Chronic ethanol consumption before retrovirus infection is a cofactor in the development of immune dysfunction during murine AIDS

Cytokine profiling of exosomes derived from the plasma of HIV-infected alcohol drinkers and cigarette smokers

Cytokines and chemokines circulate in plasma and may be transferred to distant sites, via exosomes. HIV infection is associated with dysregulation of cytokines and chemokines, which subsequently contribute to the pathogenesis of HIV. Alcohol and tobacco exposure, which are prevalent in HIV-infected individuals, may induce changes in the expression of cytokines and chemokines. Therefore, our aim in this study was to quantify plasma exosomal cytokines and chemokines that we expect to exacerbate toxicity or disease progression in HIV-positive drug abusers. We measured the levels of cytokines and chemokines in the plasma and plasma exosomes of 39 patients comprising six groups: HIV-negative and HIV-positive non drug abusers, HIV-negative and HIV-positive alcohol users, and HIV-negative and HIV positive tobacco smokers. We measured six cytokines (TNF-α, IL-1β, IL-8, IL-6, IL-1ra, IL-10) and two chemokines (MCP-1 and RANTES). All were present in exosomes of healthy subjects, but their levels varied between different study groups. HIV-positive alcohol drinkers had higher levels of plasma IL-8 compared to those of HIV-positive non-drinkers. The IL-1ra level was significantly higher in exosomes of non-HIV-infected alcohol drinkers compared to those of HIV-positive alcohol drinkers. Interestingly, the IL-10 level was higher in exosomes compared with their respective plasma levels in all study groups except HIV-positive non-alcohol drinkers. IL-10 was completely packaged in exosomes of HIV-positive smokers. HIV-positive smokers had significantly higher levels of plasma IL-8 compared with HIV-positive non-smokers and significantly higher exosomal IL-6 levels compared with HIV-negative subjects. HIV-positive smokers had significantly increased plasma levels of IL-1ra compared to HIV-positive non-smokers. The MCP-1 levels in the plasma of HIV-positive smokers was significantly higher than in either HIV-positive non-drug abusers or HIV-negative smokers. Overall, the findings suggest that plasma cytokines and chemokines are packaged in exosomes at varying degrees in different study groups. Exosomal cytokines and chemokines are likely to have a significant biological role at distant sites including cells in the brain.

Alcohol and HIV: Experimental and Clinical Evidence of Combined Impact on the Lung

Despite antiretroviral therapy, lung disease is a leading cause of death in individuals infected with human immunodeficiency virus type 1 (HIV). Individuals infected with HIV are susceptible to serious bacterial and viral infections, such as pneumococcus and influenza, which are particularly problematic for lung health, resulting in lung injury. Additionally, HIV-infected individuals are susceptible to a number of pulmonary diseases for unknown reasons. Alcohol, the most commonly abused drug in the world, continues to exact an enormous toll on morbidity and mortality in individuals living with HIV. Chronic alcohol abuse has been shown to affect lung immunity, resulting in significant lung injury. There is a paucity of literature on the additive effects of HIV and alcohol, two diseases of immune senescence, in the lung. This chapter begins by discussing the latest literature evaluating the epidemiology of HIV, alcohol use, and lung health focusing on two prevalent infections, tuberculosis and pneumococcal pneumonia. In parallel, we discuss the interactions of alcohol and HIV on the risk for acute lung injury and subsequent morbidity and mortality. We then discuss the pathophysiology of how these two diseases of immune dysfunction affect the lung, with a focus on the oxidative stress, alveolar macrophage host immune capacity, and immunomodulatory role of zinc in the airway. Finally, we review the latest literature on how HIV and alcohol affect other pulmonary disorders including chronic obstructive pulmonary disease, pulmonary hypertension, and lung cancer.

Effects of alcohol consumption on antigen-specific cellular and humoral immune responses to SIV in rhesus macaques

BACKGROUND

Simian immunodeficiency virus (SIV) infection in macaques chronically receiving ethanol results in significantly higher plasma viral loads and more rapid progression to end-stage disease. We thus hypothesized that the increased plasma viral load in ethanol-treated, SIV-infected macaques would negatively correlate with antigen-specific immune responses.

METHODS

Rhesus macaques were administered ethanol or sucrose (n = 12 per group) by indwelling gastric catheters for 3 months and then intravenously infected with SIVMAC251. Peripheral blood T- and B-cell immunophenotyping and quantification were performed. Plasma was examined for viremia, levels of SIVEnv-specific binding, and neutralizing antibodies. Virus-specific interferon γ and tumor necrosis factor α cytokine responses to SIV-Nef, Gag, or Env peptide pools were measured in peripheral blood CD8 T cells.

