The complex role of T-cell-based immunity in atherosclerosis.

Although the pathogenic role of T cells in atherogenesis is well established, the function of the various T-cell subsets is far from clear. Whereas activation of the T-helper type 1 (Th1) subset promotes inflammatory and proatherogenic responses and activation of Th2 cells mediates both proatherogenic and antiatherogenic effects, the newly discovered regulatory T-cell subset seems to attenuate atherogenesis. However, the dynamics of T-cell response within the plaque are still poorly understood, and both antigen-dependent and antigen-independent stimuli may be involved in the expansion of T cells in atherosclerotic plaques. Nevertheless, the different nature of the various T-cell subsets and their complex role in atherogenesis underscore the need for future research in this field of atheroimmunology. This research is not only of interest for the basic research field, but may also have relevance for clinical cardiology, potentially leading to new targets for therapy in atherosclerotic disorders.