Atopic allergy is associated with allergen-specific CD4+ T cells showing a bias to production of the type-2 cytokines interleukin (IL)-4 and IL-5. There are indications that this bias is also evident in atopic T-helper (Th) cells with other antigen specificities. The balance between the production of type-1 and type-2 cytokines is influenced by various factors present in the microenvironment of the Th cells during their activation. Factors of special interest are antigen-presenting cell-derived IL-12 and prostaglandin E2, skewing to type-1 and type-2 cytokine production, respectively. The production of IL-12 and prostaglandin E2 is induced by the interaction between CD40 and CD40 ligand expressed by Th cells, and by biologically active agents such as micro-organisms or their products. The IL-12/prostaglandin E2 production ratio depends on the antigen-presenting cell type, the type of stimulus and the presence of certain cytokines. Other Th-cytokine-skewing factors are autocrine or paracrine IFN-γ and IL-4. In fact, the type-1/type-2 cytokine production balance in Th cells is under the control of various soluble products that act in a complex network of type-1 (e.g. IL-12, IFN-γ) or type-2 (e.g. IL-4, IL-10 and prostaglandin E2) factors and are produced by Th cells and their accessory antigen-presenting or bystander cells. The levels of these factors may further be determined by gene polymorphisms or aberrant hormone levels. Despite the growing knowledge of the regulation of Th-cell cytokine production, the etiology of biased cytokine production in atopic allergic individuals is still enigmatic.

Keywords:
Atopic allergy, T cells, Cytokines, IL-4, IFN-γ, 1L-12, Antigen-presenting cells
This content is only available via PDF.
© 1996 S. Karger AG, Basel
1996
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.