Cardiac morbidity in HIV infection is associated with checkpoint inhibitor LAG-3 on CD4 T cells

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.

The relationship between soluble lymphocyte activation gene-3 and coronary artery disease

Background

Soluble lymphocyte activation gene 3 (sLAG3) may be used for diagnosis or prognosis in various diseases. However, the relationship between sLAG3 and coronary artery disease (CAD) are still unclear. This study aimed to investigate the levels of sLAG3 in patients with CAD, and its potential clinical association with the disease.

Methods

A total of 66 subjects (49 patients with CAD and 17 control subjects without CAD) were enrolled. The sLAG3 level was measured using enzyme-linked immunosorbent assay (ELISA) kits. Clinical variables included demographics, biochemical markers, coronary angiography status, and ejection fraction of the heart (EF) were collected, and Gensini scores were calculated. LAG3 gene data was extracted from three datasets (GSE23561, GSE61144, GSE60993) in Gene Expression Omnibus (GEO) to compare differential expression between CAD and control subjects.

Results

The sLAG3 level was significantly lower in the CAD vs. the controls (P < 0.05), and negatively associated with CAD [odds ratio (OR): 0.212, 95% confidential interval (CI): 0.060–0.746, P < 0.05]. Furthermore, the area under the curve (AUC) of sLAG3 level was significant (P < 0.05). The sLAG3 level in subjects with body mass index (BMI) ≥ 24 kg/m² was lower compared to those with BMI < 24 kg/m² (P < 0.05). The sLAG3 level was also negatively associated with BMI and diabetes mellitus (P < 0.05), though not associated with the Gensini scores or EF (P > 0.05). Lastly, the LAG3 gene expression in peripheral whole blood of patients with CAD were down-regulated compared to healthy controls (P < 0.05).

Conclusion

The sLAG3 level was negatively associated with the occurrence but not severity of CAD. Meanwhile, the sLAG3 was negatively associated with BMI and diabetes mellitus, suggesting the reduced sLAG3 might be a novel risk factor for developing CAD.

Immune correlates of cardiovascular co-morbidity in HIV infected participants from South India

BACKGROUND

Understanding the immune correlates of cardiovascular disease (CVD) risk in HIV infection is an important area of investigation in the current era of aging with HIV infection. Less is known about CVD risk and HIV infection in developing nations where additional risk factors may be playing a role in the CVD development. In this study, we assessed the effects of systemic inflammation, microbial translocation (MT), T cell immune activation (IA), and nadir CD4 counts on cardiac function and arterial stiffness as markers of subclinical atherosclerosis in HIV-infected individuals.

METHODS

People with HIV (PWH) who were ART naïve (n = 102) or virally suppressed on ART (n = 172) were stratified on nadir CD4 counts and compared to HIV-uninfected controls (n = 64). Determination was made of cardiac function via radial pulse wave and carotid intima thickness (C-IMT) measurements. Plasma biomarkers of inflammation and MT by ELISA or multiplex assays, and immune activation (IA) of T cells based HLA-DR and CD38 expression were investigated by flow cytometry. T-test, Mann-Whitney U test, and Spearman correlation were used to analyze study parameters.

RESULTS

Reduction in cardiac function with lower cardiac ejection time (p < 0.001), stroke volume (p < 0.001), cardiac output (p = 0.007), higher arterial stiffness (p < 0.05) were identified in ART-naïve participants, compared to PWH on ART (p < 0.05). No significant difference in C-IMT values were noted. Higher inflammatory and MT markers were found in the ART-naïve group compared to treated group who were comparable to uninfected participants, except for having higher TNF-α (p < 0.001) and sCD14 (p < 0.001). Immune activation of CD4 and CD8 T-cells was greater in ART-naïve participants compared to ART-treated and uninfected controls (p < 0.05). Lower nadir CD4 counts, higher inflammation, and higher MT predicted poor cardiac measures in the ART-naïve with nadir CD4 < 200cells/mm³ manifesting the highest arterial stiffness, and lowest cardiac function, whereas ART-treated, even with nadir < 200 cells/mm³ were similar to uninfected in these measures.

CONCLUSIONS

In HIV-infected individuals, initiation of ART even at nadir of < 200 cells/mm³ may prevent or reverse cardiovascular disease outcomes that are easily measurable in low income countries.

