment of incomplete immune reconstitution.

Prevalence of and prognosis for poor immunological recovery by virally suppressed and aged HIV-infected patients

Background

Antiretroviral therapy (ART) prolongs lifespan and decreases mortality of HIV infected patients. However, many patients do not achieve optimal immune reconstitution. The influence of non-optimal immune recovery on non-AIDS related diseases is not well defined in aged HIV-infected patients receiving ART.

Methods

A retrospective study was conducted at Tianjin Second People's Hospital, China to evaluate the association of an inadequate immunological response and non-AIDS diseases in HIV infected patients ≥60 years of age and virally suppressed for at least 2 years by ART.

Results

The study included patients (n = 666) who initiated ART between August 2009 and December 2020. The prevalence of patients with an inadequate immunological response was 29.6%. The percentage of non-AIDS diseases such as hypertension, cardiovascular disease (CVD), diabetes, tumor, and chronic kidney disease (CKD) was 32.9, 9.9, 31, 4.1, and 13%, respectively. In addition to baseline CD4+ T cell counts, CVD and tumor were associated with poor immune reconstitution in aged Chinese HIV-1 infected patients. The adjusted odds ratios (95% confidence interval) were AOR 2.45 (95% CI: 1.22-4.93) and 3.06 (95% CI: 1.09-8.56, p = 0.03). Inadequate immunological response was associated with greater mortality (AOR: 2.83, 95% CI: 1.42-5.67, p = 0.003) in this cohort.

Conclusion

These results tend to demonstrate appropriate drug selection at ART initiation and prevention of non-AIDS complications during ART decreased mortality of and an inadequate immunological response in aged HIV infected patients.

Pillars of long-term antiretroviral therapy success

BACKGROUND

Meeting the challenge of antiretroviral therapy (ART) whose efficacy can last a lifetime requires continuous updating of the virological, pharmacological, and quality of life outcomes to be pursued and a continuous review of literature data on the efficacy and tolerability of new drugs and therapeutic strategies.

METHODS

With the aim of identifying open questions and answers about the current controversies in modern ART, we adapted the Design Thinking methodology to the needs of the design phase of a scientific article, involving a team of experts in HIV care.

RESULTS

Five main pillars of treatment success were discussed: sustained virologic suppression over time; immunological recovery; pharmacological attributes; long-term tolerability and safety of ART; and people's satisfaction and quality of life. The definition of the outcomes to be achieved in each thematic area and the tools to achieve them were reviewed and discussed.

CONCLUSIONS

Long-term treatment success should be intended as a combination of HIV-RNA suppression, immune recovery, and high quality of life. To achieve this, the regimen should be well-tolerated, with high potency, genetic barrier, and forgiveness, and should be tailored by a person-centered perspective, based on individual needs, preferences, and therapeutic history.

An Immunological Non-responder Human Immunodeficiency Virus/Hepatitis C Virus Coinfected Patient: Considerations About a Clinical Case

Human immunodeficiency virus (HIV) and hepatitis C virus (HCV) infections are two chronic viral infections that share the same mode of transmission, making HIV/HCV coinfection frequent. Highly active antiretroviral therapy (HAART) was a turning point in HIV treatment and has been shown to successfully restore immune function and reduce the frequency of opportunistic infections. Despite a virological response to HAART, a proportion of patients fail to achieve substantial immune recovery, as measured by peripheral CD4 cell counts. Herein, we present the case of a patient with HIV/HCV coinfection who did not achieve successful immune function restoration despite HIV suppression and HCV treatment. Our goal is to promote discussion. Despite considerable advances in the understanding of the impact of HCV on HIV disease progression, there are many individual variables that influence a patient's immune function. In addition, we consider hypogammaglobulinemia as a possible contributor. Further understanding and improvement of immune reconstitution in patients infected with HIV remain an important field of scientific research.

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.

Metabolism-dependent ferroptosis promotes mitochondrial dysfunction and inflammation in CD4+ T lymphocytes in HIV-infected immune non-responders

BACKGROUND

HIV immune non-responders (INRs) are described as a failure to reestablish a pool of CD4⁺ T lymphocytes (CD4 cells) after antiretroviral therapy (ART), which is related to poor clinical results. Ferroptosis is a newly discovered form of cell death characterised by iron-dependent lipid peroxidation and the accumulation of reactive oxygen species (ROS). The mechanism of unrecoverable CD4 cells in INRs and whether ferroptosis plays a role are not fully understood.

