CD23特异性配体对B细胞增殖及分化的影响

STUDIES OF CD23 LIGANDS IN B CELL PROLIFERATION ANDDIFFERENTIATION

ＣＤ２３特异性配体（抗ＣＤ２３ＭｃＡｂ和ＩｇＥ免疫复合物）与表达ＣＤ２３分子的活化８细胞共育，然后分析其对Ｂ细胞增殖和分化的影响。结果表明：抗ＣＤ２３单抗及ＩｇＥ免疫复合物（ＩｇＥＩＣ）对Ｂ细胞增殖呈促进和抑制双向调节效应，即：在高浓度（ＣＤ２３单抗＞０。１６μｇ／ｍｌ，ＩｇＥＩＣ＞２．５μｇ／ｍｌ）时呈剂量依赖性抑制，而在某一适当浓度范围内ＣＤ２３ＭｃＡｂ在（０．００２５～０．０５μｇ／ｍｌ，ＩｇＥＩＣ在０．０８～０．３２μｇ／ｍｌ）呈促增殖效应。ＦＡＣＳ分析观察到促Ｂ细胞增殖浓度的ＣＤ２３单抗交联膜ＣＤ２３分子（ｍＣＤ２３）可促进Ｂ细胞表面免疫球蛋白（ｓＩｇ）的转型，即使ＩｇＭ＋／ＩｇＤ＋Ｂ细胞进一步向浆细胞（ＡＦＣ）或记忆细胞分化。ＣＤ２３ＭｃＡｂ对Ｂ细胞增殖、分化的调节有赖于Ｂ细胞ｍＣＤ２３的表达。其次，适当浓度的交联使ＣＤ２３ＭｃＡｂ与其所抗不同表位结合而传递阳性信号，促使Ｂ细胞Ｉｇ重链转型。这一发现表明ｍＣＤ２３在Ｂ细胞增殖、分化中起重要的调节作用。

irst of all,Blymphocytes pretrated with SAC were cultured with CD23 ligands,anti-CD23McAb and IgE immuno complex(IgEIC)respectively.By MTT colorimetric assay,we foundthat anti-CD23 McAb and IgEIC could significantly influence the proliferation of CD23￣+ B cellsat a figure of twoway phenomenon,that high concentration of ligands inhibited the proliferationof B cells whereas in1proved the proliferation in a suitable concentration of ligands. Furtherly,we selected a optimal CD23 McAb concentration(0.05 μg/ml)for crosslinking mCD23.BY FACSanalysis,the results indicated that antiCD23 McAb could transmit B cells proliferation signals,promote the expression of Ig in B lymphocytes,induce Ig switching and increase the steadiness ofmembranous CD23.