Thymic accessory cells required for the increased responsiveness of thymocyte subpopulations to interleukin 1-like monokine in guinea pigs.
The proliferative response of guinea-pig thymocytes to co-mitogenic stimulation with phytohaemagglutinin and the guinea-pig interleukin 1 (IL-1)-like lymphocyte-activating monokine was lost by removing the cells that adhere to a Sephadex G-10 (G-10) column or the cells of low density in a Ficoll-Conray gradient. The diminished response in the G-10 non-adherent thymocyte or high-density thymocyte fraction was restored by the addition of a macrophage-depleted G-10 adherent thymocyte fraction or a low-density, Ia-positive thymocyte fraction but not by the addition of peritoneal macrophages. These results suggest that the accessory cells which mediate the increased responsiveness of thymocytes to the IL-1-like monokine existed in G-10 adherent cell fractions and the cells with this accessory function were not macrophages. The accessory cells were shown to be of low density, glass-non-adherent, G-10-adherent, Fc receptor-negative, and Ia-positive. These results also suggest that the G-10-non-adherent and high-density thymocyte subpopulation, which is unresponsive or responds very little to the IL-1-like monokine by itself, acquires responsiveness to the monokine and proliferates by stimulation with the IL-1-like monokine and lectin in the presence of the accessory cells.
Aida
Y
Y
Department of Endodontics and Periodontics, Kyushu University, Tokyo, Japan.
Kakimoto
K
K
Kawakami
K
K
Chiba
J
J
Aono
M
M
Onoue
K
K
D000818:Animals; D000938:Antigen-Presenting Cells / Q000276:immunology*; D002448:Cell Adhesion; D002469:Cell Separation; D006168:Guinea Pigs; D000949:Histocompatibility Antigens Class II; D007163:Immunosorbent Techniques; D007375:Interleukin-1 / Q000502:physiology*; D007958:Leukocyte Count; D008213:Lymphocyte Activation; D008264:Macrophages / Q000276:immunology; D010641:Phenotype; D010835:Phytohemagglutinins; D013601:T-Lymphocytes / Q000145:classification* / Q000276:immunology; D013950:Thymus Gland / Q000276:immunology*
D000949:Histocompatibility Antigens Class II; D007375:Interleukin-1; D010835:Phytohemagglutinins