Mannhalter J W, Ahmad R, Pinzker H, Wolf H, Eibl M M
Clin Immunol Immunopathol. 1986 Jun;39(3):491-503. doi: 10.1016/0090-1229(86)90176-5.
Circulating immune complexes are considered to have a profound effect on host defense mechanisms against invading pathogens and to modulate cellular interactions required for an appropriate course of the immune response. In this study we have investigated the influence of polymeric IgG (used as a model system for immune complexes) on accessory functions of human monocytes. We show that a short (1 hr) incubation of human monocytes in the presence of polymeric IgG (16 hr prior to antigen pulsing) led to a significant decrease of these cells' antigen-presenting capacity while accessory functions in alloantigen- or mitogen-driven proliferation systems remained unimpaired. The polymeric IgG-induced impairment of antigen presentation, which was assessed by diminished proliferation of antigen-reactive T cells following stimulation by antigen-pulsed polymeric IgG-treated or Dulbecco's phosphate-buffered saline (PBS-D)-treated control monocytes, could not be attributed to the generation of suppressor mechanisms (no release of soluble suppressor factors, no induction of suppressive monocytes). The release of interleukin-1 by polymeric IgG-treated monocytes and PBS-D-treated monocytes was comparable and polymeric IgG did not down modulate major histocompatibility complex (MHC) class II molecules already expressed in the monocyte plasma membrane. Profound changes in the monocyte plasma membrane occurring subsequent to polymeric IgG treatment possibly accompanied by altered kinetics of MHC class II reexpression are likely to contribute to the observed decrease of antigen presentation.
循环免疫复合物被认为对宿主抵御入侵病原体的防御机制具有深远影响，并调节免疫反应适当进程所需的细胞间相互作用。在本研究中，我们研究了聚合IgG（用作免疫复合物的模型系统）对人单核细胞辅助功能的影响。我们发现，在聚合IgG存在下（抗原脉冲前16小时）将人单核细胞短时间（1小时）孵育会导致这些细胞的抗原呈递能力显著下降，而在同种异体抗原或丝裂原驱动的增殖系统中的辅助功能仍未受损。通过抗原脉冲处理的聚合IgG或杜尔贝科磷酸盐缓冲盐水（PBS-D）处理的对照单核细胞刺激后，抗原反应性T细胞增殖减少来评估的聚合IgG诱导的抗原呈递损伤，不能归因于抑制机制的产生（无可溶性抑制因子释放，无抑制性单核细胞诱导）。聚合IgG处理的单核细胞和PBS-D处理的单核细胞释放白细胞介素-1的情况相当，并且聚合IgG不会下调单核细胞质膜中已表达的主要组织相容性复合体（MHC）II类分子。聚合IgG处理后单核细胞质膜发生的深刻变化，可能伴随着MHC II类重新表达动力学的改变，很可能导致观察到的抗原呈递减少。
