Elevated Level of CD4+ T Cell Immune Activation in Acutely HIV-1-Infected Stage Associates With Increased IL-2 Production and Cycling Expression, and Subsequent CD4+ T Cell Preservation

Comprehensive transcriptomic analyses identify the immunosuppressive effects of LLDT-8 in ART-treated SIV-infected rhesus macaques

BACKGROUND

Chronic immune activation plays a significant role in the pathogenesis and disease progression of human immunodeficiency virus (HIV), and the existing interventions to address this issue are limited. In a phase II clinical trial, (5R)-5-hydroxytriptolide (LLDT-8) demonstrated promising potential in enhancing CD4+ T cell recovery. However, the therapeutical effects of LLDT-8 remained to be systemic explored.

METHODS

To assess the treatment effects of LLDT-8, we conducted flow cytometry and RNA-seq analyses on eight Chinese rhesus monkeys infected with simian immunodeficiency virus (SIV). Additionally, we performed comprehensive transcriptomic analyses, including cross-sectional and longitudinal differentially expressed gene (DEG) analysis, gene set enrichment analysis (GSEA), weighted gene co-expression network analysis (WGCNA), and deconvolution analysis using peripheral blood mononuclear cell (PBMC) samples from 14-time points. These findings were further validated with RNA-seq analysis on patients who received LLDT-8 treatment, along with in vitro cellular experiments using human PBMCs.

RESULTS

Flow cytometry analysis revealed that LLDT-8 treatment significantly reduced the percentage of HLA-DR+CD38+CD8+ T cells in SIV-infected rhesus monkeys (P < 0.001). The cross-sectional and longitudinal analysis identified 2531 and 1809 DEGs, respectively. GSEA analysis indicated that LLDT-8 treatment led to significant downregulation of proliferation-related pathways, such as E2F targets, G2M checkpoint, and mitotic spindle pathways. WGCNA analysis identified two modules and 202 hub genes associated with CD8 activation levels. Deconvolution analysis showed a significant decrease in the proportion of CD8+ T cells and activated CD4+ T cells during LLDT-8 treatment. Gene ontology results demonstrated that the common DEGs between LLDT-8-treated patients and rhesus monkeys were primarily enriched in cell activation and cell cycle progression. Furthermore, in vitro cellular experiments validated the consistent impact of LLDT-8 in inhibiting proliferation, activation (HLA-DR and CD38 expression), exhaustion (PD-1 expression), and IFN-γ production in human CD4+ and CD8+ T cells.

CONCLUSION

LLDT-8 exhibited notable efficacy in alleviating immune activation in both an in vivo animal model and in vitro human cell experiments. These findings suggest that LLDT-8 may hold potential as a drug for managing systemic immune activation associated with SIV/HIV infection, warranting further prospective clinical exploration.

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

Background

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

Methods

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

Results

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

Conclusion

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

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

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

Characteristics of CD8+ Stem Cell-Like Memory T Cell Subset in Chronic Hepatitis C Virus Infection

The dysfunction of memory CD8⁺ T cell cannot be reverted by successful clearance of hepatitis C virus (HCV) after direct-acting antivirals (DAAs) therapy, increasing the risk of reinfection with HCV. Stem cell-like memory T cells (Tscm) with superior properties of long-lasting, self-renewing, and multipotency contribute to the maintenance of immune function. We investigated the impact of HCV infection on CD8⁺ Tscm, and their possible role in disease progression, by using DAA-naive HCV-infected and human immunodeficiency virus (HIV)/HCV-coinfected cohorts. The distribution of memory CD8⁺ T cell subsets and the level of T cell immune activation were determined by flow cytometry. Associations between CD8⁺ Tscm and other memory T cell subsets, HCV viral load, as well as the level of T cell immune activation were analyzed. We observed that the proportion of CD8⁺ Tscm increased in both HCV and HIV/HCV individuals. The proportion of CD8⁺ Tscm had positive and negative correlation with CD8⁺ Tcm (central memory T cells) and CD8⁺ Tem (effector memory T cell), respectively, representing the contribution of CD8⁺ Tscm in T cell homeostasis. In addition, higher frequency of CD8⁺ Tscm indicated lower HCV viral load and less T cell immune activation in HCV infection, which suggested that CD8⁺ Tscm is likely associated with effective control of HCV replication for protective immunity. Considering the characteristics of Tscm, our current findings provide implications for Tscm-based vaccine design and immunotherapy development to achieve HCV elimination.

