Kurita T, Kiyono H, McGhee M L, McGhee J R
Department of Microbiology, University of Alabama, Birmingham.
Adv Exp Med Biol. 1987;216A:81-7.
Fc alpha receptor (Fc alpha R)+ T cell hybridomas (Th HA cells) were derived from fusion of Peyer's patch T helper cells (PP Th A cell) which preferentially select sIgA+ B cells and support IgA responses, with the R1.1 T lymphoma cell line. Expression of Fc alpha R on Th HA cells was extensively characterized by several methods, i.e., immunocytoadherence, colloidal gold-immunoelectron microscopy, FACS and ELISA. All four assays clearly demonstrated expression of Fc alpha R on Th HA cells. The use of FACS and ELISA also suggested the expression of Fc alpha R as well as the presence of lower amounts of Fc mu R on these cell lines. The significance of coexpression of Fc alpha R and Fc mu R is currently under extensive investigation in our group. Solubilized membrane fractions derived from Th HA cells were tested for the presence of Fc alpha R on ELISA and for their ability to support in vitro IgA responses. Both Fc alpha R and Fc mu R were detected in cell membrane fractions of Th HA cells. The cell membrane fraction which contained Fc alpha R, supported in vitro IgA anti-SRBC PFC responses when added to PP B cell cultures in the presence of SRBC. This activity was removed by adsorption to an IgA affinity column. On the other hand, the bound fraction contained sFc alpha R and supported IgA anti-SRBC PFC responses in PP B cell cultures, a response pattern that was similar to those obtained with IBF alpha. Taken together, these results suggest that Fc alpha R and IBF alpha are similar molecules and both exhibit functional activity.(ABSTRACT TRUNCATED AT 250 WORDS)
Fcα受体（FcαR）阳性T细胞杂交瘤（Th HA细胞）源自派伊尔结T辅助细胞（PP Th A细胞）与R1.1 T淋巴瘤细胞系的融合，PP Th A细胞优先选择sIgA阳性B细胞并支持IgA应答。通过免疫细胞黏附、胶体金免疫电子显微镜、荧光激活细胞分选术（FACS）和酶联免疫吸附测定（ELISA）等多种方法对Th HA细胞上FcαR的表达进行了广泛表征。所有这四种检测方法均清楚地证明了Th HA细胞上FcαR的表达。FACS和ELISA的结果还表明这些细胞系上存在FcαR以及少量FcμR。目前我们小组正在广泛研究FcαR和FcμR共表达的意义。对源自Th HA细胞的可溶性膜部分进行ELISA检测，以确定是否存在FcαR，并检测其支持体外IgA应答的能力。在Th HA细胞的细胞膜部分检测到了FcαR和FcμR。含有FcαR的细胞膜部分在存在绵羊红细胞（SRBC）的情况下添加到PP B细胞培养物中时，可支持体外IgA抗SRBC空斑形成细胞（PFC）应答。这种活性可通过吸附到IgA亲和柱上去除。另一方面，结合部分含有可溶性FcαR（sFcαR），并在PP B细胞培养物中支持IgA抗SRBC PFC应答，其应答模式与用免疫结合因子α（IBFα）获得的应答模式相似。综上所述，这些结果表明FcαR和IBFα是相似分子，且均表现出功能活性。（摘要截短至250字）
