HLA-mismatched allogeneic adoptive immune therapy in patients with severely immunosuppressed AIDS: a multicenter, open-label, controlled, phase 2a study.

Recurrent opportunistic infections (OIs) in patients with severely immunosuppressed AIDS remain an unresolved medical challenge despite advancements in antiretroviral therapy (ART). To address this gap, we developed an HLA-mismatched allogeneic adoptive immune therapy (AAIT) specifically targeting this patient population. The safety and efficacy of this novel therapeutic approach were preliminarily confirmed in our phase 1 trial. Subsequently, a multicenter, open-label, controlled, phase 2a trial was conducted to evaluate the efficacy of AAIT in combination with ART compared with the conventional ART-only regimen. No difference in the incidence of adverse events (AEs) was observed between the two groups at the 96-week follow-up. AAIT treatment improved CD4+ T cell recovery at weeks 72 (P = 0.048) and 96 (P = 0.024) compared to the Control Group. Additionally, stratified analysis of patients in the AAIT Group showed that donor/recipient sex mismatch was significantly associated with the likelihood of patients achieving an immunological response (OR = 8.667; 95% CI, 2.010-37.377; P = 0.004). These findings suggest that AAIT serves as a promising adjunct therapy for improving the outcomes of patients with severely immunosuppressed AIDS. Further studies are needed to elucidate the immunological mechanisms underlying AAIT and identify the subpopulations that respond optimally to this therapeutic approach. This trial is registered at www.clinicaltrials.gov (NCT04098770).Trial registration: ClinicalTrials.gov identifier: NCT04098770.Trial registration: ClinicalTrials.gov identifier: NCT02651376.

Effect of SARS-CoV-2 Breakthrough Infection on HIV Reservoirs and T-Cell Immune Recovery in 3-Dose Vaccinated People Living with HIV.

People living with human immunodeficiency virus (PLWH) are a vulnerable population with a higher risk of severe coronavirus disease 2019 (COVID-19); therefore, vaccination is recommended as a priority. Data on viral reservoirs and immunologic outcomes for PLWH breakthrough infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are currently limited. In this study, we investigated the effects of SARS-CoV-2 breakthrough infection on hematological parameters, human immunodeficiency virus (HIV) reservoir size, and T-cell recovery in PLWH receiving antiretroviral therapy (ART) after SARS-CoV-2 booster vaccination. The results indicated that during breakthrough infection, booster vaccination with homologous and heterologous vaccines was safe in PLWH after receiving two doses of inactivated vaccination. The absolute CD4 counts decreased in the heterologous group, whereas the CD8 counts decreased in the homologous booster group after breakthrough infection in PLWH. Breakthrough infection increased HIV reservoirs and was associated with increased T-cell activation in PLWH who received virally suppressed ART and a 3-dose vaccination. According to our data, the breakthrough infection of SARS-CoV-2 may put PLWH at a greater risk for increased HIV reservoirs, even if these individuals were virally suppressed with ART after 3-dose SARS-CoV-2 vaccination.

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.

Implications of the accumulation of CXCR5+ NK cells in lymph nodes of HIV-1 infected patients.

BACKGROUND: B cell follicles are immune-privileged sites where intensive HIV-1 replication and latency occur, preventing a permanent cure. Recent study showed that CXCR5+ NK cells in B cell follicles can inhibit SIV replication in African green monkeys, but this has not been reported in HIV-1 infected patients. METHODS: Lymphocytes and tissue sections of lymph node were collected from 11 HIV-1 positive antiretroviral therapy (ART)-naive and 19 HIV-1 negative donors. We performed immunofluorescence and RNA-scope to detect the location of CXCR5+ NK cells and its relationship with HIV-1 RNA, and performed flow cytometry and RNA-seq to analyze the frequency, phenotypic and functional characteristics of CXCR5+ NK cells. The CXCL13 expression were detected by immunohistochemistry. FINDINGS: CXCR5+ NK cells, which accumulated in LNs from HIV-1 infected individuals, expressed high levels of activating receptors such as NKG2D and NKp44. CXCR5+ NK cells had upregulated expression of CD107a and ß-chemokines, which were partially impaired in HIV-1 infection. Importantly, the frequency of CXCR5+NK cells was inversely related to the HIV-1 viral burden in LNs. In addition, CXCL13-the ligand of CXCR5-was upregulated in HIV-1 infected individuals and positively correlated with the frequency of CXCR5+ NK cells. INTERPRETATION: During chronic HIV-1 infection, CXCR5+ NK cells accumulated in lymph node, exhibit altered immune characteristics and underlying anti-HIV-1 effect, which may be an effective target for a functional cure of HIV-1.