RESULTS

Macaques receiving ethanol had both higher plasma viremia and virus-specific cellular immune responses compared with the sucrose-treated group. The emergence of virus-specific cytokine responses temporally correlated with the decline in mean plasma viral load after 14 days postinfection in all SIV-infected animals. However, neither the breadth and specificity nor the magnitude of virus-specific CD8 T-cell responses correlated with early postpeak reductions in plasma viral loads. In fact, increased cytokine responses against Gag, gp120, and gp41 positively correlated with plasma viremia. Levels of SIV envelope-specific immunoglobulin G and neutralizing antibodies were similar over the disease course in both groups of macaques.

CONCLUSIONS

Persistently higher antigen-specific cytokine responses in animals receiving ethanol are likely an effect of the higher viral loads and antigen persistence, rather than a cause of the increased viremia.

Spinal infections in patients with compromised immune systems

Spinal infections are relatively uncommon but have potentially devastating consequences if not diagnosed and treated correctly. Compromised immunologic responsiveness, either transient or permanent, predisposes patients to more frequent and more severe infections. Through a Medline review of the English-language literature from 1990 to 2005, we examined the current understanding of the etiology of common immunocompromising conditions, how these diagnoses impact the relative spine infection rates including diagnosis and therapeutic monitoring, and practice trends regarding surgical intervention.

LEVEL OF EVIDENCE

Level V (expert opinion). Please see Guidelines for Authors for a complete description of the levels of evidence.

Microbial infections, immunomodulation, and drugs of abuse

The use of recreational drugs of abuse has generated serious health concerns. There is a long-recognized relationship between addictive drugs and increased levels of infections. Studies of the mechanisms of actions of these drugs became more urgent with the advent of AIDS and its correlation with abused substances. The nature and mechanisms of immunomodulation by marijuana, opiates, cocaine, nicotine, and alcohol are described in this review. Recent studies of the effects of opiates or marijuana on the immune system have demonstrated that they are receptor mediated, occurring both directly via specific receptors on immune cells and indirectly through similar receptors on cells of the nervous system. Findings are also discussed that demonstrate that cocaine and nicotine have similar immunomodulatory effects, which are also apparently receptor mediated. Finally, the nature and mechanisms of immunomodulation by alcohol are described. Although no specific alcohol receptors have been identified, it is widely recognized that alcohol enhances susceptibility to opportunistic microbes. The review covers recent studies of the effects of these drugs on immunity and on increased susceptibility to infectious diseases, including AIDS.

Side-stream cigarette smoke accentuates immunomodulation during murine AIDS

Side-stream cigarette smoke has become a hotly debated social, political, and scientific health and safety issue for nonsmokers. The harmful influences of side-stream cigarette smoke on human health are its adverse effects on the immune system, especially when already compromised by other agents. Acquired immune deficiency syndrome (AIDS) is a clinical disorder caused by human immunodeficiency virus (HIV). To facilitate studies, murine AIDS was induced in C57BL/6 mice by LP-BM5 murine leukemia virus infection, which mimics human AIDS. After 2 weeks of retroviral infection, the mice were exposed to side-stream cigarette smoke for 30 min, 5 days/week for 12 weeks using a side-stream cigarette smoke exposure system. Murine retrovirus infection reduced the in vitro proliferation of T lymphocytes stimulated by concanavalin A, increased the release of pro-inflammatory cytokine interleukin-6 (IL-6) tumor necrosis factor-alpha (TNF-alpha), increased the hepatic lipid peroxidation and decreased the alpha-tocopherol levels in liver, lung and heart. Concomitant side-stream cigarette smoke exposure for 12 weeks further inhibited the proliferation of T cells, increased the release of TNF-alpha, IL-6 cytokines and enhanced the hepatic lipid peroxidation from retrovirus infected mice. The loss of alpha-tocopherol was also further enhanced by side-stream cigarette smoke exposure during retrovirus infection. Our conclusions are that side-stream cigarette smoke induced increasing oxidative stress, reducing nutrient concentrations and suppressing immune function could make mice with murine AIDS more susceptible to opportunistic infections, potentially accelerating murine AIDS progression. Thus, the reduction of side-stream cigarette smoke exposure is an important health issue in AIDS patients to improve the quality and quantity of their lives.

