Pembrolizumab induces HIV latency reversal in people living with HIV and cancer on antiretroviral therapy

The interconnection between periodontitis and HIV-1 latency: Molecular mechanisms and therapeutic insights

Periodontitis is one of the major global public health problems associated with the occurrence and development of diverse systemic diseases, especially acquired immune deficiency syndrome (AIDS), necessitating further research and clinical attention. The persistence of HIV-1 latency poses a significant challenge to the attainment of a functional cure for AIDS, despite the introduction of highly active antiretroviral therapy (HAART). A similar mechanistic basis between periodontitis and HIV-1 latency has been revealed by many studies, suggesting possible mechanisms whereby periodontitis and HIV-1 latency may mutually influence each other. Therefore, we aimed to systematically summarize the current research on periodontitis and HIV-1 latency to investigate their potential correlations. This study revealed several common hubs for periodontitis and HIV-1 latency in the nuclear factor kappa-B (NF-κB) signaling pathway and other signaling pathways, including the Wnt/β-catenin pathway, bromodomain-containing protein 4 (BRD4), protein kinase C (PKC), the NOD-like receptor thermal protein domain associated protein 3 (NLRP3) inflammasome, programmed cell death protein 1 (PD-1), histone deacetylases (HDACs), and the phosphatidylinositol-3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) pathway. Furthermore, we will discuss the hypothesis that periodontal pathogens may represent the unifying mechanism elucidating the intricate interconnection between periodontitis and HIV-1 latency. This article presents a detailed and comprehensive overview of the relationship underlying periodontitis and HIV-1 latency in terms of molecular mechanisms, which may provide novel theoretical insight into the pathogenesis of periodontitis and HIV-1 latency and reveal suitable therapeutic targets for the two diseases.

Application of MIDD to accelerate the development of anti-infectives: Current status and future perspectives

This review examines the role of model-informed drug development (MIDD) in advancing antibacterial and antiviral drug development, with an emphasis on the inclusion of host system dynamics into modeling efforts. Amidst the growing challenges of multidrug resistance and diminishing market returns, innovative methodologies are crucial for continuous drug discovery and development. The MIDD approach, with its robust capacity to integrate diverse data types, offers a promising solution. In particular, the utilization of appropriate modeling and simulation techniques for better characterization and early assessment of drug resistance are discussed. The evolution of MIDD practices across different infectious disease fields is also summarized, and compared to advancements achieved in oncology. Moving forward, the application of MIDD should expand into host system dynamics as these considerations are critical for the development of "live drugs" (e.g. chimeric antigen receptor T cells or bacteriophages) to address issues like antibiotic resistance or latent viral infections.

Immune checkpoint inhibitors in infectious disease

Following success in cancer immunotherapy, immune checkpoint blockade is emerging as an exciting potential treatment for some infectious diseases, specifically two chronic viral infections, HIV and hepatitis B. Here, we will discuss the function of immune checkpoints, their role in infectious disease pathology, and the ability of immune checkpoint blockade to reinvigorate the immune response. We focus on blockade of programmed cell death 1 (PD-1) to induce durable immune-mediated control of HIV, given that anti-PD-1 can restore function to exhausted HIV-specific T cells and also reverse HIV latency, a long-lived form of viral infection. We highlight several key studies and future directions of research in relation to anti-PD-1 and HIV persistence from our group, including the impact of immune checkpoint blockade on the establishment (AIDS, 2018, 32, 1491), maintenance (PLoS Pathog, 2016, 12, e1005761; J Infect Dis, 2017, 215, 911; Cell Rep Med, 2022, 3, 100766) and reversal of HIV latency (Nat Commun, 2019, 10, 814; J Immunol, 2020, 204, 1242), enhancement of HIV-specific T cell function (J Immunol, 2022, 208, 54; iScience, 2023, 26, 108165), and investigating the effects of anti-PD-1 and anti-CTLA-4 in vivo in people with HIV on ART with cancer (Sci Transl Med, 2022, 14, eabl3836; AIDS, 2021, 35, 1631; Clin Infect Dis, 2021, 73, e1973). Our future work will focus on the impact of anti-PD-1 in vivo in people with HIV on ART without cancer and potential combinations of anti-PD-1 with other interventions, including therapeutic vaccines or antibodies and less toxic immune checkpoint blockers.

Sirolimus reduces T cell cycling, immune checkpoint marker expression, and HIV-1 DNA in people with HIV

Key HIV cure strategies involve reversing immune dysfunction and limiting the proliferation of infected T cells. We evaluate the safety of sirolimus, a mammalian target of rapamycin (mTOR) inhibitor, in people with HIV (PWH) and study the impact of sirolimus on HIV-1 reservoir size and HIV-1-specific immunity in a single-arm study of 20 weeks of treatment in PWH on antiretroviral therapy (ART). Sirolimus treatment does not impact HIV-1-specific CD8 T cell responses but leads to a significant decrease in CD4+ T cell-associated HIV-1 DNA levels at 20 weeks of therapy in the primary efficacy population (n = 16; 31% decline, p = 0.008). This decline persists for at least 12 weeks following cessation of the study drug. Sirolimus treatment also leads to a significant reduction in CD4+ T cell cycling and PD-1 expression on CD8+ lymphocytes. These data suggest that homeostatic proliferation of infected cells, an important mechanism for HIV persistence, is an intriguing therapeutic target.

Dual blockade of IL-10 and PD-1 leads to control of SIV viral rebound following analytical treatment interruption

Human immunodeficiency virus (HIV) persistence during antiretroviral therapy (ART) is associated with heightened plasma interleukin-10 (IL-10) levels and PD-1 expression. We hypothesized that IL-10 and PD-1 blockade would lead to control of viral rebound following analytical treatment interruption (ATI). Twenty-eight ART-treated, simian immunodeficiency virus (SIV)mac239-infected rhesus macaques (RMs) were treated with anti-IL-10, anti-IL-10 plus anti-PD-1 (combo) or vehicle. ART was interrupted 12 weeks after introduction of immunotherapy. Durable control of viral rebound was observed in nine out of ten combo-treated RMs for >24 weeks post-ATI. Induction of inflammatory cytokines, proliferation of effector CD8+ T cells in lymph nodes and reduced expression of BCL-2 in CD4+ T cells pre-ATI predicted control of viral rebound. Twenty-four weeks post-ATI, lower viral load was associated with higher frequencies of memory T cells expressing TCF-1 and of SIV-specific CD4+ and CD8+ T cells in blood and lymph nodes of combo-treated RMs. These results map a path to achieve long-lasting control of HIV and/or SIV following discontinuation of ART.

Anti-PD-L1 antibody ASC22 in combination with a histone deacetylase inhibitor chidamide as a "shock and kill" strategy for ART-free virological control: a phase II single-arm study

The combination of ASC22, an anti-PD-L1 antibody potentially enhancing HIV-specific immunity and chidamide, a HIV latency reversal agent, may serve as a strategy for antiretroviral therapy-free virological control for HIV. People living with HIV, having achieved virological suppression, were enrolled to receive ASC22 and chidamide treatment in addition to their antiretroviral therapy. Participants were monitored over 24 weeks to measure changes in viral dynamics and the function of HIV-specific CD8+ T cells (NCT05129189). 15 participants completed the study. At week 8, CA HIV RNA levels showed a significant increase from baseline, and the values returned to baseline after discontinuing ASC22 and chidamide. The total HIV DNA was only transiently increased at week 4 (P = 0.014). In contrast, integrated HIV DNA did not significantly differ from baseline. Increases in the proportions of effector memory CD4+ and CD8+ T cells (TEM) were observed from baseline to week 24 (P = 0.034 and P = 0.002, respectively). The combination treatment did not succeed in enhancing the function of HIV Gag/Pol- specific CD8+ T cells. Nevertheless, at week 8, a negative correlation was identified between the proportions of HIV Gag-specific TEM cells and alterations in integrated DNA in the T cell function improved group (P = 0.042 and P = 0.034, respectively). Nine adverse events were solicited, all of which were graded 1 and resolved spontaneously. The combined treatment of ASC22 and chidamide was demonstrated to be well-tolerated and effective in activating latent HIV reservoirs. Further investigations are warranted in the context of analytic treatment interruption.