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.

Human umbilical cord mesenchymal stem cell transfusion in immune non-responders with AIDS: a multicenter randomized controlled trial.

We examined the safety and efficacy of human umbilical cord mesenchymal stem cell (hUC-MSC) infusion for immune non-responder (INR) patients with chronic HIV-1 infection, who represent an unmet medical need even in the era of efficient antiretroviral therapy (ART). Seventy-two INR patients with HIV were enrolled in this phase II randomized, double-blinded, multicenter, placebo-controlled, dose-determination trial (NCT01213186) from May 2013 to March 2016. They were assigned to receive high-dose (1.5 × 106/kg body weight) or low-dose (0.5 × 106/kg body weight) hUC-MSC, or placebo. Their clinical and immunological parameters were monitored during the 96-week follow-up study. We found that hUC-MSC treatment was safe and well-tolerated. Compared with baseline, there was a statistical increase in CD4+ T counts in the high-dose (P < 0.001) and low-dose (P < 0.001) groups after 48-week treatment, but no change was observed in the control group. Kaplan-Meier analysis revealed a higher cumulative probability of achieving an immunological response in the low-dose group compared with the control group (95.8% vs. 70.8%, P = 0.004). However, no significant changes in CD4/CD8+ T counts and CD4/CD8 ratios were observed among the three groups. In summary, hUC-MSC treatment is safe. However, the therapeutic efficacy of hUC-MSC treatment to improve the immune reconstitution in INR patients still needs to be further investigated in a large cohort study.

Reversal of the CD8+ T-Cell Exhaustion Induced by Chronic HIV-1 Infection Through Combined Blockade of the Adenosine and PD-1 Pathways.

Background: Targeting immune checkpoints for HIV treatment potentially provides a double benefit resulting from the ability to restore viral-specific CD8+ T-cell functions and enhance HIV production from reservoir cells. Despite promising pre-clinical data, PD-1 blockade alone in HIV-1-infected patients with advanced cancer has shown limited benefits in controlling HIV, suggesting the need for additional targets beyond PD-1. CD39 and PD-1 are highly co-expressed on CD8+ T cells in HIV-1 infection. However, the characteristics of CD39 and PD-1 dual-positive CD8+ T-cell subsets in chronic HIV-1 infection remain poorly understood. Methods: This study enrolled 72 HIV-1-infected patients, including 40 treatment naïve and 32 ART patients. A total of 11 healthy individuals were included as controls. Different subsets of CD8+ T cells defined by CD39 and/or PD-1 expression were studied by flow cytometry. The relationships between the frequencies of the different subsets and parameters indicating HIV-1 disease progression were analyzed. Functional (i.e., cytokine secretion, viral inhibition) assays were performed to evaluate the impact of the blockade of adenosine and/or PD-1 signaling on CD8+ T cells. Results: The proportions of PD-1+, CD39+, and PD-1+CD39+ CD8+ T cells were significantly increased in treatment naïve patients but were partially lowered in patients on antiretroviral therapy. In treatment naïve patients, the proportions of PD-1+CD39+ CD8+ T cells were negatively correlated with CD4+ T-cell counts and the CD4/CD8 ratio, and were positively correlated with viral load. CD39+CD8+ T cells expressed high levels of the A2A adenosine receptor and were more sensitive to 2-chloroadenosine-mediated functional inhibition than their CD39- counterparts. In vitro, a combination of blocking CD39/adenosine and PD-1 signaling showed a synergic effect in restoring CD8+ T-cell function, as evidenced by enhanced abilities to secrete functional cytokines and to kill autologous reservoir cells. Conclusion: In patients with chronic HIV-1 infection there are increased frequencies of PD-1+, CD39+, and PD-1+CD39+ CD8+ T cells. In treatment naïve patients, the frequencies of PD-1+CD39+ CD8+ T cells are negatively correlated with CD4+ T-cell counts and the CD4/CD8 ratio and positively correlated with viral load. Combined blockade of CD39/adenosine and PD-1 signaling in vitro may exert a synergistic effect in restoring CD8+ T-cell function in HIV-1-infected patients.

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.

Transforming growth factor-ß promotes the function of HIV-specific CXCR5+ CD8 T cells.

