UNASSIGNED: Exposure to blood-stage @entity281 in endemic areas is persistent, leading to generation of CD4 effector and effector memory T cells that contribute to protection. We showed previously that chronic exposure to blood-stage @entity21552 maintains the best protection from @entity5895 and @entity281 , correlating with an increase in Th1 cells. While much is known about the features of resting or exhausted memory T cells, little is known about the functional capacities of chronically stimulated, but protective T cells. To determine the functional capacity of CD4 T cells generated by @entity281 , on re-exposure to parasite, we compared their responses to known features of classical Tmem. Representation of cytokine producing T cells increased after @entity281 in the polyclonal population, suggesting an increase in pathogen-specific T cells. Malaria antigen-specific B5 TCR Tg T cells from @entity281 proliferated on re- @entity281 , and were highly sensitive to @entity20432 stimulation without co-stimulation, as shown for Tmem in acute stimulations. However, B5 Tmem did not accumulate more than na  ve B5 T cells in vivo or in vitro, and became apoptotic. Failure to accumulate was partly the result of chronic stimulation, as eliminating persistent parasite before re- @entity281 slightly increased the accumulation of B5 Tg T cells on second @entity281 . Specific IFN-y(+)IL-10(+) T cells, which protect animals from pathology, were increased after @entity281 . These data demonstrate that while @entity281 generates a protective T cell population with increased TCR sensitivity and cytokine production, they do not re-expand on re-exposure, due to increased apoptosis.

Chronic XXXX Infection Generates CD4 Memory T cells with Increased TCR Sensitivity but Poor Secondary Expansion and Increased Apoptosis.

@entity281 :: ('MESH:D007239', 'Disease') :: ['pathology in re-infection', 'infection', 'malaria infection', 'chronic infection'] @entity21552 :: ('5825', 'Species') :: ['Plasmodium chabaudi'] @entity20432 :: ('C007145', 'Chemical') :: ['TCR'] @entity5895 :: ('MESH:D018512', 'Disease') :: ['parasitemia']
@entity21552 :: (5825,Species) :: ['Plasmodium chabaudi']
