STUDIES ON ANTIGENICITY. THE RELATIONSHIP BETWEEN IN VIVO AND IN VITRO ENZYMATIC DEGRADABILITY OF HAPTEN-POLYLYSINE CONJUGATES AND THEIR ANTIGENICITIES IN GUINEA PIGS

ANTIGENICITY OF POLYPEPTIDES (POLY ALPHA AMINO ACIDS). 13. IMMUNOLOGICAL STUDIES WITH SYNTHETIC POLYMERS CONTAINING ONLY D- OR D- AND L-ALPHA-AMINO ACIDS

It has been demonstrated that polymers consisting solely of D-alpha-amino acids are not immunogenic in rabbits, guinea pigs, man, and mouse, whereas the same polymers of L-alpha-amino acids are very effective antigens. This has been attributed to the importance of metabolizability of a polymer in contributing to its immunogenicity. In the glu-lys-ala series of polymers, the immunogenicity of a polymer of 2 L-amino acids and a D-amino acid appears to be governed by the immunogenicity of the 2 L-amino acids. However, some of the specificity may be directed towards configurations containing the D-amino acid. It has been noted that injections of rabbits with polymers of D-amino acids has resulted in a reduced response against the isomeric L polymer.

A cellular basis for genetically controlled immunologic unresponsiveness in mice: tolerance induction in T-cells

H-2(q) mice (DBA/1) do not make an antibody response to a synthetic aminoacid polymer, (Glu, Ala,Tyr(10)), after an immunizing regimen that produces a good antibody response in mouse strains with other H-2 alleles. Their thymocytes, however, show evidence of recognizing this antigen since they synthesize DNA when they meet the antigen in the spleen. This recognition event does not lead to memory production, as it does in genetic responders, since the thymocytes fail to respond to a second immunization with (Glu,Ala,Tyr(10)). Nonresponder mice do make antibody to (Glu,Ala,Tyr(10)) when they are immunized with it complexed to an immunogenic carrier, but previous treatment with free polymer can temporarily abolish this response. Thus, we suggest that the basis for the unresponsiveness of these mice is that their T-cells (thymus-processed lymphocytes) have an inordinate propensity to become (or to induce other cells to become) immunologically tolerant.

Genetic control of immunological responsiveness in guinea pigs to 2,4-dinitrophenyl conjugates of poly-L-arginine, protamine, and poly-L-ornithine

The ability of guinea pigs to respond immunologically to dinitrophenyl (DNP)-poly-L-arginine, DNP-protamine, DNP polyornithine, and to unsubstituted poly-L-arginine and protamine is linked to the presence of the poly-L-lysine gene. This gene has previously been demonstrated to control the immune response of guinea pigs to poly-L-lysine, to a copolymer of L-glutamic acid and L-lysine and to haptenic derivatives of these materials. Although the ability to respond to each of these highly charged compounds is linked to the presence of the poly-L-lysine gene, the cellular immune responses to these antigens is highly individually specific.

The genetic control of contact sensitization to inorganic metal compounds in guinea-pigs

Only a proportion of outbred guinea-pigs can be sensitized to K₂Cr₂O₇, BeF₂ and HgCl₂. Inbred Strain II can be sensitized to K₂Cr₂O₇ and BeF₂, but not to HgCl₂. Inbred strain XIII can be sensitized to HgCl₂ but not to K₂Cr₂O₇ or BeF₂. The ability to become sensitized appears to be transmitted as a dominant characteristic which is not sex linked.

Immune and non-immune responses to monovalent low molecular weight penicilloyl-polylysines and penicilloyl-bacitracin in rabbits and guinea-pigs

Rabbits and guinea-pigs have been immunized with low molecular weight penicilloyl—polylysines (BPO₁—PLL_{1 2}, BPO₆—PLL_{1 2}) with varying degrees of substitution and with monovalent penicilloyl—bacitracin (BPO₁—BAC). The immune response to the penicilloyl (BPO) determinant has been followed by skin tests, passive haemagglutination, passive cutaneous anaphylaxis (PCA), immunodiffusion and immunoelectrophoresis.

