Ethanol and cytokine secretion

Activated lymphocytes (CD25+ CD69+ cells) and decreased CD19+ cells in well-nourished chronic alcoholics without ethanol-related diseases

To assess lymphocyte subsets and expression of activation antigens in peripheral blood lymphocytes (PBLs) in chronic alcoholism, a cross-sectional study with 30 well-nourished chronic alcoholics and 30 controls was performed. Studies included detailed clinical and laboratory evaluation, nutritional status assessment, and determination of lymphocyte subpopulations, as well as activation antigens. A significant decrease of B cells (CD19+) was observed in chronic alcoholics, compared with controls (p < 0.001). A significant increase of PBLs expressing CD69 and CD25 (p < 0.01, both) in chronic alcoholics was also detected, whereas CD71 expression was unaffected. In addition, T lymphocytes expressing HLA-DR were significantly higher in chronic alcoholics than controls (p < 0.05). The serum level of soluble interleukin-2 receptor was also significantly higher in the alcoholic group, compared with controls (p = 0.04). Moreover, the estimated total lifetime dose of ethanol consumed correlated positively with the percentage of PBLs expressing CD25 (r = 0.48; p = 0.01) and negatively with PBLs expressing CD71 (r = -0.39; p = 0.04). By contrast, the changes were not related to age, nutritional status, or the presence of other ethanol-related diseases. In conclusion, chronic alcoholics present a significant decrease of B cells and an "incomplete activation state" of PBLs that depends on the dose of ethanol consumed.

Serotonin-immune interactions in detoxified chronic alcoholic patients without apparent liver disease: activation of the inflammatory response system and lower plasma total tryptophan

The aims of the present study were to examine (1) the inflammatory response system (IRS), through measurements of serum interleukin-6 (IL-6), soluble IL-6 receptor (sIL-6R), sgp130 (the soluble form of the IL-6 transducer signal protein), CC16 (Clara Cell protein; an endogenous anti-cytokine), IL-1R antagonist (IL-1RA), IL-8 and sCD14; and (2) the availability of plasma total tryptophan to the brain in chronic alcoholic patients without apparent liver disease (AWLD). Detoxified AWLD patients had significantly lower plasma tryptophan and serum CC16 and significantly higher serum IL-1RA and IL-8 concentrations than normal volunteers. There were significant correlations between the availability of tryptophan to the brain and serum IL-6, IL-8 and IL-1RA (all negative) and CC16 (positive). The results suggest that (1) there is, in detoxified AWLD patients, an activation of the monocytic arm of cell-mediated immunity and a lowered anti-inflammatory capacity of the serum; and that (2) lower availability of plasma tryptophan to the brain in detoxified AWLD patients is related to activation of the IRS. Lower CC16 may be one factor predisposing chronic alcoholic patients toward infectious disorders.

Zonated expression of cytokines in rat liver: effect of chronic ethanol and the cytochrome P450 2E1 inhibitor, chlormethiazole

The release of proinflammatory cytokines by endotoxins and during oxidative stress is considered to be an early key step in the pathogenesis of alcoholic liver disease (ALD). Ethanol-inducible cytochrome P450 2E1 (CYP2E1) has potentially pro-oxidative and toxicological properties, and its expression is restricted to the perivenous region of liver. We investigated zonal differences of cytokine expression in rat liver and how these are affected by alcohol exposure and by chlormethiazole (CMZ), a transcriptional and posttranslational inhibitor of hepatic CYP2E1. Periportal and perivenous cell lysates were obtained by the digitonin pulse technique from livers of rats treated with ethanol and CMZ for 38 days. Cytokine expression on the mRNA and protein levels was quantified using competitive polymerase chain reaction (PCR) and Western blot, respectively. Chronic ethanol treatment significantly increased the expression of CYP2E1, microsomal p-nitrophenol hydroxylase activity (indicative for CYP2E1 enzyme activity), and the expression of transforming growth factor beta1 (TGF-beta1), tumor necrosis factor alpha (TNF-alpha), and interleukin (IL)-1beta (1.4- to 4.6-fold). In contrast, ethanol caused a decrease in IL-4 expression and had no influence on IL-6 expression. CMZ treatment caused a reduction in hepatic CYP2E1 expression and in the ethanol-induced cytokine expression by 40% to 60%. Expression of IL-6, IL-2, and IL-4 mRNA occurred preferentially in the periportal region, whereas ethanol caused a pronounced increase in the perivenous expression of TGF-beta1, which was inhibited by CMZ as monitored both on the mRNA and protein levels. These results show the zonated expression of several cytokines and the counteraction of CMZ on all effects of ethanol on cytokine expression. The data further strengthen a link between increased CYP2E1 expression and enhanced cytokine expression as important events in the development of ALD.

