Like any competitive sport, your immune system needs to field its best players in order to win the match against pathogens. Investigators report in the January issue of Nature Immunology that T cells aggressively compete with one another for access to the bits of antigen sitting on "antigen-presenting cells". This struggle ultimately benefits the host, as only the most effective T cells survive, honing the immune response to a fine point in the hopes of "tipping the scales" against the foreign invaders.
Ross Kedl, working with Pippa Marrack and colleagues at the National Jewish Medical Research Center in Denver, shows that when T cells with a range of abilities to bind antigens are vying for access to antigen-presenting cells, only the T cells with the best binding get much "face time". These "high-affinity" T cells dominate the antigen-presenting cells, virtually excluding the lower-affinity T cells. And part of the strategic plan entails the stripping of antigen from the surface of the presenting cell, thus making interactions with lower affinity T cells almost impossible. It's this type of competition that leads to consistently better immune responses - and good immunization.
Ross M. Kedl
St Paul, MN
Tel: +1 651 733 4821
Additional contact for comment on paper:
Institute for Research in Biomedicine
Tel: +41 91 820 0300
(C) Nature Immunology press release.
Message posted by: Trevor M. D'Souza