Study on the Mechanism of Improving HIV/AIDS Immune Function with Jian Aikang Concentrated Pill Based on Network Pharmacology Combined with Experimental Validation

Purpose

This study was the first to screen the active compounds of Jian Aikang Concentrated Pill (JAKCP) with network pharmacology, predict its potential targets, screen the signaling pathways, and combine with cellular experimental validation to explore the potential mechanism of JAKCP for the treatment of acquired immunodeficiency syndrome (AIDS).

Methods

The main compounds and targets of Chinese herbs in JAKCP were identified by TCMSP; the targets of AIDS were collected from Genecards, Online Mendelian Inheritance in Man (OMIM), Disgenet, Therapeutic Target Database (TTD) and Drugbank; the network of “Chinese herbs-active compounds-targets” for JAKCP was constructed by Cytoscape, and protein–protein interaction (PPI) network was constructed using STRING to generate the intersection targets, Metascape was conducted to analyze the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG), and the network of “main active compounds-core targets-pathways” was constructed by Cytoscape. Finally, the effect of JAKCP on the survival rate of HIV pseudovirus-infected MT-4 cells was investigated by CCK-8 assay, and the predicted targets were verified by ELISA, qPCR and Western blot.

Results

A total of 147 active compounds of JAKCP were screened covering 351 targets and 416 AIDS disease targets were obtained, besides 140 intersection targets and 321 KEGG pathways were collected. Ultimately, quercetin, kaempferol, stigmasterol, beta-sitosterol, epigallocatechin gallate were identified as the important compounds, the core targets are HSP90AA1, IL-10, IL-6, TNF, IL-1β, TP53, and IL-1ɑ, and the biological pathways and processes mainly include T cell activation, regulation of DNA-binding transcription factor activity and apoptotic signaling pathway. Experiments on the targets of “T cell activation” demonstrated that JAKCP promotes the survival of HIV pseudovirus-infected MT-4 cells. Also, JAKCP down-regulated mRNA and protein levels of IL-1ɑ, IL-1β, and IL-6 while up-regulated mRNA and protein levels of IL-2, IL-6ST, and IL-10 in vitro.

Conclusion

JAKCP exerted regulatory immune functions through multi-component, multi-target and multi-pathway, thereby providing novel ideas and clues for the treatment of AIDS.

New world Leishmania spp. infection in people living with HIV: Concerns about relapses and secondary prophylaxis

Coinfection with the human immunodeficiency virus (HIV) and Leishmania impairs immune responses, increases treatment failure and relapse rates in patients with American tegumentary leishmaniasis (ATL), as well as visceral leishmaniasis (VL). There is insufficient data on the treatment, relapse, and secondary prophylaxis in patients coinfected with HIV/Leishmania in Brazil. This study investigated patients with HIV/ATL and HIV/VL to describe the outcome of leishmaniasis in patients assisted at a referral hospital of Brazilian midwestern region. Patients with HIV/ATL (n = 21) mainly presented cutaneous diseases (76.2%) with an overall relapse rate of 28.57% after treatment, whereas HIV/VL (n = 28) patients accounted for 17.5% of the cases. The counts of CD4⁺ T cells and CD8⁺ T cells and the CD4⁺/CD8⁺ cell ratios at diagnosis or relapses were not significantly different between relapsing and non-relapsing patients. Patients with HIV/ATL or HIV/VL showed high levels of activation markers in CD4⁺ and CD8⁺ T cells. The regular use of highly active antiretroviral therapy (HAART) and viral load at the time of diagnosis did not influence the relapse rates. Relapses occurred in 36.4% (4/11) of the patients with HIV/VL receiving secondary prophylaxis and in 5.9% (1/17) of the patients who did not receive secondary prophylaxis (p = 0.06). These data are relevant for the therapeutic management of the patients coinfected with HIV/Leishmania.

Tryptophan potentiates CD8+ T cells against cancer cells by TRIP12 tryptophanylation and surface PD-1 downregulation

BACKGROUND

Tryptophan catabolites suppress immunity. Therefore, blocking tryptophan catabolism with indoleamine 2,3-dioxygenase (IDO) inhibitors is pursued as an anticancer strategy.

METHODS

The intracellular level of tryptophan and kynurenine was detected by mass spectrum analysis. The effect of tryptophan and IDO inhibitors on cell surface programmed cell death protein 1 (PD-1) level were measured by flow cytometry. A set of biochemical analyses were used to figure out the underlying mechanism. In vitro co-culture system, syngeneic mouse models, immunofluorescent staining, and flow cytometry analysis were employed to investigate the role of tryptophan and IDO inhibitor in regulating the cytotoxicity of CD8⁺ T cells.

