Reconstitution of genetically regulated responses against random and ordered synthetic polypeptides by methylated bovine serum albumin as analyzed by isoelectric focusing

Abstract

In previous publications it was shown by avidity measurements, cross-reactivity patterns and genetic analyses, that the tetrapeptide T-T-G-G is the immuno-dominant epitope of the synthetic polypeptide (T, G)-A--L. In the present study this close immunological relationship between the random multichain copolymer (T, G)-A--L and the ordered analogue (T-T-G-G)-A--L is extended by two additional criteria. First, the immune response against (T-T-G-G)-A--L in H-2k nonresponder mouse strains can be reconstituted to high antibody levels by complexing this antigen to methylated bovine serum albumin, as was tested earlier for (T,G)-A--L. The antibodies elicited upon reconstitution in both antigenic systems are directed mainly against the same determinant, T-T-G-G. Second, isoelectric focusing analysis of specific antisera developed with radiolabeled antigen revealed restricted 7 S IgG antibody populations in high responder and reconstituted high and low responder mice. The spectra were found to be of similar complexity in the (T,G)-A--L and in the (T-T-G-G)-A--L system. From these data it was concluded that the repertoires of specific B cells to T-T-G-G are very similar in high and low responder strains, and the defect in the H-2k low responder systems should be located at the level of T-B cell cooperation.

Efficient genetically controlled formation of antibody to a synthetic antigen [poly(LTyr, LGlu)-poly(DLAla)- -poly(LLys)] covalently bound to a synthetic adjuvant (N-acetylmuramyl-L-alanyl-D-isoglutamine).

“…Mice were injected with 10 ,tg of (T, Radioimmunoassay. Antibody response was determined by a modification of a solid-phase binding assay (13,14 Isoelectric Focusing of Antisera Against (T,G)A--L. Analytical isoelectric focusing of antisera against (T,G)-A--L was done as described (15). (wt/vol) polyacrylamide gels containing 4.5 M urea and 2% (wt/vol) ampholytes (LKB) at pH 5-8.…”

Liposomes as immunological adjuvants in eliciting antibodies specific to the synthetic polypeptide poly(LTyr, LGlu)‐poly(DLAla)–poly(LLys) with high frequency of site‐associated idiotypic determinants

“…Slices were cut out of the gel and counted. Analytical IEF of pooled antisera to (T,G)-A--L was carried out as previously described [24]. Samples of antisera elicited bound (T,G)-A--L was also shown by the absence of binding of radiolabeled F(ab'), of anti-(T,G)-A--L antibodies (data not shown).…”