T-cell specificity for H-2 and Ir gene phenotype correlates with the phenotype of thymic antigen-presenting cells.
Experiments with chimaeric animals have demonstrated that the H-2 restriction specificity and immune response (Ir) gene phenotype of the T cell is acquired during development in the thymus. The mechanism by which this process occurs is unclear. One level of obligate expression of H-2 and Ir gene products is on the surface of antigen-presenting cells (APCs) which come from bone marrow precursors. We have now examined the turnover of APCs in the thymuses of F1 leads to parent (P) radiation-induced bone marrow chimaeras and found that APCs of donor phenotype appear at about 2 months after reconstitution. If the peripheral T-cell population is depleted after this time, new T cells emerging from the parental thymus (containing F1 APCs) behaving like F1 T cells, suggesting that cells from the bone marrow can influence thymic-directed T-cell differentiation. The thymic APC is an attractive condidate to play such a part in the development of the T-cell repertoire.
D000818:Animals; D001853:Bone Marrow / Q000276:immunology; D002454:Cell Differentiation; D005802:Genes, MHC Class II; D006183:H-2 Antigens / Q000235:genetics*; D008211:Lymphocyte Cooperation; D051379:Mice; D010641:Phenotype; D011828:Radiation Chimera; D011948:Receptors, Antigen, T-Cell / Q000502:physiology; D013601:T-Lymphocytes / Q000276:immunology*; D013950:Thymus Gland / Q000276:immunology; D013997:Time Factors
D006183:H-2 Antigens; D011948:Receptors, Antigen, T-Cell