Efavirenz induces interactions between leucocytes and endothelium through the activation of Mac-1 and gp150,95

HIV Infection, Antiretroviral Drugs, and the Vascular Endothelium

Endothelial cell activation, injury, and dysfunction underlies the pathophysiology of vascular diseases and infections associated with vascular dysfunction, including human immunodeficiency virus (HIV) and acquired immunodeficiency syndrome. Despite viral suppression with combination antiretroviral therapy (ART), people living with HIV (PLWH) are prone to many comorbidities, including neurological and neuropsychiatric complications, cardiovascular and metabolic diseases, premature aging, and malignancies. HIV and viral proteins can directly contribute to the development of these comorbidities. However, with the continued high prevalence of these comorbidities despite viral suppression, it is likely that ART or some antiretroviral (ARVs) drugs contribute to the development and persistence of comorbid diseases in PLWH. These comorbid diseases often involve vascular activation, injury, and dysfunction. The purpose of this manuscript is to review the current literature on ARVs and the vascular endothelium in PLWH, animal models, and in vitro studies. I also summarize evidence of an association or lack thereof between ARV drugs or drug classes and the protection or injury/dysfunction of the vascular endothelium and vascular diseases.

The Emerging Role of the Innate Immune Response in Idiosyncratic Drug Reactions

Idiosyncratic drug reactions (IDRs) range from relatively common, mild reactions to rarer, potentially life-threatening adverse effects that pose significant risks to both human health and successful drug discovery. Most frequently, IDRs target the liver, skin, and blood or bone marrow. Clinical data indicate that most IDRs are mediated by an adaptive immune response against drug-modified proteins, formed when chemically reactive species of a drug bind to self-proteins, making them appear foreign to the immune system. Although much emphasis has been placed on characterizing the clinical presentation of IDRs and noting implicated drugs, limited research has focused on the mechanisms preceding the manifestations of these severe responses. Therefore, we propose that to address the knowledge gap between drug administration and onset of a severe IDR, more research is required to understand IDR-initiating mechanisms; namely, the role of the innate immune response. In this review, we outline the immune processes involved from neoantigen formation to the result of the formation of the immunologic synapse and suggest that this framework be applied to IDR research. Using four drugs associated with severe IDRs as examples (amoxicillin, amodiaquine, clozapine, and nevirapine), we also summarize clinical and animal model data that are supportive of an early innate immune response. Finally, we discuss how understanding the early steps in innate immune activation in the development of an adaptive IDR will be fundamental in risk assessment during drug development. SIGNIFICANCE STATEMENT: Although there is some understanding that certain adaptive immune mechanisms are involved in the development of idiosyncratic drug reactions, the early phase of these immune responses remains largely uncharacterized. The presented framework refocuses the investigation of IDR pathogenesis from severe clinical manifestations to the initiating innate immune mechanisms that, in contrast, may be quite mild or clinically silent. A comprehensive understanding of these early influences on IDR onset is crucial for accurate risk prediction, IDR prevention, and therapeutic intervention.

Interactions of HIV and Antiretroviral Therapy With Neutrophils and Platelets

Neutrophils are important components of the innate immune system that mediate pathogen defense by multiple processes including phagocytosis, release of proteolytic enzymes, production of reactive oxygen species, and neutrophil extracellular trap formation. Abnormalities of neutrophil count and function have been described in the setting of HIV infection, with the majority of antiretroviral agents (ARVs), excluding zidovudine, having been reported to correct neutropenia. Questions still remain, however, about their impact on neutrophil function, particularly the possibility of persistent neutrophil activation, which could predispose people living with HIV to chronic inflammatory disorders, even in the presence of virally-suppressive treatment. In this context, the effects of protease inhibitors and integrase strand transfer inhibitors, in particular, on neutrophil function remain poorly understood and deserve further study. Besides mediating hemostatic functions, platelets are increasingly recognized as critical role players in the immune response against infection. In the setting of HIV, these cells have been found to harbor the virus, even in the presence of antiretroviral therapy (ART) potentially promoting viral dissemination. While HIV-infected individuals often present with thrombocytopenia, they have also been reported to have increased platelet activation, as measured by an upregulation of expression of CD62P (P-selectin), CD40 ligand, glycoprotein IV, and RANTES. Despite ART-mediated viral suppression, HIV-infected individuals reportedly have sustained platelet activation and dysfunction. This, in turn, contributes to persistent immune activation and an inflammatory vascular environment, seemingly involving neutrophil-platelet-endothelium interactions that increase the risk for development of comorbidities such as cardiovascular disease (CVD) that has become the leading cause of morbidity and mortality in HIV-infected individuals on treatment, clearly underscoring the importance of unraveling the possible etiologic roles of ARVs. In this context, abacavir and ritonavir-boosted lopinavir and darunavir have all been linked to an increased risk of CVD. This narrative review is therefore focused primarily on the role of neutrophils and platelets in HIV transmission and disease, as well as on the effect of HIV and the most common ARVs on the numbers and functions of these cells, including neutrophil-platelet-endothelial interactions.