Role of Kupffer cells, endotoxin and free radicals in hepatotoxicity due to prolonged alcohol consumption: studies in female and male rats

Alcohol ingestion results in increases in the release of endotoxin from gut bacteria or membrane permeability of the gut to endotoxin, or both. Female rats are more sensitive to these changes. Elevated levels of endotoxin activate Kupffer cells to release substances such as eicosanoids, tumor necrosis factor-alpha and free radicals. Prostaglandins increase oxygen uptake and most likely are responsible for the hypermetabolic state in the liver. The increase in oxygen demand leads to hypoxia in the liver, and on reperfusion, alpha-hydroxyethyl free radicals are formed that lead to tissue damage in oxygen-poor pericentral regions of the liver lobule.

Biological responses to administered interferon in alcoholics

To elucidate the influence of chronic alcohol intake on interferon (IFN) therapy in patients with various diseases, 3 million units of natural IFN (nHuIFN-alpha Ly) was administered once to alcoholics, nonalcoholic chronic hepatitis C (CH-C) patients, and healthy subjects. The serial changes of serum activity of 2'-5' oligoadenylate synthetase, serum levels of beta 2-microglobulin, C-reactive protein (CRP), and body temperature were monitored. The increase in the activity of 2'-5' oligoadenylate synthetase, the response of serum-reactive protein, and body temperature after IFN administration were significantly lower in the alcoholics than those in CH-C group, and healthy subjects (control group). The serum beta 2-microglobulin level was already higher in the alcoholics before IFN administration than those of the control group and the CH-C group. These findings suggest that physiological responses to exogenous IFN in alcoholics are generally decreased. Hence, for the maximum effect of IFN therapy, it is important for patients to abstain from alcohol intake and for doctors to carefully consider the timing of initiation.

Identification of the nuclear transcription factor NFkappaB in rat after in vivo ethanol administration

NFkappaB, a nuclear transcription factor, was induced in the brain nuclear fraction of naive rats after an acute injection of ethanol, 2 g/kg. In contrast, rats which had been chronically alcoholised showed the constitutively active NFkappaB-like complex only after a further acute dose of ethanol. Hepatic nuclear fractions did not exhibit the specific NFkappaB-like complex during the first 45 min after acute ethanol injection, beyond that which was normally constitutively present. Such activation of NFkappaB-like complex in the brains of the naive rats may play an important role in the cellular protective response.

Effects of chronic ethanol administration on the endocytosis of cytokines by rat hepatocytes

The effects of chronic ethanol administration on the endocytosis of three representative cytokines were investigated in isolated rat hepatocytes. When hepatocytes were isolated from rats that were fed an ethanol liquid diet for 12 to 13 weeks, these cells exhibited a decreased ability to internalize and degrade transforming growth factor-alpha, tumor necrosis factor-alpha and interleukin-6, compared with hepatocytes from the pair-fed controls. This impaired endocytosis of all three cytokines was accompanied by significant decreases in the amount of hepatocyte surface-bound cytokine. Changes in cytokine binding to surface receptors and reduced rates of receptor-cytokine complex internalization into the cells seem to be major contributors to defective endocytosis in hepatocytes from the ethanol-fed rats. Impaired hepatocyte endocytosis could lead to altered steady-state levels of cytokines in the liver and modified physiological responses to cytokines. These changes could affect homeostasis among the various cell types in the liver and could contribute to liver dysfunction and injury.