RESULTS

Here, we reported that IDO inhibitors activated CD8⁺ T cells also by accumulating tryptophan that downregulated PD-1. Tryptophan and IDO inhibitors administration, both increased intracellular tryptophan, and tryptophanyl-tRNA synthetase (WARS) overexpression decreased Jurkat and mice CD8⁺ T cell surface PD-1. Mechanistically, WARS tryptophanylated lysine 1136 of and activated E3 ligase TRIP12 to degrade NFATc1, a PD-1 transcription activator. SIRT1 de-tryptophanylated TRIP12 and reversed the effects of tryptophan and WARS on PD-1. Tryptophan or IDO inhibitors potentiated CD8⁺ T cells to induce apoptosis of co-cultured cancer cells, increased cancer-infiltrating CD8⁺ T cells and slowed down tumor growth of lung cancer in mice.

CONCLUSIONS

Our results revealed the immune-activating efficacy of tryptophan, and suggested tryptophan supplemental may benefit IDO inhibitors and PD-1 blockade during anticancer treatments.

Evolution and Diversity of Immune Responses during Acute HIV Infection

Understanding the earliest immune responses following HIV infection is critical to inform future vaccines and therapeutics. Here, we review recent prospective human studies in at-risk populations that have provided insight into immune responses during acute infection, including additional relevant data from non-human primate (NHP) studies. We discuss the timing, nature, and function of the diverse immune responses induced, the onset of immune dysfunction, and the effects of early anti-retroviral therapy administration. Treatment at onset of viremia mitigates peripheral T and B cell dysfunction, limits seroconversion, and enhances cellular antiviral immunity despite persistence of infection in lymphoid tissues. We highlight pertinent areas for future investigation, and how application of high-throughput technologies, alongside targeted NHP studies, may elucidate immune response features to target in novel preventions and cures.

Modulating oxidative stress counteracts specific antigen-induced regulatory T-cell apoptosis in mice

Treg are known to have a central role in orchestrating immune responses, but less is known about the destiny of Treg after being activated by specific Ags. This study aimed to investigate the role of superoxide dismutase, an active molecule in the regulation of oxidative stress in the body, in the prevention of Treg apoptosis induced by specific Ags. Ag-specific Tregs were isolated from the DO11.10 mouse intestine. A food allergy mouse model was developed with ovalbumin as the specific Ag and here, we observed that exposure to specific Ag induced Treg apoptosis through converting the precursor of TGF-β to its mature form inside the Tregs. Oxidative stress was induced in Tregs upon exposure to specific Ags, in which Smad3 bound the latency-associated peptide to induce its degradation, converting the TGF-β precursor to its mature form, TGF-β. Suppressing oxidative stress in Tregs alleviated the specific Ag-induced Treg apoptosis in in vitro experiments and suppressed experimental food allergy by preventing the specific Ag-induced Treg apoptosis in the intestine. In conclusion, exposure to specific Ags induces Treg apoptosis and it can be prevented by upregulating superoxide dismutase or suppressing reactive oxidative species in Tregs.

Upregulation of IL-32 Isoforms in Virologically Suppressed HIV-Infected Individuals: Potential Role in Persistent Inflammation and Transcription From Stable HIV-1 Reservoirs

BACKGROUND

Human IL-32 is a polyfunctional cytokine that was initially reported to inhibit HIV-1 infection. However, recent data suggest that IL-32 may enhance HIV-1 replication by activating the HIV-1 primary targets, CD4 T-cells. Indeed, IL-32 is expressed in multiple isoforms, some of which are proinflammatory, whereas others are anti-inflammatory.

SETTING AND METHODS

Here, we aimed to determine the relative expression of IL-32 isoforms and to test their inflammatory nature and potential to induce HIV-1 production in latently infected cells from virologically suppressed HIV-infected individuals. IL-32 and other cytokines were quantified from plasma and supernatant of CD4 T-cells by ELISA. Transcripts of IL-32 isoforms were quantified by qRT-PCR in peripheral blood mononuclear cells. The impact of recombinant human IL-32 isoforms on HIV-1 transcription was assessed in CD4 T-cells from HIV-1cART individuals by qRT-PCR.