Carbon Monoxide Controllable Targeted Gas Therapy for Synergistic Anti-inflammation

Carbon monoxide (CO) plays an important role in the regulation of a variety of physiological processes and thus is regarded as a promising pharmaceutical agent. Nevertheless, therapeutic applications of CO are severely hampered by the difficulty of the delivery of controlled amounts of CO to biological targets. To address this deficiency, we present a spatiotemporally controllable CO-releasing platform (designated as Neu-MnO2/Fla) for synergistic anti-inflammation. With the assistance of neutrophil membrane coating, Neu-MnO2/Fla can target to inflammatory sites. Subsequently, excess H2O2 at the inflamed tissues can be decomposed into oxygen because of MnO2 as nanozymes possessing catalase (CAT) activity, which not only relieves oxidative stress but also achieves in situ rapid photo-induced CO release. The in vitro and in vivo results indicate our CO-releasing platform exhibits a strong synergistic anti-inflammatory effect. Our work will shed light on targeted CO release to avoid side effects of therapeutic applications of CO.

Do Combination Antiretroviral Therapy Regimens for HIV Infection Feature Diverse T-Cell Phenotypes and Inflammatory Profiles?

Immune abnormalities featuring HIV infection persist despite the use of effective combination antiretroviral therapy (cART) and may be linked to the development of noninfectious comorbidities. The aim of the present narrative, nonsystematic literature review is to understand whether cART regimens account for qualitative differences in immune reconstitution. Many studies have reported differences in T-cell homeostasis, inflammation, coagulation, and microbial translocation parameters across cART classes and in the course of triple vs dual regimens, yet such evidence is conflicting and not consistent. Possible reasons for discrepant results in the literature are the paucity of randomized controlled clinical trials, the relatively short follow-up of observational studies, the lack of clinical validation of the numerous inflammatory biomarkers utilized, and the absence of research on the effects of cART in tissues. We are currently thus unable to establish if cART classes and regimens are truly accountable for the differences observed in immune/inflammation parameters in different clinical settings. Questions still remain as to whether an early introduction of cART, specifically in the acute stage of disease, or newer drugs and novel dual drug regimens are able to significantly impact the quality of immune reconstitution and the risk of disease progression in HIV-infected subjects.

Endothelial Colony-Forming Cell Function Is Reduced During HIV Infection

BACKGROUND

Human immunodeficiency virus (HIV) may be related to cardiovascular disease through monocyte activation-associated endothelial dysfunction.

METHODS

Blood samples from 15 HIV-negative participants (the uninfected group), 8 HIV-positive participants who were not receiving antiretroviral therapy (ART) (the infected, untreated group), and 15 HIV-positive participants who were receiving ART (the infected, treated group) underwent flow cytometry of endothelial colony-forming cells (ECFCs) and monocyte proportions. IncuCyte live cell imaging of 8 capillary proliferative capacity parameters were obtained from cord blood ECFCs treated with participant plasma.

