Interleukin-2 therapy in patients with HIV infection

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.

Effective and targeted latency reversal in CD4+ T cells from individuals on long term combined antiretroviral therapy initiated during chronic HIV-1 infection

To date, an affordable, effective treatment for an HIV-1 cure remains only a concept with most "latency reversal" agents (LRAs) lacking specificity for the latent HIV-1 reservoir and failing in early clinical trials. We assessed HIV-1 latency reversal using a multivalent HIV-1-derived virus-like particle (HLP) to treat samples from 32 people living with HIV-1 (PLWH) in Uganda, US and Canada who initiated combined antiretroviral therapy (cART) during chronic infection. Even after 5-20 years on stable cART, HLP could target CD4+ T cells harbouring latent HIV-1 reservoir resulting in 100-fold more HIV-1 release into culture supernatant than by common recall antigens, and 1000-fold more than by chemotherapeutic LRAs. HLP induced release of a divergent and replication-competent HIV-1 population from PLWH on cART. These findings suggest HLP provides a targeted approach to reactivate the majority of latent HIV-1 proviruses among individuals infected with HIV-1.

Association between CD4 lymphocyte count and the incidence of comorbidities in Human immunodeficiency virus positive patients with virological suppression after antiretroviral treatment

BACKGROUND

The incidence of comorbidities is higher in HIV-positive patients than in the general population due to factors, such as HIV-related chronic inflammation. There is no consensus on whether a low CD4 lymphocyte count after virological suppression at long-term follow-up increases the risk of comorbidities. This study evaluates the association between CD4 lymphocyte count and the incidence of comorbidities during the first 5 years of virological suppression after highly active antiretroviral treatment.

METHODS

We conducted a cohort study of HIV-positive adults who achieved virological suppression in an HIV program between 2002 and 2016 in Colombia. A generalized equation estimation model was used to estimate the association between CD4 lymphocyte count and the incidence of comorbidities.

RESULTS

A follow-up period of at least 1 year was completed in 921 HIV-positive patients with virological suppression. We found 71 comorbidities during a maximum of 5 years of follow-up; 41 (59%) were AIDS-defining comorbidities and 19 (46%) of them occurred during the first semester. Thirty cases of non-AIDS- defining comorbidities were diagnosed.We did not find any association between CD4 lymphocyte count and the incidence of comorbidities (OR 0.92, CI 95% 0.45 -1.91 for CD4 201-499 cells/µL vs CD4 ≤200 cells/µL, and OR 0.55, 95% CI 0.21-1.44 for CD4 ≥500 cells/µL vs CD4 ≤200 cells/µL).

CONCLUSION

No association was found between CD4 lymphocyte count and the incidence of AIDS-defining or non-AIDS-defining comorbidities in patients with virological suppression. Further studies are needed to assess the risk of comorbidities in this population to design interventions aimed at improving their prognosis.

Safety and Virologic Impact of Haploidentical NK Cells Plus Interleukin 2 or N-803 in HIV Infection

BACKGROUND

Natural killer (NK) cells are dysfunctional in chronic human immunodeficiency virus (HIV) infection as they are not able to clear virus. We hypothesized that an infusion of NK cells, supported by interleukin 2 (IL-2) or IL-15, could decrease virus-producing cells in the lymphatic tissues.

METHODS

We conducted a phase 1 pilot study in 6 persons with HIV (PWH), where a single infusion of haploidentical related donor NK cells was given plus either IL-2 or N-803 (an IL-15 superagonist).

RESULTS

The approach was well tolerated with no unexpected adverse events. We did not pretreat recipients with cyclophosphamide or fludarabine to "make immunologic space," reasoning that PWH on stable antiretroviral treatment remain T-cell depleted in lymphatic tissues. We found donor cells remained detectable in blood for up to 8 days (similar to what is seen in cancer pretreatment with lymphodepleting chemotherapy) and in the lymph nodes and rectum up to 28 days. There was a moderate decrease in the frequency of viral RNA-positive cells in lymph nodes.

CONCLUSIONS

There was a moderate decrease in HIV-producing cells in lymph nodes. Further studies are warranted to determine the impact of healthy NK cells on HIV reservoirs and if restoring NK-cell function could be part of an HIV cure strategy. Clinical Trials Registration. NCT03346499 and NCT03899480.

HIV immunological non-responders are characterized by extensive immunosenescence and impaired lymphocyte cytokine production capacity

Introduction

Immunological non-responders (INR) are people living with HIV (PLHIV) who fail to fully restore CD4+ T-cell counts despite complete viral suppression with antiretroviral therapy (ART). INR are at higher risk for non-HIV related morbidity and mortality. Previous research suggest persistent qualitative defects.

Methods

The 2000HIV study (clinical trials NTC03994835) enrolled 1895 PLHIV, divided in a discovery and validation cohort. PLHIV with CD4 T-cell count <350 cells/mm3 after ≥2 years of suppressive ART were defined as INR and were compared to immunological responders (IR) with CD4 T-cell count >500 cells/mm3. Logistic and rank based regression were used to analyze clinical data, extensive innate and adaptive immunophenotyping, and ex vivo monocyte and lymphocyte cytokine production after stimulation with various stimuli.

Results

The discovery cohort consisted of 62 INR and 1224 IR, the validation cohort of 26 INR and 243 IR. INR were older, had more advanced HIV disease before starting ART and had more frequently a history of non-AIDS related malignancy. INR had lower absolute CD4+ T-cell numbers in all subsets. Activated (HLA-DR+, CD38+) and exhausted (PD1+) subpopulations were proportionally increased in CD4 T-cells. Monocyte and granulocyte immunophenotypes were comparable. INR lymphocytes produced less IL-22, IFN-γ, IL-10 and IL-17 to stimuli. In contrast, monocyte cytokine production did not differ. The proportions of CD4+CD38+HLA-DR+ and CD4+PD1+ subpopulations showed an inversed correlation to lymphocyte cytokine production.

Conclusions

INR compared to IR have hyperactivated and exhausted CD4+ T-cells in combination with lymphocyte functional impairment, while innate immune responses were comparable. Our data provide a rationale to consider the use of anti-PD1 therapy in INR.

CD4+ T-cell recovery in HIV/hepatitis C co-infected patients following successful hepatitis C treatment

INTRODUCTION

Hepatitis C virus (HCV)/HIV co-infection has been identified as a risk for impaired CD4+ T-cell recovery, possibly mediated by HCV-induced liver fibrosis and/or immune activation. As HCV direct-acting antivirals (DAAs) may partially reverse liver fibrosis and immune activation, sustained HCV virological response (SVR) may lead to improved CD4 recovery. We explored the effect of HCV DAA-induced SVR on CD4 recovery among patients living with both HCV and HIV, including those with poor CD4 recovery on antiretroviral therapy (immunological non-responders [INRs]).

METHODS

Subjects aged ≥18 years living with both HIV and HCV who achieved SVR with DAA were included. Pre-DAA CD4 counts were included only after sustained HIV viral suppression and HIV viral suppression was maintained for the duration of the study. Segmented regression of interrupted time series analysis was used to evaluate changes in median CD4 count in the pre-DAA period (-36 months) versus the post-DAA period (+36 months).

