0
views
0
recommends
+1 Recommend
1 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: found

      Modulation of Delayed-Type Hypersensitivity Responses in Hairless Guinea Pigs by Peptides Derived from Enkephalin

      Read this article at

      ScienceOpenPublisherPubMed
      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          Although opioid peptides such as methionine (met)-enkephalin have been previously shown to enhance or suppress immune responses, few studies in animal models have addressed the immunomodulatory activity of their metabolic derivatives. Hairless (IAF/HA-HO) guinea pigs immunized with Freund’s complete adjuvant containing Mycobacterium tuberculosis and repeatedly skin tested with purified protein derivative of tuberculin (PPD) display high levels of stable delayed-type hypersensitivity (DTH) to PPD. Met-enkephalin (YGGFM) and two of its metabolites (YGG, YG) enhanced and accelerated PPD-elicited DTH inflammatory reactions when injected together with elicitor in these animals. At 24 h, 5 × 10<sup>–3</sup> pmol met-enkephalin significantly enhanced DTH responses by 30% over PPD alone, while 5 × 10<sup>–5</sup> pmol of YGG and 5 × 10<sup>–9</sup> pmol of YG significantly enhanced these responses by 62 and 32%, respectively. At much higher doses (5 × 10<sup>3</sup> pmol), met-enkephalin and its metabolites significantly suppressed DTH reactions by 25–32%. Tyrosine and glycine had no effect on PPD-elicited DTH. All DTH reactions (control, enhanced, suppressed) displayed typical perivascular mononuclear cell infiltrates. We conclude that the immunoactivity of met-enkephalin resides in its first two amino acids and suggest that cleavage of enkephalin molecules to YG occurs in serum and/or on the cell surface.

          Related collections

          Most cited references 11

          • Record: found
          • Abstract: found
          • Article: not found

          Pathogen-specific regulatory T cells provoke a shift in the Th1/Th2 paradigm in immunity to infectious diseases.

          Current dogma suggests that immunity to infection is controlled by distinct type 1 (Th1) and type 2 (Th2) subpopulations of T cells discriminated on the basis of cytokine secretion and function. However, a further subtype of T cells, with immunosuppressive function and cytokine profiles distinct from either Th1 or Th2 T cells, termed regulatory T (Tr) cells has been described. Although considered to have a role in the maintenance of self-tolerance, recent studies suggest that Tr cells can be induced against bacterial, viral and parasite antigens in vivo and might prevent infection-induced immunopathology or prolong pathogen persistence by suppressing protective Th1 responses. These observations have significant implications for our understanding of the role of T cells in immunity to infectious diseases and for the development of new therapies for immune-mediated disorders.
            Bookmark
            • Record: found
            • Abstract: found
            • Article: not found

            Stimulation of human peripheral blood lymphocytes by bioactive peptides derived from bovine milk proteins.

             H Meisel,  H Kayser (1996)
            The in vitro modulation of the proliferation of human peripheral blood lymphocytes by different synthetic peptides derived from milk proteins was investigated. Therefore, proliferation changes were followed up after incorporation of BrdU into the DNA, and the influence on protein biosynthesis was measured using the [3H]leucine incorporation test. Tyr-Gly and Tyr-Gly-Gly significantly enhanced (maximal 90 and 35%, respectively) the proliferation of PBL. For beta-casomorphin-7 and beta-casomorphin-10,lymphocyte proliferation was suppressed at lower concentrations, but stimulated at higher concentrations (> or = 10(-7) mol/l). Protein synthesis was stimulated (maxima at 25%) only with Tyr-Gly and Tyr-Gly-Gly. The findings point to a need for further studies on the possible function of peptides derived from milk proteins as orally bioavailable immunopotentiatory compounds.
              Bookmark
              • Record: found
              • Abstract: not found
              • Article: not found

              Th1-Th2 Paradigm: Insights from Leprosy

                Bookmark

                Author and article information

                Journal
                NIM
                Neuroimmunomodulation
                10.1159/issn.1021-7401
                Neuroimmunomodulation
                S. Karger AG
                1021-7401
                1423-0216
                2004
                April 2004
                14 April 2004
                : 11
                : 3
                : 141-148
                Affiliations
                aDepartment of Biological Sciences, Alcorn State University, Alcorn State, Miss., bDepartment of Dermatology and Pathology, SUNY-Downstate Medical Center, Brooklyn, N.Y., and cDepartment of Pathology, New York Medical College, Valhalla, N.Y., USA
                Article
                76763 Neuroimmunomodulation 2004;11:141–148
                10.1159/000076763
                15067205
                © 2004 S. Karger AG, Basel

                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.

                Page count
                Figures: 4, References: 33, Pages: 8
                Categories
                Original Paper

                Comments

                Comment on this article