We previously found that chronic alcohol consumption inhibits CD8+ T cell immunity in B16BL6 melanoma-bearing mice and also decreases their survival. Recent reports indicate that lack of B cells, especially mature B cells, compromises CD8+ T cell anti-tumor immunity. It is unknown if alcohol consumption affects B cells in tumor-bearing hosts. Herein, we studied the effects of chronic alcohol consumption on B cell phenotypes in B16BL6 melanoma-bearing mice. Alcohol consumption did not alter the number of B cells in the bone marrow (BM), spleen or lymph nodes, but decreased B cells in the peritoneal cavity (PC) and blood. Notably, the B cell number decreased 3-4 fold in blood. The percentage of CD19+IgMhiIgDlo immature B cells slightly increased in the BM. Alcohol decreased marginal zone B cells and increased CD23-CD93+ immature B cells, and did not alter follicular B cells in the spleen. The percentage of CD19+CD5+ cells increased in the PC and CD19+CD5- cells decreased. The percentage of CD21+CD23-CD19+ B cells increased 2-fold in blood while CD19+CD23+ cells decreased. Alcohol consumption altered the gene expression of sphingosine-1-phosphate (S1P) receptor-1 (SIPR1) and S1P lyase. Collectively, these data indicate that alcohol decreases mature B cells in the blood and PC by impairing B cell circulation in melanoma-bearing mice. Altered S1P/S1PR1 signaling could contribute to impaired B cell circulation.
- Copyright © 2011 by The American Association of Immunologists, Inc.