Cancer in People with HIV

We review the intersection of human immunodeficiency virus (HIV) and cancer globally, including the complex interplay of oncogenic infections, chronic inflammation, and behavioral and other factors in increasing cancer risk among people with HIV (PWH). We discuss current cancer screening, prevention, and treatment recommendations for PWH. Specific interventions include vaccination, behavioral risk reduction, timely HIV diagnosis and treatment, screening for specific cancer sites, and multifaceted treatment considerations unique to PWH including supportive care and drug interactions. Finally, the potential of novel therapies and the need for inclusive cancer clinical trials are highlighted. Collaborative multidisciplinary efforts are critical for continued progress against cancer among PWH.

Advancing Toward a Human Immunodeficiency Virus Cure: Initial Progress on a Difficult Path

Therapies to eradicate human immunodeficiency virus (HIV) infection, sparing lifelong antiviral therapy, are a still-distant goal. But significant advances have been made to reverse HIV latency while antiretroviral therapy (ART) is maintained to allow targeting of the persistent viral reservoir, to test interventions that could clear cells emerging from latent infection, and to improve HIV cure research assays and infrastructure. Steady progress gives hope that future therapies to clear HIV infection may relieve individuals and society of the burden of HIV.

Real-World Multicenter Study of PD-1 Blockade in HIV-Associated Classical Hodgkin Lymphoma Across the United States

BACKGROUND

Despite a higher risk of classical Hodgkin lymphoma (cHL) in people with HIV and the demonstrated safety and efficacy of PD-1 blockade in cHL, there are limited data on the use of these agents in HIV-associated cHL (HIV-cHL).

PATIENTS/METHODS

We retrospectively identified patients with HIV-cHL from the "Cancer Therapy using Checkpoint inhibitors in People with HIV-International (CATCH-IT)" database who received nivolumab or pembrolizumab, alone or in combination with other agents, and reviewed records for demographics, disease characteristics, immune-mediated adverse events (imAEs), and treatment outcomes. Changes in CD4+ T-cell counts with treatment were measured via Wilcoxon signed-rank tests. Overall response rate (ORR) was defined as the proportion of patients with partial or complete response (PR/CR) per 2014 Lugano classification.

RESULTS

We identified 23 patients with HIV-cHL who received a median of 6 cycles of PD-1 blockade: 1 as 1st-line, 6 as 2nd-line, and 16 as ≥3rd-line therapy. Seventeen (74%) patients received monotherapy, 5 (22%) received nivolumab plus brentuximab vedotin, and 1 received nivolumab plus ifosfamide, carboplatin, and etoposide. The median baseline CD4+ T-cell count was 155 cells/µL, which increased to 310 cells/µL at end-of-treatment (P = .009). Three patients had grade 3 imAEs; none required treatment discontinuation. The ORR was 83% with median duration of response of 19.7 months. The median progression-free survival was 21.2 months and did not differ between patients with <200 versus ≥200 CD4+ cells/µL (P = .95).

CONCLUSION

Our findings support the use of PD-1 blockade in HIV-cHL for the same indications as the general population with cHL.

Differential susceptibility of cells infected with defective and intact HIV proviruses to killing by obatoclax and other small molecules

OBJECTIVES

Some drugs that augment cell-intrinsic defenses or modulate cell death/survival pathways have been reported to selectively kill cells infected with HIV or Simian Immunodeficiency Virus (SIV), but comparative studies are lacking. We hypothesized that these drugs may differ in their ability to kill cells infected with intact and defective proviruses.

DESIGN

To investigate this hypothesis, drugs were tested ex vivo on peripheral blood mononuclear cells (PBMC) from nine antiretroviral therapy (ART)-suppressed individuals.

METHODS

We tested drugs currently in clinical use or human trials, including auranofin (p53 modulator), interferon alpha2A, interferon gamma, acitretin (RIG-I inducer), GS-9620/vesatolimod (TLR7 agonist), nivolumab (PD-1 blocker), obatoclax (Bcl-2 inhibitor), birinapant [inhibitor of apoptosis proteins (IAP) inhibitor], bortezomib (proteasome inhibitor), and INK128/sapanisertib [mammalian target of rapamycin mTOR] [c]1/2 inhibitor). After 6 days of treatment, we measured cell counts/viabilities and quantified levels of total, intact, and defective HIV DNA by droplet digital PCR (Intact Proviral DNA Assay).

RESULTS

Obatoclax reduced intact HIV DNA [median = 27-30% of dimethyl sulfoxide control (DMSO)] but not defective or total HIV DNA. Other drugs showed no statistically significant effects.

CONCLUSION

Obatoclax and other Bcl-2 inhibitors deserve further study in combination therapies aimed at reducing the intact HIV reservoir in order to achieve a functional cure and/or reduce HIV-associated immune activation.

Immune checkpoint inhibition as a therapeutic strategy for HIV eradication: current insights and future directions

PURPOSE OF REVIEW

HIV-1 infection contributes substantially to global morbidity and mortality, with no immediate promise of an effective prophylactic vaccine. Combination antiretroviral therapy (ART) suppresses HIV replication, but latent viral reservoirs allow the virus to persist and reignite active replication if ART is discontinued. Moreover, inflammation and immune disfunction persist despite ART-mediated suppression of HIV. Immune checkpoint molecules facilitate immune dysregulation and viral persistence. However, their therapeutic modulation may offer an avenue to enhance viral immune control for patients living with HIV-1 (PLWH).

RECENT FINDINGS

The success of immune checkpoint inhibitor (ICI) therapy in oncology suggests that targeting these same immune pathways might be an effective therapeutic approach for treating PLWH. Several ICIs have been evaluated for their ability to reinvigorate exhausted T cells, and possibly reverse HIV latency, in both preclinical and clinical HIV-1 studies.

SUMMARY

Although there are very encouraging findings showing enhanced CD8 + T-cell function with ICI therapy in HIV infection, it remains uncertain whether ICIs alone could demonstrably impact the HIV reservoir. Moreover, safety concerns and significant clinical adverse events present a hurdle to the development of ICI approaches. This review provides an update on the current knowledge regarding the development of ICIs for the remission of HIV-1 in PWH. We detail recent findings from simian immunodeficiency virus (SIV)-infected rhesus macaque models, clinical trials in PLWH, and the role of soluble immune checkpoint molecules in HIV pathogenesis.

Pembrolizumab in an HIV-infected patient with glioblastoma

Persons living with human immunodeficiency virus (PLWH) carry increased risk for developing malignancies, including glioblastoma. Despite extensive investigations, both human immunodeficiency virus (HIV) and glioblastoma are incurable. Treatment for a patient with combined glioblastoma and HIV remains an unexplored need. Preliminary evidence suggests that immunotherapy may be effective for the simultaneous treatment of both HIV and cancer by reversing HIV latency and T cell exhaustion. We present a case of glioblastoma in a PLWH who was treated with pembrolizumab. Treatment was well tolerated and safe with a mixed response. Our patient did not develop any opportunistic infections, immune-related adverse events, or worsening of his immunodeficiency. To our knowledge, this is the first reported case of a PLWH and glioblastoma treated with immunotherapy.

Immune targeting of HIV-1 reservoir cells: a path to elimination strategies and cure

Successful approaches for eradication or cure of HIV-1 infection are likely to include immunological mechanisms, but remarkably little is known about how human immune responses can recognize and interact with the few HIV-1-infected cells that harbour genome-intact viral DNA, persist long term despite antiretroviral therapy and represent the main barrier to a cure. For a long time regarded as being completely shielded from host immune responses due to viral latency, these cells do, on closer examination with single-cell analytic techniques, display discrete footprints of immune selection, implying that human immune responses may be able to effectively engage and target at least some of these cells. The failure to eliminate rebound-competent virally infected cells in the majority of persons likely reflects the evolution of a highly selected pool of reservoir cells that are effectively camouflaged from immune recognition or rely on sophisticated approaches for resisting immune-mediated killing. Understanding the fine-tuned interplay between host immune responses and viral reservoir cells will help to design improved interventions that exploit the immunological vulnerabilities of HIV-1 reservoir cells.

