CD4 and allergic disease: There is already abundant data to support such a role for T cells in allergic diseases [7, 13, 14, 22, 33], and we show that T depletion, particularly of both CD4+ and CD8+ cells following the protocol described in Fig. 6 abolishes the ability of the Ig treatment used to suppress Th2 immunity, in keeping with decreased numbers of CD4+ and/or CD8+ cells recovered from such mice.