The RhLA Complex of Rhesus Monkeys. XI: Positive MLC Reactions between Identical Sibs Caused by Alloimmunization¹

Abstract

D‐locus identical pairs of monkeys were alloimmunized. An exchange of skin and blood between initially MLC‐negative unrelated monkeys frequently led to strong mutual reactivity in mixed cultures. This was not the case when RhLA identical siblings were similarly (mutually) immunized. These data led to the postulation of a second RhLA‐linked MLC locus, named D', which exerts its influence only after alloimmunization. Interestingly, strong MLC responsiveness between the RhLA identical siblings could be provoked after further immunization with tissue from a third party animal. This unexpected MLC‐reactivity is ascribed to the influence of minor non MHC linked loci which express themselves if the responder has been sensitized against a disparate D'‐product. It is suggested that the postulated D' locus has a “helper function” in that it assists in triggering proliferative responses in mixed cultures against the products of these non MHC loci.

The Major Histocompatibility Complex of Rhesus Monkeys XII: Cellular Typing for D Locus Antigens in Families1

“…l o ) The animals in question are DA, AD, and DW of Table 3 as well as CL and GZ of Table 4. All other ambiguous assignments in Tables 3-5 are attributed to recent alloimmunization (with available informative preimmunization values; see van Es & Balner 1978b) or to disproportionally low autologous cpm values as described in the current paper.…”

“…Interestingly, offspring FN showed a clearly positive response to TC 2D in a culture which was performed shortly after strong alloimmunization of animal FN. This unexpected response to a TC "homozygous" for a haplotype of the offspring's father is almost certainly due to conversion after alloimmunization (van Es & Balner 1978b). Antigen TC 75'-1 is segregating with the paternal b haplotype.…”

Mixed lymphocyte reactivity in cattle

“…Knowing that MLR was associated with the BOLA complex it was possible to set threshold values for the classification of positive and negative tests using the indices. The chosen values of 40 for the RR and of 3 for the SI were similar to those chosen for MLR research in other species (Balner & Toth 1973, van Es & Balner 1979, Grosse-Wilde et al 1973, Jonker & Balner 1980, Jorgensen et al 1973).…”

Mixed Lymphocyte Reactivity in Chimpanzees II. Family Studies and Identification of D Locus Antigens*

“…Thus, a cumulative effect of disparities of the products of minor MLC loci can be responsible for a strong MLC reaction between D identical individuals (Dupont et al 1974, Termijtelen et al 1977, Festenstein et al 1971, Klein 1975. Further, alloimmunization can change a negative (MLC) into a positive MLC (van Es & Balner 1979a) and also a positive into a negative MLC (Kristensen & Jmgensen 1978). These phenomena, called "conversions", can also influence typing cell responses and thus interfere with the identification of D locus antigens.…”

“…can show "false positive" MLC reactions; i.e.,Balner 1979a). Animals displaying these the negative MLC test among D-identical phenomena are marked as H, L or Im on the combinations can convert from negative to tables and figures.positive after alloimmunization (van Es &The MLC data for each separated harem…”