Frequency analysis of lymphokine-secreting CD4+ and CD8+ T cells activated in a graft-versus-host reaction.
Lymphokine secretion by in vivo-activated T cells was analyzed at the population and single-cell levels in lymphocytes from mice undergoing an acute allogeneic graft-vs-host reaction (GVHR). Three observations were made. First, constitutive lymphokine production by these cells was very low but could be dramatically up-regulated by TCR ligation. Thus, even when harvested at the peak of the GVHR, fewer than 0.1% of lymphocytes secreted detectable granulocyte-macrophage (GM)-CSF, IFN-gamma, or IL-3 in the first 24 h in vitro, and average production of these lymphokines in bulk cultures was less than 10(-5) U/cell. However, when cultured for 24 h with anti-CD3 antibody under conditions which activated less than 0.1% of normal cells, about 30% of GVHR T cells secreted GM-CSF, IFN-gamma, and/or IL-3, and average production levels were increased by 10(3)- to 10(4)-fold. Together with evidence that host alloantigen-induced lymphokine secretion was 10 to 100 times lower than the anti-CD3 response, these data suggest that physiologic lymphokine synthesis by most T cells is low (less than 10(-18) mol of IL-3 per cell) but can be raised above the threshold of detection by TCR cross-linking. Second, individual GVHR lymphocytes varied markedly in their total and relative production of different lymphokines in response to anti-CD3 stimulation, with some cells secreting IL-3 alone, some secreting IL-3 accompanied by other lymphokines (GM-CSF and/or IFN-gamma), and some secreting other lymphokines without detectable IL-3. Finally, both CD4+ and CD8+ T cells from GVHR mice responded to anti-CD3 antibody by secreting IL-3 and other lymphokines: purified CD4+ cells contained an average of 16% and CD8+ cells an average of 10% anti-CD3-inducible lymphokine-secreting cells. By contrast, only 2 to 3% of cells of either subset formed clones in cultures with host allogeneic cells and IL-2, suggesting that clonogenic alloreactive cells were a minority of the T cells activated in the GVHR.
Kelso
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Walter and Eliza Hall Institute of Medical Research, Royal Melbourne Hospital, Parkville, Australia.
D000818:Animals; D000945:Antigens, Differentiation, T-Lymphocyte / Q000032:analysis / Q000502:physiology; D017252:CD3 Complex; D015704:CD4 Antigens / Q000032:analysis; D015496:CD4-Positive T-Lymphocytes / Q000378:metabolism; D016827:CD8 Antigens; D002999:Clone Cells; D003115:Colony-Stimulating Factors / Q000494:pharmacology; D006087:Graft vs Host Reaction / Q000276:immunology*; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D006133:Growth Substances / Q000494:pharmacology; D066298:In Vitro Techniques; D007371:Interferon-gamma / Q000494:pharmacology; D007376:Interleukin-2 / Q000494:pharmacology; D007377:Interleukin-3 / Q000494:pharmacology; D015847:Interleukin-4 / Q000494:pharmacology; D008213:Lymphocyte Activation; D008222:Lymphokines / Q000378:metabolism*; D051379:Mice; D008815:Mice, Inbred Strains; D011948:Receptors, Antigen, T-Cell / Q000502:physiology; D013601:T-Lymphocytes / Q000378:metabolism*
D000945:Antigens, Differentiation, T-Lymphocyte; D017252:CD3 Complex; D015704:CD4 Antigens; D016827:CD8 Antigens; D003115:Colony-Stimulating Factors; D006133:Growth Substances; D007376:Interleukin-2; D007377:Interleukin-3; D008222:Lymphokines; D011948:Receptors, Antigen, T-Cell; D015847:Interleukin-4; D007371:Interferon-gamma; D016178:Granulocyte-Macrophage Colony-Stimulating Factor