Chronic ethanol intoxication enhances the production of cytokine-induced neutrophil chemoattractant and macrophage inflammatory protein-2 by hepatocytes after human immunodeficiency virus-1 glycoprotein 120 vaccination

Abstract 

Chemokines are implicated in the pathogenesis of alcoholic liver disease and human immunodeficiency virus-1 (HIV-1) infection. Thus, this work examined the regulation of chemokines — i.e., cytokine-induced neutrophil chemoattractant (CINC) and macrophage inflammatory protein-2 (MIP-2) — produced by hepatocytes after HIV-1 glycoprotein 120 (gp120) vaccination in Wistar rats fed with ethanol for 30 weeks. HIV-1 gp120 in complete Freund's adjuvant was given by intrainguinal route at a dose of 5 μg/kg, followed by two booster shots in incomplete Freund's adjuvant at a weekly interval. Samples were taken 1 week after the last injection was given. Results show that anti-HIV-1 gp120 antibody titer was suppressed by 40% in the ethanol-fed rats, compared with findings in the parallel controls. However, serum CINC and MIP-2 levels were more elevated in the ethanol-fed rats than in the pair-fed group. The likely sources of these chemokines are the hepatocytes. After HIV-1 gp120 treatment, isolated hepatocytes obtained from the ethanol-fed group produced more CINC and MIP-2 than did those of pair-fed rats. Concomitantly, mRNA expression for these two chemokines and hepatic sequestration of neutrophils were upregulated. Ethanol feeding alone suppressed chemokine release, but it did not alter mRNA expression in isolated hepatocytes. Administration of Freund's adjuvant (without HIV-1 gp120) did not induce chemokine release in vivo and did not prime isolated hepatocytes for enhanced chemokine production in vitro. These results show that chronic ethanol intoxication affects the ability of the host to respond to HIV-1 gp120 vaccination.

Keywords:  Immunosuppression, Inflammation, Chemokines, Transcription, Gene expression, Liver injury, Rat