A mammalian C-type lectin receptor type is identified which is shown to bind IgG antibodies or Fc fragments, thus inducing IVIG-related reversal of inflammation associated with various immune disorders. The identification of a DC-SIGN receptor type which interacts with IgG to promote a biological response reducing inflammation associated with immune disorders provides for methods of screening and selecting compounds which may be useful in treating various immune disorders by acting to modulate a DC-SIGN(+) cell to signal a second effector macrophage, causing an increase in expression of the FcγRIIB receptor and in turn inhibiting a cellular-mediated inflammatory response.