METHODS

Ninety-two people living with HIV (PLHIVs) who experienced four-year ART with sustained viral suppression, including 27 INRs, 34 partial responders (PRs), and 31 complete responders (CRs); and 26 uninfected control participants (UCs) were analysed for 16 immune parameters with flow cytometry. Then plasma lipid, iron and oxidation, and antioxidant indicators were detected by ELISA, and CD4 cells were sorted out and visualised under transmission electron microscopy. Finally, ferroptosis inhibitors were added, and alterations in CD4 cell phenotype and function were observed.

FINDINGS

We found decreased recent thymic emigrants (RTE), over-activation and over-proliferation phenotypes, diminished killing function, decreased IL-7R and more severe inflammation; increased lipid peroxidation in the mitochondria and disruptions of the mitochondrial structure, showing typical features of ferroptosis in CD4 cells in INRs. Additionally, ferroptosis inhibitors could reduce inflammation and repair mitochondrial damage. Meanwhile, ELISA results showed increased plasma free fatty acids (FFA) and an imbalance of oxidative and antioxidant systems in INRs. Flow cytometry results displayed alterations of both transferrin receptor (CD71) and lipid transporter (CD36) expressions on the surface of CD4 cells. Mechanistically, there was a stronger correlation between CD36 expression and mitochondrial lipid peroxidation production, ferroptosis makers, and inflammation indicators; while amino acid transporter (CD98) was more related to killing functions; and CD71 was more closely related to activation status in CD4 cells.

INTERPRETATION

Cellular metabolism was closely correlated with its diverse functions in INRs. Ferroptosis was observed in CD4 cells of INRs, and inhibiting ferroptosis through modulating mitochondrial disorders and inflammation may offer an alternative immunological strategy for reinvigorating CD4 cells in INRs.

FUNDING

This research was supported by the 13th Five-year Plan, Ministry of Science and Technology of China (2018ZX10302-102), Beijing Municipal Administration of Hospitals' Ascent Plan (DFL20191802), and Beijing Municipal Administration of Hospitals Clinical Medicine Development of Special Funding Support (ZYLX202126).

Comparative Transcriptional Analysis Identified Characteristic Genes and Patterns in HIV-Infected Immunological Non-Responders

Purpose

The incomplete immune reconstitution is a complex phenomenon among human immunodeficiency virus (HIV)-infected patients despite the fact that they have achieved persistent viral suppression under the combined antiretroviral therapy. This study aims to screen and verify the immunological characteristics and underlying mechanisms of immunological non-responders (INRs).

Methods

The RNA-seq and the differentially expressed genes (DEGs) analysis were used to explore potential characteristics among INRs. Gene Ontology (GO) enrichment, ingenuity pathway analysis (IPA) analysis, Gene set enrichment analysis (GSEA) analysis, and the weighted gene co-expression network analysis (WGCNA) were used to explore the potential mechanism. The transcriptional meta-analysis was used to analyze the external efficiency.

Results

The RNA-seq identified 316 DEGs among INRs. The interferon signaling pathway was enriched via GO and IPA analysis among DEGs. The combined GSEA and WGCNA analysis confirmed that the IFN response was more correlated with INR. Furthermore, IFI27 (IFN-α Inducible Protein 27, also known as ISG12) was chosen based on combined DEG analysis, WGCNA analysis, and the transcriptional meta-analysis conducted on other published datasets about INRs. The expression of IFI27 was significantly negatively correlated with the CD4+ T-cell counts of PLWH, and the predictive efficiency of IFI27 level in distinguishing PLWH with poor immune recovery was also with significant power (AUC = 0.848).

Conclusion

The enhanced expression of IFI27 and the IFN response pathway are among the important immunological characteristics of INRs and exhibited promising efficiency as biomarkers for CD4⁺ T-cell recovery.

Treg Cell Evaluation in Patients with Acquired Immune Deficiency Syndrome with Poor Immune Reconstitution and Human Immunodeficiency Virus-Infected Treg Cell Prevention by Polymeric Nanoparticle Drug Delivery System

To better deliver antiretroviral drugs for treating patients with acquired immune deficiency syndrome (AIDS) with poor immune reconstitution, a novel nanopole capsule was designed in this study. Forty-eight patients with AIDS with poor immune reconstitution were chosen as subjects to test their immune state. CD4⁺ T and Regulatory T cells (Treg) infected with HIV were cultured to test polyethyleneimine (PEI) and polychitosan (PC) drug delivery system efficiency. The infiltration efficiency test was performed to study the drug delivery efficiency of the delivery systems, and the cell numbers of CD4⁺ T and Treg cells infected with HIV were calculated to evaluate the therapeutic effect. The results showed that patients with AIDS with poor immune reconstitution had lower CD4⁺ T cell count and higher Treg cell count. Furthermore, the infiltration efficiency of the PC drug delivery system was higher than that of the PEI drug delivery system, and the therapy efficiency of antiretroviral drugs was greatly improved in the PC group. Additionally, the improvement of CD4⁺ T and Treg cells damaged by HIV was greater in the PC group. Sequentially, the PC system can better deliver and release loaded antiretroviral drugs and may be a better choice for treating patients with AIDS with poor immune reconstitution in the future.