Autoantibody against a 78 kDa membrane protein of HepG2 cell in the sera of patients with alcoholic liver diseases

Sera from 14 normal control subjects, 30 patients with alcoholic liver diseases (fatty liver, n = 8; hepatitis, n = 13; liver cirrhosis, n = 9), 7 controls with chronic hepatitis B, and 8 controls with chronic hepatitis C were masured for their concentrations of antibodies against HepG2 membrane protein by a binding assay utilizing 125I-labeled protein A. When the cut-off level was set as the mean value plus 2 SD of normal control subjects, the incidence of positivity was 75%, 69.2%, and 77.8% in patients with alcoholic fatty liver, alcoholic hepatitis, and alcoholic cirrhosis, respectively. Both the mean serum antibody values and the positive incidence were significantly higher in patients with alcoholic liver diseases than in either the normal controls or in the control patients with chronic hepatitis. Sodium dodecylsulfate polyacrylamide gel electrophoresis of 125I-labeled HepG2 membrane protein precipitated with IgG from patients with alcoholic liver diseases revealed an immunoreactive band at a molecular weight of 78,000 daltons (gp78). The antibody activity remained after immunoabsorption by human liver-specific lipoprotein (LSP) but decreased when HepG2 cells were pre-treated with trypsin or neuraminidase. Consequently, gp78 appears to be a glycoprotein distinct from LSP, and is specifically recognized by IgG from patients with alcoholic liver diseases. This assay may provide a new system to measure autoantibody to hepatocytes in alcoholic liver diseases.

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.

Effect of alcohol use on allograft rejection rates after liver transplantation for alcoholic liver disease

Alcoholic liver disease is a major cause of liver disease and has become an ever-increasing indication for liver transplantation (LTx). Follow-up studies have reported a higher rate of alcohol recidivism in patients transplanted for alcoholic hepatitis, compared with those transplanted for endstage alcohol-associated cirrhosis. It is assumed widely that recurrent alcohol use is associated with reduced compliance with immune suppression and, as a result, an increased risk of graft rejection and loss. To assess this question, 209 alcoholic patients transplanted for either alcoholic hepatitis with cirrhosis or cirrhosis alone between January 1, 1986 and December 31, 1991 were followed, with a mean follow-up of 4.4 +/- 0.6 years. There were 175 episodes of acute cellular rejection (ACR) that occurred in 137 patients, for an overall rejection rate of 83.7% or at a rate of 1.25 episodes/patient with rejection. The rate of ACR was three times as great in those who remained alcohol-abstinent (2.24 episodes/patient), compared with those who admitted to continued alcohol use (0.75 episodes/patient) (p < 0.01). A total of 33 episodes of chronic rejection occurred in 26 patients, for an overall rate of 12.4%. As was the case for ACR, the chronic rejection rate was greater among those who were continuously alcohol-abstinent, compared with those who intermittently used alcohol after successful LTx. There were no differences in the mean FK 506 or cyclosporin A levels in the groups with and without a rejection episode at the time the rejection episode was documented by liver biopsy.(ABSTRACT TRUNCATED AT 250 WORDS)

Role of Kupffer cells in failure of fatty livers following liver transplantation and alcoholic liver injury

Kupffer cells have been implicated in mechanisms of pathophysiology following liver transplantation. Recently, postoperative injury in ethanol-induced fatty liver has been evaluated because fatty livers often fail following transplantation. The low-flow, reflow liver perfusion model was used to study the role of Kupffer cells (KC) in reperfusion injury to fatty livers from rats fed a diet containing ethanol for 4-5 weeks. Treatment with GdCl3, which selectively destroys KC, decreased cell death significantly. Thus, destruction of KC minimized hepatic reperfusion injury, most likely by inhibiting free radical formation and improving microcirculation. Since it was demonstrated recently that destruction of KC prevented the hypermetabolic state observed with acute alcohol exposure, their involvement in events leading to alcohol-induced liver disease was investigated. In rats exposed to ethanol continuously via intragastric feeding for up to 4 weeks, GdCl3 treatment prevented elevation of aspartate aminotransferase (AST) and dramatically reduced the average hepatic pathological score. These results indicate that KC participate in the early phases of alcohol-induced liver injury. Endotoxaemia occurs in alcoholics and activates KC; therefore, we evaluated the effect of minimizing bacterial endotoxin by intestinal sterilization with the antibiotics polymyxin B and neomycin. Antibiotics diminished plasma endotoxin levels significantly and prevented ethanol-induced increases in AST values. These results indicate that endotoxin is involved in the mechanism of ethanol-induced liver injury. A six-line radical spectrum was detected with electron paramagnetic resonance spectroscopy in bile from alcohol-treated rats which was blocked by GdCl3. The free radical adducts had hyperfine coupling constants characteristic of lipid-derived free radical products. In conclusion, these studies demonstrate that KC are involved in reperfusion injury to ethanol-induced fatty livers and hepatic injury due to long-term treatment with ethanol.

