SEQUENTIAL IGM AND IGG2 ANTI-DNP ANTIBODY-RESPONSES AGAINST DNP-E-COLI AND DNP-LIPOPOLYSACCHARIDES IN GUINEA-PIGS

  • 1 January 1977
    • journal article
    • research article
    • Vol. 32  (4) , 435-443
Abstract
When 2,4-dinitrophenylated cells (DNP-Escherichia coli) and lipopolysaccharides (DNP-LPS) of E. coli were injected i.p. into guinea pigs, they were capable of inducing sequential production of Ig[immunoglobulin]M and IgG2 anti-DNP antibodies, both of which were substantially thymus-independent, but only a trace of IgG1 anti-DNP antibody was produced. Thymus-dependent DNP-bovine serum albumin (DNP-BSA) induced (concomitantly) IgG1 and IgG2 antibody responses in the presence of LPS. The preferential IgG2 antibody response against DNP-LPS seems to be elicited with DNP-LPS itself and not by a combination of mitogenic stimulation with LPS and haptenic stimulation with other contaminating substances carrying DNP residues. The response may not be related to affinity of the antibodies produced since there was no significant difference in the affinity for DNP residue between the IgG2 and IgG1 anti-DNP antibodies produced with DNP-E. coli and DNP-BSA, respectively.