HDL Cholesterol Efflux Capacity in Newly Diagnosed HIV and Effects of Antiretroviral Therapy

HDL-based therapeutics: A promising frontier in combating viral and bacterial infections

Low levels of high-density lipoprotein (HDL) and impaired HDL functionality have been consistently associated with increased susceptibility to infection and its serious consequences. This has been attributed to the critical role of HDL in maintaining cellular lipid homeostasis, which is essential for the proper functioning of immune and structural cells. HDL, a multifunctional particle, exerts pleiotropic effects in host defense against pathogens. It functions as a natural nanoparticle, capable of sequestering and neutralizing potentially harmful substances like bacterial lipopolysaccharides. HDL possesses antiviral activity, preventing viruses from entering or fusing with host cells, thereby halting their replication cycle. Understanding the complex relationship between HDL and the immune system may reveal innovative targets for developing new treatments to combat infectious diseases and improve patient outcomes. This review aims to emphasize the role of HDL in influencing the course of bacterial and viral infections and its and its therapeutic potential.

HIV-related cardiovascular disease: any role for high-density lipoproteins?

The introduction of antiretroviral therapy (ART) has improved the life expectancy of patients infected with human immunodeficiency virus (HIV). However, this population is at an increased risk for noncommunicable diseases, including atherosclerotic cardiovascular disease (CVD). Both ART and viral infection may be potential contributors to the pathophysiology of HIV-related CVD. The mechanisms behind this remain unclear, but it is critical to delineate early biomarkers of cardiovascular risk in the HIV population. In this review, we postulate that potential biomarkers could include alterations to high-density lipoprotein (HDL). Indeed, recent data suggest that HIV and ART may induce structural changes of HDL, thus resulting in shifts in HDL subclass distribution and HDL functionality.

Effects of Integrase Inhibitor-Based ART on the NLRP3 Inflammasome Among ART-Naïve People With HIV

The NOD-like receptor protein family pyrin domain containing 3 (NLRP3) inflammasome, activated in the setting of HIV, contributes to pro-atherogenic inflammation. Among antriretroviral therapy–naïve people with HIV (vs controls), levels of caspase-1—a key component of the NLRP3 inflammasome—were significantly increased. Six months of elvitegravir/cobicistat/emtricitabine/tenofovir disoproxil fumarate significantly decreased caspase-1 levels in association with CD4+/CD8+ ratio recovery.

Trial registration. ClinicalTrials.gov NCT 01766726.

Brief Report: Hyperbilirubinemia Is Associated With a Decreased Risk of Carotid Atherosclerosis in HIV-Infected Patients on Virological Suppression

OBJECTIVE

To investigate the association between total, direct, and indirect bilirubin and the presence of carotid lesions in a large sample of HIV-1-infected patients on virological suppression.

DESIGN

Retrospective study on adult HIV-1-infected patients, with a carotid ultrasound (CUS) examination performed between January 2008 and August 2016, with HIV-RNA <50 copies per milliliter at CUS and without previous cardiovascular events.

METHODS

Intima media thickness was measured in 4 segments: carotid common artery and bifurcation on the left and right sides. Carotid lesion was defined as an intima media thickness ≥1.5 mm in ≥1 region at CUS. Patients were classified as: normal if all bilirubin values before CUS were below the upper normal limit and with hyperbilirubinemia if ≥1 bilirubin value above upper normal limit before CUS was recorded. Multivariate logistic regression was used to determine whether hyperbilirubinemia showed association with the presence of ≥1 carotid lesion, after adjusting for confounding factors.

RESULTS

Overall, 903 patients were evaluated, 511 with ≥1 and 392 without carotid lesions. At multivariate analysis, total [adjusted odds ratio (95% confidence interval) 0.57 (0.36 to 0.90), P = 0.016] and indirect hyperbilirubinemia before CUS [adjusted odds ratio (95% confidence interval) 0.62 (0.40 to 0.97), P = 0.036] were associated with a lower risk of carotid lesions in addition to younger age, negative hepatitis C virus antibodies, higher nadir CD4, lower low-density lipoprotein cholesterol, higher high-density lipoprotein cholesterol, lower triglycerides, and no use of statin; no effect of atazanavir treatment on carotid lesions was detected.

CONCLUSIONS

In HIV-1-treated patients, total or indirect hyperbilirubinemia was likely associated with the absence of carotid lesions.

Cholesterol efflux responds to viral load and CD4 counts in HIV+ patients and is dampened in HIV exposed

Cholesterol efflux (CE) capacity has been inversely associated with atherosclerosis and may provide an insight on inflammation occurring in human immunodeficiency virus (HIV) individuals. We address this by studying CE in HIV patients at different stages of HIV disease progression. In this cross-sectional study, CE from ApoB-depleted plasma, lipids levels, viral load (VL), CD4+/CD8+ T-cells, high-sensitive C-reactive protein (hsCRP), and lipoprotein (a) were evaluated in untreated HIV-infected patients (UHIVs; n = 43), elite controllers (ECs; n = 8), HIV-exposed seronegative individuals (HESNs; n = 32), and healthy controls (HCs; n = 14). Among UHIVs, those with CD4+ <500 cells/mm³ presented the lowest significant CE, HDL cholesterol (HDL-C), and ApoAI levels. ECs showed similar HDL-C, ApoAI, and CE compared with HCs. Among UHIVs, CE positively correlated with CD4+ T-cell counts (Beta: 1.05; 95% CI: 1.02; 1.07), and for VL higher than 3.8 log, CE was inversely associated with VL (Beta: 0.70; 95% CI: 0.51; 0.95). Remarkably, HESNs presented higher CE (0.78 ± 0.14) than UHIVs (0.65 ± 0.17; P = 0.0005), but lower than HCs (0.90 ± 0.13; P = 0.009). hsCRP levels were highest in the UHIV group (0.45 ± 0.49). CE was sensitive to HIV disease progression. Low CE in HIV patients was associated with lower CD4+ T-cells and higher VL and hsCRP. CE was also lower in HESNs compared with HCs. Our results suggest that immune status secondary to HIV progression and exposure influence plasma HDL-CE capacity.

Mindin deficiency in macrophages protects against foam cell formation and atherosclerosis by targeting LXR-β

Mindin, which is a highly conserved extracellular matrix protein, has been documented to play pivotal roles in regulating angiogenesis, inflammatory processes, and immune responses. The aim of the present study was to assess whether mindin contributes to the development of atherosclerosis. A significant up-regulation of Mindin expression was observed in the serum, arteries and atheromatous plaques of ApoE-/- mice after high-fat diet treatment. Mindin-/-ApoE-/- mice and macrophage-specific mindin overexpression in ApoE-/- mice (Lyz2-mindin-TG) were generated to evaluate the effect of mindin on the development of atherosclerosis. The Mindin-/-ApoE-/- mice exhibited significantly ameliorated atherosclerotic burdens in the entire aorta and aortic root and increased atherosclerotic plaque stability. Moreover, bone marrow transplantation further demonstrated that mindin deficiency in macrophages was largely responsible for the alleviated atherogenesis. The Lyz2-mindin-TG mice exhibited the opposite phenotype. Mindin deficiency enhanced foam cell formation by increasing the expression of cholesterol effectors, including ABCA1 and ABCG1. The mechanistic study indicated that mindin ablation promoted LXR-β expression via a direct interaction. Importantly, LXR-β inhibition largely reversed the ameliorating effect of mindin deficiency on foam cell formation and ABCA1 and ABCG1 expression. The present study demonstrated that mindin deficiency serves as a novel mediator that protects against foam cell formation and atherosclerosis by directly interacting with LXR-β.