Regulation of IgG antibody-dependent cellular cytotoxicity in vitro by IgM antibodies. Mechanism and characterization of effector lymphocytes

H. Perlmann, P. Perlmann, L. Moretta, M. Ronnholm

Research output: Contribution to journalArticle

Abstract

IgM antibodies have previously been reported to either inhibit or induce antibody-dependent lymphocyte cytotoxicity (ADCC). Here the authors show that human lymphocytes lyse bovine erythrocytes (Eb) in the presence of either IgM or IgG anti-Eb from rabbits. Seven out of 20 IgM preparations (Sephadex G-200) were ADCC-active. IgG-dependent ADCC was inhibited by human IgG but not by IgM. In contrast, IgM ADCC was inhibited by both IgG and IgM. The effector cells in IgM ADCC were a subpopulation of lymphocytes with distinct Fc receptors for both IgG and IgM. Most of them also had sheep erythrocyte receptors. Extensive purification of the ADCC-active IgM antibody preparations indicated that very small amounts of contaminating IgG anti-Eb were responsible for ADCC induction. When purified and ADCC-inactive IgM antibodies were mixed with suboptimal concentrations of IgG antibodies, a strong enhancement of ADCC was found. To achieve enhancement, the two antibody isotypes had to be present on the surface of the same target cells, and the IgM effect was not due to the release of soluble ADCC-enhancing factors. Thus, in this system, IgM antibodies are not capable of inducing ADCC on their own. However, they enhance ADCC by improving the contactual interaction between target cells and a special subset of effector cells.

Original languageEnglish
Pages (from-to)47-60
Number of pages14
JournalScandinavian Journal of Immunology
Volume14
Issue number1
Publication statusPublished - 1981

ASJC Scopus subject areas

  • Immunology

Fingerprint Dive into the research topics of 'Regulation of IgG antibody-dependent cellular cytotoxicity in vitro by IgM antibodies. Mechanism and characterization of effector lymphocytes'. Together they form a unique fingerprint.

  • Cite this