Acquired Tolerance to Skin Homografts in Mice

[摘要] A quantitative analysis was carried out on the induction and maintenance of homograft tolerance in the CBA → C3H strain combination of mice. These strains share the H2-histocompatability locus. The results indicate that the incidence of tolerance, as measured by the ability of neonatally injected C3H mice to accept CBA skin grafts for 2 months or longer, decreases proportionally with spleen cell doses of less than 2 million. One-eighth million CBA spleen cells will induce 22% tolerance. CBA lymph node cells are slightly less capable in inducing tolerance than spleen cells. F1 hybrid lymph node cells are equally as effective in inducing tolerance as parental homologous lymph node cells. When the duration of tolerance is determined the results suggest that the length of the tolerant period cannot be correlated to the initial size of the donor cell population. The duration of tolerance is variable, even within groups of mice injected with equal cell doses of homologous spleen cells. Tracing the fate of donor cells by radioautography during the early phases of tolerance and by the “chimera” test during the later stages, indicates that the injected donor cells settle primarily in the spleen and lymph nodes of the tolerant host. Donor cells can be detected by chimera analysis, during all stages of graft acceptance, graft contraction, and even shortly after graft rejection. The results are discussed in the light of the hypothesis that in the CBA → C3H strain combination of mice, induction and maintenance of homograft tolerance is dependent on a critical balance between the immune potential of the host and the size of the donor lymphoid cell population.

[学科分类] 生物科学（综合）