PROTAC-mediated degradation of HIV-1 Nef efficiently restores cell-surface CD4 and MHC-I expression and blocks HIV-1 replication

The HIV-1 Nef accessory factor enhances the viral life cycle in vivo, promotes immune escape of HIV-infected cells, and represents an attractive antiretroviral drug target. However, Nef lacks enzymatic activity and an active site, complicating traditional occupancy-based drug development. Here we describe the development of proteolysis targeting chimeras (PROTACs) for the targeted degradation of Nef. Nef-binding compounds, based on an existing hydroxypyrazole core, were coupled to ligands for ubiquitin E3 ligases via flexible linkers. The resulting bivalent PROTACs induced formation of a ternary complex between Nef and the cereblon E3 ubiquitin ligase thalidomide-binding domain in vitro and triggered Nef degradation in a T cell expression system. Nef-directed PROTACs efficiently rescued Nef-mediated MHC-I and CD4 downregulation in T cells and suppressed HIV-1 replication in donor PBMCs. Targeted degradation is anticipated to reverse all HIV-1 Nef functions and may help restore adaptive immune responses against HIV-1 reservoir cells in vivo.

Expression and prognostic significance of the PD-1/PD-L1 pathway in AIDS-related non-Hodgkin lymphoma

OBJECTIVE

Immune tolerance and evasion play a critical role in virus-driven malignancies. However, the phenotype and clinical significance of programmed cell death 1 (PD-1) and its ligands, PD-L1 and PD-L2, in aggressive acquired immunodeficiency syndrome (AIDS)-related non-Hodgkin lymphoma (AR-NHL) remain poorly understood, particularly in the Epstein-Barr virus (EBV)-positive subset.

METHODS

We used in situ hybridization with EBV-encoded RNA (EBER) to assess the EBV status. We performed immunohistochemistry and flow cytometry analysis to evaluate components of the PD-1/PD-L1/L2 pathway in a multi-institutional cohort of 58 patients with AR-NHL and compared EBV-positive and EBV-negative cases.

RESULTS

The prevalence of EBV+ in AR-NHL was 56.9% and was associated with a marked increase in the expression of PD-1/PD-L1/PD-L2 in malignant cells. Patients with AR-NHLs who tested positive for both EBER and PD-1 exhibited lower survival rates compared to those negative for these markers (47.4% vs. 93.8%, p = 0.004). Similarly, patients positive for both EBER and PD-L1 also demonstrated poorer survival (56.5% vs. 93.8%, p = 0.043). Importantly, PD-1 tissue-expression demonstrated independent prognostic significance for overall survival in multivariate analysis and was correlated to elevated levels of LDH (r = 0.313, p = 0.031), increased PD-1+ Tregs (p = 0.006), and robust expression of EBER (r = 0.541, p < 0.001) and PD-L1 (r = 0.354, p = 0.014) expression.

CONCLUSIONS

These data emphasize the importance of PD-1-mediated immune evasion in the complex landscape of immune oncology in AR-NHL co-infected with EBV, and contribute to the diagnostic classification and possible definition of immunotherapeutic strategies for this unique subgroup.

Kaposi's sarcoma: epidemiologic aspects, the immune reconstitution inflammatory syndrome, and more along the Silk Road of cognition

Kaposi's sarcoma remains enignmatic with many clinical and epidemiological patterns. We review them and describe the groove sign, an important association worthy of recognition. We also stress Kaposi's sarcoma (KS) without coexistent human immunodefiency virus infection, with recent data from China describing an extraordinarily high classical KS prevalence rate among Uygurs and Kazaks in the Xinjiang Uygur Autonomous Region in northwestern China, presumably derived from elderly men residing there. The possible travel of HHV-8 along the ancient silk road from Italy to the Xinjiang Uyghur region remains intriguing. If only one in 10,000 HHV-8-infected patients develops classical KS worldwide, then triggers for its overrepresentation in this population within China are of particular concern. The KS-related immune reconstitution inflammatory syndrome is also emphasized.

A novel high-throughput microwell outgrowth assay for HIV-infected cells

Although antiretroviral therapy (ART) is effective at suppressing HIV replication, a viral reservoir persists that can reseed infection if ART is interrupted. Curing HIV will require elimination or containment of this reservoir, but the size of the HIV reservoir is highly variable between individuals. To evaluate the size of the HIV reservoir, several assays have been developed, including PCR-based assays for viral DNA, the intact proviral DNA assay, and the quantitative viral outgrowth assay (QVOA). QVOA is the gold standard assay for measuring inducible replication-competent proviruses, but this assay is technically challenging and time-consuming. To begin progress toward a more rapid and less laborious tool for quantifying cells infected with replication-competent HIV, we developed the Microwell Outgrowth Assay, in which infected CD4 T cells are co-cultured with an HIV-detecting reporter cell line in a polydimethylsiloxane (PDMS)/polystyrene array of nanoliter-sized wells. Transmission of HIV from infected cells to the reporter cell line induces fluorescent reporter protein expression that is detected by automated scanning across the array. Using this approach, we were able to detect HIV-infected cells from ART-naïve people with HIV (PWH) and from PWH on ART with large reservoirs. Furthermore, we demonstrate that infected cells can be recovered from individual rafts and used to analyze the diversity of viral sequences. Although additional development and optimization will be required for quantifying the reservoir in PWH with small latent reservoirs, this assay may be a useful prototype for microwell assays of infected cells.IMPORTANCEMeasuring the size of the HIV reservoir in people with HIV (PWH) will be important for determining the impact of HIV cure strategies. However, measuring this reservoir is challenging. We report a new method for quantifying HIV-infected cells that involves culturing cells from PWH in an array of microwells with a cell line that detects HIV infection. We show that this approach can detect rare HIV-infected cells and derive detailed virus sequence information for each infected cell.

Inhibition of SFTSV replication in humanized mice by a subcutaneously administered anti-PD1 nanobody

Severe fever with thrombocytopenia syndrome (SFTS) is a life-threatening disease caused by a novel bunyavirus (SFTSV), mainly transmitted by ticks. With no effective therapies or vaccines available, understanding the disease's mechanisms is crucial. Recent studies found increased expression of programmed cell death-1 (PD-1) on dysfunctional T cells in SFTS patients. However, the role of the PD-1/programmed cell death-ligand 1 (PD-L1) pathway in SFTS progression remains unclear. We investigated PD-1 blockade as a potential therapeutic strategy against SFTSV replication. Our study analyzed clinical samples and performed in vitro experiments, revealing elevated PD-1/PD-L1 expression in various immune cells following SFTSV infection. An anti-PD-1 nanobody, NbP45, effectively inhibited SFTSV infection in peripheral blood mononuclear cells (PBMCs), potentially achieved through the mitigation of apoptosis and the augmentation of T lymphocyte proliferation. Intriguingly, subcutaneous administration of NbP45 showed superior efficacy compared to a licensed anti-PD-1 antibody in an SFTSV-infected humanized mouse model. These findings highlight the involvement of the PD-1/PD-L1 pathway during acute SFTSV infection and suggest its potential as a host target for immunotherapy interventions against SFTSV infection.

Safety and Immune Responses Following Anti-PD-1 Monoclonal Antibody Infusions in Healthy Persons With Human Immunodeficiency Virus on Antiretroviral Therapy

Background

T cells in people with human immunodeficiency virus (HIV) demonstrate an exhausted phenotype, and HIV-specific CD4+ T cells expressing programmed cell death 1 (PD-1) are enriched for latent HIV, making antibody to PD-1 a potential strategy to target the latent reservoir.

Methods

This was a phase 1/2, randomized (4:1), double-blind, placebo-controlled study in adults with suppressed HIV on antiretroviral therapy with CD4+ counts ≥350 cells/μL who received 2 infusions of cemiplimab versus placebo. The primary outcome was safety, defined as any grade 3 or higher adverse event (AE) or any immune-related AE (irAE). Changes in HIV-1-specific polyfunctional CD4+ and CD8+ T-cell responses were evaluated.

