Dear friends, In order to evaluate the distribution of naove, memory, and effector T lymphocytes, several combinations of MAb have been used. For CD8+ T lymphocytes, Hamman et al. have nicely described how to separate the subsets (Phenotypic and functional separation of memory and effector human CD8+ T cells. J Exp Med. 1997 Nov 3;186(9):1407-18). However, for CD4+ T lymphocytes, seems that the separation of these subset does not respect the same pattern. I am listing some publications on this matter (Jong et al. The CD27- subset of peripheral blood memory CD4+ lymphocytes contains functionally differentiated T lymphocytes that develop by persistent antigenic stimulation in vivo. Eur J Immunol. 1992 Apr;22(4):993-9; Baars et al. Heterogeneity of the circulating human CD4+ T cell population. Further evidence that the CD4+CD45RA-CD27- T cell subset contains specialized primed T cells. J Immunol. 1995 Jan 1;154(1):17-25). Would you like to send comments on the following points: 1. It is a consensus that the double positive (CD27+CD45RA+) population is representative of naove cells 2. CD27+CD45RA- cells are of rare occurrence 3. CD27-CD45RA- represent late differentiated memory cells 4. Some evidences have suggested that CD27+CD45RA- represent effector cells. However, I am afraid this may not be entirely correct. Would you agree with this statement? Thanks a lot to all Esper Georges Kallas, M.D., Ph.D. Immunology Laboratory Infectious Diseases Unit Federal University of Sao Paulo Rua Pedro de Toledo 781, 15o andar 04039-032 - Sco Paulo, SP, Brazil Phone +55 (11) 5571 2130 Fax +55 (11) 5081 5394
This archive was generated by hypermail 2b29 : Sun Jan 05 2003 - 19:01:32 EST