Recombinant, enzymatic active phospholipase A2 from bee venom (PLA2) is a potent inducer of IgE antibody formation in CBA/J (H-2k) mice. In contrast, a recombinant mutant protein lacking enzymatic activity due to an amino acid exchange in the active site of the enzyme fails to induce IgE antibodies under identical immunization conditions. Peptide mapping and T-cell stimulation experiments with 18-mer overlapping peptides locate the T-helper cell-activating epitopes in the C-terminal region of the PLA2 protein. No T-cell epitopes are found in the area around position 34, the center of the enzymatically active site. The data support a model in which initially an enzymatic activation of mast cells or basophiles leads to IL-4 production which in a paracrine way drives T-helper cells, concomitantly activated by antigen, into Th2 differentiation. This ultimately favors B-cell activation for an IgE response.

Keywords:
Phospholipase A2, T-cell epitopes, Peptides, IgE, Enzymatic activity
This content is only available via PDF.
© 1997 S. Karger AG, Basel
1997
Copyright / Drug Dosage / Disclaimer
Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher.
Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug.
Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.
You do not currently have access to this content.