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Rat and Human Natural Killers Exhibit Contrasting Immunoglobulin G Subclass Specificities in Antibody‐Dependent Cellular Cytotoxicity Reflecting Differences in Their Fc Receptors (FcγR)
Author(s) -
Song Elizabeth S.,
Young Katrina,
Sears Duane W.
Publication year - 1990
Publication title -
journal of leukocyte biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.819
H-Index - 191
eISSN - 1938-3673
pISSN - 0741-5400
DOI - 10.1002/jlb.48.6.524
Subject(s) - subclass , biology , antibody , cytotoxicity , receptor , fc receptor , immunoglobulin fc fragments , immunology , immunoglobulin g , antibody dependent cell mediated cytotoxicity , microbiology and biotechnology , genetics , in vitro , monoclonal antibody
Rat and human natural killers (rtNK and huNK, respectively) were compared in quantitative antibody‐dependent cellular cytotoxicity (ADCC) assays for their capacity to recognize mouse and rat IgG monoclonal antibodies (MAb) of different subclasses. NK from these two species exhibit considerably different patterns of IgG subclass recognition as determined by the relative antibody concentrations required for comparable levels of target cells lysis. ADCC assays with a panel of 16 MAb revealed that the efficiency of rtNK‐mediated target lysis diminished according to IgG subclass in the following order: molgG1 > rtlgG2a > molgG2b ≍ molgG2a > rtlgG2b > molgG3. By comparison, huNK recognized the same antibodies with nearly the opposite order of efficiency: rtlgG2b >> molgG2a > molgG3 > molgG2b » rtlgG2a ≍ molgG1. Only molgG2a antibodies were equally potent with rtNK and huNK. The contrasting difference in IgG subclass recognition by rat and human NK reflects the comparatively low protein sequence homology between their respective IgG Fc receptors (FcγR).