RESULTS

The ECFC percentage determined by flow cytometry was not different between the study groups; however, values of the majority of capillary proliferative capacity parameters (ie, cell area, network length, network branch points, number of networks, and average tube width uniformity) were significantly lower in infected, untreated participants as compared to values for uninfected participants or infected, treated participants (P < .00625 for all comparisons). CD14+CD16+ intermediate monocytes and soluble CD163 were significantly and negatively correlated with several plasma-treated, cord blood ECFC proliferative capacity parameters in the combined HIV-positive groups but not in the uninfected group.

CONCLUSIONS

Cord blood ECFC proliferative capacity was significantly impaired by plasma from infected, untreated patients, compared with plasma from uninfected participants and from infected, treated participants. Several ECFC functional parameters were adversely associated with monocyte activation in the HIV-positive groups, thereby suggesting a mechanism by which HIV-related inflammation may impair vascular reparative potential and consequently increase the risk of cardiovascular disease during HIV infection.

Metabolic and Cardiovascular Complications in HIV/HCV-Co-infected Patients

PURPOSE OF REVIEW

Fifteen to thirty percent of HIV-infected persons in North America and Europe are co-infected with chronic hepatitis C (HCV). The latter is associated with a significant number of extra-hepatic metabolic complications that could compound HIV-associated increased cardiovascular risk. This article reviews the basic science and epidemiologic and clinical evidence for increased cardio-metabolic risk among HIV/HCV-co-infected patients and discusses potential underlying mechanisms. We will finally review the impact of control of HCV viremia on the cardio-metabolic morbidity and mortality of HIV/HCV-co-infected patients.

RECENT FINDINGS

HCV infection is associated with a number of immune-related complications such as cryoglobulinemia but also metabolic complications including dyslipidemias, hepatic steatosis, insulin resistance, diabetes, and chronic kidney disease. The incidence of these complications is higher among HIV-co-infected patients and might contribute to increased mortality. The potential mechanisms of increased cardiovascular risk among HIV/HCV-co-infected subjects include endothelial dysfunction, chronic inflammation and immune activation, the cardio-metabolic effects of HCV-induced hepatic steatosis and fibrosis or insulin resistance, and chronic kidney disease. However, epidemiologic studies show discordant findings as to whether HCV co-infection further increases the risk of atherosclerotic cardiovascular diseases (acute myocardial infarctions and strokes) among HIV-infected patients. Nonetheless, successful treatment of HCV is associated with significant improvements in cardio-metabolic risk factors including diabetes mellitus. HCV co-infection is associated with a higher incidence of metabolic complications-and likely increased risk of cardiovascular events-that might contribute to increased mortality in HIV. These appear to improve with successful HCV therapy.

The potential effects of efavirenz on Oreochromis mossambicus after acute exposure

Antiretroviral drugs (ARVs) are hazardous therapeutic pharmaceuticals present in South African surface water. Efavirenz is an ARV commonly used in human immunodeficiency virus (HIV) treatment in South Africa. Although little is known about the toxic effects of efavirenz on fish health, threats of toxicity to the aquatic environment have been reported. Oreochromis mossambicus were exposed under controlled conditions to environmentally-relevant efavirenz concentrations (10.3ng/l) as measured in rivers that flow into the Nandoni Dam in the Vhembe District, South Africa. Acute (96h) exposures were conducted using efavirenz concentrations of 10.3ng/l and 20.6ng/l. The overall health of exposed fish was determined using a histology-based fish health assessment index. Necropsies and haematology were conducted and somatic indices calculated after which the liver, kidney, heart, gills and gonads were microscopically quantitatively assessed. Results indicated that fish exposed to 20.6ng/l efavirenz had significantly (p<0.02) higher liver indices than the control fish, indicating increased liver damage including steatosis and frank necrosis. Fish exposed to 20.6ng/l efavirenz presented with significantly (p<0.02) higher total fish indices, representative of declined overall health compared to control fish. It was concluded that the exposure of O. mossambicus to efavirenz resulted in liver damage and overall decline in fish health. These novel findings may indicate a health risk for O. mossambicus and other biota exposed to efavirenz in aquatic ecosystems. Thus, ARV's in water sources of South Africa pose a definite threat to wildlife and ultimately human health.

