Immunodeviation by passive antibody, an expression of selective immunodepression. I. Action of guinea pig IgG 1 and IgG 2 anti-hapten antibodies.

Abstract

AbstractThe effect of passively administered anti‐2,4‐dinitrophenyl (DNP) IgG1 and IgG2 antibodies on their own production has been studied.Guinea pigs were immunized with immune complexes emulsified in complete Freund's adjuvant. These complexes were made at 4 times equivalence with IgG1 and/or IgG2 anti‐DNP antibodies having the same affinity. Humoral IgG1 and IgG2 anti‐DNP antibody contents were assayed at weekly intervals, and 4 and 10 days after a booster injection of antigen in saline given on the 12th week.Active anti‐DNP IgG2 antibody production is strongly inhibited by passive IgG2, IgG1 and F(ab')2 antibody fragments.Active anti‐DNP IgG1 antibody production of the same animals is inhibited by passive IgG2 and F(ab')2, to an extent similar to active IgG2 antibody inhibition, but the response after boosting is normal. On the other hand, passive IgG1 antibodies lead to a delayed enhanced active IgG1 antibody response.The effect of a 1 : 1 mixture of both passive antibody classes is intermediate to what is observed with either class alone.These differential effects according to the class (i.e. the Fc fragment) of the passive antibodies used show the importance of immune complexes in not only the quantitative, but also the qualitative, regulation of the immune response.