Polarization of Th1/Th2 in human CD4 T cells separated by CD62L: analysis by transcription factors

T-cell surface antigens that differentiate clearly between Th1 and Th2 have not been identified. Discrimination of Th1/Th2 subpopulations by CD62L expression has been reported. We investigated the expression of transcription factors that regulate Th1/Th2 cytokine synthesis in human CD4+ T-cell subpopulations separated by CD45RO and CD62L, and compared the ratio of CD62L+ to CD62L- cells between healthy individuals and patients with allergic diseases.

Human peripheral blood samples were obtained from healthy volunteers and patients. CD4+ T cells were isolated by negative selection. Three CD4+ T-cell subpopulations separated by CD45RO and CD62L were isolated using three-color fluorescence. Sorted cells were stimulated with anti-CD3 monoclonal antibody, and the cytokine levels were measured using a Cytometric Bead Array Kit. Transcription factor expression was examined by reverse transcriptase polymerase chain reaction (RT-PCR) and real-time RT-PCR.

Interleukin (IL)-4 and IL-5 production levels by CD45RO+CD62L+CD4+ T cells were higher than those of CD45RO+CD62L-CD4+ T cells (P < 0.05), whereas interferon-gamma and tumor necrosis factor-alpha production were lower levels (P < 0.05). T-cell immunoglobulin mucin-3 and T-bet expression were detected in CD45RO-CD62L+ and CD45RO+CD62L- cells following stimulation, but not in CD45RO+CD62L+ cells. However, the ratio of CD62L+ to CD62L- cells was the same in both healthy individuals and patients (P = 0.54). There was no difference in Th1/Th2 cytokine synthesis by CD4+ T cells.

Analyses of cytokine syntheses and transcription factor expression demonstrated that CD62-negative and -positive subpopulations of human CD45RO+CD4+ T cells represent characteristics of Th1 and Th2, respectively.