Results

Five men were enrolled (median CD4+ count, 911 cells/μL; median age, 51 years); 2 received 1 dose of cemiplimab, 2 received 2 doses, and 1 received placebo. One participant had a probable irAE (thyroiditis, grade 2); another had a possible irAE (hepatitis, grade 3), both after a single low-dose (0.3 mg/kg) infusion. The Safety Monitoring Committee recommended no further enrollment or infusions. All 4 cemiplimab recipients were followed for 48 weeks. No other cemiplimab-related serious AEs, irAEs, or grade 3 or higher AEs occurred. One 2-dose recipient of cemiplimab had a 6.2-fold increase in polyfunctional, Gag-specific CD8+ T-cell frequency with supportive increases in plasma HIV RNA and decreases in total HIV DNA.

Conclusions

One of 4 participants exhibited increased HIV-1-specific T-cell responses and transiently increased HIV-1 expression following 2 cemiplimab infusions. The occurrence of irAEs after a single, low dose may limit translating the promising therapeutic results of cemiplimab for cancer to immunotherapeutic and latency reversal strategies for HIV. Clinical Trials Registration. NCT03787095.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

TRIAL REGISTRATION

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

Breaking the Silence: Regulation of HIV Transcription and Latency on the Road to a Cure

Antiretroviral therapy (ART) has brought the HIV/AIDS epidemic under control, but a curative strategy for viral eradication is still needed. The cessation of ART results in rapid viral rebound from latently infected CD4+ T cells, showing that control of viral replication alone does not fully restore immune function, nor does it eradicate viral reservoirs. With a better understanding of factors and mechanisms that promote viral latency, current approaches are primarily focused on the permanent silencing of latently infected cells ("block and lock") or reactivating HIV-1 gene expression in latently infected cells, in combination with immune restoration strategies to eliminate HIV infected cells from the host ("shock and kill"). In this review, we provide a summary of the current, most promising approaches for HIV-1 cure strategies, including an analysis of both latency-promoting agents (LPA) and latency-reversing agents (LRA) that have shown promise in vitro, ex vivo, and in human clinical trials to reduce the HIV-1 reservoir.

Immune checkpoint inhibitors as potential therapy for reverting T-cell exhaustion and reverting HIV latency in people living with HIV

The immune system of people living with HIV (PLWH) is persistently exposed to antigens leading to systemic inflammation despite combination antiretroviral treatment (cART). This inflammatory milieu promotes T-cell activation and exhaustion. Furthermore, it produces diminished effector functions including loss of cytokine production, cytotoxicity, and proliferation, leading to disease progression. Exhausted T cells show overexpression of immune checkpoint molecules (ICs) on the cell surface, including programmed cell death protein 1 (PD-1), cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4), T-cell immunoglobulin and mucin-domain containing-3 (TIM-3), T-cell immunoglobulin and immunoreceptor tyrosine-based inhibitory motif domain (TIGIT), and lymphocyte activation gene-3 (LAG-3). The ICs also play a crucial role in T-cell exhaustion by reducing the immune response to cancer antigens. Immunotherapy based on immune checkpoint inhibitors (ICIs) has changed the management of a diversity of cancers. Additionally, the interest in exploring this approach in the setting of HIV infection has increased, including AIDS-defining cancers and non-AIDS-defining cancers in PLWH. To date, research on this topic suggests that ICI-based therapies in PLWH could be a safe and effective approach. In this review, we provide an overview of the current literature on the potential role of ICI-based immunotherapy not only in cancer remission in PLWH but also as a therapeutic intervention to restore immune response against HIV, revert HIV latency, and attain a functional cure for HIV infection.

Pharmacological and Behavioral Interventions to Mitigate Premature Aging in Patients with HIV

PURPOSE OF REVIEW

We sought to review pharmacological and behavioral interventions that have been publicly presented, published, or are currently ongoing to prevent or mitigate the effect of premature HIV-associated comorbidities.

RECENT FINDINGS

Multiple studies have been conducted in hopes of finding an effective intervention. While the choice of antiretroviral regimen influences recovery of immune function, several drugs used as adjunct treatments have proven effective to mitigate premature aging. Additionally, few behavioral interventions have exhibited some efficacy. Statins, angiotensin-receptor blockers, and anti-hyperglycemic agents as well as optimal adherence, exercise, and intermittent fasting among others have had beneficial impact on markers of immune activation and levels of inflammatory biomarkers. However, several investigations had inconclusive outcomes so further studies with larger sample sizes are warranted.

GITR activation ex vivo impairs CD8 T cell function in people with HIV on antiretroviral therapy

Glucocorticoid-induced tumor necrosis factor related protein (GITR) is a co-stimulatory immune checkpoint molecule constitutively expressed on regulatory T cells (Tregs) and on activated T conventional cells (Tconv). In blood collected from PWH on suppressive ART, GITR expression was reduced in multiple activated CD4 and CD8 T cell subsets but was increased in Tregs. HIV specific CD8 T cells expressed higher levels of GITR and programmed cell death protein 1 (PD-1) compared to total CD8 T cells. Following stimulation with HIV peptides and GITR-ligand (L), we demonstrated a significant decrease in killing by HIV specific CD8 T cells and an increased exhausted profile. T cell receptor co-stimulation with GITR-L abrogated Treg suppression and induced expansion of CD4 Tconv. We conclude that GITR activation is an additional factor contributing to an impaired HIV immune response in PWH on ART and that GITR agonist antibodies should not be pursued for HIV cure strategies.

Bcl-2 Antagonist Obatoclax Reactivates Latent HIV-1 via the NF-κB Pathway and Induces Latent Reservoir Cell Apoptosis in Latently Infected Cells

The implementation of combined antiretroviral therapy (cART) has rendered HIV-1 infection clinically manageable and efficiently improves the quality of life for patients with AIDS. However, the persistence of a latent HIV-1 reservoir is a major obstacle to achieving a cure for AIDS. A "shock and kill" strategy aims to reactivate latent HIV and then kill it by the immune system or cART drugs. To date, none of the LRA candidates has yet demonstrated effectiveness in achieving a promising functional cure. Interestingly, the phosphorylation and activation of antiapoptotic Bcl-2 protein induce resistance to apoptosis during HIV-1 infection and the reactivation of HIV-1 latency in central memory CD4+ T cells from HIV-1-positive patients. Therefore, a Bcl-2 antagonist might be an effective LRA candidate for HIV-1 cure. In this study, we reported that a pan-Bcl-2 antagonist obatoclax induces HIV-1 reactivation in latently infected cell lines in vitro and in PBMCs/CD4+ T cells of HIV-infected individuals ex vivo. Obatoclax promotes HIV-1 transcriptional initiation and elongation by regulating the NF-κB pathway. Obatoclax activates caspase 8 and does not induce the phosphorylation of the antiapoptotic protein Bcl-2 in latent HIV-1 infected cell lines. More importantly, it preferentially induces apoptosis in latently infected cells. In addition, obatoclax exhibited potent anti-HIV-1 activity on target cells. The abilities to reactivate latent HIV-1 reservoirs, inhibit HIV-1 infection, and induce HIV-1 latent cell apoptosis make obatoclax worth investigating for development as an ideal LRA for use in the "shock and kill" approach.

Immune Checkpoint Inhibitors and Infection: What Is the Interplay?

Immune checkpoint molecules are receptors expressed on immune cells, especially T-cells, which activate immunosuppressive pathways and lead them to a state known as T-cell exhaustion. Immune checkpoint inhibitors (ICIs) constitute a group of specific antibodies that target these molecules, restoring T-cell effector function. Several ICIs have already been approved by the FDA as therapeutic options for certain malignancies. However, evidence in the literature remains unclear regarding the possible risk of infection in patients receiving this treatment. A thorough examination of existing literature was carried out to investigate whether the use of ICIs increases the likelihood of specific infections and to explore the potential beneficial effects of ICIs on the treatment of infections. Our review found most infectious complications are related to immunosuppressive therapy for immune-related adverse events caused by checkpoint blockade. Current evidence shows that ICIs per se do not seem to generally increase the risk of infection, yet they might increase susceptibility to certain infections, such as tuberculosis. On the other hand, reinvigoration of immune responses triggered by ICIs might play a significant role in pathogen clearance, establishing a possible positive impact of ICIs, especially on chronic infectious diseases, such as HIV infection. Data from preclinical models are limited and larger clinical trials are warranted to shed more light on the effect of immune checkpoint blockade on specific pathogens.

