Beyond T Cells: IgA Incites Immune Recognition in Endometrial Cancer.

While T cells are established major players in antitumor immunity, tumor-associated B cells and antibodies have recently emerged as critical components in modulating immunity in the tumor microenvironment. In the current issue of Cancer Research, Mandal and colleagues show that tumor-infiltrating B cells are associated with improved outcomes in endometrial cancers. Mechanistically, the investigators demonstrate that the immune response is mediated by class-switched IgA binding to the polymeric immunoglobulin receptor in tumor cells, resulting in tumor cell-intrinsic activation of inflammatory pathways. These findings highlight that coordinated B-cell and T-cell responses may predict improved outcomes in patients with endometrial cancer and set the groundwork to further investigate the mechanisms by which humoral immunity could be exploited for cancer immunotherapy. See related article by Mandal et al., p. 859.