Phenotypic analysis of the medullary-type CD4(-)CD8(+) thymocytes in mice

Phenotypic analysis of the medullary-type CD4(-)CD8(+) (CD8SP) thymocytes h as revealed phenotypic heterogeneity within this cell population. The pheno type of mature peripheral CD8(+)T cells is TCR alpha beta(+)CD3(+)Qa-2(+)HS A(-)3G11(-)6C10(-), whereas in the medullary-type CD8SP thymocytes, 20% are Qa-2(+); 33%, HAS(-); 30%, 3G11(-); and 70% are 6C10(-). The disparate exp ression patterns of these four cell surface markers suggest that medullary- type CD8SP thymocytes may undergo phenotypic maturation process. According to the distribution of these four cell surface markers, six subgroups of CD 8SP thymocytes have been identified, The precursor-progeny relationship alo ng with developmental pathway is postulated as follows: 6C10(+)HSA(+)3G11(- )Qa-2(-)-->6C10(+)HSA(+) 3G11(+)Qa-2(-)-->6C10(-)HSA(+)3G11(+)Qa-2(-)-->6C1 0(-)HSA(-)3G11(+)Qa-2(-)-->6C10(-)HSA(-)3G11Qa-2(-)-->6C10(-)HA S(-)3G11(-) Qa-2(+), the cells in the last subgroup exit the thymus and home into perip hery.