RESULTS

In total, 156 patients were included. In the full cohort, median CD4 counts increased by 15% (p = 0.002) in the 6-month period following DAA initiation, whereafter CD4 counts decreased by 2.7% per 6-month period (p = 0.004). Among the 13 INRs, there was no immediate effect on median CD4 in the first 6 months after DAA initiation, whereafter there was a sustained CD4 increase (4.1% per 6-month time interval [p = 0.02]). In total, 54% of INRs recorded a post-DAA CD4 count of >350 cells/mm3.

CONCLUSIONS

Successful DAA therapy induced a modest immediate CD4 immunological reconstitution among this cohort of patients living with both HIV and HCV, although this effect waned with time. By contrast, among INRs, achieving HCV SVR led to slower but sustained CD4 count recovery.

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.

Editorial to the Special Issue "Clinical Immunology in Italy, with Special Emphasis to Primary and Acquired Immunodeficiencies: A Commemorative Issue in Honor of Prof. Fernando Aiuti"

Fernando Aiuti (Figure 1), born in Urbino on 8 June 1935, suddenly died on 9 January 2019, leaving a great void not only among his family members and those who knew him and appreciated his great humanity and acute intelligence, but in the entire immunological scientific community [...].

Development trends of immune activation during HIV infection in recent three decades: a bibliometric analysis based on CiteSpace

This study aimed to evaluate and pinpoint the status, hot areas, and frontiers of immune activation during HIV infection utilizing CiteSpace. From 1990 to 2022, we searched for studies on immune activation during HIV infection in the Web of Science Core Collection. CiteSpace was used to visually analyze the publications to identify the research status and pertinent research hotspots and frontiers in terms of the countries, institutions, authors, references, journals, and keywords. The Web of Science Core Collection yielded 5321 articles on immune activation during HIV infection. With 2854 and 364 articles, the United States and the University of California, San Francisco were the leading nation and institution in this domain. Steven G. Deeks has published 95 papers and is the most published author. The top cited articles on microbial translocation as a significant factor during HIV infection were published by Brenchley et al. Research on molecular/biology/genetics is often referenced in publications in the journals of molecular/biology/immunology. Inflammation, risk, mortality, cardiovascular disease, persistence, and biomarkers will be high-frequency words that are hot topics of research. According to the results, there was a strong collaboration between countries and organizations but little collaboration among authors. Molecular biology, immunology, and medicine are the main study subjects. The current hot topics in research are inflammation, risk, mortality, cardiovascular disease, persistence, and biomarkers. Future studies should concentrate on reducing the pathological changes caused by inflammation and altering the mechanisms of immune activation to reduce the size of the viral reservoir.

Beyond Undetectable: Modeling the Clinical Benefit of Improved Antiretroviral Adherence in Persons With Human Immunodeficiency Virus With Virologic Suppression

Background

Incomplete antiretroviral therapy (ART) adherence has been linked to deleterious immunologic, inflammatory, and clinical consequences, even among virally suppressed (<50 copies/mL) persons with human immunodeficiency virus (PWH). The impact of improving adherence in the risk of severe non-AIDS events (SNAEs) and death in this population is unknown.

Methods

We estimated the reduction in the risk of SNAEs or death resulting from an increase in ART adherence by (1) applying existing data on the association between adherence with high residual inflammation/coagulopathy in virally suppressed PWH, and (2) using a Cox proportional hazards model derived from changes in plasma interleukin 6 (IL-6) and D-dimer from 3 randomized clinical trials. Comparatively, assuming 100% ART adherence in a PWH who achieves viral suppression, we estimated the number of persons in whom a decrease in adherence to <100% would need to be observed for an additional SNAE or death event to occur during 3- and 5-year follow-up.

Results

Increasing ART adherence to 100% in PWH who are suppressed on ART despite imperfect adherence translated into a 6%-37% reduction in the risk of SNAEs or death. Comparatively, based on an anticipated 12% increase in IL-6, 254 and 165 PWH would need to decrease their adherence from 100% to <100% for an additional event to occur over 3- and 5-year follow-up, respectively.

Conclusions

Modest gains in ART adherence could have clinical benefits beyond virologic suppression. Increasing ART adherence (eg, via an intervention or switch to long-acting ART) in PWH who remain virally suppressed despite incomplete adherence should be evaluated.

Investigation of Causal Effects of Protein Biomarkers on Cardiovascular Disease in Persons With HIV

BACKGROUND

There is an incompletely understood increased risk for cardiovascular disease (CVD) among people with HIV (PWH). We investigated if a collection of biomarkers were associated with CVD among PWH. Mendelian randomization (MR) was used to identify potentially causal associations.

METHODS

Data from follow-up in 4 large trials among PWH were used to identify 131 incident CVD cases and they were matched to 259 participants without incident CVD (controls). Tests of associations between 460 baseline protein levels and case status were conducted.

RESULTS

Univariate analysis found CLEC6A, HGF, IL-6, IL-10RB, and IGFBP7 as being associated with case status and a multivariate model identified 3 of these: CLEC6A (odds ratio [OR] = 1.48, P = .037), HGF (OR = 1.83, P = .012), and IL-6 (OR = 1.45, P = .016). MR methods identified 5 significantly associated proteins: AXL, CHI3L1, GAS6, IL-6RA, and SCGB3A2.

CONCLUSIONS

These results implicate inflammatory and fibrotic processes as contributing to CVD. While some of these biomarkers are well established in the general population and in PWH (IL-6 and its receptor), some are novel to PWH (HGF, AXL, and GAS6) and some are novel overall (CLEC6A). Further investigation into the uniqueness of these biomarkers in PWH and the role of these biomarkers as targets among PWH is warranted.

Association between ten-eleven methylcytosine dioxygenase 2 genetic variation and viral load in people with HIV

INTRODUCTION

Identifying genetic factors that influence HIV-pathogenesis is critical for understanding disease pathways. Previous studies have suggested a role for the human gene ten-eleven methylcytosine dioxygenase 2 (TET2) in modulating HIV-pathogenesis.

METHODS

We assessed whether genetic variation in TET2 was associated with markers of HIV-pathogenesis using both gene level and single nucleotide polymorphism (SNP) level association in 8512 HIV-positive persons across five clinical trial cohorts.

RESULTS

Variation at both the gene and SNP-level of TET2 was found to be associated with levels of HIV viral load (HIV-VL) consistently in the two cohorts that recruited antiretroviral-naïve participants. The SNPs occurred in two clusters of high linkage disequilibrium (LD), one associated with high HIV-VL and the other low HIV-VL, and were predominantly found in Black participants.

CONCLUSION

Genetic variation in TET2 was associated with HIV-VL in two large antiretroviral therapy (ART)-naive clinical trial cohorts. The role of TET2 in HIV-pathogenesis warrants further investigation.