Proviral location affects cognate peptide-induced virus production and immune recognition of HIV-1-infected T cell clones

BACKGROUNDHIV-1-infected CD4+ T cells contribute to latent reservoir persistence by proliferating while avoiding immune recognition. Integration features of intact proviruses in elite controllers (ECs) and people on long-term therapy suggest that proviruses in specific chromosomal locations can evade immune surveillance. However, direct evidence of this mechanism is missing.METHODSIn this case report, we characterized integration sites and full genome sequences of expanded T cell clones in an EC before and after chemoradiation. We identified the cognate peptide of infected clones to investigate cell proliferation and virus production induced by T cell activation, and susceptibility to autologous CD8+ T cells.RESULTSThe proviral landscape was dominated by 2 large clones with replication-competent proviruses integrated into zinc finger (ZNF) genes (ZNF470 and ZNF721) in locations previously associated with deeper latency. A third nearly intact provirus, with a stop codon in Pol, was integrated into an intergenic site. Upon stimulation with cognate Gag peptides, infected clones proliferated extensively and produced virus, but the provirus in ZNF721 was 200-fold less inducible. While autologous CD8+ T cells decreased the proliferation of cells carrying the intergenic provirus, they had no effect on cells with the provirus in the ZNF721 gene.CONCLUSIONSWe provide direct evidence that upon activation of infected clones by cognate antigen, the lower inducibility of intact proviruses in ZNF genes can result in immune evasion and persistence.FUNDINGOffice of the NIH Director and National Institute of Dental & Craniofacial Research; NIAID, NIH; Johns Hopkins University Center for AIDS Research.

Identifying physiological tissue niches that support the HIV reservoir in T cells

Successful antiretroviral therapy (ART) can efficiently suppress Human Immunodeficiency Virus-1 (HIV-1) replication to undetectable levels, but rare populations of infected memory CD4+ T cells continue to persist, complicating viral eradication efforts. Memory T cells utilize distinct homing and adhesion molecules to enter, exit, or establish residence at diverse tissue sites, integrating cellular and environmental cues that maintain homeostasis and life-long protection against pathogens. Critical roles for T cell receptor and cytokine signals driving clonal expansion and memory generation during immunity generation are well established, but whether HIV-infected T cells can utilize similar mechanisms for their own long-term survival is unclear. How infected, but transcriptionally silent T cells maintain their recirculation potential through blood and peripheral tissues, or whether they acquire new capabilities to establish unique peripheral tissue niches, is also not well understood. In this review, we will discuss the cellular and molecular cues that are important for memory T cell homeostasis and highlight opportunities for HIV to hijack normal immunological processes to establish long-term viral persistence.

Immunotherapy-induced cytotoxic T follicular helper cells reduce numbers of retrovirus-infected reservoir cells in B cell follicles

Antiretroviral therapy (ART) transformed HIV from a life-threatening disease to a chronic condition. However, eliminating the virus remains an elusive therapy goal. For several decades, Friend virus (FV) infection serves as a murine model to study retrovirus immunity. Similar to HIV, FV persists at low levels in lymph nodes B cell follicles avoiding elimination by immune cells. Such immune-privileged reservoirs exclude cytotoxic T cells from entry. However, CXCR5+ T cells are permitted to traffic through germinal centers. This marker is predominantly expressed by CD4+ follicular helper T cells (Tfh). Therefore, we explored immunotherapy to induce cytotoxic Tfh, which are rarely found under physiological conditions. The TNF receptor family member CD137 was first identified as a promising target for cancer immunotherapy. We demonstrated that FV-infected mice treatment with αCD137 antibody resulted in an induction of the cytotoxic program in Tfh. The therapy significantly increased numbers of cytotoxic Tfh within B cell follicles and contributed to viral load reduction. Moreover, αCD137 antibody combined with ART delayed virus rebound upon treatment termination without disturbing the lymph node architecture or antibody responses. Thus, αCD137 antibody therapy might be a novel strategy to target the retroviral reservoir and an interesting approach for HIV cure research.

The safety and efficacy of PD-1 inhibitors in patients with advanced cancers and HIV/AIDS in China

Purpose-Immunotherapy has revolutionized cancer therapy, becoming the standard of care for various malignancy treatments. Human immunodeficiency virus (HIV) patients, however, are an underserved group with limited access to clinical trials and cancer therapy. This study was to evaluate the safety and efficacy of programmed cell death 1 (PD - 1) inhibitors in patients with advanced cancer and HIV/acquired immunodeficiency syndrome (AIDS). Methods and Materials-We performed a prospective, open-label, nonrandomized, phase 1 single center study. Patients with advanced cancer and HIV/AIDS received the treatment of PD - 1 inhibitors (camrelizumab, 200 mg, administered intravenously every 3 weeks), along with combination antiretroviral therapy (cART) for HIV. Results-Sixteen participants (12 men and 4 women; median age, 46.5 (29 - 78) years) were enrolled; 1 had non - Hodgkin lymphoma (NHL), and 15 had non - AIDS - defining cancers. Safety was observed over 130 cycles of treatment with camrelizumab. Most treatment-emergent adverse events at least possibly attributed to camrelizumab were grade 1 or 2, including reactive cutaneous capillary endothelial proliferation (RCCEP) (9 participants), hearing loss (1 participant), hypophysitis (1 participant). 3 participants experienced hemorrhage due to poor performance status. HIV was controlled in all participants. Best tumor responses included 3 complete response, 5 partial response, 2 stable disease, and 6 progressive disease. The 2 years progression-free survival (PFS) was 67.0% (95% CI: -0.05, 0.00) and overall survival (OS) was 55.3% (95% CI: -0.05, 0.01) for the 16 patients who had received camrelizumab. Conclusions-This study demonstrates that camrelizumab treatment in patients with advanced cancers and HIV/AIDS was feasible and the clinical outcomes were acceptable.

Selective loss of CD107a TIGIT+ memory HIV-1-specific CD8+ T cells in PLWH over a decade of ART

The co-expression of inhibitory receptors (IRs) is a hallmark of CD8+ T-cell exhaustion (Tex) in people living with HIV-1 (PLWH). Understanding alterations of IRs expression in PLWH on long-term antiretroviral treatment (ART) remains elusive but is critical to overcoming CD8+ Tex and designing novel HIV-1 cure immunotherapies. To address this, we combine high-dimensional supervised and unsupervised analysis of IRs concomitant with functional markers across the CD8+ T-cell landscape on 24 PLWH over a decade on ART. We define irreversible alterations of IRs co-expression patterns in CD8+ T cells not mitigated by ART and identify negative associations between the frequency of TIGIT+ and TIGIT+ TIM-3+ and CD4+ T-cell levels. Moreover, changes in total, SEB-activated, and HIV-1-specific CD8+ T cells delineate a complex reshaping of memory and effector-like cellular clusters on ART. Indeed, we identify a selective reduction of HIV-1 specific-CD8+ T-cell memory-like clusters sharing TIGIT expression and low CD107a that can be recovered by mAb TIGIT blockade independently of IFNγ and IL-2. Collectively, these data characterize with unprecedented detail the patterns of IRs expression and functions across the CD8+ T-cell landscape and indicate the potential of TIGIT as a target for Tex precision immunotherapies in PLWH at all ART stages.

PROTAC-mediated Degradation of HIV-1 Nef Efficiently Restores Cell-surface CD4 and MHC-I Expression and Blocks HIV-1 Replication

The HIV-1 Nef accessory factor is critical to the viral life cycle in vivo where it promotes immune escape of HIV-infected cells and viral persistence. While these features identify Nef as an attractive antiretroviral drug target, Nef lacks enzymatic activity and an active site, complicating development of occupancy-based drugs. Here we describe the development of proteolysis targeting chimeras (PROTACs) for the targeted degradation of Nef. Nef-binding compounds, based on a previously reported hydroxypyrazole core, were coupled to ligands for ubiquitin E3 ligases via flexible linkers. The resulting bivalent PROTACs induced formation of a ternary complex between Nef and the Cereblon E3 ubiquitin ligase, resulting in ubiquitylation of Nef and proteolytic degradation. Nef-directed PROTACs efficiently rescued Nef-mediated MHC-I and CD4 downregulation in T cells and suppressed HIV-1 replication in donor PBMCs. Targeted degradation of Nef is anticipated to reverse all HIV-1 Nef functions and may help restore adaptive immune responses against HIV-1 reservoir cells in vivo .

