Bleicher P A, Cohen N
J Immunol. 1981 Oct;127(4):1549-55.
The role of SIgM+ lymphocytes in frog mitogen responses and mixed lymphocyte reactions was examined. A murine monoclonal antibody with specificity for Xenopus laevis IgM was produced. The anti-IgM activity was not inhibited by glycoproteins other than Xenopus IgM, but could be inhibited with periodate-treated frog IgM. Fluorescent microsphere-coupled anti-IgM was used to show that adult and larval thymocytes had few sIgM+ lymphocytes, whereas spleens contained 19 to 34% sIgM+ lymphocytes. The spleens of larvally thymectomized adults were greatly enriched for sIgM+ cells. Lymphocyte suspensions were depleted of sIgM+ cells by incubation of spleen cells on plastic Petri dishes coated with anti-IgM monoclonal antibody. Compared with unseparated controls, the nonadherent cells cultured in serum-free medium were enriched for Con A and PHA mitogen responses and mixed lymphocyte culture (MLC) reactivity. Nonadherent cells were partially depleted of LPS mitogen responsiveness. Depletion or enrichment of the mitogen response was not a result of changes in kinetics or dose-response characteristics of the cells. In 1% FCS-supplemented cultures, the LPS response was not depleted, whereas the PHA response was still enriched. Thus, thymus-dependent and thymus-independent mitogen and MLC responses can be separated by the criterion of sIgM positivity in this anuran species.
研究了SIgM⁺淋巴细胞在青蛙有丝分裂原反应和混合淋巴细胞反应中的作用。制备了一种对非洲爪蟾IgM具有特异性的鼠单克隆抗体。除非洲爪蟾IgM外，其他糖蛋白不会抑制该抗IgM活性，但经高碘酸盐处理的青蛙IgM可抑制其活性。使用荧光微球偶联的抗IgM来显示，成年和幼虫胸腺细胞中几乎没有sIgM⁺淋巴细胞，而脾脏中含有19%至34%的sIgM⁺淋巴细胞。幼虫期胸腺切除的成年青蛙脾脏中sIgM⁺细胞大量富集。通过将脾细胞在包被有抗IgM单克隆抗体的塑料培养皿上孵育，淋巴细胞悬液中的sIgM⁺细胞被耗尽。与未分离的对照相比，在无血清培养基中培养的非贴壁细胞对刀豆蛋白A和PHA有丝分裂原反应以及混合淋巴细胞培养（MLC）反应性增强。非贴壁细胞对LPS有丝分裂原反应性部分降低。有丝分裂原反应的降低或增强不是细胞动力学或剂量反应特性变化的结果。在补充1%胎牛血清的培养物中，LPS反应未降低，而PHA反应仍增强。因此，在这种无尾两栖类动物中，胸腺依赖性和胸腺非依赖性有丝分裂原及MLC反应可以通过sIgM阳性标准来区分。