T-cell exhaustion and stemness in antitumor immunity: Characteristics, mechanisms, and implications

T cells play a crucial role in the regulation of immune response and are integral to the efficacy of cancer immunotherapy. Because immunotherapy has emerged as a promising treatment for cancer, increasing attention has been focused on the differentiation and function of T cells in immune response. In this review, we describe the research progress on T-cell exhaustion and stemness in the field of cancer immunotherapy and summarize advances in potential strategies to intervene and treat chronic infection and cancer by reversing T-cell exhaustion and maintaining and increasing T-cell stemness. Moreover, we discuss therapeutic strategies to overcome T-cell immunodeficiency in the tumor microenvironment and promote continuous breakthroughs in the anticancer activity of T cells.

Extracellular vesicles as potential biomarkers and treatment options for liver failure: A systematic review up to March 2022

Introduction

Extracellular vesicles (EVs) carrying functional cargoes are emerging as biomarkers and treatment strategies in multiple liver diseases. Nevertheless, the potential of EVs in liver failure remains indistinct. In this systematic review, we comprehensively analyzed the potential of EVs as biomarkers of liver failure and the therapeutic effects and possible mechanisms of EVs for liver failure.

Methods

We conducted a systematic review by comprehensively searching the following electronic databases: PubMed, Web of Science, Embase and Cochrane Central Register of Controlled Trials from inception to March 2022. The used text words (synonyms and word variations) and database-specific subject headings included "Extracellular Vesicles", "Exosomes", "Liver Failure", "Liver Injury", etc.

Results

A total of 1479 studies were identified. After removing 680 duplicate studies and 742 irrelevant studies, 57 studies were finally retained and analyzed. Fourteen studies revealed EVs with functional cargoes could be used to make the diagnosis of liver failure and provide clues for early warning and prognostic assessment of patients with liver failure. Forty-three studies confirmed the administration of EVs from different sources alleviated hepatic damage and improved survival through inhibiting inflammatory response, oxidative stress as well as apoptosis or promoting hepatocyte regeneration and autophagy.

Conclusions

EVs and their cargoes can be used not only as superior biomarkers of early warning, early diagnosis and prognostic assessments for liver failure, but also as potentially effective treatment options for liver failure. In the future, large-scale studies are urgently needed to verify the diagnostic, predictive and therapeutic value of EVs for liver failure.

Translating the observed differences in interleukin-6 levels between some antiretroviral regimens into potential long-term risk of serious non-AIDS events: A modeling study

Introduction

Variable levels of systemic inflammation are observed in people with HIV (PWH), but the clinical significance of differences among antiretroviral therapy (ART) regimens on associated levels of inflammatory markers is unclear. Based on data from previous epidemiologic studies that defined the predicted change in risk of serious non-AIDS events (SNAEs)/death by changes in interleukin-6 (IL-6) and D-dimer, we modeled the effects of differences in these markers between specific ART regimens on the long-term risk of clinical outcomes.

Methods

We used a Markov model to compare the risk of SNAEs/death with differences in IL-6 and D-dimer levels associated with remaining on specific three-drug regimens versus switching to specific two-drug ART regimens over 5 years of treatment. We used IL-6 and D-dimer data based on trajectories over time from the randomized TANGO and observational AIR studies. Age at model entry was set at 39 years. The primary endpoint was the number needed to treat for one additional SNAE/death.

Results

Over 144 weeks, PWH on one of the three-drug regimens studied were predicted to spend 22% more time in the low IL-6 quartile and 13% less time in the high IL-6 quartile compared with those on one of the two-drug regimens. Over 144 weeks, the predicted mean number of SNAEs/deaths per 100 PWH was 5.6 for a three-drug regimen associated with lower IL-6 levels versus 6.8 for a two-drug regimen associated with higher IL-6 levels. The number needed to treat for one additional SNAE/death among PWH receiving a two-drug versus three-drug regimen for 240 weeks was 43. Approximately 2,900 participants would be required for a 240-week clinical study to evaluate the accuracy of the model.

Conclusions

Our Markov model suggests that higher IL-6 levels associated with switching from specific three- to two- drug ART regimens may be associated with an increase in the risk of SNAEs/death. Clinical studies are warranted to confirm or refute these results.

Impact of age and gender disparity on CD4+ cell counts to control disease progression using specific HAART in HIV-1 positive patients: A case-control study

BACKGROUND

Highly Active Antiretroviral Therapy (HAART) is composed of several drugs in the antiretroviral class to better treat human immunodeficiency virus type 1 (HIV-1) patients. The estimation of CD4+ T cell counts and HIV-1 viral load in plasma is required to evaluate the treatment success of a specific HAART.

METHODOLOGY

The study included the effects of NRTIs (nucleoside reverse transcriptase inhibitors) and novel protease inhibitors (HAART) on normal control subjects and HIV-1 positive subjects from SGPGIMS, Lucknow, with different age groups and genders. Furthermore, the study was conducted by the estimation of HIV through ELISA, measurement of absolute CD4+ cell count, and the measurement of viral load through qRT-PCR. Furthermore, NRTIs (Retrovir and Epivir) were administered orally one tablet daily in the morning followed by newly FDA-approved protease inhibitors (fosamprenavir and darunavir) orally in the evening at the same dose. Furthermore, CD4+T cell counts and HIV-1 viral load were investigated and correlated in patients with different genders and age groups.

RESULT

Administration of NRTIs and novel protease inhibitors (HAART) in HIV patients had a significant effect on the CD4+ cell count in various age intervals among males and females. The mean comparison of viral load distribution based on gender in CD4 +ve patients in the case group exhibited a viral load higher in females compared to males, indicating a statistically significant difference between males and females (p<0.05). A notable association between virological and immunological parameters was observed with a reciprocal relationship between viral load and CD4 cell count in CD4 +ve patients, demonstrating multiple correlation coefficients with an R-value of 0.853.

CONCLUSION

The administration of specific HAART (NRTIs and novel protease inhibitors) in HIV patients had a notable improvement in the CD4+ cell count and viral load with significant age and gender disparity.

Oncology Healthcare Professionals’ Mental Health during the COVID-19 Pandemic

The paper begins by reviewing the literature on oncology healthcare professionals’ (HCP) mental health. We summarize and present the current data on HCP mental health in order to understand the baseline state of oncology HCPs’ mental health status prior to the COVID-19 pandemic. At each juncture, we will discuss the implications of these mental health variables on the personal lives of HCPs, the healthcare system, and patient care. We follow by reviewing the literature on these parameters during the COVID-19 pandemic in order to better understand the impact of COVID-19 on the overall mental health of HCPs working in oncology. By reviewing and summarizing the data before and after the start of the pandemic, we will get a fuller picture of the pre-existing stressors facing oncology HCPs and the added burden caused by pandemic-related stresses. The second part of this review paper will discuss the implications for the oncology workforce and offer recommendations based on the research literature in order to improve the lives of HCPs, and in the process, improve patient care.