Diminished proliferation of B blast cell in response to cytokines in ethanol-consuming mice

We and others have demonstrated that ethanol suppresses the antibody response in humans and animals. The purpose of this study was to determine whether ethanol affects cytokine-induced proliferative responses of splenic B blast cells, and whether the decreased response was due to an imbalance of the cytokine activity. Thus, the ability of spleen cells from individual ethanol-diet-fed C57BL/6 mice to proliferate and produce cytokines was determined. The ability of anti-IgM monoclonal antibodies (mAb)-activated splenic B blast cells in response to mouse recombinant IL-2 (rIL-2) or rIL-4 was also assessed. A thymidine incorporation assay was used to determine cell proliferation, and the conventional bioassays for cytokine-dependent cell proliferation were used for determining the bioactivity of cytokines. Data were analyzed with general linear model procedure. Our results showed that ethanol weakened the proliferative response of B cells in response to mitogen as well as to mouse rIL-2 and rIL-4. The decreased B cell responses may result from an increase in the production of IL-4 by helper T cells. Finally, in the presence of excessive dose of rIL-4, the proliferative responses of B blast cells from all three groups of mice were diminished (p<0.01). Thus, our data clearly indicated that the diminished B cell proliferation in ethanol-consuming mice was due in part to an excessive amount of IL-4 produced and an inability of the B cell to interact properly with IL-4 that was secreted by helper T cells. The results should extend our basic understanding of the mechanism by which chronic alcoholism impairs the interactions and interdependence of T- and B-cell immune functions.

Cocaethylene and heart disease during murine AIDS

Cocaethylene is an active cocaine metabolite believed to play a causative role in the increased incidence of sudden cardiac death in individuals who co-administer alcohol and cocaine. Prolonged and excessive abuse of cocaine and alcohol will result in marked alteration of host immunity to increased susceptibility to infection. To test the chronic direct effect of cocaethylene on the heart function, a conductance catheter system (CCS) was used in vivo in this study. To test whether cocaethylene injection exacerbates coxsackievirus B3 (CVB3) or cytomegalovirus (CMV) cardiomyopathy during murine AIDS, female C57BL/6 mice were infected with LP-BM5 retrovirus and superinfected with CVB3 or CMV. Daily, mice were injected intraperitoneally with cocaethylene in 0.9% saline solution (concentration increased gradually from 15 to 25 mg/ml). Histopathology of heart tissue was analyzed in all groups, and cytokines of spleen were measured in the CMV-infected groups. Results showed there was little effect on the cardiovascular system after cocaethylene injection. Cocaethylene injection during murine retrovirus infection greatly exacerbated the pathogenesis of CVB3 or CMV infection, whereas CMV-infected mice showed relatively moderate cardiac pathology compared with CVB3 infection. Both CMV and retrovirus infection suppressed the Th1 response. Our data suggest that cocaethylene treatment shifts the cytokine balance and suppresses Th1 response particularly, facilitating increased CVB3- or CMV-induced myocarditis.

Effect of ethanol on monocytic function in human immunodeficiency virus type 1 infection

We have developed a novel system to study monocytic function after human immunodeficiency virus type 1 (HIV-1) infection by infecting a series of human macrophage hybridoma cell lines with HIV-1. Since ethanol has detrimental effects on immune function, we investigated the effect of ethanol and its metabolites acetaldehyde and acetate on monocytic function by utilizing one human macrophage hybridoma cell line, clone 43, as well as primary monocytes. Pretreatment of clone 43 and primary monocytes with ethanol and its metabolites resulted in diminished accessory cell function for mitogen-, anti-CD3-, and antigen-induced T-cell proliferation. The decreased accessory cell function was associated with reduced interleukin 1alpha (IL-1alpha), IL-1beta, and tumor necrosis factor alpha production with loss of intracellular cytokine and mRNA production and the induction of transforming growth factor beta. In ethanol-, acetaldehyde-, and acetate-treated HIV-1-infected clone 43 cells (43HIV), there was a more rapid loss (3 days after infection) of accessory cell function at a lower infecting dose of HIV-1 than that in untreated 43HIV cells. We also observed a more rapid loss of surface class II antigen expression in the ethanol-, acetaldehyde-, and acetate-treated 43HIV cells, but no change in surface expression of CD80 or CD86. Ethanol-induced impairment of monocytic function may compound the immunologic defects of AIDS, making the infected individual more susceptible to the complications of the disease.