The efficacy and tolerability of latency-reversing agents in reactivating the HIV-1 reservoir in clinical studies: a systematic review

Introduction

Understanding the clinical potency of latency-reversing agents (LRAs) on the HIV-1 reservoir is useful to deploy future strategies. This systematic review evaluated the effects of LRAs in human intervention studies.

Methods

A literature search was performed using medical databases focusing on studies with adults living with HIV-1 receiving LRAs. Eligibility criteria required participants from prospective clinical studies, a studied compound hypothesised as LRA, and reactivation or tolerability assessments. Relevant demographical data, LRA reactivation capacity, reservoir size, and adverse events were extracted. A study quality assessment with analysis of bias was performed by RoB 2 and ROBINS-I tools. The primary endpoints were HIV-1 reservoir reactivation after LRA treatment quantified by cell-associated unspliced HIV-1 RNA, and LRA tolerability defined by adverse events. Secondary outcomes were reservoir size and the effect of LRAs on analytical treatment interruption (ATI) duration.

Results

After excluding duplicates, 5182 publications were screened. In total 45 publications fulfilled eligibility criteria including 26 intervention studies and 16 randomised trials. The risk of bias was evaluated as high. Chromatin modulators were the main investigated LRA class in 24 studies. Participants were mostly males (90.1%). Where reported, HIV-1 subtype B was most frequently observed. Reactivation after LRA treatment occurred in 78% of studies and was observed with nearly all chromatin modulators. When measured, reactivation mostly occurred within 24 h after treatment initiation. Combination LRA strategies have been infrequently studied and were without synergistic reactivation. Adverse events, where reported, were mostly low grade, yet occurred frequently. Seven studies had individuals who discontinued LRAs for related adverse events. The reservoir size was assessed by HIV-1 DNA in 80% of studies. A small decrease in reservoir was observed in three studies on immune checkpoint inhibitors and the histone deacetylase inhibitors romidepsin and chidamide. No clear effect of LRAs on ATI duration was observed.

Conclusion

This systematic review provides a summary of the reactivation of LRAs used in current clinical trials whilst highlighting the importance of pharmacovigilance. Highly heterogeneous study designs and underrepresentation of relevant patient groups are to be considered when interpreting these results. The observed reactivation did not lead to cure or a significant reduction in the size of the reservoir. Finding more effective LRAs by including well-designed studies are needed to define the required reactivation level to reduce the HIV-1 reservoir.

Immunophenotypic analysis in participants with Kaposi sarcoma following pomalidomide administration

OBJECTIVE

The aim of this study was to evaluate baseline differences by HIV status and the impact of pomalidomide on lymphocyte counts and T-cell subsets in patients with Kaposi sarcoma.

DESIGN

We prospectively evaluated CD4 + and CD8 + T-cell phenotypes in 19 participants with Kaposi sarcoma enrolled on a phase 1/2 study of pomalidomide (NCT01495598), seven without HIV and 12 with HIV on antiretroviral therapy.

METHODS

Trial participants received pomalidomide 5 mg orally for 21 days of 28-day cycles for up to 1 year. Flow cytometry was performed on peripheral blood mononuclear cells at baseline, after three cycles, and at end-of-treatment. Lymphocyte count and T-cell subset comparisons were evaluated by Wilcoxon signed-rank and Mann--Whitney tests.

RESULTS

At baseline, HIV + participants had lower CD4 + cell counts (median 416 vs. 742 CD4 + T cells/μl, P  = 0.006), and a decreased proportion of CD57 + (senescent) CD8 + T cells ( P  = 0.007) compared with HIV - participants. After three cycles, pomalidomide led to an increased proportion of CD45RO + CD27 + (central memory) CD4 + ( P  = 0.002) and CD8 + ( P  = 0.002) T cells, a decrease in CD45RO - CD27 - (effector) CD4 + cells ( P  = 0.0002), and expansion of CD38 + /HLADR + (activated) CD4 + ( P  = 0.002) and CD8 + ( P  ≤ 0.0001) T cells. Increased numbers of activated CD8 + T cells persisted at end-of-treatment ( P  = 0.002). After three cycles and at end-of-treatment, there was reduction in the proportion of CD57 + (senescent) CD4 + ( P  = 0.001, 0.0006), and CD8 + ( P  =  < 0.0001, 0.0004) T cells.

CONCLUSION

Administration of pomalidomide decreased T-cell senescence and increased T-cell activation in patients with Kaposi sarcoma, suggesting pomalidomide activity in Kaposi sarcoma stems in part from its immunomodulatory effects.

New Concepts in Therapeutic Manipulation of HIV-1 Transcription and Latency: Latency Reversal versus Latency Prevention

Antiretroviral therapy (ART) has dramatically improved the prognosis for people living with HIV-1, but a cure remains elusive. The largest barrier to a cure is the presence of a long-lived latent reservoir that persists within a heterogenous mix of cell types and anatomical compartments. Efforts to eradicate the latent reservoir have primarily focused on latency reversal strategies. However, new work has demonstrated that the majority of the long-lived latent reservoir is established near the time of ART initiation, suggesting that it may be possible to pair an intervention with ART initiation to prevent the formation of a sizable fraction of the latent reservoir. Subsequent treatment with latency reversal agents, in combination with immune clearance agents, may then be a more tractable strategy for fully clearing the latent reservoir in people newly initiating ART. Here, we summarize molecular mechanisms of latency establishment and maintenance, ongoing efforts to develop effective latency reversal agents, and newer efforts to design latency prevention agents. An improved understanding of the molecular mechanisms involved in both the establishment and maintenance of latency will aid in the development of new latency prevention and reversal approaches to ultimately eradicate the latent reservoir.

Safety and Activity of Immune Checkpoint Inhibitors in People Living With HIV and Cancer: A Real-World Report From the Cancer Therapy Using Checkpoint Inhibitors in People Living With HIV-International (CATCH-IT) Consortium

PURPOSE

Compared with people living without HIV (PWOH), people living with HIV (PWH) and cancer have traditionally been excluded from immune checkpoint inhibitor (ICI) trials. Furthermore, there is a paucity of real-world data on the use of ICIs in PWH and cancer.

METHODS

This retrospective study included PWH treated with anti-PD-1- or anti-PD-L1-based therapies for advanced cancers. Kaplan-Meier method was used to estimate overall survival (OS) and progression-free survival (PFS). Objective response rates (ORRs) were measured per RECIST 1.1 or other tumor-specific criteria, whenever feasible. Restricted mean survival time (RMST) was used to compare OS and PFS between matched PWH and PWOH with metastatic NSCLC (mNSCLC).

RESULTS

Among 390 PWH, median age was 58 years, 85% (n = 331) were males, 36% (n = 138) were Black; 70% (n = 274) received anti-PD-1/anti-PD-L1 monotherapy. Most common cancers were NSCLC (28%, n = 111), hepatocellular carcinoma ([HCC]; 11%, n = 44), and head and neck squamous cell carcinoma (HNSCC; 10%, n = 39). Seventy percent (152/216) had CD4+ T cell counts ≥200 cells/µL, and 94% (179/190) had HIV viral load <400 copies/mL. Twenty percent (79/390) had any grade immune-related adverse events (irAEs) and 7.7% (30/390) had grade ≥3 irAEs. ORRs were 69% (nonmelanoma skin cancer), 31% (NSCLC), 16% (HCC), and 11% (HNSCC). In the matched mNSCLC cohort (61 PWH v 110 PWOH), 20% (12/61) PWH and 22% (24/110) PWOH had irAEs. Adjusted 42-month RMST difference was -0.06 months (95% CI, -5.49 to 5.37; P = .98) for PFS and 2.23 months (95% CI, -4.02 to 8.48; P = .48) for OS.

CONCLUSION

Among PWH, ICIs demonstrated differential activity across cancer types with no excess toxicity. Safety and activity of ICIs were similar between matched cohorts of PWH and PWOH with mNSCLC.