Cancer immunotherapy in adult patients with HIV

The availability of antiretroviral therapy (ART) has increased the life expectancy of people with HIV (PWH) and reduced the incidence of AIDS-associated malignancies, yet PWH have a significantly increased incidence of malignancy and less favorable outcomes of cancer treatment compared with the general population.Immunotherapy has revolutionized cancer therapy, becoming the standard of care for various malignancy treatments. However, PWH are an underserved population with limited access to clinical trials and cancer treatment.This review of the available evidence on different classes of cancer immunotherapy in PWH is mostly based on case reports, case series, but few prospective studies and clinical trials due to the exclusion of PWH from most oncologic clinical trials. The results of the available evidence support the safety of immunotherapy in PWH. Immunotherapy has similar effectiveness in PWH, an acceptable toxicity profile, and has no clinically significant impact on HIV viral load and CD4-T cell count. In addition, there is no reported change in the incidence of opportunistic infections and other complications for PWH with well-controlled viremia.This review aims to briefly summarize the current state of immunotherapy in cancer, guide clinicians in the management of immunotherapy in cancer PWH, and encourage the inclusion of PWH in clinical trials of cancer immunotherapy.

Summary of 2021 Clinical Guidelines for the Diagnosis and Treatment of HIV/AIDS in HIV-infected Koreans

Since the establishment of the Committee for Clinical Guidelines for the Diagnosis and Treatment of human immunodeficiency virus/acquired immune deficiency syndrome (HIV/AIDS) by the Korean Society for AIDS in 2010, clinical guidelines have been prepared in 2011, 2013, 2015, and 2018. As new research findings on the epidemiology, diagnosis, and treatment of AIDS have been published in and outside of Korea along with the development and introduction of new antiretroviral medications, a need has arisen to revise the clinical guidelines by analyzing such new data. The clinical guidelines address the initial evaluation of patients diagnosed with HIV/AIDS, follow-up tests, appropriate timing of medication, appropriate antiretroviral medications, treatment strategies for patients who have concurrent infections with hepatitis B or C virus, recommendations for resistance testing, treatment for patients with HIV and tuberculosis coinfections, and treatment in pregnant women. Through these clinical guidelines, the Korean Society for AIDS and the Committee for Clinical Guidelines for the Diagnosis and Treatment of HIV/AIDS contributes to overcoming AIDS by delivering latest data and treatment strategies to healthcare professionals who treat AIDS in the clinic.

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.

Shocking HIV-1 with immunomodulatory latency reversing agents

The "shock-and-kill" strategy is one of the most explored HIV-1 cure approaches to eliminate latent virus. This strategy is based on HIV-1 reactivation using latency reversing agents (LRAs) to reactivate latent proviruses (the "shock" phase) and to induce subsequent elimination of the reactivated cells by immune responses or virus-induced cytopathic effects (the "kill" phase). Studies using immunomodulatory LRAs such as blockers of immune checkpoint molecules, toll-like receptor agonists, cytokines and CD8⁺ T cell depleting antibodies showed promising potential as LRAs inducing directly or indirectly cellular pathways known to control HIV transcription. However, the precise molecular mechanisms by which these immunomodulatory LRAs reverse latency remain incompletely understood. Together with the heterogenous nature of HIV-1 latency, this lack of understanding complicates efforts to develop more efficient and safer cure strategies. Hence, deciphering those mechanisms is pivotal in designing approaches to eliminate latent HIV infection.

Causal Organic Indirect and Direct Effects: Closer to the Original Approach to Mediation Analysis, with a Product Method for Binary Mediators

Mediation analysis, which started in the mid-1980s, is used extensively by applied researchers. Indirect and direct effects are the part of a treatment effect that is mediated by a covariate and the part that is not. Subsequent work on natural indirect and direct effects provides a formal causal interpretation, based on cross-worlds counterfactuals: outcomes under treatment with the mediator set to its value without treatment. Organic indirect and direct effects avoid cross-worlds counterfactuals, using so-called organic interventions on the mediator while keeping the initial treatment fixed at treatment. Organic indirect and direct effects apply also to settings where the mediator cannot be set. In linear models where the outcome model does not have treatment-mediator interaction, both organic and natural indirect and direct effects lead to the same estimators as in the original formulation of mediation analysis. Here, we generalize organic interventions on the mediator to include interventions combined with the initial treatment fixed at no treatment. We show that the product method holds in linear models for organic indirect and direct effects relative to no treatment even if there is treatment-mediator interaction. Moreover, we find a product method for binary mediators. Furthermore, we argue that the organic indirect effect relative to no treatment is very relevant for drug development. We illustrate the benefits of our approach by estimating the organic indirect effect of curative HIV treatments mediated by two HIV persistence measures, using data on interruption of antiretroviral therapy without curative HIV treatments combined with an estimated or hypothesized effect of the curative HIV treatments on these mediators. See video abstract at http://links.lww.com/EDE/B796.

Genome-wide association study of high-sensitivity C-reactive protein, D-dimer, and interleukin-6 levels in multiethnic HIV+ cohorts

OBJECTIVES

Elevated levels of interleukin-6 (IL-6), D-dimer, and C-reactive protein (hsCRP) are associated with increased incidence of comorbid disease and mortality among people living with HIV (PLWH). Prior studies suggest a genetic basis for these biomarker elevations in the general population. The study objectives are to identify the genetic basis for these biomarkers among PLWH.

METHODS

Baseline levels of hsCRP, D-dimer, and IL-6, and single nucleotide polymorphisms (SNPs) were determined for 7768 participants in three HIV treatment trials. Single variant analysis was performed for each biomarker on samples from each of three ethnic groups [African (AFR), Admixed American (AMR), European (EUR)] within each trial including covariates relevant to biomarker levels. For each ethnic group, the results were pooled across trials, then further pooled across ethnicities.

RESULTS

The transethnic analysis identified three, two, and one known loci associated with hsCRP, D-dimer, and IL-6 levels, respectively, and two novel loci, FGB and GCNT1, associated with D-dimer levels. Lead SNPs exhibited similar effects across ethnicities. Additionally, three novel, ethnic-specific loci were identified: CATSPERG associated with D-dimer in AFR and PROX1-AS1 and TRAPPC9 associated with IL-6 in AFR and AMR, respectively.

CONCLUSION

Eleven loci associated with three biomarker levels were identified in PLWH from the three studies including six loci known in the general population and five novel loci associated with D-dimer and IL-6 levels. These findings support the hypothesis that host genetics may partially contribute to chronic inflammation in PLWH and help to identify potential targets for intervention of serious non-AIDS complications.

Residual immune dysfunction under antiretroviral therapy

The usage of combination antiretroviral therapy in people with HIV (PWH) has incited profound improvement in morbidity and mortality. Yet, PWH may not experience full restoration of immune function which can manifest with non-AIDS comorbidities that frequently associate with residual inflammation and can imperil quality of life or longevity. In this review, we discuss the pathogenesis underlying chronic inflammation and residual immune dysfunction in PWH, as well as potential therapeutic interventions to ameliorate them and prevent incidence or progression of non-AIDS comorbidities. Current evidence advocates that early diagnosis and prompt initiation of therapy at high CD4 counts may represent the best available approach for an improved immune recovery in PWH.

