The costimulatory and differentiating activity of soluble class I MHC antigens for an autologous thymocyte population.
Combined cultivation of macrophages with syngeneic thymocytes resulted in accumulation of soluble H-2Kk antigens in culture medium. Incubation of intact autologous thymocytes with these soluble class I MHC molecules was shown to induce functional maturation of thymocytes assayed in local graft-vs-host reaction. Similar thymocyte costimulating activity was detected for the papain-solubilized purified H-2Kk antigens. Soluble class I antigens were shown to costimulate IL2 production by thymocytes in response to submitogenic doses of exogenous IL2 and to increase PHA-induced thymocyte proliferation. Soluble class I molecules were shown to increase the level of expression of function-associated membrane antigens, H-2Kk, CD8 and CD4, and to trigger thymocyte differentiation. The expression of I-Ak antigens remained invariable. It was also shown that soluble autologous class I molecules may function as direct amplifiers of thymocyte proliferation in autologous, but not allogeneic, mixed leukocyte reactions. It is concluded that soluble MHC class I molecules are capable of triggering functional and phenotype differentiation of syngeneic thymocytes and acting as restricted coaccessory molecules when thymocyte activation is induced by a submitogenic dose of different stimuli.
Dudich
E I
EI
Institute of Immunology, Lyubuchany, Moscow Region, Chekhov District, Russia.
Semenkova
L N
LN
Dudich
I V
IV
Anfalova
T V
TV
Galaktionov
V G
VG
D000818:Animals; D002454:Cell Differentiation / Q000276:immunology; D006087:Graft vs Host Reaction; D006183:H-2 Antigens / Q000302:isolation & purification / Q000502:physiology*; D007376:Interleukin-2 / Q000096:biosynthesis; D007519:Isoantigens / Q000276:immunology; D008213:Lymphocyte Activation; D007959:Lymphocyte Culture Test, Mixed; D051379:Mice; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D010835:Phytohemagglutinins / Q000494:pharmacology; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D013950:Thymus Gland / Q000166:cytology / Q000276:immunology*
D006183:H-2 Antigens; C024755:H-2K(K) antigen; D007376:Interleukin-2; D007519:Isoantigens; D010835:Phytohemagglutinins