Pro-T cells in fetal thymus express c-kit and RAG-2 but do not rearrange the gene encoding the T cell receptor beta chain.
Ten percent of 15-day fetal thymocytes of mice were Pgp-1+Thy-1lo cells. Half were strongly stained with monoclonal antibodies (mAb) recognizing the oncogene product, c-kit, but were not stained with mAb against non-T cell markers such as B220, Mac-1 and Gr-1. The isolated Pgp-1+c-kit+ thymocytes showed no rearranged bands for V-DJ and D-J of T cell receptor (TcR) beta, but Pgp-1(-)-c-kit- thymocytes showed D-J rearranged bands. Both cells expressed the RAG-2 gene which is required for the V(D)J recombination process. When Pgp-1+c-kit+ thymocytes were cultured in 2-deoxyguanosine-treated alymphocytic fetal thymus, they became TcR-expressing mature type T cells, but this differentiation was reduced by the addition of anti c-kit mAb. These data indicate that Pgp-1+c-kit+ thymocytes are pro-T cells with the potential to differentiate mature T cells in the thymic environment. This study also indicates that c-kit-mediated signals promote the differentiation of thymocytes during their early stages.
Hozumi
K
K
Department of Immunology, Tokai University School of Medicine, Isehara, Japan.
Kobori
A
A
Sato
T
T
Nozaki
H
H
Nishikawa
S
S
Nishimura
T
T
Habu
S
S
D000818:Animals; D001483:Base Sequence; D002454:Cell Differentiation; D004268:DNA-Binding Proteins; D005434:Flow Cytometry; D015333:Gene Rearrangement, beta-Chain T-Cell Antigen Receptor; D051379:Mice; D008809:Mice, Inbred C3H; D008969:Molecular Sequence Data; D009924:Organ Culture Techniques; D016133:Polymerase Chain Reaction; D014176:Protein Biosynthesis; D011518:Proto-Oncogene Proteins / Q000096:biosynthesis*; D019009:Proto-Oncogene Proteins c-kit; D020794:Receptor Protein-Tyrosine Kinases / Q000096:biosynthesis*; D016184:Receptors, Colony-Stimulating Factor / Q000096:biosynthesis*; D013601:T-Lymphocytes / Q000378:metabolism*; D013950:Thymus Gland / Q000166:cytology / Q000196:embryology* / Q000378:metabolism
D004268:DNA-Binding Proteins; D011518:Proto-Oncogene Proteins; C499308:Rag2 protein, mouse; D016184:Receptors, Colony-Stimulating Factor; C064655:V(D)J recombination activating protein 2; D019009:Proto-Oncogene Proteins c-kit; D020794:Receptor Protein-Tyrosine Kinases