Sharing CD4+ T Cell Loss: When COVID-19 and HIV Collide on Immune System

COVID-19 is a distinctive infection characterized by elevated inter-human transmission and presenting from absence of symptoms to severe cytokine storm that can lead to dismal prognosis. Like for HIV, lymphopenia and drastic reduction of CD4+ T cell counts in COVID-19 patients have been linked with poor clinical outcome. As CD4+ T cells play a critical role in orchestrating responses against viral infections, important lessons can be drawn by comparing T cell response in COVID-19 and in HIV infection and by studying HIV-infected patients who became infected by SARS-CoV-2. We critically reviewed host characteristics and hyper-inflammatory response in these two viral infections to have a better insight on the large difference in clinical outcome in persons being infected by SARS-CoV-2. The better understanding of mechanism of T cell dysfunction will contribute to the development of targeted therapy against severe COVID-19 and will help to rationally design vaccine involving T cell response for the long-term control of viral infection.

Validation of the D:A:D chronic kidney disease risk score in people living with HIV: the IeDEA West Africa Cohort Collaboration

OBJECTIVES

A risk score for long-term prediction of chronic kidney disease (CKD) in people living with HIV (PLHIV) has been developed using data from the D:A:D cohort. We assessed the performance of the D:A:D risk score in a cohort of PLHIV in West Africa.

METHODS

Data from PLHIV starting antiretroviral treatment in four clinics in Burkina Faso, Côte d'Ivoire and Togo participating in the IeDEA West Africa collaboration were analysed. CKD was defined as two consecutive estimated glomerular filtration rates (eGFRs) of ≤ 60 mL/min/1.73 m² . The D:A:D score (short version) was calculated using age, gender, nadir CD4 and baseline eGFR and was categorized into low, medium, and high-risk groups.

RESULTS

In 14 930 participants (70% female, median age = 38 years; median nadir CD4 count = 183 cells/µL) followed for a median duration of 5.7 years, 660 (4.4%) progressed to CKD, with an incidence [95% confidence interval (CI)] of 7.8 (7.2-8.4) per 1000 person-years (PY). CKD incidence rates were 2.4 (2.0-2.8), 8.1 (6.8-9.6) and, 30.9 (28.0-34.1) per 1000 PY in the low-, medium- and high-risk groups, respectively. In the high-risk group, 14.7% (95% CI: 13.3; 16.3) had progressed to CKD at 5 years. Discrimination was good [C-statistics = 0.81 (0.79-0.83)]. In all, 79.4% of people who progressed to CKD were classified in the medium- to high-risk group at baseline (sensitivity) and 66.5% of people classified in the low risk group at baseline did not progress to CKD (specificity).

CONCLUSIONS

These findings confirm the validity of the D:A:D score in identifying individuals at risk of developing CKD who could benefit from enhanced kidney monitoring in West African HIV clinics.

Pediatric HIV: the Potential of Immune Therapeutics to Achieve Viral Remission and Functional Cure

PURPOSE OF REVIEW

In the absence of antiretroviral therapy (ART), more than 50% of perinatally HIV-infected children die by 2 years of age. Early ART from infancy is therefore a global recommendation and significantly improves immune health, child survival, and disease outcome. However, even early treatment does not prevent or eradicate the latent reservoir necessitating life-long ART. Adherence to life-long ART is challenging for children and longstanding ART during chronic HIV infection led to higher risks of non-AIDS co-morbidities and virologic failure in infected children. Thus, HIV-infected children are an important population for consideration for immune-based interventions to achieve ART-free remission and functional cure. This review summarizes how the uniqueness of the early life immune system can be harnessed for the development of ART-free remission and functional cure, which means complete virus control in absence of ART. In addition, recent advances in therapeutics in the HIV cure field and their potential for the treatment of pediatric HIV infections are discussed.

RECENT FINDINGS

Preclinical studies and clinical trials demonstrated that immune-based interventions target HIV replication, limit size of virus reservoir, maintain virus suppression, and delay time to virus rebound. However, these studies have been performed so far only in carefully selected HIV-infected adults, highlighting the need to evaluate the efficacy of immune-based therapeutics in HIV-infected children and to design interventions tailored to the early life maturing immune system. Immune-based therapeutics alone or in combination with ART should be actively explored as potential strategies to achieve viral remission and functional cure in HIV-infected pediatric populations.

Harnessing regulatory T cell neuroprotective activities for treatment of neurodegenerative disorders

Emerging evidence demonstrates that adaptive immunity influences the pathobiology of neurodegenerative disorders. Misfolded aggregated self-proteins can break immune tolerance leading to the induction of autoreactive effector T cells (Teffs) with associated decreases in anti-inflammatory neuroprotective regulatory T cells (Tregs). An imbalance between Teffs and Tregs leads to microglial activation, inflammation and neuronal injury. The cascade of such a disordered immunity includes the drainage of the aggregated protein antigens into cervical lymph nodes serving to amplify effector immune responses. Both preclinical and clinical studies demonstrate transformation of this altered immunity for therapeutic gain. We posit that the signs and symptoms of common neurodegenerative disorders such as Alzheimer's and Parkinson's diseases, amyotrophic lateral sclerosis, and stroke can be attenuated by boosting Treg activities.

Idiopathic CD4 Lymphocytopenia: Current Insights

Idiopathic CD4 lymphocytopenia is a condition characterized by low CD4 counts. It is rare and most of the information about this illness comes from case reports. Presentation is usually in the 4th decade of life with opportunistic infections, autoimmune disease or neoplasia. The pathophysiology of this condition is not well understood. Management revolves around treatment of the presenting condition and close follow-up of these patients. This review presents a narrative summary of the current literature on idiopathic CD4 lymphocytopenia.

Interleukin-2 Therapy of Autoimmunity in Diabetes (ITAD): a phase 2, multicentre, double-blind, randomized, placebo-controlled trial

Type 1 diabetes is a common autoimmune disease due to destruction of pancreatic β cells, resulting in lifelong need for insulin. Evidence suggest that maintaining residual β-cell function can improve glucose control and reduce risk of hypoglycaemia and vascular complications. Non-clinical, preclinical and some preliminary clinical data suggest that low-dose interleukin-2 (IL-2) therapy could block pancreatic β cells destruction by increasing the number of functional regulatory T cells (Tregs) that inhibit islet-specific autoreactive effector T cells (Teffs). However, there is lack of data on the effect of low-dose IL-2 in newly diagnosed children and adolescents with T1D as well as lack of specific data on its potential effect on β-cell function. The ' Interleukin-2 Therapy of Autoimmunity in Diabetes (ITAD)' is a phase 2, multicentre, double-blind, randomised, placebo-controlled trial in children and adolescents (6-18 years; having detectable C-peptide) initiated within 6 weeks of T1D diagnosis. A total of 45 participants will be randomised in a 2:1 ratio to receive either ultra-low dose IL-2 (aldesleukin), at a dose of 0.2 x 10 6 IU/m 2 twice-weekly, given subcutaneously, or placebo, for 6 months. The primary objective is to assess the effects of ultra-low dose aldesleukin administration on endogenous β-cell function as measured by frequent home dried blood spot (DBS) fasting and post-prandial C-peptide in children and adolescents with newly diagnosed T1D. The secondary objectives are: 1) to assess the efficacy of regular dosing of aldesleukin in increasing Treg levels; 2) to confirm the clinical safety and tolerability of ultra-low dose aldesleukin; 3) to assess changes in the immune system indicating benefit or potential risk for future gains/loss in β-cell function and immune function; 4) to assess treatment effect on glycaemic control. Trial registration: EudraCT 2017-002126-20 (06/02/2019).

