Atherosclerotic plaques contain inflammation, composed largely of macrophages and
lymphocytes. A proportion of lymphocytes shows signs of activation, but the question arises
whether they are activated in an antigen specific way. The expression of costimulatory
molecules-receptors that provide accessory signals during antigen-specific activation is a
prerequisite for such a condition. This aspect of inflammation in atherosclerotic lesions has
not been investigated. Human arterial segments with diffuse intimal thickening, fatty streaks …