Epitopes associated with MHC restriction site of T cells. III. I-J epitope on MHC-restricted T helper cells.

Abstract

I-J epitopes were found to be associated with the functional site of the class II MHC-restricted helper T (Th) cells: Virtually all of the H-2k-restricted Th cell function of H-2kxbF1 T cells was inhibited by the anti-I-Jk mAb, leaving the H-2b-restricted function unaffected. The I-Jk epitope was inducible in Th cells of different genotype origin according to the environmental class II antigens present in the early ontogeny of T cells. Although above results suggested that I-J is the structure reflecting the inducible MHC restriction specificity, further studies revealed some interesting controversies: First, the I-J phenotype did not always correlate with the class II restriction specificity, e.g., I-Ab-restricted Th from 5R was I-Jk-positive, whereas I-Ak-restricted Th of 4R was not. Second, there was no trans expression of parental I-J phenotypes and restriction specificities in F1 Th, e.g., the I-J phenotype was detected only on I-Ab-restricted Th of (4R X 5R)F1, whereas it was absent on I-Ak-restricted Th. This strict linkage between the restriction specificity and I-J phenotype was also found on Th cells developed in bone marrow chimera constructed with intra-H-2-recombinant mice. The expression of I-Jk was always associated with the restriction specificity of the relevant host. Thus, the restriction specificity of Th cells followed the host type, and the I-J expression on Th was exactly the same as that expressed by the host haplotype. These results indicate that I-J is an isomorphic structure adaptively expressed on Th cells that is involved in the unidirectional regulatory cell interactions, and that the polymorphism cannot be explained merely by the restriction specificity of the conventional T cell receptor heterodimer.

Maternal Bias of Immunity to Her Offspring: Possibility of an Autoimmunity Twist out from Maternal Immunity to Her Young

“…When young mice as a donors for the cell transfer, there were few reports of CD4 cells as effector cells for suppression [48][49][50][51]. The case for this suppression is that when we processed conventional cell analyses in SRBC-immunized mice that were the same age as the control young, the CD8 but not CD4 cells suppressed further antigenic stimulation in our laboratory as usually expected [43][44][45][46][52][53][54].…”

“…Immune suppression is usually attributed to CD8 positive or so called suppressor cells [38][39][40][41][42][43][44][45][46]. In this suppression system, the effector cells were identified by the adoptive transfer system.…”