Vaccine against MUC1 antigen expressed in inflammatory bowel disease and cancer lessens colonic inflammation and prevents progression to colitis associated colon cancer

摘要

Association of chronic inflammation with an increased risk of cancer is well established but the contributions of innate versus adaptive immunity are not fully delineated. There has furthermore been little consideration of the role played by chronic inflammation-associated antigens, including cancer antigens, and the possibility to use them as vaccines to lower the cancer risk. We studied the human tumor antigen MUC1 that is abnormally expressed in colon cancers and also in inflammatory bowel disease (IBD) that gives rise to colitis associated colon cancer (CACC). Using our new mouse model of MUC1⁺ IBD that progresses to CACC, IL-10^−/− mice crossed with MUC1 transgenic mice, we show that vaccination against MUC1 delays IBD and prevents progression to CAAC. One mechanism is the induction of MUC1-specific adaptive immunity (anti-MUC1 IgG, anti-MUC1 CTL) that appears to eliminate abnormal MUC1⁺ cells in IBD colons. The other mechanism is the change in the local and the systemic microenvironments. Compared to IBD in vaccinated mice, IBD in control mice is dominated by larger numbers of neutrophils in the colon and myeloid-derived suppressor cells (MDSC) in the spleen, which can compromise adaptive immunity and facilitate tumor growth. This suggests that the tumor-promoting microenvironment of chronic inflammation can be converted to a tumor-inhibiting environment by increasing adaptive immunity against a disease-associated antigen.