Characterization of T-Cell specific immune responses among alcohol consumers in a fisher folk community of Lake Victoria

Abstract

Background: Alcohol is an immunosuppressant which acts directly through T cell apoptosis, mitochondrial damage, and inhibition of T cell responses. Alcohol abuse and its social and behavioral consequences have been associated with increased incidence and severity of HIV infection, though with insignificant success towards HIV prevention strategies. Hypotheses from animal studies which suggest that alcohol may increase biological susceptibility to HIV through effects on T-cell responses are yet to be proven in humans. This study sought to characterize T-cell specific responses among alcohol consumers in a fisherfolk community of Lake Victoria. Methods: This study was cross-sectional, and nested into a larger study titled “A stimulated Vaccine Efficacy Trial (SiVET) Among Adults in Fishing Communities in Entebbe, Uganda.” The SiVET Study recruited 250 HIV-negative, male and female (not pregnant) study participants aged 18 to 49 years. The WHO AUDIT questionnaire was administered to 60 alcohol sub-study participants who were classified as alcohol consumers or non-consumers based on the tool’s scores. We employed flow cytometry in immunophenotyping and intracellular cytokine staining to determine and compare median peripheral T- cell subset frequency and percentage T-cell cytokine production among alcohol and non-alcohol consumers respectively. Results: This study analyzed 52 samples including 19, 20 and 13 for mild, moderate and nonconsumers respectively. The study revealed that alcohol consumers had reduced median frequencies of peripheral CD4+ and CD8+ T-cells in comparison with non-consumers. The study indicated that alcohol consumers exhibited lower median percentage of IL-2 producing CD4+ cells than nonconsumers. In contrast, alcohol consumers had higher median percentages of IL-13 producing CD4+ cells than non-consumers. Conclusion: This study revealed that mild/moderate alcohol consumption can potentially suppress and potentiate T cell specific responses through a reduction of peripheral CD4+, CD8+ frequencies, and IL-2 production by Th1 cells while enhancing IL-13 production by Th2 cells respectively. Recommendations: More in-vitro human studies characterizing T-cell specific responses in alcohol consumers need to be done to augment the design of biological mechanisms for integration into HIV prevention strategies.