Increased serum IgE in alcohol abusers

BACKGROUND

It has been reported that total serum IgE is increased in patients with alcoholic cirrhosis, but it is not clear if this fact is related to alcoholic liver disease or to alcohol intake.

OBJECTIVE

To measure serum IgE in a group of chronic alcoholics with different stages of liver injury in order to elucidate if IgE increase in related to alcoholic liver damage.

PATIENTS AND METHODS

Total serum IgE was determined by enzyme immunoassay in 186 chronic alcoholic patients (137 male/49 female) and 101 healthy controls. Patients and controls with known reasons for IgE elevation were excluded. Among alcoholic patients, 24 had fatty liver, 28 hepatic fibrosis, 29 alcoholic hepatitis, and 67 liver cirrhosis (38 patients were not evaluable concerning liver injury).

RESULTS

Total serum IgE was found to be increased in alcoholics (median 154.5 IU/mL, range 1-7329 IU/mL) with respect to healthy controls (median 20 IU/mL, range < 1-1417 IU/mL) (P < 0.001). IgE increase was moderate (180-1000 IU/mL) in 60 alcoholics (32.3%) and marked ( > 1000 IU/mL) in 27 (14.5%). Male alcoholics had higher IgE levels than females (median 191 IU/mL and range 1-7329 IU/mL vs 105 IU/mL and range 2-2189 IU/mL) ( P = 0.009). On logistic regression analysis, alcoholism, male sex and younger age (but not smoking) were independently associated with higher IgE levels. No clear relationship was noted between serum IgE and severity of alcoholic liver disease. Thus, no correlation was observed between IgE and parameters of liver function (serum bilirubin, albumin or prothrombin index). Likewise, IgE concentrations were not significantly different in patients with liver cirrhosis with respect to patients with less severe liver disease. Serum IgE was increased ( > 180 IU/mL) in 47.8% of cirrhotics and in 44% of patients without liver cirrhosis. In contrast, other immunoglobulins (IgG, IgA and IgM) were significantly correlated with liver dysfunction.

CONCLUSION

Chronic alcoholism should be considered as a cause of increased total serum IgE, regardless of the severity of the underlying liver disease.

Acetaldehyde-serum protein adducts inhibit interleukin-2 secretion in concanavalin A-stimulated murine splenocytes: a potential common pathway for ethanol-induced immunomodulation

Variable immunobiological changes occur with alcohol consumption. Previous studies have shown that acetaldehyde forms stable adducts with serum proteins, including albumin. These adducts are elevated in persons and animals consuming ethanol. We examined the effect of serum protein-acetaldehyde adducts formed with fetal bovine serum (FBS) on concanavalin A-stimulated murine splenocytes. Interleukin-2 (IL-2) secretion and IL-2 receptor (IL-2R) expression were determined as a function of the effect of the acetaldehyde-protein adduct(s). FBS was incubated with acetaldehyde (500, 100, 50, 25, 10, and 0 microM) for 1 hr at 37 degrees C. Excess acetaldehyde was removed by ultrafiltration using a 500 molecular weight cut-off membrane in 3 volumes. Free as well as bound acetaldehyde was quantified using fluorigenic HPLC before and after incubation. Recovered acetaldehyde correlated with the amount added (r2 = 0.996). Splenocytes were cultured for 48 hr in complete medium containing 5% acetaldehyde-treated and 5% untreated FBS with 4 micrograms/ml concanavalin A. Although cell viability was unchanged, acetaldehyde-treated FBS mixed with native FBS decreased IL-2 secretion in a dose-dependent manner. The percentage of cells expressing IL-2R was reduced only at the highest acetaldehyde-FBS dose. Therefore, immunological effects ascribed to ethanol may result in part from the toxic properties of acetaldehyde-protein adducts on IL-2 secretion.