Combination Immune Checkpoint Blockade Enhances IL-2 and CD107a Production from HIV-Specific T Cells Ex Vivo in People Living with HIV on Antiretroviral Therapy

In people with HIV (PWH) on antiretroviral therapy (ART), immune dysfunction persists, including elevated expression of immune checkpoint (IC) proteins on total and HIV-specific T cells. Reversing immune exhaustion is one strategy to enhance the elimination of HIV-infected cells that persist in PWH on ART. We aimed to evaluate whether blocking CTL-associated protein 4 (CTLA-4), programmed cell death protein 1 (PD-1), T cell Ig domain and mucin domain 3 (TIM-3), T cell Ig and ITIM domain (TIGIT) and lymphocyte activation gene-3 (LAG-3) alone or in combination would enhance HIV-specific CD4⁺ and CD8⁺ T cell function ex vivo. Intracellular cytokine staining was performed using human PBMCs from PWH on ART (n = 11) and expression of CD107a, IFN-γ, TNF-α, and IL-2 was quantified with HIV peptides and Abs to IC. We found the following: 1) IC blockade enhanced the induction of CD107a and IL-2 but not IFN-γ and TNF-α in response to Gag and Nef peptides; 2) the induction of CD107a and IL-2 was greatest with multiple combinations of two Abs; and 3) Abs to LAG-3, CTLA-4, and TIGIT in combinations showed synergistic induction of IL-2 in HIV-specific CD8⁺ and CD107a and IL-2 production in HIV-specific CD4⁺ and CD8⁺ T cells. These results demonstrate that the combination of Abs to LAG-3, CTLA-4, or TIGIT can increase the frequency of cells expressing CD107a and IL-2 that associated with cytotoxicity and survival of HIV-specific CD4⁺ and CD8⁺ T cells in PWH on ART. These combinations should be further explored for an HIV cure.

Short Communication: Plasma Lymphocyte Activation Gene 3 and Subclinical Coronary Artery Disease in the Multicenter AIDS Cohort Study

Chronic inflammation, including among people with HIV (PWH), elevates immune cell expression of lymphocyte activation gene 3 (LAG3); however, low plasma LAG3 predicts cardiovascular disease (CVD) events in the general population. The associations among LAG3 plasma levels, subclinical atherosclerosis, inflammation, and HIV infection have not been well described. We measured plasma LAG3 in 704 men with and without HIV from the multicenter AIDS cohort study, who underwent coronary computed tomography angiography. HIV serostatus was not independently associated with LAG3 after adjustment for sociodemographic and CVD risk factors. Current smoking status and African American race were associated with lower LAG3, and age and sTNFαRI concentration were associated with greater LAG3. LAG3 was not associated with coronary artery stenosis. Thus, no difference was found in plasma LAG3 concentration by HIV serostatus, and no association between LAG3 and subclinical coronary atherosclerosis in men with and without HIV was observed.

Association of HIV Infection and Antiretroviral Therapy With Arterial Stiffness: A Systematic Review and Meta-Analysis

[Figure: see text].

Dangerous liaisons? The role of inflammation and comorbidities in HIV and SARS-CoV-2 infection

INTRODUCTION

In people living with HIV (PLWH), immune activation and inflammation levels are high even when viral suppression is maintained, potentially contributing to several comorbidities, and hampering the immune response to infections such as the recent SARS-CoV-2 disease 2019 (COVID-19).

AREAS COVERED

Immune activation and inflammation play a role in SARS-CoV-2 infection. Severe COVID-19 patients may experience cytokine release syndrome (CRS), leading to alveolar damage, pulmonary fibrinolysis, dysregulated coagulation, and pulmonary injury. Into the systemic circulation, cytokines in excess might leak out of pulmonary circulation, causing systemic symptoms and possibly a multiple-organ dysfunction syndrome. Preexisting comorbidities are also linked to worse COVID-19 outcome: studies suggest that diabetes and hypertension are linked to higher mortality rates. Such comorbidities are more frequent in PLWH, but it is unclear if they have worse outcomes in the case of COVID-19. The literature was searched in PubMed/MEDLINE and EMBASE, and manually in COVID-19 resources.

EXPERT OPINION

A body of evidence shows that HIV and SARS-CoV-2 are able to activate inflammatory pathways, acute in the case of SARS-CoV-2, chronic in the case of HIV, while the comorbidities seem to represent, in the first case, a contributory cause, in the second an effect of the virus-induced damage.

