Editors' ChoiceImmunology

The IgGs Have It

Science's STKE  06 Dec 2005:
Vol. 2005, Issue 313, pp. tw437
DOI: 10.1126/stke.3132005tw437

Different classes of antibody (the immunoglobulins IgA, IgD, IgE, IgG, and IgM) perform divergent functions within the immune system. IgG has also evolved further into subclasses that vary considerably in their potency in particular types of immune responses. Each IgG subclass possesses a range of binding affinities for the different inhibitory and activating receptors that engage the constant Fc region of the antibody molecule. Nimmerjahn and Ravetch (see the Perspective by Woof) used this observation to construct antibodies bearing the same antigenic specificity combined with the subclass-specific portions of Fc. The ability of these hybrid antibodies to mediate their immunological effects in vivo could be predicted by the strength with which the Fc portion bound the different activating or inhibitory Fc receptor (FcR). Thus, the specificity and strength of FcR binding is a central means by which IgG subclasses determine their dominance in a particular immune response.

F. Nimmerjahn, J. V. Ravetch, Divergent immunoglobulin G subclass activity through selective Fc receptor binding. Science 310, 1510-1512 (2005). [Abstract] [Full Text]

J. M. Woof, Tipping the scales toward more effective antibodies. Science 310, 1442-1443 (2005). [Summary] [Full Text]