Recent Advance on LFA-1/ICAM-1 Costimulatory Signal of T Cell——Review

LFA-1/ICAM-1 costimulation plays an important role in immunologic reaction of many different T cell populations. After TCR/CD3 complex cross-linking MHC/peptide,LFA-1,expressed on T cell increases a higher affinity and avidity for ICAM-1 rapidly. LFA-1 is a key molecule in formation of the immune synapse. LFA-1/ICAM-1 costimulation can engage various signaling events of T cell by up-regulating the activities of PI 3-kinase,sphingomyelinase,and c-Jun NH2-terminal kinase. With the costimulation of LFA-1/ICAM-1,engagement of TCR molecules results in a significant increase of T cell activities,including higher Th1 cytokines production,strongly proliferative response and higher T cell cytotoxicity.