The immune system: genes, receptors, signals : [proceedings] / edited by Eli E. Sercarz, Alan R. Williamson [and] C. Fred Fox.

  • ICN-UCLA Symposium on Molecular Biology
Date:
1974
Catalogue details

Licence: Attribution-NonCommercial 4.0 International (CC BY-NC 4.0)

Credit: The immune system: genes, receptors, signals : [proceedings] / edited by Eli E. Sercarz, Alan R. Williamson [and] C. Fred Fox. Source: Wellcome Collection.

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    H. о. McDEVITTera/. recombinant strains. Another approach would be the use of well-defined la antisera for inhibition of ^ vitro l3rmpho- cyte stimulation by antigen. In such systems, specific inhibition of given reactions by sera controlled by la loci, which map in the same position as the gene regulating the specific immune reaction studied, would suggest the identity of some J_a and Ir genes. The existence of recombinant H-2 chromosomes which are identical at Ir-IA and Ir-IB but differ for la antigens, and the MLR reactions observed in H-2 versus H-2^ , across subregion I-C which does not contain any known I^ genes, already suggest that not all la or Lad anti¬ gens correlate with ^ gene function, and that these genes may be separate and serve distinct functions. DISCUSSION It is clear that the available information on the prop¬ erties of the 1 region and their relationship to specific ^r gene function is not yet sufficient to permit a clear deci¬ sion as to the major issues concerning gene function and its relation to antigen recognition. There is extensive cir¬ cumstantial evidence to indicate that ^ genes are expressed selectively in T cells and control foreign antigen recogni¬ tion by T cells, perhaps because the ^ genes are structural genes for the T cell antigen receptor [ref. 1,2,3]. However, it must be emphasized that none of these experiments offers definitive proof that Ir_ genes are expressed solely in T cells. Indeed there are at least two lines of experimenta¬ tion which question this hypothesis. The first is the demon¬ stration of H-2 linked genetic control of specific immune responses which has been shown by Mozes et al. [44] and by Bluestein et al. [45]. The demonstration in these experi¬ ments that histocompatibility linked Ir^ genes affect not only carrier antigenic recognition but the specificity of the resultant antibody suggests that this type of gene might also be expressed in В cells. The second type of experiment which questions the hypothesis of I^ gene expression in T cells is the limiting dilution studies of Shearer and Mozes [9,46]. In the absence of direct chemical information on the nature of the ^r^ gene product, we are forced for the moment to rely on a variety of biological experiments to attempt to unravel the interrelationships between Ix genes, the antigens responsible for the mixed lymphocyte culture reaction and the graft vs. host reaction, the la antigens, and the cellu¬ lar interaction effects of the major histocompatibility com¬ plex. The close relationship of all of these functions has 626
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