The body’s own immune system could be a potent weapon in the war on cancer if the cloaking mechanisms tumor cells use to elude it could be deactivated. In an article published in the February 15 issue of the Journal of Immunology, one of those cloaking mechanisms was identified in B cell tumors by a team of MUSC immunologists led by Azizul Haque, PhD (above right), MUSC Health hematologist/oncologist Robert Stuart, M.D. (above left), and their colleagues at the University of Indiana and German Research Center for Environmental Health. They reported that overexpression of the c-MYC protein, one of the most commonly activated genes in human cancers that is implicated in the cancer-related deaths of about 100,000 people worldwide, is linked to the ability of B cell tumors to “hide” from the immune system.1 Specifically, they showed for the first time that overexpression of the c-MYC protein in Burkitt’s lymphoma interferes with human leucocyte antigen (HLA) class II antigen presentation. T cells can mount an immune response against antigens only if they can “see” them; they “see” them when TCRs (T cell receptors) on their surface recognize antigen fragments bound to HLA class II molecules on the surface of antigen-presenting cells. When tumor antigen is not presented properly due to c-MYC overexpression, it remains invisible to the T cells. The article also provided evidence that treatment of c-MYC-overexpressing cells with a c-MYC inhibitor decreased c-MYC expression and partially restored HLA class II-mediated antigen presentation. These results suggest that c-MYC inhibitors could help “unmask” B cell lymphomas and promote a more robust immune response. According to Haque, “This study uncovers a mechanism by which c-MYC impairs immune detection of malignant tumors, which could be targeted in future treatments for B cell lymphomas and other malignancies.” The article by Haque and colleagues was highlighted in the “In This Issue” section of the Journal of Immunology, reserved for the top 10% of articles published in the journal.
1 God JM, Cameron, C, Figueroa J, Amria S, Hossain A, Kempkes B, Bornkamm GW, Stuart RK, Blum JS, Haque A. Elevation of c-MYC Disrupts HLA Class II–Mediated Immune Recognition of Human B Cell Tumors. The Journal of Immunology 2015;194:1434–1445.