RESULTS

All IL-32 isoforms were significantly upregulated in HIV-1cART compared to HIV individuals with IL-32β representing the dominantly expressed isoform, mainly in T-cells and NK-cells. At the functional level, although IL-32γ induced typical proinflammatory cytokines (IL-6 and IFN-γ) in TCR-activated CD4 T-cells, IL-32α showed an anti-inflammatory profile by inducing IL-10 but not IL-6 or IFN-γ. However, IL-32β showed a dual phenotype by inducing both pro- and anti-inflammatory cytokines. Interestingly, consistent with its highly pro-inflammatory nature, IL-32γ, but not IL-32α or IL-32β, induced HIV-1 production in latently infected CD4 T-cells isolated from combined antiretroviral therapy-treated individuals.

CONCLUSIONS

Our data report on the differential expression of IL-32 isoforms and highlight the potential role of IL-32, particularly the γ isoform, in fueling persistent inflammation and transcription of viral reservoir in HIV-1 infection.

Cytokine levels of interleukin-2 and 7 amongst antiretroviral therapy success and failure HIV patients attending the University Teaching Hospital, Yaoundé, Cameroon

BACKGROUND

Immune reconstitution complications (IRC) are a major problem faced by HIV treated patients world wide. Interleukin (IL)-2 and IL-7 play vital roles in peripheral T-cell homeostasis. Our study objective was to measure and compare the blood plasma levels of IL-2 and IL-7 amongst antiretroviral therapy (ART) patients attending the Yaoundé University Teaching Hospital, Cameroon.

METHODS

We performed a cross-sectional study with 296 HIV positive patients enrolled between July 2017 and May 2018 at the Yaoundé University Teaching Hospital. IL-2, IL-7, T-cell profile counts and plasma viral load were measured on whole blood specimens. Data obtained were analyzed using Graph Pad Prism 5.0 and Epi info 7.0. Software.

RESULTS

IL-2 and IL-7 plasma concentration levels were higher in patients with ART failure compared to ART success, with a mean SD of 19.4±8 and 17.1±6 pg /ml, 35.26±11 and 21.5±5 pg/ml, with p < 0.001 and < 0.001. There was a direct and significant correlation between viral load, IL-2 and IL-7 with p values = 0.028, and 0.020, respectively. There was an association between IL-2, IL-7 and viral load in relation to the duration on treatment (DT), with p values = 0.003 (R²=0.041, CI= 0.069 - 0.34) ,0.017 (R²=0.027, CI=-0.30 - 0.030), and 0.001 (R²=0.048, CI=-0.047-0.76).

CONCLUSION

Considering that limited surrogate markers are availiable for monitoring immune reconstitution and high associated mortality rates, IL-2 and IL-7 could be a good immunological predictor for ART failure and success in HIV infected individuals.

HLA-DR Class II expression on myeloid and lymphoid cells in relation to HLA-DRB1 as a genetic risk factor for visceral leishmaniasis

Genetic variation at HLA-DRB1 is a risk factor for visceral leishmaniasis (VL) caused by Leishmania donovani. The single nucleotide polymorphism rs9271252 upstream of the DRB1 gene provides a perfect tag for protective versus risk HLA-DRB1 four-digit alleles. In addition to the traditional role of the membrane-distal region of HLA class II molecules in antigen presentation and CD4 T-cell activation, the membrane-proximal region mediates 'non-traditional' multi-functional activation, differentiation, or death signals, including in DR-expressing T cells. To understand how HLA-DR contributes to disease pathogenesis, we examined expression at the protein level in circulating myeloid (CD14⁺ , CD16⁺ ) and lymphoid (CD4⁺ , CD8⁺ , CD19⁺ ) cells of VL patients (pre- and post-treatment) compared with endemic healthy controls (EHC). Although DR expression is reduced in circulating myeloid cells in active disease relative to EHC and post-treatment groups, expression is enhanced on CD4⁺  DR⁺ and CD8⁺  DR⁺ T cells consistent with T-cell activation. Cells of all myeloid and lymphoid populations from active cases were refractory to stimulation of DR expression with interferon-γ (IFN-γ). In contrast, all populations except CD19⁺ B cells from healthy blood bank controls showed enhanced DR expression following IFN-γ stimulation. The rs9271252 genotype did not impact significantly on IFN-γ-activated DR expression in myeloid, B or CD8⁺ T cells, but CD4⁺ T cells from healthy individuals homozygous for the risk allele were particularly refractory to activated DR expression. Further analysis of DR expression on subsets of CD4⁺ T cells regulating VL disease could uncover additional ways in which pleiotropy at HLA DRB1 contributes to disease pathogenesis.