Alcohol consumption alters cytokine release during murine AIDS

Acquired immune deficiency syndrome (AIDS) is a clinical disorder caused by a human immunodeficiency virus (HIV), representing the end point in a progressive sequence of immunosuppressive changes. HIV, the key causative agent of AIDS, induces immunosuppression that render the body highly susceptible to opportunistic infections and neoplasm. However, the onset of clinical symptoms of AIDS (e.g., low CD4+ T cells count, opportunistic infections, and tumors) is quite variable among HIV+ individuals with a mean incubation times 3-10 years following seroconversion. Because of the deleterious effects of chronic alcohol (EtOH) consumption on cytokine release, immune response, host defense, nutritional status, and oxidative stress, it has been believed to be a possible cofactor that could enhance the host's susceptibility to HIV infection, and subsequently accelerate the development of AIDS. The purpose of this review is to present evidence of EtOH-induced cytokine dysregulation during murine AIDS. Our results done in murine AIDS indicate the EtOH consumption may accelerate the development of AIDS by disrupting cytokine production. These EtOH-induced abnormalities in cytokine release may promote a more rapid development of AIDS as a cofactor, which exacerbates the immune dysfunctions initiated by retrovirus infection.

Immunomodulation by pycnogenol in retrovirus-infected or ethanol-fed mice

Pycnogenol is a commercial mixture of bioflavonoids that exhibits antioxidative activity. The effects of dietary pycnogenol on immune dysfunction in normal mice as well as those fed ethanol or infected with the LP-BM5 murine retrovirus were determined. The ethanol consumption and retrovirus infection caused abnormalities in the function and/or structure of a broad array of cells involved in humoral and cellular immunity. Pycnogenol enhanced in vitro IL-2 production by mitogen-stimulated splenocytes if its production was suppressed in ethanol-fed or retrovirus-infected mice. Mitogenesis of splenocytes did not show a significant change in mice treated with pycnogenol. It reduced the elevated levels of interleukin-6 produced in vitro by cells from retrovirus infected mice and IL-10 secreted by spleen cells from mice consuming ethanol. Natural killer cell cytotoxicity was increased with pycnogenol treatment.

Is alcohol consumption a cofactor in the development of acquired immunodeficiency syndrome?

Excessive alcohol (EtOH) consumption and acquired immunodeficiency syndrome (AIDS) are two major public health problems in the United States. Overwhelming evidence is showing that heavy EtOH ingestion broadly suppresses the various arms of immune response, seriously impairing the body's normal host defense to invading microbes and tumorigenesis. The onset of clinical symptoms of AIDS (low CD4+ T cells count, opportunistic infections, and tumors) is quite variable among HIV+ individuals with a mean incubation time 3-10 years following seroconversion. Because of the deleterious effects of chronic EtOH consumption on cytokine release, immune response, host defense, nutritional status, and oxidative stress, it has been believed to be a possible cofactor that could enhance the host's susceptibility to infections, and subsequently increase the rate of AIDS development. The purpose of this review is to present evidence indicating clinical disorders during EtOH ingestion in murine AIDS. These EtOH-induced abnormalities may promote a more rapid development of AIDS in HIV-infected individuals.

Chronic ethanol consumption prior to retrovirus infection alters cytokine production by thymocytes during murine AIDS

Chronic ethanol (EtOH) consumption may be a cofactor in the development of acquired immune deficiency syndrome (AIDS). As the thymus is an unique site for T cell maturation, we investigated whether thymocytes from EtOH consuming mice were more predisposed to aberrant cytokine production due to retrovirus infection. Adult female C57BL/6 mice were fed 4.5% (v/v) in liquid diet or control liquid diet without EtOH for 10 weeks. All diets contained nutrients at only the recommended daily intake level for mice. Then all mice were infected LP-BM5 retrovirus and were fed control liquid diets without EtOH. The body and thymus weights were not affected by EtOH consumption. However, thymocyte number and proliferation, which had been reduced during murine AIDS, were significantly further reduced by EtOH use. The production of IL-2 and IL-6 by thymocytes, which was lessened during retrovirus infection, were significantly further suppressed by dietary EtOH at 6 weeks postinfection, whereas levels of IL-4 and IFN-gamma by thymocytes, which were elevated during retrovirus infection, were significantly and slightly further increased by EtOH-treated mice prior to retrovirus infection, respectively. These data suggest that dietary EtOH consumption can modulate cytokine production by thymocytes, adversely affecting T cell differentiation, especially during retrovirus infection. These results provide additional evidence that EtOH consumption should be a cofactor during development of AIDS via producing altered cytokine production and then disrupting T cell differentiation.