CUTTING EDGE - IDENTIFICATION OF THE MOUSE IGG3 RECEPTOR - IMPLICATIONS FOR ANTIBODY EFFECTOR FUNCTION AT THE INTERFACE BETWEEN INNATE AND ADAPTIVE IMMUNITY
Al. Gavin et al., CUTTING EDGE - IDENTIFICATION OF THE MOUSE IGG3 RECEPTOR - IMPLICATIONS FOR ANTIBODY EFFECTOR FUNCTION AT THE INTERFACE BETWEEN INNATE AND ADAPTIVE IMMUNITY, The Journal of immunology, 160(1), 1998, pp. 20-23
Mouse IgG3 appears early in immune responses independently of T cell h
elp and, as such, is an early effector molecule of the immune system,
Yet, a specific IgG3 cellular receptor remains undefined, In transfect
ion experiments, mouse Fc gamma RI was clearly able to bind immune com
plexes of IgG3, whereas mouse Fc gamma RII could not, Furthermore, mac
rophages from mice expressing Fc gamma RII and Fc gamma RIII but lacki
ng Fc gamma RI were unable to phagocytose IgG3 immune complexes, thus
identifying mouse Fc gamma RI as the sole receptor for IgG3 immune com
plexes, Competition studies demonstrated that monomeric mouse IgC3 cou
ld inhibit IgG2a binding to mouse Fc gamma RI with an ID50 approximate
to 10(-7) M (fivefold lower than IgG2a). The identification of mouse
Fc gamma RI as the IgG3 receptor establishes Fc gamma RI as a particip
ant in events at the interface between innate and adaptive immunity, i
mplying a greater role for this receptor in the development of normal
and pathologic immune responses than previously recognized.