Project description:The events controlling transition of T cells from effector to memory remain poorly understood. Herein, we defined two types of effectors on the basis of cell division, expression of activation markers and production of effector cytokines and investigated their potential for memory generation. The results indicated that the moderately activated early effectors readily transit to memory while highly activated late effectors develop minimal memory. Boosting with antigen-free adjuvant, however, rescues the late effectors from cell death and sustains both survival and cytokine responses through toll-like receptor function. Also, the genome-wide microarray analysis among early and late effectors pointed to a set og defined as well as less known genes that may play a role in transition to memory. CFSE-labeled DO11.10 CD4 naïve T cells were transferred into Balb/c mice and the hosts were immunized with OVA peptide in CFA. Within 3 days, the lymph node cells were harvested and each effector division (from division 2 to 8) was sorted based on CFSE dilution and then they were either transferred into naive hosts to generate memory cells or their RNAs were extracted to perform genome-wide microarray analysis. To correlate gene expression with memory potential, division 4 (D4), which readily transit to memory, and divisions 3 (D3), 6 (D6) and 8 (D8), which display reduced potential for memory transition, were included. The data were derived from 3 independent experiments (3 samples per division, 12 samples total).