CCL5 and inflammatory bowel disease: However, interestingly, CD8αβ+ T cells appeared also to produce higher levels of proinflammatory cytokines (IFNG), as well as chemokines (CCL3, CCL4, CCL5, and XCL1) in the gut mucosa of patients with IBD (Supplemental Figure 8, A and B), suggesting a potential key role for CD8αβ+ T cells in human pathogenesis of IBD.