Inactivation of Kupffer cells prevents early alcohol-induced liver injury

It is well recognized that consumption of alcohol leads to liver disease in a dose-dependent manner; however, the exact mechanisms remain unclear. Hypoxia subsequent to a hypermetabolic state may be involved; therefore, when it was observed recently that inactivation of Kupffer cells prevented stimulation of hepatic oxygen uptake by alcohol, the idea that Kupffer cells participate in early events that ultimately lead to alcohol-induced liver disease became a real possibility. The purpose of this study was to test that hypothesis. Male Wistar rats were exposed to ethanol continuously by means of intragastric feeding for up to 4 weeks using the model developed by Tsukamoto and French. In this model, ethanol causes fatty liver, necrosis and inflammation--changes characteristic of alcohol-induced liver disease in human beings. Kupffer cells were inactivated by twice weekly treatment with gadolinium chloride (GdCl3), a selective Kupffer cell toxicant. AST levels were elevated to 192 +/- 13 and 244 +/- 56 IU/L in rats exposed to ethanol for 2 and 4 wk, respectively (control value, 88 +/- 7). This injury was prevented almost completely by GdCl3 treatment. Fatty changes, inflammation and necrosis were also all reduced dramatically by GdCl3 treatment. The average hepatic pathological score of rats treated with ethanol for 4 wk was 4.3 +/- 0.6, which was reduced significantly in ethanol- and GdCl3-treated rats to 1.8 +/- 0.5 (p < 0.05). Rates of ethanol elimination were elevated 2- to 3-fold in rats exposed to ethanol for 2 to 4 wk. This elevation was blocked by GdCl3 treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Ethanol-induced suppression of interleukin 1-like activity: reversal by a quinone derivative

Chronic ethanol intake impairs several parameters of immune function. Since there is evidence that cytokine production by immune cells may contribute to the immunosuppressive effect of ethanol, we examined interleukin 1 (IL1) production by liver non-parenchymal cells (NPC) in ethanol-fed rats. Male Wistar rats (225-250 g) were fed by continuous intragastric infusion. The source of fat was either saturated fat or polyunsaturated fat. In addition, the effect of a quinone compound on IL1 production was assessed. Animals were fed for various periods: 1 week, 2 weeks, 1 month and 2 months. NPC were isolated and stimulated by lipopolysaccharide. IL1 production by NPC and the ratio of stimulated to unstimulated (S:U) IL1 production were evaluated in the different groups and related to the presence of liver injury. As expected, animals fed corn oil and ethanol (CO+E) developed pathologic liver injury, whereas animals fed saturated fat and ethanol (SF+E) had no liver injury. A progressive decrease in the S:U IL1 ratio was seen in the CO+E group over the 8-week period. The ratio in the SF+E group was higher. The quinone compound reversed the suppressive effect of ethanol on IL1 production. In summary, ethanol-induced suppression of IL1 production was modulated by diet and the presence of liver injury. This suppression of IL1 production was reversed by a quinone compound; the exact mechanism for the reversal of this inhibition is unknown.

Effect of ethanol on the interaction between the macrophage and Mycobacterium avium

Chronic ethanol ingestion predisposes to tuberculosis and bacterial pneumonia. Mycobacterium avium complex organisms cause bacteremia in patients with AIDS. Human macrophages and murine Kupffer cells exposed to ethanol are more permissive towards intracellular growth of M. avium than control mononuclear phagocytes. Ethanol also has been shown to impair the ability of human macrophages and murine Kupffer cells to respond to stimulation with tumor necrosis factor (TNF) and granulocyte macrophage colony stimulating factor (GM-CSF), and to produce cytokines such as interleukin-1, interleukin-6, and TNF when properly stimulated. The impairment is dependent in part on a downregulation in the number of TNF receptors on the macrophage's membrane. Recent evidence suggests that ethanol in nonlethal concentrations induces stress-related proteins in M. avium, leading to the inhibition of intracellular pathways in the macrophage and, consequently, impairing some of its functions. In summary, ethanol acts both on the host and on the mycobacterium in a complex sequence of events that influence the outcome of the infection.

Influence of chronic dietary ethanol on cytokine production by murine splenocytes and thymocytes