Treating Cancer in People With HIV

The Oncology Grand Rounds series is designed to place original reports published in the Journal into clinical context. A case presentation is followed by a description of diagnostic and management challenges, a review of the relevant literature, and a summary of the authors' suggested management approaches. The goal of this series is to help readers better understand how to apply the results of key studies, including those published in Journal of Clinical Oncology, to patients seen in their own clinical practice.People with HIV (PWH) have an increased lifetime risk of developing certain cancers, even when HIV is well-controlled with antiretroviral therapy. Despite the tremendous advancements in HIV and cancer care over the past several decades, PWH have lower cancer-related survival compared with the general population. Treating HIV-associated cancers requires a multidisciplinary team to manage concurrent opportunistic infections, potential drug-drug interactions, and the co-occurrence of more than one cancer in the same patient. Many factors may lead PWH to receive inappropriate dose adjustments, exclusion from emerging therapies and clinical trials, or no cancer therapy at all. In general, PWH should receive the same standard, full-dose cancer therapy used in the general population unless there are data for specific cancer regimens in PWH. Agents targeting PD-1 and PD-L1 have US Food and Drug Administration (FDA)-approved indications in many HIV-associated cancers, including Hodgkin lymphoma, cervical cancer, head and neck cancer, hepatocellular carcinoma, and non-small-cell lung cancer; however, PWH were excluded from all clinical trials that led to FDA approval of these agents. Several prospective studies and an international retrospective study of PWH with advanced cancer have shown anti-PD-(L)-1 agents to be safe and effective across expected cancer types and CD4+ T-cell counts, supporting their use in PWH for FDA-approved indications. Learning from the experience in anti-PD-(L)-1 agents, future cancer clinical trials should include and seek to actively enroll PWH, so that they have equal and timely access to emerging cancer therapies.

Clinical trials aimed at HIV cure or remission: new pathways and lessons learned

INTRODUCTION

The main barrier to finding a cure against HIV is the latent HIV reservoir, which persists in people living with HIV (PLWH) despite antiretroviral treatment (ART). Here, we discuss recent findings from interventional studies using mono- and combination therapies aimed at enhancing immune-mediated killing of the virus with or without activating HIV from latency.

AREAS COVERED

We discuss latency reversal agents (LRAs), broadly neutralizing antibodies, immunomodulatory therapies, and studies aimed at inducing apoptosis.

EXPERT OPINION

The landscape of clinical trials for HIV cure and remission has evolved considerably over the past 10 years. Several novel interventions such as immune checkpoint inhibitors, therapeutic vaccines, and broadly neutralizing antibodies have been tested either alone or in combination with LRAs but studies have so far not shown a meaningful impact on the frequency of latently infected cells. Immunomodulatory therapies could work differently in the setting of antigen expression, that is, during active viremia, and timing of interventions could therefore, be key to future therapeutic success. Lessons learned from clinical trials aimed at HIV cure indicate that while we are still far from reaching a complete eradication cure of HIV, clinical interventions capable of inducing enhanced control of HIV replication in the absence of ART might be a more feasible goal.

The effect of blocking immune checkpoints LAG-3 and PD-1 on human invariant Natural Killer T cell function

Invariant Natural Killer T (iNKT) cells undergo immune exhaustion during chronic activation caused by cancer and viral infections, such as HIV. Exhaustion is marked by cell dysfunction and increased expression of immune checkpoint proteins programmed cell-death-1 (PD-1) and lymphocyte-activation-gene-3 (LAG-3). We hypothesize that blockade of PD-1 and/or LAG-3 will enhance iNKT cell function. Utilizing peripheral blood mononuclear cells from healthy donors, LAG-3 and PD-1 expression on iNKT cells was assessed using flow cytometry following in vitro stimulation with iNKT-specific stimulant α-galactosylceramide (n = 4). Efficacy of anti-LAG-3 and/or anti-PD-1 antibody blockades in enhancing iNKT cell function was assessed by determining proliferative capacity and IFN-γ production (n = 9). LAG-3 and PD-1 expression on iNKT cells peaked at Day 4 (98.8%; p ≤ 0.0001 and 98.8%; p = 0.005, respectively), followed by steep decrease by Day 10, coinciding with peak iNKT cell proliferation. In a 10-day blocking assay, both the anti-PD-1 alone and dual anti-PD-1 and anti-LAG-3 significantly increased iNKT proliferation (6 and 6.29 log2 fold-change respectively) compared to the no blockade control (ANOVA-p = 0.0005) with the dual blockade system being more effective (t-test-p = 0.013). This provides proof-of-concept for LAG-3 and PD-1 as immunotherapeutic targets to enhance human iNKT cell function, with the long-term goal of addressing immune exhaustion.

Antigen specificities of HIV-infected cells: A role in infection and persistence?

Antigen-experienced memory CD4⁺ T cells are the major target of HIV infection and support both productive and latent infections, thus playing a key role in HIV dissemination and persistence, respectively. Here, we reviewed studies that have shown direct association between HIV infection and antigen specificity. During untreated infection, some HIV-specific cells host productive infection, while other pathogen-specific cells such as cytomegalovirus (CMV) and Mycobacterium tuberculosis also contribute to viral persistence on antiretroviral therapy (ART). These patterns could be explained by phenotypic features differing between these pathogen-specific cells. Mechanisms involved in these preferential infection and selection processes include HIV entry and restriction, cell exhaustion, survival, self-renewal and immune escape. For instance, MIP-1β expressing cells such as CMV-specific memory cells were shown to resist infection by HIV CCR5 coreceptor downregulation/inhibition. Conversely, HIV-infected CMV-specific cells undergo clonal expansion during ART. We have identified several research areas that need further focus such as the role of other pathogens, viral genome intactness, inducibility and phenotypic features. However, given the sheer diversity of both the CD4⁺ T cell repertoire and antigenic history of each individual, studying HIV-infected, antigen-experienced cells still imposes numerous challenges.

Immune reconstitution inflammatory syndrome drives emergence of HIV drug resistance from multiple anatomic compartments in a person living with HIV

Reservoirs of HIV maintained in anatomic compartments during antiretroviral therapy prevent HIV eradication. However, mechanisms driving their persistence and interventions to control them remain elusive. Here we report the presence of an inducible HIV reservoir within antigen-specific CD4+T cells in the central nervous system of a 59-year-old male with progressive multifocal leukoencephalopathy immune reconstitution inflammatory syndrome (PML-IRIS). HIV production during PML-IRIS was suppressed by modulating inflammation with corticosteroids; selection of HIV drug resistance caused subsequent breakthrough viremia. Therefore, inflammation can influence the composition, distribution and induction of HIV reservoirs, warranting it as a key consideration for developing effective HIV remission strategies.

Use of programmed cell death protein 1 (PD-1) inhibitor therapy in HIV-infected patients with advanced cancer: a single-center study from China

BACKGROUND

Anti-PD-1 antibodies have been approved for treating several cancer. However, data regarding the safety and efficacy of these agents in HIV-infected patients with cancer is lacking, because these patients are frequently omitted from clinical trials.

OBJECTIVES

The primary aim of our research is to assess the safety, activity, and long-term outcomes of PD-1 inhibitors in the treatment of HIV-infected patients with advanced cancer.

METHOD

We retrospectively analyzed data from HIV-infected patients with advanced cancers who were treated with PD-1 inhibitors at Shanghai Public Health Clinical Center, Shanghai, China.

RESULTS

Fifteen HIV-infected patients (all are men; asian; median age, 44) with cancer who were treated with chemotherapy and/or combined the other oncology treatments [along with combined antiretroviral therapy (cART)] prior to Sintilimab (12 out of 15) or Nivolumab (1 out of 11) or Camrelizumab (2 out of 11) injection were identified. Eight patients responded to treatment (disease control rate 53.3%), with 1 got partial response (PR) and 7 were stable. Most treatment-emergent adverse events (TEAEs) were grade 1 or 2 including anemia, leukopenia, hyperglycemia, granulocytopenia, and thrombocytopenia. Eight patients (53.3%) experienced treatment-related AEs (TRAEs) with grades 3/4including myelosuppression, infection, and neurological disorders. CD4⁺ T cell count and plasma HIV RNA remained stable throughout the treatment.