HIV-Sheltering Platelets From Immunological Non-Responders Induce a Dysfunctional Glycolytic CD4+ T-Cell Profile

Immunological non-responders (InRs) are HIV-infected individuals in whom the administration of combination antiretroviral therapy (cART), although successful in suppressing viral replication, cannot properly reconstitute patient circulating CD4⁺ T-cell number to immunocompetent levels. The causes for this immunological failure remain elusive, and no therapeutic strategy is available to restore a proper CD4⁺ T-cell immune response in these individuals. We have recently demonstrated that platelets harboring infectious HIV are a hallmark of InR, and we now report on a causal connection between HIV-containing platelets and T-cell dysfunctions. We show here that in vivo, platelet–T-cell conjugates are more frequent among CD4⁺ T cells in InRs displaying HIV-containing platelets (<350 CD4⁺ T cells/μl blood for >1 year) as compared with healthy donors or immunological responders (IRs; >350 CD4⁺ T cells/μl). This contact between platelet containing HIV and T cell in the conjugates is not infectious for CD4⁺ T cells, as coculture of platelets from InRs containing HIV with healthy donor CD4⁺ T cells fails to propagate infection to CD4⁺ T cells. In contrast, when macrophages are the target of platelets containing HIV from InRs, macrophages become infected. Differential transcriptomic analyses comparing InR and IR CD4⁺ T cells reveal an upregulation of genes involved in both aerobic and anaerobic glycolysis in CD4⁺ T cells from InR vs. IR individuals. Accordingly, InR platelets containing HIV induce a dysfunctional increase in glycolysis-mediated energy production in CD4⁺ T cells as compared with T cells cocultured with IR platelets devoid of virus. In contrast, macrophage metabolism is not affected by platelet contact. Altogether, this brief report demonstrates a direct causal link between presence of HIV in platelets and T-cell dysfunctions typical of InR, contributing to devise a platelet-targeted therapy for improving immune reconstitution in these individuals.

Treating older patients with AIDS using Traditional Chinese Medicine Combined with Conventional Western Medicine in China

Acquired immunodeficiency syndrome (AIDS) is a chronic and incurable disease. People with human immunodeficiency virus (HIV) require lifelong care. Traditional Chinese Medicine (TCM) has played an important role in AIDS treatment since the year 2004. TCM offers many advantages including a rich resource of Chinese herbs, lower cost and fewer side effects. In addition to the widespread use of antiviral therapy, TCM offers unique humanistic care and holistic adjustment of the body system. To date, more and more patients are benefiting from TCM not only in China. In this article, we describe the feasibility of treating AIDS with TCM.

HIV-Related Immune Activation and Inflammation: Current Understanding and Strategies

Although antiretroviral therapy effectively controls human immunodeficiency virus (HIV) replication, a residual chronic immune activation/inflammation persists throughout the disease. This aberrant immune activation and inflammation are considered an accelerator of non-AIDS-related events and one of the driving forces of CD4⁺ T cell depletion. Unfortunately, HIV-associated immune activation is driven by various factors, while the mechanism of excessive inflammation has not been formally clarified. To date, several clinical interventions or treatment candidates undergoing clinical trials have been proposed to combat this systemic immune activation/inflammation. However, these strategies revealed limited results, or their nonspecific anti-inflammatory properties are similar to previous interventions. Here, we reviewed recent learnings of immune activation and persisting inflammation associated with HIV infection, as well as the current directions to overcome it. Of note, a more profound understanding of the specific mechanisms for aberrant inflammation is still imperative for identifying an effective clinical intervention strategy.

Polymorphisms in TNF-α/TNFR1 pathway genes are associated with CD4+ T cells recovery in HIV-1-infected individuals on antiretroviral therapy

BACKGROUND

Antiretroviral therapy (ART) is an important hallmark of HIV-1 treatment, enabling viral load suppression to undetectable levels and CD4+ T cells recovery. However, some individuals do not recover the CD4+ T cell count to normal levels, despite viral suppression. We hypothesize that variation in genes involved in extrinsic apoptosis pathways may influence interindividual immune recovery during ART.

