N. Nagata et al., A MONOCLONAL-ANTIBODY REACTIVE WITH A GLYCOPHOSPHATIDYLINOSITOL-ANCHORED MOLECULE ON T-CELLS DEFINES CD4-CELL SUBSETS( T), European Journal of Immunology, 23(5), 1993, pp. 1193-1196
A hybridoma, 25T3 (IgM, kappa), was established from MRL/+ mice immuni
zed with an autoreactive T cell line (1/+T1). The antigenicity of the
antigen recognized by hybridoma 25T3 (25T3-Ag) expressed on thymic and
splenic cells was abolished by treatment with phosphatidylinositol-sp
ecific phospholipase C, showing that 25T3-Ag is a glycophosphatdidylin
ositol-anchored Ag. 25T3-Ag was expressed on approximately 90% of thym
ocytes. Double-negative, double-positive and CD8 single-positive cells
were highly positive for the expression of 25T3-Ag, whereas CD4 singl
e-positive cells were weakly positive (approximately 40%) or negative
(approximately 60%). In the spleen, only CD3+ cells (and not B220+ nor
Mac-1+ cells) reacted with 25T3 monoclonal antibody (mAb), indicating
that 25T3 mAb is specific for T cells. The majority of splenic CD8+ T
cells were positive for the expression of 25T3-Ag, although the inten
sity was weaker than that of thymocytes. In contrast, splenic CD4+ T c
ells were divided into negative (60-70%) and positive (30-40%) populat
ions. Similar staining profiles were observed in BALB/c, C57BL/6, C3H/
HeN and AKR/J mice. When BALB/c CD4+ T cell subsets were sorted and cu
ltured with irradiated (25 Gy) antigen-presenting cells, stimulation w
ith immobilized anti-CD3 mAb for 2 days resulted in CD4+25T3+ cells se
creting more interleukin-2 and less interleukin-4 than did CD4+25T3- s
ubsets, although the proliferative responses of the cells on day 2 of
culture were similar. This suggests that CD4+ T cells can be divided i
nto two populations and relatively defined as T helper 1 and T helper
2 cells using this 25T3 mAb. Immunoprecipitation and SDS-PAGE revealed
that 25T3-Ag was approximately 70 kDa. These findings are discussed i
n relation to CD4+ T cell subsets.