Efavirenz: What is known about the cellular mechanisms responsible for its adverse effects

The HIV infection remains an important health problem worldwide. However, due to the efficacy of combined antiretroviral therapy (cART), it has ceased to be a mortal condition, becoming a chronic disease instead. Efavirenz, the most prescribed non-nucleoside analogue reverse transcriptase inhibitor (NNRTI), has been a key component of cART since its commercialization in 1998. Though still a drug of choice in many countries, its primacy has been challenged by the arrival of newer antiretroviral agents with better toxicity profiles and treatment adherence. The major side effects related to EFV have been widely described in clinical studies, however the mechanisms that participate in their pathogenesis remain largely ununderstood. This review provides an insight into the cellular and molecular mechanisms responsible for the development of the most significant undesired effects induced by efavirenz, both short- and long-term, revealed by in vitro and in vivo experimental pharmacological research. Growing evidence implicates the drug in energy metabolism, mitochondrial function, and other cellular processes involved in stress responses including oxidative stress, inflammation and autophagy.

Endothelial Glycocalyx Damage and Renal Dysfunction in HIV Patients Receiving Combined Antiretroviral Therapy

Widespread use of combined antiretroviral therapy (cART) increased HIV patients' life expectancy, however, favored the development of kidney and cardiovascular diseases. The aim of this study was to investigate endothelial glycocalyx (eGC) damage and its association with renal function in HIV patients receiving cART. This is a cross-sectional study with HIV-infected patients with no renal and cardiovascular disease, recruited in public health centers in Brazil. Clinical and laboratory parameters of HIV patients were compared according to cART use and with a healthy control group. Blood ICAM-1 and syndecan-1 levels were quantified by ELISA kit. Estimated glomerular filtration rate (eGFR) was evaluated. A total of 69 HIV patients were included, with mean age of 33.4 ± 8.9 years, and 77.3% were male. Serum urea, creatinine, and eGFR were similar in all groups. No HIV patient had decreased GFR <60 ml/min. All HIV patients had higher systemic syndecan-1 compared with healthy controls (71.8 ± 25.4 ng/ml vs. 36.5 ± 14.3 ng/ml, p < .001). Syndecan-1 showed a significant positive correlation with serum creatinine (r = 0.437, p = .001), serum urea levels (r = 0.352, p = .006), and a negative correlation with eGFR (r = -0.315, p = .015) in HIV patients. Syndecan-1 remained independently associated with serum creatinine and reduced GFR even after we forced variables related with HIV infection status, tenofovir use, treatment time, dyslipidemia, and others in a multivariate analysis. HIV patients using cART with no clinical renal and cardiovascular disease presented eGC damage and it is associated with clinical markers of kidney dysfunction. Syndecan-1 may be a useful early biomarker to monitoring renal dysfunction in HIV patients in chronic use of cART. Further research is needed to evaluate this applicability.

Innate Immunity and Asthma Risk in Amish and Hutterite Farm Children

BACKGROUND

The Amish and Hutterites are U.S. agricultural populations whose lifestyles are remarkably similar in many respects but whose farming practices, in particular, are distinct; the former follow traditional farming practices whereas the latter use industrialized farming practices. The populations also show striking disparities in the prevalence of asthma, and little is known about the immune responses underlying these disparities.

METHODS

We studied environmental exposures, genetic ancestry, and immune profiles among 60 Amish and Hutterite children, measuring levels of allergens and endotoxins and assessing the microbiome composition of indoor dust samples. Whole blood was collected to measure serum IgE levels, cytokine responses, and gene expression, and peripheral-blood leukocytes were phenotyped with flow cytometry. The effects of dust extracts obtained from Amish and Hutterite homes on immune and airway responses were assessed in a murine model of experimental allergic asthma.

RESULTS

Despite the similar genetic ancestries and lifestyles of Amish and Hutterite children, the prevalence of asthma and allergic sensitization was 4 and 6 times as low in the Amish, whereas median endotoxin levels in Amish house dust was 6.8 times as high. Differences in microbial composition were also observed in dust samples from Amish and Hutterite homes. Profound differences in the proportions, phenotypes, and functions of innate immune cells were also found between the two groups of children. In a mouse model of experimental allergic asthma, the intranasal instillation of dust extracts from Amish but not Hutterite homes significantly inhibited airway hyperreactivity and eosinophilia. These protective effects were abrogated in mice that were deficient in MyD88 and Trif, molecules that are critical in innate immune signaling.