Pathways towards human immunodeficiency virus elimination

Antiretroviral therapy (ART) suppresses human immunodeficiency virus (HIV) infection. Research seeking to transform viral suppression into elimination has generated novel immune, chemical and molecular antiviral agents. However, none, to date, have excised latent integrated proviral DNA or removed infected cells from infected persons. These efforts included, but are not limited to, broadly neutralizing antibodies, "shock" and "kill" latency-reversing agents, innate immune regulators, and sequential long-acting antiretroviral nanoformulated prodrugs and CRISPR-Cas9 gene editing. While, the latter, enabled the complete excision of latent HIV-1 from the host genome success was so far limited. We contend that improvements in antiretroviral delivery, potency, agent specificity, or combinatorial therapies can provide a pathway towards complete HIV elimination.

The management of treatment-experienced HIV patients (including virologic failure and switches)

Significant advances in the potency and tolerability of antiretroviral therapy (ART) have led to very high rates of virologic success for most who remain adherent to therapy. As a result, the life expectancy of people living with HIV (PLWH) has increased significantly. PLWH do, however, continue to experience a significantly higher risk of noninfectious comorbidities and chronic age-related complications, including cardiovascular disease and malignancies, which are now the biggest drivers of this excess morbidity and mortality. Therefore, in addition to virologic failure, the management of the treatment-experienced patient increasingly requires optimization of ART to enhance tolerability, avoid drug-drug interactions, and mitigate non-AIDS complications and comorbid conditions. This article will present principles of the management of virologic failure, poor immunologic recovery, and strategies for optimizing ART in the setting of virologic suppression.

HIV therapeutic vaccines aimed at intensifying combination antiretroviral therapy

Introduction: Although successful at suppressing HIV replication, combination antiretroviral therapy (cART) only partially restores immune functions and fails to reduce the latent HIV reservoir, thus requiring novel interventions for its intensification.Areas covered: Here are reviewed therapeutic vaccine candidates that are being developed to this goal. Among them, the Tat vaccine has been shown to promote immune restoration, including CD4+ T-cell recovery in low immunological responders, and to reduce the virus reservoirs well beyond what achieved with long-term suppressive cART.Expert opinion: The authors propose the Tat vaccine as a promising vaccine candidate for cART intensification toward HIV reservoirs depletion, functional cure, and eradication strategies, suggesting that targeting a key protein in the virus life cycle is pivotal to success.

Cytokine Milieu in Infectious Disease: A Sword or a Boon?

Cytokines have a myriad role in an infectious disease, whether being pathogenic, bacterial, or viral. All proinflammatory and anti-inflammatory cytokine biological function are dependent on its concentration, followed by combination with the other cytokines and the stage of the disease. Plasticity in switching off from one phenotype to the other of these regulatory mediators in congruence with the traditional concept of inhibitory and stimulatory effects on immune system is dealt with. This review highlights the dual functionality of some of these cytokines and cytokine-based immunotherapy.

Two types of poor immunological responder showing distinct responses to long-term HAART

OBJECTIVES

Most previous studies on poor immunological responders (PIRs) have been performed on one cohort at one time-point following highly active antiretroviral therapy (HAART). The aim of this study was to investigate whether there are different subtypes of PIR and whether a certain population might achieve better immune reconstitution following longer HAART.

METHODS

This study was designed as an ambispective cohort study, including a 4-5-year retrospective study and a 2-year prospective follow-up investigation. Thymic output, activated T cell and regulatory T cell (Treg) subset frequencies, expression levels of interferon-stimulated genes, and plasma concentrations of neopterin were determined at 4-5 years and 6-7 years following HAART initiation.

RESULTS

PIRs were subdivided into two populations after 4-5 years of HAART, according to the kinetics of T cell recovery. Type II PIRs exhibited a significantly lower percentage of naïve CD4⁺ T cells and CD31⁺ naïve CD4⁺ T cells compared with type I PIRs. After an additional 2 years of HAART treatment, type I PIRs showed a better outcome than type II PIRs. Furthermore, it was found that 2 years of additional HAART could persistently improve thymic output.

CONCLUSIONS

The two PIR subgroups are different in terms of immune characteristics and the response to prolonged HAART.

Progress in achieving long-term HIV remission

PURPOSE OF REVIEW

The purpose of the present review is to describe the major barriers to HIV eradication and assess the most promising cure strategies under investigation.

RECENT FINDINGS

There are significant challenges to achieve HIV eradication. These include the establishment of persistent latently infected cells, systemic chronic immune activation, and immune dysfunction. Since the announcement of the first HIV cure involving the Berlin patient, several attempts to reproduce these results have failed. Thus, it is widely accepted that long-term HIV remission would be a more feasible approach. Optimization of ART, immune-based therapies, therapeutic vaccinations, and gene editing, amongst others, are strategies aimed at controlling HIV in the absence of ART. These new strategies alone or in combination are being developed in preclinical studies and clinical trials and will provide further insight into whether long-term HIV remission is possible.

SUMMARY

The present review discusses several mechanisms that mediate the persistence of the HIV reservoir, clinical cases that provide hope in finding a functional cure of HIV, and promising interventional strategies being tested in preclinical studies and clinical trials that attempt to reduce the HIV reservoirs and/or boost the immune responses to control HIV in the absence of ART.

HIV therapeutic vaccine enhances non-exhausted CD4+ T cells in a randomised phase 2 trial

VAC-3S is a therapeutic vaccine comprising a highly conserved HIV-gp41 motif coupled with the CRM197 carrier protein. High levels of anti-3S antibodies (Abs) have been associated with improved protection of CD4⁺ T-cell survival. A previous phase 1 study demonstrated the safety of VAC-3S. This multicentre, randomised, double-blind, placebo-controlled phase 2 clinical trial enroled between January 2014 and March 2015 HIV-1-infected patients under ART with plasma HIV RNA levels below 50 copies/mL and CD4 counts between 200 and 500 cells/μL. Participants were immunised with 16, 32, or 64 μg of VAC-3S, and compared to placebo. The primary outcome was immunogenicity assessed by changes from baseline of anti-3S Abs levels at week 12. Secondary outcomes included adverse events and the course of plasma HIV RNA level, CD4 count, CD4/CD8 ratio, inflammation and immune checkpoints from week 0 to week 48. Vaccination was well tolerated with no serious adverse events and induced a significant increase in anti-3S Ab response in vaccinated patients (p < 0.0001), compared to placebo. In high responders, the robust increased of CD4 count was associated with a significant and sustained reduction of PD-1 expression on CD4⁺ T cells through week 48 (variance p = 0.0017). PD-1 expression was correlated with level of anti-3S Abs (p = 0.0092, r = −0.68) and expression of NKp44L (p < 0.0001; r = 0.54) in CD4⁺ T cells. Our findings regarding the increase of non-exhausted CD4⁺ T cells have potentially important application in personalised HIV vaccination for HIV-infected patients with high level of PD-1 to improve their T-cell immune function.