METHODS

We assessed clinic-epidemiological variables, and the allelic/genotypic distribution of functional single nucleotide polymorphisms in genes involved in extrinsic apoptosis pathways (TNFRSF1A: rs1800692, rs767455; TNFAIP3: rs2270926; NFKBIA: rs8904; TNF-α: rs1800629) and their relationship with immune recovery in ART treated (one year) HIV-1-infected individuals. We enrolled 155 HIV-1 infected individuals, 102 showing immunological success and 53 with immunological failure.

RESULTS

Through univariate analysis, we observed that the male sex (60.4%, p=0.002) showed higher median of age at treatment onset (34.8 years, p=0.034) and higher time until virological suppression (6 months, p=0.035), both risk factors for immune failure. Survival analysis revealed that individuals who started ART treatment with T CD4+ cells count <200 cells/mm3 took a longer time to immunological recovery (median time = 27 months, p=0.029). ART containing zidovudine (AZT) also was associated with immune recovery in univariate e multivariate analysis. Variants in TNFRSF1A (rs767455: T, TT; rs1800692-rs767455: T-T combination) and NFKBIA (rs8904: A) genes associated with immune failure, while NFKBIA (rs8904: GA) and TNF-α (rs1800629: GA), with CD4+ T cells recovery.

CONCLUSIONS

Clinic-epidemiological and variants in genes involved in extrinsic apoptosis pathways might influence the CD4+ T cells immune recovery.

Dynamics of HIV reservoir decay and naïve CD4 T-cell recovery between immune non-responders and complete responders on long-term antiretroviral treatment

BACKGROUND

The dynamics of viral reservoir decay and naïve CD4 T-cell recovery between immunological non-responders (INR) and complete responders (CR) during long-term antiretroviral treatment (ART) are not fully known.

METHODS

Twenty-eight chronic HIV-infected individuals on 5-year ART were divided into two groups: INR (CD4 counts ≤350 cells/μL, n = 13) and CR (CD4 counts ≥500 cells/μL, n = 15). The levels of HIV DNA and cell-associated HIV RNA (CA-RNA), CD4 counts, naïve CD4 counts and their correlations were analyzed at baseline, years 1, 3 and 5 of ART between the two groups. Expression of PD-1 on CD4 T-cells was quantified by flow cytometry. Linear mixed effect models were used to estimate the change procession in repeated measurements over 5 years. Slopes of the above-mentioned indicators were estimated using participant-specific linear regressions, respectively.

RESULTS

INR maintained higher levels of HIV DNA and CA-RNA with higher percentages of PD-1⁺CD4 T-cells compared with CR during 5-year ART, concurrent with lower naïve CD4 T-cells. However, the rates of HIV DNA and CA-RNA decay in INR were not different from that in CR over time, and INR had higher rates of naïve CD4 T-cell percentage recovery. The baseline levels of HIV DNA were positively associated with the 5-year levels of HIV DNA, but negatively associated with the 5-year naïve CD4 counts.

CONCLUSIONS

INR maintained significantly higher viral reservoir and lower naïve CD4 T-cells compared with CR during 5-year ART, however, the rates of reservoir decay and naïve CD4 T-cell percentage growth within INR were not lower than that in CR over time.

Differences in pyroptosis of recent thymic emigrants CD4+ T Lymphocytes in ART-treated HIV-positive patients are influenced by sex

Pyroptosis cell death in recent thymus emigrants (RTE) CD4+ T lymphocytes plays an important role on HIV-1 infection as a cause of CD4+ T cell depletion, being influenced by several factors, among them, the sex. Thus, the aim of this study was evaluated pyroptosis levels in RTE CD4+ T lymphocytes of individuals under antiretroviral therapy (ART) stratified by sex. Thirty-seven ART-treated HIV-positive patients (22 females and 15 males) and 12 (seven females and five males) clinically health subjects were recruited. Analysis by flow-cytometry of RTE CD4+ cells (CD4+ CD31+ /fluorescent-labeled inhibitors of caspases-Caspase-1+) were performed. Clinical and sociodemographic aspects were also evaluated from medical records. We observed statistically higher levels of pyroptosis RTE CD4+ T cells in male individuals (69.3%) compared with female group (39.1%) (P = 0.0356). Pre- and post-treatment CD4+ T cell counts were also higher in women than men (P = 0.004 and P = 0.012, respectively). Our data provides important evidence of the sex as a potential predictor of immunological reconstitution in ART-treated individuals.