CONCLUSIONS

The results of our studies in humans and mice indicate that the Amish environment provides protection against asthma by engaging and shaping the innate immune response. (Funded by the National Institutes of Health and others.).

Inflammation, immune activation, and cardiovascular disease in HIV

Cardiovascular disease is one of the leading causes of morbidity and mortality in people living with HIV. Several epidemiological studies have shown an increased risk of myocardial infarction and stroke compared to uninfected controls. Although traditional risk factors contribute to this increased risk of cardiovascular disease, HIV-specific mechanisms likely also play a role. Systemic inflammation has been linked to cardiovascular disease in several populations suffering from chronic inflammation, including people living with HIV. Although antiretroviral therapy reduces immune activation, levels of inflammatory markers remain elevated compared to uninfected controls. The causes of this sustained immune response are likely multifactorial and incompletely understood. In this review, we summarize the evidence describing the relationship between inflammation and cardiovascular disease and discuss potential anti-inflammatory treatment options for cardiometabolic disease in people living with HIV.

Phenotype and Polyfunctional Deregulation Involving Interleukin 6 (IL-6)- and IL-10-Producing Monocytes in HIV-Infected Patients Receiving Combination Antiretroviral Therapy Differ From Those in Healthy Older Individuals

BACKGROUND

Despite the relevance of monocytes as promoters of the inflammatory response, whether human immunodeficiency virus (HIV) infection induces premature age-related changes to the phenotype and function of monocytes or whether these alterations are different and/or specifically driven by HIV remains to be mechanistically determined.

METHODS

We assayed the activation phenotype and the responsiveness in vitro to Toll-like receptor (TLR) agonists in classical, intermediate, and nonclassical subsets of monocytes by assessing intracellular interleukin 1α (IL-1α), IL-1β, interleukin 6 (IL-6), interleukin 8, tumor necrosis factor α, and interleukin 10 (IL-10) production in 20 HIV-infected patients receiving combination antiretroviral therapy (cART) and 2 groups of uninfected controls (20 age-matched young individuals and 20 older individuals aged >65 years).

RESULTS

HIV-infected patients showed a more activated phenotype of monocytes than older controls. Regarding functionality, under unstimulated conditions HIV-infected patients showed a higher percentage of classical monocytes producing IL-6 and IL-10 than control subjects. The percentage of cells with production of multiple cytokines (polyfunctionality), including IL-10, in response to TLR agonists was greater among HIV-infected patients than among control subjects.

CONCLUSIONS

Inflammatory alterations associated with monocytes during HIV infection are different from those in aging individuals. This monocyte dysfunction, mainly characterized by high levels of IL-6- and IL-10-producing monocytes, may have clinical implications in HIV-infected patients that are different from those in aging individuals.

Risk of coronary heart disease in patients with HIV infection

The lives of individuals infected with HIV who have access to combination antiretroviral therapy (cART) are substantially prolonged, which increases the risk of developing non-AIDS comorbidities, including coronary heart disease (CHD). In Europe and the USA, individuals with HIV infection have a ∼1.5-fold increased risk of myocardial infarction relative to uninfected individuals. In Africa, the relative risk of myocardial infarction is unknown, but broadened access to life-extending cART suggests that rates of CHD will rise in this and other resource-constrained regions. Atherogenesis in HIV is affected by complex interactions between traditional and immune risk factors. cART has varied, regimen-specific effects on metabolic risk factors. Overall, cART seems to lessen proatherogenic immune activation, but does not eliminate it even in patients in whom viraemia is suppressed. Current strategies to decrease the risk of CHD in individuals infected with HIV include early initiation of cART regimens with the fewest metabolic adverse effects, and careful management of traditional CHD risk factors throughout treatment. Future strategies to prevent CHD in patients with HIV infection might involve the use of HIV-tailored CHD risk-prediction paradigms and the administration of therapies alongside cART that will further decrease proatherogenic HIV-specific immune activation.