Histocompatibility studies in pigs from outbred and semi-inbred families

Serologically defined specificities of the pig main histocompatibility complex (SL-A)

Six antigens detectable by the complement-dependent lymphocytotoxic technique were determined in pigs by six groups of alloimmune sera. It was confirmed that these specificities are controlled by the main histocompatibility region (SL-A). Serological and genetic studies showed that the given specificities (provisionally designated L1 to L6) form at least 6 haplotypes. In addition, family studies confirmed the linkaged between SL-A region and C blood group locus. Maximum lod score values are in recombination fraction omicron = 0.2.

Detection of a new non-MHC alloantigenic system (SLD) in pigs

A new, non-MHC cell membrane leucocyte alloantigen was detected in pigs by the complement dependent lymphocytotoxic technique. The new leucocyte system was designated SLD. Its product antigen SLD-1 was demonstrated to segregate independently of the SLA, SLB, SLC, A and E antigens. Family studies supplied evidence of a dominant inheritance of SLD-1. Since an allelic antigen could not be demonstrated, only two alleles for this locus are reported, namely SLD1 and SLD-. No evidence of linkage was detected between the above mentioned leucocyte alloantigenic systems and SLD. The antigen was detected on enriched suspensions of T and B cells from peripheral blood, but it was not detected on erythrocytes, granulocytes and thrombocytes.

Non-MHC alloantigenic system in pigs (SLC) detected by leucoagglutination

Two cell membrane leucocyte alloantigens were detected in pigs by simple direct agglutination tests. Family studies showed that the locus controlling these antigens was not identical, or in close linkage, with the SLA major histocompatibility complex, SLB leucocyte locus or with the A, E, and N blood group loci. In the studied population, the locus termed SLC (Swine Leucocyte C locus) has two alleles controlling mutually exclusive antigens SLC-1 and SLC-2. The frequency of SLC1 and SLC2 alleles is 0.10 and 0.90, respectively. The antigens have not been detected on erythrocytes and thrombocytes but are well determined on granulocytes, peritoneal macrophages, mononuclears from different sources (thymus, spleen, bone marrow, lymph nodes) and enriched T and B cells from peripheral blood.

The presence of blood group and lymphocyte antigens on porcine granulocytes

Suspensions of highly viable (less than 95%) granulocytes minimally contaminated by other cell types were isolated from the peripheral blood of pigs by a single centrifugation with low molecular weight dextran and after preferential lysis of erythrocytes by hypotonic shock. A complement-dependent cytotoxic test showed the presence of antigens of the SLA major histocompatibility complex, the SLB leucocyte system and the A and E blood group systems on the granulocytes. Some SLA typing reagents against class I (SD) antigens did not react with granulocytes, however, or yielded dubious reactions. The findings showed that the reactivity of SLA sera resembles the reactivity fo human HLA sera. The results also show that compatibility in the SLA, SLB, A and E systems will have to be taken into account when preparing alloimmune sera for the determination of granulocyte-specific antigens of pigs.

SLB, a new alloantigenic system of the pig

An alloantigen segregating in the double back-cross families, distinct from serologically determinalble transplantation antigens controlled by the major histocompatibility complex (SLA), was detected in pigs by the complement-dependent lymphocytotoxic technique. The system was designated SLB and its product (antigen SLB-A1) was demonstrated in all lymphocytes from the lymph nodes, thymus and peripheral blood, but not in the erythrocytes. Back-cross matings supplied evidence of the dominant heredity of SLB-A1. Detection of further SLB antigens was unsuccessful, so that only two alleles (SLB-A1 and SLB-A-) could be determined in families. Double back-cross families revealed a close linkage between the SLB locus and the L blood group locus. Maximun lod score values were calculated in recombination fraction theta=theta.10.

Linkage of the pig main histocompatibility complex and the J blood group system

Linkage of the main histocompatibility complex (MHC) and the J blood locus was demonstrated in pgis by means of segregation data in families of double back-cross matings. A recombination frequency of 9.82% was estimated. No evidence of close association with the blood group systems A, B, D, E, F, G, H, I, K, L, M, N and O was found.