Thymic Involution and Altered Naive CD4 T Cell Homeostasis in Neuromyelitis Optica Spectrum Disorder

Circulating T helper cells with a type 17-polarized phenotype (TH17) and expansion of aquaporin-4 (AQP4)-specific T cells are frequently observed in patients with neuromyelitis optica spectrum disorder (NMOSD). However, naive T cell populations, which give rise to T helper cells, and the primary site of T cell maturation, namely the thymus, have not been studied in these patients. Here, we report the alterations of naive CD4 T cell homeostasis and the changes in thymic characteristics in NMOSD patients. Flow cytometry was performed to investigate the naive CD4⁺ T cell subpopulations in 44 NMOSD patients and 21 healthy controls (HC). On immunological evaluation, NMOSD patients exhibited increased counts of CD31^+thymic naive CD4⁺ T cells and CD31^-cental naive CD4⁺ T cells along with significantly higher fraction and absolute counts of peripheral blood CD45RA⁺ CD62L⁺ naive CD4⁺ T cells. Chest computed tomography (CT) images of 60 NMOSD patients and 65 HCs were retrospectively reviewed to characterize the thymus in NMOSD. Thymus gland of NMOSD patients exhibited unique morphological characteristics with respect to size, shape, and density. NMOSD patients showed exacerbated age-dependent thymus involution than HC, which showed a significant association with disease duration. These findings broaden our understanding of the immunological mechanisms that drive severe disease in NMOSD.

Platelets from HIV-infected individuals on antiretroviral drug therapy with poor CD4+ T cell recovery can harbor replication-competent HIV despite viral suppression

In addition to hemostasis, human platelets have several immune functions and interact with infectious pathogens including HIV in vitro. Here, we report that platelets from HIV-infected individuals on combined antiretroviral drug therapy (ART) with low blood CD4+ T cell counts (<350 cells/μl) contained replication-competent HIV despite viral suppression. In vitro, human platelets harboring HIV propagated the virus to macrophages, a process that could be prevented with the biologic abciximab, an anti–integrin αIIb/β3 Fab. Furthermore, in our cohort, 88% of HIV-infected individuals on ART with viral suppression and with platelets containing HIV were poor immunological responders with CD4+ T cell counts remaining below <350 cells/μl for more than one year. Our study suggests that platelets may be transient carriers of HIV and may provide an alternative pathway for HIV dissemination in HIV-infected individuals on ART with viral suppression and poor CD4+ T cell recovery.

Pregnancy Gestation Impacts on HIV-1-Specific Granzyme B Response and Central Memory CD4 T Cells

Pregnancy induces alterations in peripheral T-cell populations with both changes in subset frequencies and anti-viral responses found to alter with gestation. In HIV-1 positive women anti-HIV-1 responses are associated with transmission risk, however detailed investigation into both HIV-1-specific memory responses associated with HIV-1 control and T-cell subset changes during pregnancy have not been undertaken. In this study we aimed to define pregnancy and gestation related changes to HIV-1-specific responses and T-cell phenotype in ART treated HIV-1 positive pregnant women. Eleven non-pregnant and 24 pregnant HIV-1 positive women were recruited, peripheral blood samples taken, fresh cells isolated, and compared using ELISpot assays and flow cytometry analysis. Clinical data were collected as part of standard care, and non-parametric statistics used. Alterations in induced IFNγ, IL-2, IL-10, and granzyme B secretion by peripheral blood mononuclear cells in response to HIV-1 Gag and Nef peptide pools and changes in T-cell subsets between pregnant and non-pregnant women were assessed, with data correlated with participant clinical parameters and longitudinal analysis performed. Cross-sectional comparison identified decreased IL-10 Nef response in HIV-1 positive pregnant women compared to non-pregnant, while correlations exhibited reversed Gag and Nef cytokine and protease response associations between groups. Longitudinal analysis of pregnant participants demonstrated transient increases in Gag granzyme B response and in the central memory CD4 T-cell subset frequency during their second trimester, with a decrease in CD4 effector memory T cells from their second to third trimester. Gag and Nef HIV-1-specific responses diverge with pregnancy time-point, coinciding with relevant T-cell phenotype, and gestation associated immunological adaptations. Decreased IL-10 Nef and both increased granzyme B Gag response and central memory CD4 T cells implies that amplified antigen production is occurring, which suggests a period of compromised HIV-1 control in pregnancy.