Safety of low-dose subcutaneous recombinant interleukin-2: systematic review and meta-analysis of randomized controlled trials

Standard-dose intravenous recombinant interleukin-2 (rIL-2) is indicated for the treatment of some subtypes of cancer; however, severe adverse events, including venous thromboembolism (VTE), may complicate its administration. Low-dose subcutaneous rIL-2 is being studied for the management of immune-mediated diseases, since it can modulate the immunological response by specifically targeting T regulatory (T_reg) cells; importantly, it is supposed to cause fewer or no complications. In this systematic review and meta-analysis of phase II-III randomized controlled trials (RCTs), we investigated the safety of low-dose (<6 Million International Unit [MIU]/day) and ultra-low-dose (≤1 MIU/day) rIL-2 for severe adverse events (grade III-V) with a focus on VTE. Data of 1,321 patients from 24 RCTs were analysed: 661 patients were randomized to the rIL-2 arm (on top of standard of care) and 660 patients to standard of care alone or placebo. Two studies reported higher rates of thrombocytopenia in the low-dose rIL-2 arm. Ultra-low-dose rIL-2 was reported to be well tolerated in 6 studies with a negligible rate of severe adverse events. Symptomatic VTE events were not reported in any of the study arms (absolute risk difference 0% [95%CI −0.1%; +0.1%]). Our results may facilitate the study and introduction in clinical practice of low-dose rIL-2 for potentially new indications.

RNAa Induced by TATA Box-Targeting MicroRNAs

Recent studies reveal that some nuclear microRNAs (miRNA) and synthesized siRNAs target gene promoters to activate gene transcription (RNAa). Interestingly, our group identified a novel HIV-1-encoded miRNA, miR-H3, which targets specifically the core promoter TATA box of HIV-1 and activates viral gene expression. Depletion of miR-H3 significantly impaired the replication of HIV-1. miR-H3 mimics could activate viruses from CD4⁺ T cells isolated from patients receiving suppressive highly active antiretroviral therapy, which is very intriguing for reducing HIV-1 latent reservoir. Further study revealed that many cellular miRNAs also function like miR-H3. For instance, let-7i targets the TATA box of the interleukin-2 (IL-2) promoter and upregulates IL-2 expression in T-lymphocytes. In RNAa induced by TATA box-targeting miRNAs, Argonaute (AGO) proteins are needed, but there is no evidence for the involvement of promoter-associated transcripts or epigenetic modifications. We propose that the binding of small RNA-AGO complex to TATA box could facilitate the assembly of RNA Polymerase II transcription preinitiation complex. In addition, synthesized small RNAs targeting TATA box can also efficiently activate transcription of interested genes, such as insulin, IL-2, and c-Myc. The discovery of RNAa induced by TATA box-targeting miRNA provides an easy-to-use tool for activating gene expression.

Lymphopenia in Cancer Patients and its Effects on Response to Immunotherapy: an opportunity for combination with Cytokines?

Quantitative lymphocyte alterations are frequent in patients with cancer, and strongly impact prognosis and survival. The development of cancers in immunosuppressed patients has demonstrated the contribution of different T cell populations, including CD4⁺ cells, in the control of cancer occurrence.Whereas absolute numbers of neutrophils, platelets and red blood cells are routinely monitored in clinic following treatments, because of possible short-term complications, absolute lymphocyte counts (ALC), their subpopulations or diversity (phenotype, TCR) are rarely analyzed and never used to choose therapy or as prognostic criteria. The recent identification of immune checkpoint inhibitors (ICPi) as powerful therapeutic agents has revitalized immunotherapy of cancer in a broader group of diseases than anticipated. The status of the immune system is now recognized as an important biomarker for response to these novel treatments. Blood ALC values, along with tumor infiltration by CD8⁺T cells, and ICPi and ICPi-ligand expression, are likely to be a potential marker of sensitivity to anti-ICPi therapy.In this article, we review the current knowledge on the incidence and significance of lymphopenia in cancer patients, and discuss therapeutic strategies to restore lymphocyte numbers.

Role of cytokine agonists and immune checkpoint inhibitors toward HIV remission

PURPOSE OF REVIEW

The current article describes the current status of the use of cytokines and immune-checkpoint inhibitors as therapeutic strategies toward HIV remission.

RECENT FINDINGS

Clinical trials using IL-2 and IL-7 showed increased levels of circulating T cells, although no reduction to the viral reservoir was observed. Studies in nonhuman primates (NHP) demonstrated that experimental IL-15 administration increased proliferation and cytotoxicity of simian immunodeficiency virus (SIV)-specific CD8 T cells, and promoted their localization to the lymph node (LN) B cell follicles. Immune checkpoint modulators targeting programed cell death-1 and cytotoxic T-lymphocyte associated protein 4, successfully used in oncologic diseases, have shown potential to restore HIV-specific function in early stage clinical trials, while also transiently increasing plasma and cell-associated viral RNA. Due to the complexity of the mechanisms regulating HIV persistence, it is very likely that combinatorial approaches, including cytokines with immune checkpoint blockades (ICBs), will be needed to achieve HIV remission.

SUMMARY

The present review covers approaches based on cytokine agonists and immune checkpoint inhibitors that have shown promise toward therapeutic pathways for HIV remission. These strategies have been tested preclinically in animal models of HIV infection to determine their safety, activity, and mechanisms of action, with the goal to inform the design of the most synergistic combinatorial strategies. Several of these interventions are included in ongoing or planned clinical trials in HIV infection; these trials will elucidate the clinical efficacy of these innovative immunotherapy approaches toward HIV remission.

Therapeutic HIV-1 vaccine: time for immunomodulation and combinatorial strategies

PURPOSE OF REVIEW

The purpose is to recall some of the key immunological elements that are at the crossroad and need to be combined for developing a potent therapeutic HIV-1 vaccine.

RECENT FINDINGS

Therapeutic vaccines and cytokines have been commonly used to enhance and/or recall preexisting HIV-1 specific cell-mediated immune responses aiming to suppress virus replication. While the vaccine is important to stimulate HIV-1 specific T-cell responses, the cytokine may support the expansion of the stimulated virus-specific T cells. Moreover, the current success of immune checkpoint blockers in cancer therapy render them very attractive to use in HIV-1 infected individuals, with the objective to preserve the function of HIV-specific T cells from exhaustion and target directly HIV-1 cell reservoir. More recently, the development of passive immunotherapy using broad neutralizing HIV antibodies (bNAbs) and their potential capacity to elicit innate or adaptive HIV-cellular responses, beyond their neutralizing activity, offers a new opportunity to improve the efficiency of therapeutic vaccine. These major advances provide the scientific basis for developing potent combinatorial interventions in HIV-1 infected patients.

SUMMARY

Major advances in our immunological understanding resulting from basic science and clinical trials studies have paved the way and established a solid platform to jump over the stumbling blocks that prevent the field from developing a therapeutic HIV-1 vaccine. It is time for immuno-modulation and combinatorial strategies towards HIV-1 eradication.