HIV replication can be inhibited by CXCR5+ CD8 T cells (follicular cytotoxic T cell [TFC]) which transfer into B-cell follicles where latent HIV infection persists. However, how cytokines affect TFC remain unclear. Understanding which cytokines show the ability to affect TFC could be a key strategy toward curing HIV. Similar mechanisms could be used for the growth and transfer of TFCs and follicular helper T (TFH) cells; as a result, we hypothesized that cytokines IL-6, IL-21, and transforming growth factor-ß (TGF-ß), which are necessary for the differentiation of TFH cells, could also dictate the development of TFCs. In this work, lymph node mononuclear cells and peripheral blood mononuclear cells from HIV-infected individuals were cocultured with IL-6, IL-21, and TGF-ß. We then carried out T-cell receptor (TCR) repertoire analysis to compare the differences between CXCR5- and CXCR5+ CD8 T cells. Our results showed that the percentage and function of TFC can be enhanced by stimulation with TGF-ß. Besides, TGF-ß stimulation enhanced the diversity of TCR and complementarity-determining region 3 sequences. HIV DNA showed a negative correlation with TFC. The use of TGF-ß to promote the expression of CXCR5+ CD8 T cells could become a new treatment approach for curing HIV.

Expression of CD39 Is Correlated With HIV DNA Levels in Naïve Tregs in Chronically Infected ART Naïve Patients.

Background: Treg cells represent important viral reservoirs during chronic HIV infection. CD39 is closely involved in Treg-mediated immunosuppressive effects. However, CD39 expression on nTregs and mTregs and a relationship with HIV DNA levels during HIV infection is still unclear. In this study, we analyzed the distribution of HIV DNA in Treg subsets and the association between HIV DNA and CD39 expression on Treg subsets. Methods: Sixty-two HIV-infected patients with different HIV stages and 14 uninfected individuals were enrolled. nTregs (CD4+CD25+CD127lowCD45RO-) and mTregs (CD4+CD25+CD127lowCD45RO+) were isolated by magnetic selection and flow cytometric sorting. HIV DNA was quantified by real-time polymerase chain reaction (PCR). CD39 expression on nTregs and mTregs was analyzed by flow cytometry. Results: Higher levels of HIV DNA were detected in mTregs than those in nTregs during chronic HIV infection. The frequency of CD39+ nTregs and HIV DNA levels in nTregs were increased in patients with advanced HIV infection. Furthermore, HIV DNA levels in nTregs correlated positively with CD39+ nTreg frequency. CD39+ nTreg frequency was also increased in immune non-responders. Conclusions: mTregs and nTregs are both important reservoirs of virus during chronic HIV infection and HIV DNA levels increase in nTregs in patients with advanced HIV infection. We observed increased frequency of CD39+ nTregs and HIV DNA levels in nTregs in patients with advanced HIV infection. HIV DNA levels in nTregs correlated positively with CD39+ nTreg frequency.

High levels of circulating GM-CSF+CD4+ T cells are predictive of poor outcomes in sepsis patients: a prospective cohort study.

Granulocyte colony-stimulating factor (GM-CSF), produced by CD4+ T cells, has recently been implicated in the pathogenesis of inflammatory diseases, such as multiple sclerosis and juvenile arthritis. However, the role of GM-CSF-producing CD4+ T cells in sepsis remains unknown. This study reports peripheral changes in GM-CSF-producing CD4+ T cells in septic patients and the possible underlying mechanism by which GM-CSF influences the outcome of sepsis. Forty-three septic patients, 20 SIRS patients, and 20 healthy controls were enrolled in this study and followed for 28 days to assess mortality. We measured the peripheral frequency of GM-CSF+CD4+ T cells and recorded their associated relationship with disease progression. Our data demonstrated that peripheral GM-CSF-producing CD4+ T cells were significantly higher in septic patients than in both SIRS patients and healthy controls. These cells exhibit a memory phenotype and impaired IFN-γ-secreting capacity in sepsis patients. Using a receiver operating curve analysis with 8.01% as a cut-off point, the percentage of GM-CSF+CD4+ T cells could predict the outcome of septic patients. Combined with the increase in GM-CSF-producing CD4+ T cells, inflammatory cytokines IL-1ß and IL-6 were also upregulated. Using an in vitro neutrophil model, we found that GM-CSF inhibited C3aR expression, while inducing IL-8 production. Furthermore, this effect was transferrable in plasma from sepsis patients and was attenuated by inhibition of GM-CSF using an anti-GM-CSF antibody. These results indicate that GM-CSF-producing CD4+ T cells may serve as a marker of sepsis severity. Thus, targeting GM-CSF overproduction may benefit sepsis patients.

High circulating CD39(+) regulatory T cells predict poor survival for sepsis patients.