Novel human immunomodulatory T cell receptors and their double-edged potential in autoimmunity, cardiovascular disease and cancer

In the last decade, approaches based on T cells and their immunomodulatory receptors have emerged as a solid improvement in treatments for various types of cancer. However, the roles of these molecules in the therapeutic context of autoimmune and cardiovascular diseases are still relatively unexplored. Here, we review the best known and most commonly used immunomodulatory T cell receptors in clinical practice (PD-1 and CTLA-4), along with the rest of the receptors with known functions in animal models, which have great potential as modulators in human pathologies in the medium term. Among these other receptors is the receptor CD69, which has recently been described to be expressed in mouse and human T cells in autoimmune and cardiovascular diseases and cancer. However, inhibition of these receptors individually or in combination by drugs or monoclonal antibodies generates a loss of immunological tolerance and can trigger multiple autoimmune disorders in different organs and immune-related adverse effects. In the coming decades, knowledge on the functions of different immunomodulatory receptors will be pivotal for the development of new and better therapies with less harmful side effects. In this review, we discuss the roles of these receptors in the control of immunity from a perspective focused on therapeutic potential in not only cancer but also autoimmune diseases, such as systemic lupus erythematosus, autoimmune diabetes and rheumatoid arthritis, and cardiovascular diseases, such as atherosclerosis, acute myocardial infarction, and myocarditis.

The Role of Immunomodulatory Receptors in the Pathogenesis of HIV Infection: A Therapeutic Opportunity for HIV Cure?

Immune activation is the hallmark of HIV infection and plays a role in the pathogenesis of the disease. In the context of suppressed HIV RNA replication by combination antiretroviral therapy (cART), there remains immune activation which is associated to the HIV reservoirs. Persistent virus contributes to a sustained inflammatory environment promoting accumulation of "activated/exhausted" T cells with diminished effector function. These T cells show increased expression of immunomodulatory receptors including Programmed cell death protein (PD1), Cytotoxic T Lymphocyte Associated Protein 4 (CTLA4), Lymphocyte activation gene 3 (LAG3), T cell immunoglobulin and ITIM domain (TIGIT), T cell immunoglobulin and mucin domain containing 3 (TIM3) among others. More importantly, recent reports had demonstrated that, HIV infected T cells express checkpoint receptors, contributing to their survival and promoting maintenance of the viral reservoir. Therapeutic strategies are focused on viral reservoir elimination and/or those to achieve sustained cART-free virologic remission. In this review, we will discuss the immunological basis and the latest advances of the use of checkpoint inhibitors to treat HIV infection.

LAG3 (CD223) and autoimmunity: Emerging evidence

Immune checkpoint molecules play pivotal roles in maintaining the immune homeostasis. Targeting these molecules, such as the classical Cytotoxic T-Lymphocyte Antigen 4 (CTLA4) and Programmed Cell Death Protein 1 (PD1), achieves great success in treating cancers. However, not all the patients respond well. This urges the immunologists to identify novel immune checkpoint molecules. Lymphocyte activation gene-3 (LAG3; CD223) is a newly identified inhibitory receptor. It is expressed on a variety of immune cells, including CD4⁺ T cells, CD8⁺ T cells, Tregs, B cells, and NK cells. Its unique intracellular domains, signaling patterns as well as the striking synergy observed in its targeted therapy with anti-PD1 indicate the important role of LAG3 in maintaining immune tolerance. Currently, a variety of agents targeting LAG3 are in clinical trials, revealing great perspectives in the future immunotherapy. In this review, we briefly summarize the studies on LAG3, including its structure, isoforms, ligands, signaling, function, roles in multiple diseases, as well as the latest targeted therapeutic advances, with particular concern on the potential association of LAG3 with autoimmune diseases.

Pathogenesis of Aging and Age-related Comorbidities in People with HIV: Highlights from the HIV ACTION Workshop

People with HIV (PWH) experience accentuated biological aging, as defined by markers of inflammation, immune dysfunction, and the epigenetic clock. They also have an elevated risk of multiple age-associated comorbidities. To discuss current knowledge, research gaps, and priorities in aging and age-related comorbidities in treated HIV infection, the NIH program staff organized a workshop held in Bethesda, Maryland in September 2019. This review article describes highlights of discussions led by the Pathogenesis/Basic Science Research working group that focused on three high priority topics: immunopathogenesis; the microbiome/virome; and aging and senescence. We summarize knowledge in these fields and describe key questions for research on the pathogenesis of aging and age-related comorbidities in PWH. Understanding the drivers and mechanisms underlying accentuated biological aging is a high priority that will help identify potential therapeutic targets to improve healthspan in older PWH.