Control of the intracellular protozoan, Leishmania major, requires major histocompatibility complex class II (MHC II)-dependent antigen presentation and CD4+ T cell T helper cell 1 (Th1) differentiation. MHC II-positive macrophages are a primary target of infection and a crucial effector cell controlling parasite growth, yet their function as antigen-presenting cells remains controversial. Similarly, infected Langerhans cells (LCs) can prime interferon (IFN)gamma-producing Th1 CD4+ T cells, but whether they are required for Th1 responses is unknown.
View Article and Find Full Text PDFThe factors responsible for the low response of chronic hepatitis C patients to interferon-a treatment are not fully understood, although it is known that interferon requires an efficient host immune response to achieve viral clearance. This study was designed to test the hypothesis that hepatitis C virus infection is associated with functional impairment of peripheral blood mononuclear cells, which influence the response to interferon. The proliferative and apoptotic responses of peripheral blood mononuclear cells and purified T cells stimulated with polyclonal mitogenic signals were assessed in 35 chronic hepatitis C patients and 30 healthy controls.
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