K. Blaser

Molecular parameters in melittin immunogenicity.

Based on immunogenicity studies, two T‐cell epitopes in melittin were found to be functional in guinea pigs, one being centrally located, the other one residing in the C‐terminal chain. In Balb/c mice only the central epitope was found to be active. A human T‐cell clone was found by T‐cell proliferation studies to employ strictly the C‐terminal chain. Truncation of melittin peptides at the N‐terminus did not markedly affect the capacity of guinea pigs to develop anti‐IgG responses towards peptidic epitopes and towards a C‐terminally attached haptenic group. Attachment of various substituents inside and outside the T‐cell epitopic areas had no marked effect on antibody responses. In contrast, the substituents positioned within a T‐cell epitope abolished T‐cell proliferation. This difference between whole animal data and cellular in vitro responses is presently not understood.

Investigation of a syngeneic murine model for the study of IgE antibody regulation with isologous antiidiotypic antibodies.

A murine experimental model to study in vivo effects of antiidotypic antibodies (aId) on the benzylpenicilloyl- (BPO) ane phosphorylcholine- (PC) specific IgE and IgG responses has been investigated. Isologous aId against anti-BPO antibodies and against the PC-specific myeloma proteins T15 and M167 have been administered to BALB/c mice previously sensitized with (BPO) carrier protein or PC keyhole limpet hemocyanin. One single injection of aId caused depression of anti-BPO IgE antibody levels for 2-3 weeks, whereas the anticarrier protein IgE response had not been affected. Longterm depression of anti-Pc IgE was achieved when anti-T15 antiserum has been administered three time to PC keyhole limpet hemocyanin immunized mice. Suppression of anti-BPO IgE and IgG antibodies has been achieved for a long period in mice actively producing anti-BPO aId. These results show that different individuals of the BALB/c mouse strain share major idiotypic determinants in IgE and IgG antibodies and the IgE antibody formation is accessible to suppression by isologous aId. These findings permit to integrate IgE regulation into the basic concepts of autologous immune regulation and might finally lead to applications in the treatment of IgE-mediated allergic syndromes.

Effect of Epitoge Density on the Induction of the IgE Immune Response in Mice

The effect of hapten density on benzylpenicilloyl (BPO)-protein conjugates upon the induction of BPO-specific IgE immune response was investigated in BALB/c and C3H mice. Bovine γ -g

Rat Mast Cell Degranulation Triggered by Murine Anti-Idiotypic Antibodies

Triggering of rat mast cell degranulation by murine anti-idiotypic antibodies (anti-Id) was investigated, using rat passive cutaneous anaphylactic (PCA) reactions as the method of evaluation. It was shown that the interaction between isologous murine anti-Id directed against anti-benzylpenicilloyl (BPO) antibodies and BPO-specific IgE molecules on the cell surface can induce PCA reactions on rats. The mechanism of cell activation by anti-Id was briefly discussed.