[A study of proliferative responses to host Ia antigens in fully allogeneic bone marrow chimeras in mice--sequential analysis of the reactivity and characterization of the cells involved in the response].
Irradiation bone marrow chimeras were established by reconstitution of lethally irradiated AKR mice with C57BL/10 marrow cells which had pretreated with anti-Thy-1 serum. Mixed lymphocyte reactions (MLR) were carried out serially to analyze developing reactivities of lymphocytes from such chimeras, [B10----AKR], against donor, host or third party antigens. Spleen cells of [B10----AKR] chimeras 8 weeks after reconstitution regularly showed proliferative responses when stimulated with spleen cells of the strain of the irradiated recipient (AKR). However, the responsiveness was consistently lower than that generated against third party antigens. The stimulator cells were Ia positive in both anti-recipient and anti-third party responses, and the responding splenocytes were of donor origin and showed Thy-1+, Ly-1+2-, and L3T4+ phenotypes, although a minor population of Ly-2+ and L3T4- T cells might be involved in anti-third party response. Further, we found that substantial proliferative responses to Ia antigens of the recipient strain and also to third party antigens are generated by the thymocytes obtained from the irradiation chimeras at an early stage following bone marrow reconstitution. Majority of the responding thymocytes had surface traits of PNA-, donor type Thy-1+, and L3T4+ in both anti-recipient and anti-third party MLRs. However, as for the Ly-2 antigen, Ly-2+ thymocytes seemed to be, at least partially, involved in anti-host responses. This capacity of thymus cells to mount a response to antigens of the recipient strain declined shortly thereafter. The spleen cells at the same time developed a more durable capability to exhibit anti-host reactivities. Awareness of the sequence of development of these cellular reactivities and capacities to respond to host and third party alloantigens may be crucial to understanding the underlying molecular mechanisms involved in generating a T cell repertoire one component of which is restricted to Ia antigens of the recipient strain.
D000818:Animals; D001854:Bone Marrow Cells; D005260:Female; D000949:Histocompatibility Antigens Class II / Q000276:immunology*; D007519:Isoantigens / Q000276:immunology; D008213:Lymphocyte Activation; D008285:Major Histocompatibility Complex; D051379:Mice; D010641:Phenotype; D011828:Radiation Chimera; D013154:Spleen / Q000166:cytology; D013601:T-Lymphocytes / Q000276:immunology*; D013997:Time Factors
D000949:Histocompatibility Antigens Class II; D007519:Isoantigens