| Abstract: | The immunogenicity of penicilloyl polysaccharides with molecular weights from 5 000 to 400 000 was studied in two guinea pig strains. The conjugates quite regularly induced penicilloyl specific and carrier specific dermal delayed-type hypersensitivity. On the other hand, circulating antibodies were found only occasionally. In a few animals anaphylactic antibody could be demonstrated but precipitating or hemagglutinating antibodies were found in no instance. Since penicilloyl polysaccharides are relatively instable, more stable benzyldextran and nitrobenzyldextran conjugates were studied as well. These antigens also induce dermal delayed-type hypersensitivity. The capacity of the nitrobenzyldextran to induce hapten specific and carrier specific reactions was quite similar to the capacity of penicilloylated polysaccharides. Penicilloyl polysaccharides are able to elicit penicilloyl specific cutaneous anaphylactic reactions in passively immunized guinea pigs. A relatively highly penicilloylated dextran conjugate exhibited an eliciting potency quite comparable to a highly penicilloylated poly-L-lysine. Haptenic and carrier specificities in sensitisation and the possible tolerogenicity of these antigens are discussed; the question to what extent the immunogenicity of hapten-polysaccharide conjugates may be regarded as intrinsic is treated in particular. |