BACKGROUND: Sepsis encompasses two phases, the 'hyper'-reactive phase and the 'hypo'-reactive phase. The initial inflammatory stage is quickly counterbalanced by an anti-inflammatory response, which compromises the immune system, leading to immune suppression. Regulatory T cells (Tregs) have been implicated in the pathogenesis of sepsis by inducing immunosuppression; however, the role of CD39(+) Tregs in the process of sepsis is uncertain. This study investigated the dynamic levels of CD39(+) Tregs and their phenotypic change in sepsis. METHODS: Fourteen patients with systemic inflammatory response syndrome (SIRS), 42 patients with sepsis, and 14 healthy controls were enrolled. Sequential blood samples were used to analyze the numbers of CD39(+) Tregs and their phenotypic changes. Survival at 28 days was used to evaluate the capacity of CD39(+) Treg levels to predict mortality in sepsis patients. RESULTS: Sepsis patients displayed a high percentage (3.13%, 1.46%, and 0.35%, respectively) and mean fluorescence intensity (MFI) (59.65, 29.7, and 24.3, respectively) of CD39(+) Tregs compared with SIRS patients and healthy subjects. High-level expression of CD39(+) Tregs was correlated with the severity of sepsis, which was reflected by the sepsis-related organ failure assessment score (r=0.322 and r=0.31, respectively). In addition, the expression of CD39(+) Tregs was associated with survival of sepsis patients (p<0.01). By receiver-operating characteristic (ROC) curve analysis, the percentage and MFI of CD39(+) Tregs showed similar sensitivities and specificities to predict mortality (74.2% and 85.1%, and 73.9% and 84.1%, respectively). Using Kaplan-Meier curves to assess the impact of CD39(+) Tregs percentage and MFI on overall survival, we found that a high CD39(+) Tregs percentage (p<0.001; >4.1%) and MFI (p<0.001; >49.2) were significantly associated with mortality. Phenotypically, CD39(+) Tregs from sepsis patients showed high expression of CD38 and PD-1 (p<0.01 and p<0.01 respectively). CONCLUSIONS: Increased expression of CD39(+) Tregs was associated with a poor prognosis for sepsis patients, which suggests that CD39(+) Treg levels could be used as a biomarker to predict the outcome of sepsis patients.

Cytokine IL-6 is required in Citrobacter rodentium infection-induced intestinal Th17 responses and promotes IL-22 expression in inflammatory bowel disease.

Citrobacter rodentium (C. rodentium) infection is a widely used murine model to mimic human enteric bacteria infection and inflammatory bowel disease (IBD). In this model, interleukin (IL)­17A plays critical roles in increasing chemokine and cytokine production in various tissues to recruit innate cells, including monocytes and neutrophils, to the local site of infection. However, the source of IL­17A remains unclear, as the majority of cell types produce IL­17A, including intestinal endothelium cells, innate immune cells and CD4+ T cells in disease development. In the current study, wild­type B6 mice were treated with C. rodentium and the CD4+ Th17 cell subset was observed as being specifically increased in Peyer's patches (PP), but not in mesenteric draining lymph nodes. Furthermore, the research suggested that the differentiation and activation of Th17 cells in PP were dependent on the inflammatory cytokine IL­6, as blocking IL­6 signaling with neutralizing antibodies decreased Th17 cells and resulted in the mice being more susceptible to C. rodentium infection. These results confirmed that the Th17 cell subset was specifically activated in PP and demonstrated that IL­6 is required in Th17 cell activation, which are important to the clinical treatment of IBD.

[Phenotypical and functional characteristic of FoxP3(+);CD39(+); regulatory T cells in humans].

AIM: To investigate phenotypical and functional characteristics of the CD39(+);FoxP3(+);regulatory T (Treg) cells in humans. METHODS: We collected peripheral blood from 10 healthy volunteers and separated PBMC by using density gradient centrifugation, and then detected the expression of CTLA-4, HLA-DR, CD45RO and Ki-67 on CD39(+);FoxP3(+); and CD39(-);FoxP3(+);Treg cells by using flow cytometric analysis. [(3);H]-thymidine incorporation assay and ELISA were used to monitor the suppressive capacity of CD39(+); FoxP3(+); Treg cells on proliferation and IFN-gamma secretion of Treg-depleted PBMC. RESULTS: The expression of CTLA-4, HLA-DR, CD45RO and Ki-67 was significantly higher in CD39(+);FoxP3(+); Treg cells than those in CD39(-);FoxP3(+); Treg cells. The suppressive capacity of CD39(+);FoxP3(+); Treg cells on proliferation and IFN-gamma secretion of Treg-depleted PBMC was significantly higher than those of FoxP3(+);CD39(-);Treg cells. CONCLUSION: CD39(+);Fxop3(+);Treg subset may play an essential role in immune regulation of Treg, and CD39 can be used as a surface marker to identify the functional Treg cells.