CD8 T Cell Exhaustion During Chronic Viral Infection and Cancer

Exhausted CD8 T (Tex) cells are a distinct cell lineage that arise during chronic infections and cancers in animal models and humans. Tex cells are characterized by progressive loss of effector functions, high and sustained inhibitory receptor expression, metabolic dysregulation, poor memory recall and homeostatic self-renewal, and distinct transcriptional and epigenetic programs. The ability to reinvigorate Tex cells through inhibitory receptor blockade, such as αPD-1, highlights the therapeutic potential of targeting this population. Emerging insights into the mechanisms of exhaustion are informing immunotherapies for cancer and chronic infections. However, like other immune cells, Tex cells are heterogeneous and include progenitor and terminal subsets with unique characteristics and responses to checkpoint blockade. Here, we review our current understanding of Tex cell biology, including the developmental paths, transcriptional and epigenetic features, and cell intrinsic and extrinsic factors contributing to exhaustion and how this knowledge may inform therapeutic targeting of Tex cells in chronic infections, autoimmunity, and cancer.

Cytokine-Mediated Regulation of CD8 T-Cell Responses During Acute and Chronic Viral Infection

The common γ-chain cytokines, interleukin (IL)-2, IL-7, and IL-15, regulate critical aspects of antiviral CD8 T-cell responses. During acute infections, IL-2 controls expansion and differentiation of antiviral CD8 T cells, whereas IL-7 and IL-15 are key cytokines to maintain memory CD8 T cells long term in an antigen-independent manner. On the other hand, during chronic infections, in which T-cell exhaustion is established, precise roles of these cytokines in regulation of antiviral CD8 T-cell responses are not well defined. Nonetheless, administration of IL-2, IL-7, or IL-15 can increase function of exhausted CD8 T cells, and thus can be an attractive therapeutic approach. A new subset of stem-cell-like CD8 T cells, which provides a proliferative burst after programmed cell death (PD)-1 therapy, has been recently described during chronic viral infection. Further understanding of cytokine-mediated regulation of this CD8 T-cell subset will improve cytokine therapies to treat chronic infections and cancer in combination with immune checkpoint inhibitors.

Interleukin 2 modulates thymic-derived regulatory T cell epigenetic landscape

Foxp3+CD4+ regulatory T (Treg) cells are essential for preventing fatal autoimmunity and safeguard immune homeostasis in vivo. While expression of the transcription factor Foxp3 and IL-2 signals are both required for the development and function of Treg cells, the commitment to the Treg cell lineage occurs during thymic selection upon T cell receptor (TCR) triggering, and precedes the expression of Foxp3. Whether signals beside TCR contribute to establish Treg cell epigenetic and functional identity is still unknown. Here, using a mouse model with reduced IL-2 signaling, we show that IL-2 regulates the positioning of the pioneer factor SATB1 in CD4+ thymocytes and controls genome wide chromatin accessibility of thymic-derived Treg cells. We also show that Treg cells receiving only low IL-2 signals can suppress endogenous but not WT autoreactive T cell responses in vitro and in vivo. Our findings have broad implications for potential therapeutic strategies to reprogram Treg cells in vivo.

In silico thrombin generation: Plasma composition imbalance and mortality in human immunodeficiency virus

Background

Effective HIV treatment with antiretroviral therapy has prolonged survival and shifted causes of death to non-AIDS illnesses such as cardiovascular disease. We have shown that inflammation and HIV viral load associate with pro- and anticoagulant factor imbalances resulting in increased thrombin generation when mathematically modeled. We explore the hypothesis that factor compositional imbalance, corresponding to increased in silico thrombin generation, predicts mortality among HIV+ persons.

Methods

In a nested case-control study of HIV+ individuals on continuous antiretroviral therapy in two large trials, we evaluated cases (any non-violent mortality, n = 114) and matched controls (n = 318). Thrombin generation in response to a tissue-factor initiator for each individual was calculated by a mathematical model incorporating levels of factors (F)II, V, VII, VIII, IX, X, antithrombin, tissue factor pathway inhibitor, and protein C (PC) measured at study entry to the trials. In silico thrombin generation metrics included clot time, maximum rate (MaxR), maximum level (MaxL), and area under the curve (AUC).

Results

Levels of antithrombin and PC decreased, while FV and FVIII were higher in cases vs controls. This resulted in a more procoagulant phenotype with increased MaxR, MaxL, and AUC in cases compared to controls (P < 0.05 for all).

Conclusions

Antithrombin, FV, FVIII, and PC were the major contributors to the increased thrombin generation associated with mortality risk. Our results suggest that mortality in HIV is associated with an increase in in silico thrombin generation via altered balance of pro- and anticoagulant factors, likely due to an inflammatory response signal, and resulting coagulopathy.

Progressive multifocal leukoencephalopathy after allogeneic stem cell transplantation: Case report and review of the literature

Progressive multifocal leukoencephalopathy (PML) is a rare, yet typically fatal complication of allogeneic stem cell transplantation. It is caused by reactivation of the John Cunningham (JC) virus in an immunocompromised host. This report describes an unfortunate case of PML in a recipient of an allogeneic stem cell transplant for acute myelogenous leukemia. The JC virus was undetectable in the patient's cerebrospinal fluid by polymerase chain reaction (PCR); however, a positive diagnosis was made after a brain biopsy. This and other published cases demonstrate that recipients of allogeneic stem cells can develop PML. Moreover, early diagnosis of the disease is often difficult and, as demonstrated in this case, screening with PCR does not appear to have strong diagnostic significance. With no effective treatment presently available, restoration of immune function is the only intervention that can affect prognosis. Further prospective studies are needed to understand the pathophysiology and treatment of this disease.

Regulatory T cells (Tregs): A major immune checkpoint to consider in combinatorial therapeutic HIV-1 vaccines

The field of immunotherapeutics is living an exceptional time as new antibodies that take brakes off T-cells and unleash them on tumours are being approved by the US-Food and Drug Administration (FDA). For the design and development of an HIV-1 therapeutic-vaccine, one would need preferably to shift the balance T-effectors/T-regulatory cells (Teff/Tregs) towards effectors to improve vaccine-specific immune-responses. Given the success with the new immune-checkpoint-blockers (ICB), it is an appropriate time for HIV-1 field to seize this opportunity and develop new therapeutic vaccine-strategies that take into consideration ICB and other immunomodulators such as cytokines. While the vaccine is important to stimulate HIV-1-specific T-cell responses, cytokines will support the expansion of the stimulated virus-specific T-cells and ICB will reverse exhaustion and unchain cytotoxic T-cells. In this commentary, we will spotlight Tregs as another major brake for T-cell immunity and address the main stumbling-blocks that often blurs HIV-1-specific-Tregs status with regards to their role (beneficial or detrimental) and we will recall some proof-of-concept studies where therapeutic immunization skewed the HIV-1-specific response from Tregs to Teffs which impacts on the magnitude of viral replication. We will also suggest some strategies to shift the balance towards Teffs and potentiate HIV-1-specific immune-responses.