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Differential Binding of IgG Subclasses to Enzyme‐treated Human Lymphocytes
Author(s) -
GILBERT D.,
DAVEAU M.,
FONTAINE M.
Publication year - 1981
Publication title -
scandinavian journal of immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.934
H-Index - 88
eISSN - 1365-3083
pISSN - 0300-9475
DOI - 10.1111/j.1365-3083.1981.tb00180.x
Subject(s) - pronase , neuraminidase , rosette formation , receptor , trypsin , rosette (schizont appearance) , biology , microbiology and biotechnology , enzyme , in vitro , biochemistry , immunology
Human erythrocytes coaled with each of the four human IgG subclasses were used to detect Fcγ receptors on human peripheral blood lymphocytes (HPBL). Rosette formation was obtained only with erythrocytes coated with IgG3 (EAγ3). Neuraminidase treatment of HPBL induced rosette formation with EAγ1, EAγ2, and EAγ4 complexes. Pronase treatment also induced rosette formation to a lesser extent, but abolished EAγ3 rosetting. Trypsin treatment enhanced EAγ3 rosette formation. These phenomena occurred on both ‘T’ and ‘non‐T’ lymphocytes. Erythrocytes coaled with small quantities of IgG3 did not form rosettes with HPBL. Neuraminidase treatment enhanced their binding, whereas pronase did not. These two phenomena occurred only on non‐T lymphocytes. Rosette formation with EAγ1 was also obtained with lymphocytes stimulated in vitro with mitogens. After 2 days of culture, stimulated lymphocytes expressed receptors that were able to bind both EAγ1 and EAγ3 complexes. These results suggest the existence of cryptic receptors for IgG1, IgG2, and IgG4 that could be disclosed by neuraminidase and pronase treatment and exposed on stimulated lymphocytes. A hypothesis of one or several Fcγ receptors is suggested.