Maximally substituted BPO₆—PLL_{1 2} was found to be non-immunogenic. Apparently monovalent BPO₁—PLL_{1 2}, which inhibits precipitation of anti-BPO antibodies in vitro, was found to induce delayed-type hypersensitivity and antibodies for BPO in most of our random bred and in all strain 2 guinea-pigs. The delayed hypersensitivity in some of the sensitized guinea-pigs was hapten (BPO)-specific. BPO₁—PLL_{1 2} was very poorly immunogenic in rabbits.

Monovalent BPO₁—BAC induced BPO-specific delayed hypersensitivity and anti-BPO antibodies in some random bred guinea-pigs but not in strain 2 animals. BPO₁—BAC induced good levels of haemagglutinating anti-BPO antibodies in most random bred rabbits.

Truly monovalent compounds, such as BPO₁—BAC or BPO—ε-aminocaproate, do not elicit antibody-dependent reactions such as anaphylactic or Arthus reactions, but inhibit them.

On the other hand, apparently monovalent BPO₁—PLL_{1 2} was found to elicit BPO-specific PCA and Arthus reactions in immunized rabbits and guinea-pigs. When administered in higher doses, similar reactions were produced in non-immunized guinea-pigs. The possibility is discussed that some of the reactions observed with basic polypeptide antigens are due to the formation of mixed `specific antibody—polypeptide—non-specific protein' complexes formed in vivo by electrostatic interaction.

The production of antibody to bovine serum albumin in unresponsive (Sobey) mice

Mice (Sobey) bred to select lack of antibody production against bovine serum albumin have been examined for their responsiveness over a wide range of antigen doses. With low doses of antigen both Sobey mice and an outbred line of Swiss White mice produce similar amounts of antibody. Antigen in amounts greater than 500 μg produce tolerance more effectively in Sobey mice and this is the reason for their unresponsiveness at high antigen dose levels.

The behavior of hapten-poly-L-lysine conjugates as complete antigens in genetic responder and as haptens in nonresponder guinea pigs

30 to 40% of Hartley strain guinea pigs have previously been demonstrated to possess a dominant autosomal gene which enables them to recognize the antigenicity of hapten-poly-L-lysine conjugates as expressed by the development of both antihapten antibodies and delayed hypersensitivity to the immunizing antigen. In the present study, it was shown that PLL alone was weakly antigenic in such genetic responder animals. Immunization with DNP-PLL electrostatically combined with foreign albumins elicits the production of anti-DNP antibodies in all Hartley strain guinea pigs, although the percentage of animals demonstrating a delayed response to DNP-PLL and therefore considered genetic responders remains 30 to 40%. Immunization with nonantigenic polyanions combined with DNP-PLL does not produce such an effect. Some degree of PLL specificity of purified anti-DNP antibodies produced by genetic nonresponder animals by immunization with DNP-PLL combined with foreign albumins was demonstrated by means of fluorescence quenching.

Antigenicity of polypeptides (poly alpha amino acids). XVI. Genetic control of immunogenicity of synthetic polypeptides in mice

The ability of mice to form antibodies against the random terpolymer glu(57)lys(38)ala(5) is controlled by a codominant Mendelian factor. Three of 7 inbred strains were 100 per cent responders; the others were completely negative. All of these strains could make antibody to related polymers with higher alanine content (10 and 40 mole per cent). Breeding studies using the progeny of Swiss mice indicated that a similar genetic factor was involved.

GENETIC CONTROL IN GUINEA PIGS OF IMMUNE RESPONSE TO CONJUGATES OF HAPTENS AND POLY-L-LYSINE

Random-bred Hartley strain guinea pigs which do not respond immunologically to conjugates of hapten and poly-L-lysine mere mated with heterozygous guinea pigs which do. These responders were considered heterozygous for this trait since their mating resulted in at least one nonresponder offspring. Of 31 offspring from 10 breeding pairs (nonresponder x heterozygous responder) 14 were responders. There was no evidence that this trait is sex-linked. This finding confirms the view that, in guinea pigs, development of an immune response to the aforementioned conjugates is a genetically transmitted autosomal, unigenic Mendelian dominant trait.