Prolonged consumption of ethanol (ETOH) results in alterations of host defense via immune modulation, increasing susceptibility to infection. In the present study, effects of chronic dietary ETOH on cytokine production by splenocytes and thymocytes, splenocyte and thymocyte proliferation induced by mitogens, splenic natural killer cell activity, and antibody production (IgA and IgG) were examined. C57BL/6 mice were fed 5% ETOH v/v in the Lieber-DeCarli liquid diet for 11 weeks. Release of interleukin (IL)-2, IL-5, IL-6, IL-10, and interferon (IFN)-gamma produced by concanavalin A (Con A) stimulated splenocytes was significantly decreased, whereas secretion of IL-4 was slightly decreased by chronic dietary ETOH compared with controls. Production of tumor necrosis factor-alpha and IL-6 by lipopolysaccharide-stimulated splenocytes was significantly and slightly decreased by ETOH compared with controls, respectively. Splenocyte and thymocyte proliferation induced by Con A was significantly inhibited by ETOH, whereas splenocyte proliferation induced by lipopolysaccharide was not affected. Natural killer cell activity was significantly inhibited by ETOH compared with controls. The production of IgA and IgG by splenocytes were also significantly decreased by ETOH compared with controls. The levels of IL-2, IL-4, and IL-6 produced by Con A-stimulated thymocytes were significantly reduced by dietary ETOH compared with control, whereas production of IFN-gamma by thymocytes was not affected. Our results suggest that chronic dietary ETOH alters the cytokine release, thereby impairing immune response and T-cell maturation, which increase host susceptibility to infection.

Interleukin-6 and interleukin-8 production by mononuclear cells of chronic alcoholics during treatment

Chronic alcohol consumption has been associated with suppression of a number of immune parameters. This study was designed to investigate the relationship between chronic alcohol ingestion and cessation with respect to release of interleukin-6 (IL-6) and interleukin-8 (IL-8) using highly specific and sensitive ELISA assays, as well as a functional assay, natural killer cell cytotoxic activity. ELISAs were developed to determine the amount of IL-6 and IL-8 release by peripheral blood mononuclear cells (PBMCs). Two groups of subjects were recruited: young (18-22 years old), nonalcoholic users (controls) and long-term alcoholics (35-55 years old). Blood samples were collected at time 0 from all subjects and from alcoholics 28 days after treatment had begun and alcohol use had ceased. Then mitogen-stimulated release of cytokines by peripheral blood cells was determined. The abstaining controls, and the alcoholics, after 30 days of abstinence, tended to produce lower amounts of IL-6 and IL-8, although these differences were not statistically significant. Natural killer cell activity was not statistically different between the young groups, yet appeared to increase once alcohol use discontinued. Some of the cells from the controls (abstainers) were incubated with ethanol (EtOH). Its content in sealed wells was measured after the time of incubation of PBMCs. When EtOH was serially diluted in plates, some well-well diffusion was noted, but the maximum concentration of EtOH never fell below 0.3% from an initial concentration of 0.5%, and at no time was the EtOH concentration gradient completely lost, even after 66 hr of incubation.(ABSTRACT TRUNCATED AT 250 WORDS)

Ethanol-induced modulation of cytokine production by splenocytes during murine retrovirus infection causing murine AIDS

Ethanol (ETOH) consumption has been associated with general suppression of the immune response, resulting in increased susceptibility to infection. Chronic dietary ETOH consumption may be one of the cofactors accelerating development of human acquired immune deficiency syndrome (AIDS) after retrovirus infection. Chronic dietary ETOH [5% (v/v)] in the Lieber-DeCarli liquid diet was fed female C57BL/6 mice inoculated with LP-BM5 retrovirus causing murine AIDS for 11 weeks. Because cytokines are key regulators of humoral and cellular immunity, their production by concanavalin A (ConA) and lipopolysaccharide (LPS)-induced splenocytes was measured by ELISA methods. Decreased levels of interleukin (IL)-2 caused by retrovirus infection remained unchanged. Elevated levels of IL-5 and IL-6 produced in vitro by ConA-stimulated spleen cells during retrovirus infection were significantly further increased by dietary ETOH. Elevated IL-4 due to retroviral infection were not affected by dietary ETOH. Increased production of IL-10 induced by retrovirus infection, however, was significantly reduced by dietary ETOH, whereas decreased release of interferon-tau induced by retrovirus infection was significantly enhanced. Elevated levels of tumor necrosis factor-alpha produced by LPS-stimulated splenocytes from retrovirus infected mice were significantly further increased by dietary ETOH, whereas levels of IL-6 by LPS-stimulated splenocytes were not affected. Suppressed T-cell proliferation caused by retrovirus infection was significantly reduced further by dietary ETOH. However, no effect of dietary ETOH was observed on decreased B-cell proliferation by retrovirus infection. These results suggest that dietary ETOH aggravates progression of immune dysfunction leading to AIDS, because dietary ETOH modifies production of immunological regulatory cytokines.