CONCLUSIONS

When used in HIV-infected patients with advanced malignancies, PD-1 inhibitors tend to have favorable efficacy, manageable side effects, and no deteriorated impacts on plasma HIV-RNA and CD4⁺ T cell count.

Today's Kaposi sarcoma is not the same as it was 40 years ago, or is it?

This review will provide an overview of the notion that Kaposi sarcoma (KS) is a disease that manifests under diverse and divergent circumstances. We begin with a historical introduction of KS and KS-associated herpesvirus (KSHV), highlight the diversity of clinical presentations of KS, summarize what we know about the cell of origin for this tumor, explore KSHV viral load as a potential biomarker for acute KSHV infections and KS-associated complications, and discuss immune modulators that impact KSHV infection, KSHV persistence, and KS disease.

The Natural Stilbenoid (-)-Hopeaphenol Inhibits HIV Transcription by Targeting Both PKC and NF-κB Signaling and Cyclin-Dependent Kinase 9

Despite effective combination antiretroviral therapy (cART), people living with HIV (PLWH) continue to harbor replication-competent and transcriptionally active virus in infected cells, which in turn can lead to ongoing viral antigen production, chronic inflammation, and increased risk of age-related comorbidities. To identify new agents that may inhibit postintegration HIV beyond cART, we screened a library of 512 pure compounds derived from natural products and identified (-)-hopeaphenol as an inhibitor of HIV postintegration transcription at low to submicromolar concentrations without cytotoxicity. Using a combination of global RNA sequencing, plasmid-based reporter assays, and enzyme activity studies, we document that hopeaphenol inhibits protein kinase C (PKC)- and downstream NF-κB-dependent HIV transcription as well as a subset of PKC-dependent T-cell activation markers, including interleukin-2 (IL-2) cytokine and CD25 and HLA-DRB1 RNA production. In contrast, it does not substantially inhibit the early PKC-mediated T-cell activation marker CD69 production of IL-6 or NF-κB signaling induced by tumor necrosis factor alpha (TNF-α). We further show that hopeaphenol can inhibit cyclin-dependent kinase 9 (CDK9) enzymatic activity required for HIV transcription. Finally, it inhibits HIV replication in peripheral blood mononuclear cells (PBMCs) infected in vitro and dampens viral reactivation in CD4+ cells from PLWH. Our study identifies hopeaphenol as a novel inhibitor that targets a subset of PKC-mediated T-cell activation pathways in addition to CDK9 to block HIV expression. Hopeaphenol-based therapies could complement current antiretroviral therapy otherwise not targeting cell-associated HIV RNA and residual antigen production in PLWH.

HIV/Mtb Co-Infection: From the Amplification of Disease Pathogenesis to an “Emerging Syndemic”

Human immunodeficiency virus (HIV) and Mycobacterium tuberculosis (Mtb) are pathogens responsible for millions of new infections each year; together, they cause high morbidity and mortality worldwide. In addition, late-stage HIV infection increases the risk of developing tuberculosis (TB) by a factor of 20 in latently infected people, and even patients with controlled HIV infection on antiretroviral therapy (ART) have a fourfold increased risk of developing TB. Conversely, Mtb infection exacerbates HIV pathogenesis and increases the rate of AIDS progression. In this review, we discuss this reciprocal amplification of HIV/Mtb coinfection and how they influence each other’s pathogenesis. Elucidating the infectious cofactors that impact on pathogenesis may open doors for the design of new potential therapeutic strategies to control disease progression, especially in contexts where vaccines or the sterile clearance of pathogens are not effectively available.

The BAF complex inhibitor pyrimethamine reverses HIV-1 latency in people with HIV-1 on antiretroviral therapy

Reactivation of the latent HIV-1 reservoir is a first step toward triggering reservoir decay. Here, we investigated the impact of the BAF complex inhibitor pyrimethamine on the reservoir of people living with HIV-1 (PLWH). Twenty-eight PLWH on suppressive antiretroviral therapy were randomized (1:1:1:1 ratio) to receive pyrimethamine, valproic acid, both, or no intervention for 14 days. The primary end point was change in cell-associated unspliced (CA US) HIV-1 RNA at days 0 and 14. We observed a rapid, modest, and significant increase in (CA US) HIV-1 RNA in response to pyrimethamine exposure, which persisted throughout treatment and follow-up. Valproic acid treatment alone did not increase (CA US) HIV-1 RNA or augment the effect of pyrimethamine. Pyrimethamine treatment did not result in a reduction in the size of the inducible reservoir. These data demonstrate that the licensed drug pyrimethamine can be repurposed as a BAF complex inhibitor to reverse HIV-1 latency in vivo in PLWH, substantiating its potential advancement in clinical studies.

Malignancy and viral infections in Sub-Saharan Africa: A review

The burden of malignancy related to viral infection is increasing in Sub-Saharan Africa (SSA). In 2018, approximately 2 million new cancer cases worldwide were attributable to infection. Prevention or treatment of these infections could reduce cancer cases by 23% in less developed regions and about 7% in developed regions. Contemporaneous increases in longevity and changes in lifestyle have contributed to the cancer burden in SSA. African hospitals are reporting more cases of cancer related to infection (e.g., cervical cancer in women and stomach and liver cancer in men). SSA populations also have elevated underlying prevalence of viral infections compared to other regions. Of 10 infectious agents identified as carcinogenic by the International Agency for Research on Cancer, six are viruses: hepatitis B and C viruses (HBV and HCV, respectively), Epstein-Barr virus (EBV), high-risk types of human papillomavirus (HPV), Human T-cell lymphotropic virus type 1 (HTLV-1), and Kaposi's sarcoma herpesvirus (KSHV, also known as human herpesvirus type 8, HHV-8). Human immunodeficiency virus type 1 (HIV) also facilitates oncogenesis. EBV is associated with lymphomas and nasopharyngeal carcinoma; HBV and HCV are associated with hepatocellular carcinoma; KSHV causes Kaposi's sarcoma; HTLV-1 causes T-cell leukemia and lymphoma; HPV causes carcinoma of the oropharynx and anogenital squamous cell cancer. HIV-1, for which SSA has the greatest global burden, has been linked to increasing risk of malignancy through immunologic dysregulation and clonal hematopoiesis. Public health approaches to prevent infection, such as vaccination, safer injection techniques, screening of blood products, antimicrobial treatments and safer sexual practices could reduce the burden of cancer in Africa. In SSA, inequalities in access to cancer screening and treatment are exacerbated by the perception of cancer as taboo. National level cancer registries, new screening strategies for detection of viral infection and public health messaging should be prioritized in SSA's battle against malignancy. In this review, we discuss the impact of carcinogenic viruses in SSA with a focus on regional epidemiology.

Phenotypic signatures of immune selection in HIV-1 reservoir cells

Human immunodeficiency virus 1 (HIV-1) reservoir cells persist lifelong despite antiretroviral treatment1,2 but may be vulnerable to host immune responses that could be exploited in strategies to cure HIV-1. Here we used a single-cell, next-generation sequencing approach for the direct ex vivo phenotypic profiling of individual HIV-1-infected memory CD4+ T cells from peripheral blood and lymph nodes of people living with HIV-1 and receiving antiretroviral treatment for approximately 10 years. We demonstrate that in peripheral blood, cells harbouring genome-intact proviruses and large clones of virally infected cells frequently express ensemble signatures of surface markers conferring increased resistance to immune-mediated killing by cytotoxic T and natural killer cells, paired with elevated levels of expression of immune checkpoint markers likely to limit proviral gene transcription; this phenotypic profile might reduce HIV-1 reservoir cell exposure to and killing by cellular host immune responses. Viral reservoir cells harbouring intact HIV-1 from lymph nodes exhibited a phenotypic signature primarily characterized by upregulation of surface markers promoting cell survival, including CD44, CD28, CD127 and the IL-21 receptor. Together, these results suggest compartmentalized phenotypic signatures of immune selection in HIV-1 reservoir cells, implying that only small subsets of infected cells with optimal adaptation to their anatomical immune microenvironment are able to survive during long-term antiretroviral treatment. The identification of phenotypic markers distinguishing viral reservoir cells may inform future approaches for strategies to cure and eradicate HIV-1.