Yancey K B, O'Shea J, Chused T, Brown E, Takahashi T, Frank M M, Lawley T J
J Immunol. 1985 Jul;135(1):465-70.
FcIgG and C3 (CR1 and CR3) receptors are responsible for binding opsonized particles, phagocytosis, and immune adherence reactions by circulating and tissue-fixed mononuclear phagocytes. Alterations in the expression of these receptors may thus significantly influence the function of these cells. Because chemoattractants have been shown to both recruit and modulate the function of monocytes, this study specifically examines the effects of human C5a and N-formyl-methionyl-leucyl-phenyl-alanine (FMLP) on human peripheral blood monocyte FcIgG and C3 receptor expression in vitro. Adherent, elutriator-purified monocytes were incubated with C5a (10(-7) to 10(-10) M) or FMLP (10(-5) to 10(-10) M) for 30 min at 37 degrees C, and FcIgG receptor expression was assessed by rosetting with sheep erythrocytes sensitized with limiting dilutions of IgG. Human C5a caused dose-related increases in Fc rosettes of 28% at 10(-9) M, 63% at 10(-8) M, and 167% at 10(-7) M (p less than 0.01). In contrast, no significant increases in monocyte Fc receptor expression were induced by FMLP. Similar rosetting experiments were performed with sheep erythrocytes opsonized with limiting amounts of human C3b to assess C3b receptor expression on adherent human monocytes stimulated with C5a (10(-7) to 10(-10) M) or FMLP (10(-6) to 10(-9) M) for 30 min at 37 degrees C. Again, human C5a caused dose-related increases in monocyte C3b rosette formation; at 10(-8) M and 10(-7) M concentrations of C5a, these increases equaled 119% and 196%, respectively (p less than 0.05). In these experiments, 10(-6) M FMLP also caused a significant increase of 110% in monocyte C3b rosette formation (p less than 0.05). Modulation of monocyte cell surface receptors by human C5a or FMLP was also examined by measuring cell fluorescence and side scatter by dual channel flow cytometry after staining normal leukocytes in citrated venous blood with receptor-specific monoclonal antibodies. These flow cytometric studies demonstrated that both C5a and FMLP induce dose-related increases in CR1 (C3b receptor) and CR3 (iC3b receptor) expression in both monocytes and neutrophils.(ABSTRACT TRUNCATED AT 400 WORDS)
FcIgG和C3（CR1和CR3）受体负责结合调理素化颗粒，通过循环和组织固定的单核吞噬细胞进行吞噬作用和免疫黏附反应。因此，这些受体表达的改变可能会显著影响这些细胞的功能。由于趋化因子已被证明可募集并调节单核细胞的功能，本研究专门检测了人C5a和N-甲酰甲硫氨酰亮氨酰苯丙氨酸（FMLP）对人外周血单核细胞FcIgG和C3受体体外表达的影响。将贴壁的、淘洗纯化的单核细胞与C5a（10⁻⁷至10⁻¹⁰M）或FMLP（10⁻⁵至10⁻¹⁰M）在37℃孵育30分钟，通过与用有限稀释度IgG致敏的绵羊红细胞进行玫瑰花结试验评估FcIgG受体表达。人C5a导致Fc玫瑰花结呈剂量相关增加，在10⁻⁹M时增加28%，在10⁻⁸M时增加63%，在10⁻⁷M时增加167%（p＜0.01）。相比之下，FMLP未诱导单核细胞Fc受体表达显著增加。用有限量人C3b调理的绵羊红细胞进行类似的玫瑰花结试验，以评估在37℃用C5a（10⁻⁷至10⁻¹⁰M）或FMLP（10⁻⁶至10⁻⁹M）刺激30分钟后贴壁人单核细胞上C3b受体的表达。同样，人C5a导致单核细胞C3b玫瑰花结形成呈剂量相关增加；在C5a浓度为10⁻⁸M和10⁻⁷M时，这些增加分别相当于119%和196%（p＜0.05）。在这些实验中，10⁻⁶M FMLP也导致单核细胞C3b玫瑰花结形成显著增加110%（p＜0.05）。在用受体特异性单克隆抗体对枸橼酸盐抗凝静脉血中的正常白细胞进行染色后，通过双通道流式细胞术测量细胞荧光和侧向散射，也检测了人C5a或FMLP对单核细胞表面受体的调节。这些流式细胞术研究表明，C5a和FMLP均诱导单核细胞和中性粒细胞中CR1（C3b受体）和CR3（iC3b受体）表达呈剂量相关增加。（摘要截短于400字）
