Hagen M, Morrison B, Robbinson D, Strejan G H
Department of Microbiology, University of Western Ontario, London, Canada.
Int Arch Allergy Immunol. 1992;97(2):146-53. doi: 10.1159/000236110.
We reported previously that CBA mice pretreated with dinitrophenyl-Bordetella pertussis (DNP-BP) conjugates exhibited sharply decreased anti-DNP IgE, and increased IgG2a antibodies following immunization with DNP-ovalbumin (DNP-OA) in alum. The objective of the present experiments was to determine whether the decrease in anti-DNP IgE was attributed to a regulatory effect exerted by IgG2a antibodies. Anti-DNP monoclonal antibodies (Mab) of the IgG1 or IgG2a isotype were passively transferred to mice, 24 h before a primary immunization with DNP-OA in alum. Anti-DNP IgE production was drastically suppressed in recipients of IgG1 but not of IgG2a Mab. Similar results were obtained when the Mab were endogenously produced by intraperitoneal implantation of anti-DNP-secreting hybridomas into (BALB/cxCBA)F1 (BCF1) mice. However, neither IgG1 nor IgG2a isotypes suppressed IgE antibody production if the hybridoma implantation took place 10 days after hapten priming. These results are, to our knowledge, the first to show a clear dissociation between the effect of either passively transferred or endogenously secreted IgG1 and IgG2a antibodies in their ability to inhibit a primary anti-hapten IgE antibody response.
我们之前报道过，用二硝基苯基 - 百日咳博德特氏菌（DNP - BP）偶联物预处理的CBA小鼠，在用明矾中的DNP - 卵清蛋白（DNP - OA）免疫后，抗DNP IgE显著降低，而IgG2a抗体增加。本实验的目的是确定抗DNP IgE的降低是否归因于IgG₂a抗体发挥的调节作用。在初次用明矾中的DNP - OA免疫前24小时，将IgG1或IgG2a同种型的抗DNP单克隆抗体（Mab）被动转移到小鼠体内。接受IgG1 Mab的小鼠中抗DNP IgE的产生被显著抑制，但接受IgG2a Mab的小鼠则未被抑制。当通过将分泌抗DNP的杂交瘤腹腔内植入（BALB / cxCBA）F1（BCF1）小鼠内源性产生Mab时，也获得了类似结果。然而，如果在半抗原致敏10天后进行杂交瘤植入，IgG1和IgG2a同种型均未抑制IgE抗体的产生。据我们所知，这些结果首次清楚地表明，被动转移或内源性分泌的IgG1和IgG2a抗体在抑制初次抗半抗原IgE抗体反应的能力方面存在明显差异。
