Figure 2.

Summary of potential contributions by lymphocytes to IA. T- and B-lymphocytes have been identified in human IA tissue specimens, but their functions and the presence of subsets of these cells are not well characterized. IgM and IgG are present in IA, though specific populations of B1 and B2 lymphocytes have not been confirmed as the source of these immunoglobulins. Additionally, although IgG plays a proinflammatory role and IgM plays an anti-inflammatory role in atherosclerosis, these strict characterizations have not been borne out in models of IA. T_H1 lymphocytes, which express TNF-α and IFN-γ, may be present in IA and could be activated by DAMP presentation by macrophages and dendritic cells. TNF-α plays an important role in IA pathogenesis. T_reg lymphocytes may be present and could antagonize T_H1 cells through the actions of TGF-β and IL-10.