Atherosclerosis is an inflammatory disease in which immune mechanisms including monocytes and their associated chemokines and chemokines receptors are involved at all stages of atherosclerotic disease development . Chronic HIV infection is also a state of systemic inflammation. MONOCYTES PLAY A direct role in atherosclerotic lesion formation. Bone marrow-derived circulating blood monocytes are found in atherosclerotic lesions. These monocytes differentiate into tissue macrophages and subsequently foam cells. In humans, two populations of monocyte have been distinguished: Expansion of the cd monocyte subset has been described in HIV infection. monocyte have also been found to be higher in patients with coronary artery disease compared with control subjects. Compared with cd monocyte ,cd monocyte produce higher amounts of TNF to lipopolysaccaride stimulation and produce decreased amounts of the anti-inflammatory cytokine IL-10. Tilton and colleagues found HIV-infected patients,with or without antiviral therapy, had elevated spontaneous production of monocyte inflammatory cytokine jjj ,with uninfected controls. Notably, they also found HIV-infected patients on antiretroviral therapy with effective viral suppression to have highly increased frequency of monocyte producing these inflammatory cytokines.
Activated T cells also play an important role in vascular inflammation. Activated T cells are present in atherosclerotic plaques . HIV infection is state of T cell activation characterized by increased turnover of CD4+ and CD8+ T cell and expansion of activated CD8+ T cell compartment.In addition, CMV infection has also been implicated in the pathogenesis of atherosclesis and may play an important role in atherosclerotic disease associated with HIV Hsues et al. demonstrated HIV-infected patients to have higher levels of C-reactive protien, higer level of CD4 and CD8 T cell activation,and higher CMV-specific T cell response. Among these factor, these authors found CMV-specific T cell response (measured by expression of IFN-y after exposure to CMV pp65 peptide antigens) to be independently associated with higher carotid IMT in HIV-infected patiens.