The ability of guinea pigs to form immune responses specific for each of the random copolymers, L-glutamic acid and L-alanine (GA) and L-glutamic acid and L-tyrosine (GT), is under the control of distinct autosomal dominant genes. By testing for the ability to respond to these copolymers among the progeny from the reciprocal backcross mating of responder (2 x 13)F(1) animals with the appropriate nonresponder parental strain, we have demonstrated that different unigenic autosomal dominant traits control the ability to respond to GA and GT respectively. The data further shows that the GA gene is linked to the poly-L-lysine (PLL) gene and to the locus determining the major strain 2 histocompatibility specificities and that the GT gene is linked to the locus controlling the expression of major strain 13 histocompatibility specificities. Analysis of the inheritance of the GT and PLL genes among the offspring from a mating of responder (2 x 13)F(1) guinea pigs with random-bred guinea pigs unable to respond to GT or PLL demonstrate that these genes segregate away from each other. Thus, the PLL gene and the genes to which it is linked, the GA gene and the major strain 2 histocompatibility locus, behave as alleles or pseudoalleles to the GT gene and the major strain 13 histocompatibility locus.

Alanine↗

PubMed1971

In vivo studies in C4-deficient guinea pigs.

Guinea pigs with a genetically determined total deficiency of the fourth component of complement have been studied for various in vivo immunological functions. Passive cutaneous anaphylaxsis, contact and delayed hypersensitivity, and the cellular exudative response to a foreign body were normal. These animals also have normal direct and reverse passive Arthus reactions which suggest that they possess a mechanism to bypass C4 and directly activate late-acting complement components. This would appear to be an unequivocal demonstration of an alternate pathway in the complement sequence. Immune clearance of guinea pig erythrocytes sensitized with rabbit antibody was impaired in the deficient animals. Antibody production in C4-deficient animals was impaired for two of the three antigens studied.

Animals↗

PubMed1971

In vitro studies of complement function in sera of C4-deficient guinea pigs.

In vitro studies were performed utilizing sera from a strain of guinea pigs with a total absence of hemolytically active C4. Previous studies in these animals have demonstrated normal complement-dependent inflammatory reactions, suggesting that they are able to bypass their deficiency of C4. In vitro studies with C4-deficient serum also indicate normal activation of late-acting C components. Thus, endotoxin was capable of fixing normal amounts of the late components of complement (C3-9) in these sera, but did not fix C1 and C2. Antigen-antibody complexes fixed both early and late components of complement, although components beyond C4 were fixed less efficiently than in normal sera. Therefore, both in vivo and in vitro evidence indicates that the C4-deficient guinea pigs possess an alternate pathway for activation of late-acting complement components. Antigenic analysis of C4-deficient serum utilizing both guinea pig anti-C4 antibody and rabbit anti-C4 antibody suggests an absolute deficiency of C4-like molecules. Sera from animals with C4-deficiency were found to have one-half the normal level of C2. Sera from five of eight animals tested had 10-20% normal C1 activity. C3-9 assayed as a complex was normal.

Animals↗

PubMed1971