人IL_2活性测定及其影响因素的探讨

作者建立了小鼠胸腺细胞MTT比色分析法并检测了33份正常人的IL_2活性。探讨了影响人IL_2活性测定的因素并与~3H-TdR掺入法进行比较。结果表明,该法简便,稳定,可行,与~3H-TdR掺入法比较二者有较好的一致性,认为本法可用于临床IL_2样本的检测。     

脾脏切除对胸腺和淋巴结免疫功能的影响

报道脾脏切除（脾切）对动物胸腺和淋巴结免疫功能的影响，脾切后３ｗ大鼠胸腺细胞自发增殖及ＣｏｎＡ诱导增殖均无明显变化，ＣｏｎＡ诱导淋巴结细胞增殖脾切组明显高于假手术对照组，脾切后３ｗ再用ＳＲＢＣ免疫，５ｄ后小鼠腹腔淋巴结数量脾切明显高于对照组，用ＱＨＳ法测定淋巴结细胞对ＳＲＢＣ初次抗体产生脾切组则明显低于对照组。     

老年人长跑锻炼后血浆白细胞介素—1活性的变化

用刺激C_(57)小鼠胸腺细胞增生后H-TdR参入量的多少来表示IL-1活性的方法,研究长跑锻炼对老年人血浆白细胞介素-1(IL-1)活性的影响。结果表明,长跑锻炼10年以上老年人安静时血浆IL-1活性在14.7～18.7KD、3.8～7.0KD、1.5～2.6KD呈现三个淋巴细胞增生峰,分別为对照组老年人的214％、179％和146％(以对照组为100％)。对这种改变的机制和生理意义进行了讨论。     

MTEC 1分泌的趋化因子引起特定亚群胸腺细胞的定向迁移

分析胸腺髓质上皮样细胞系ＭＴＥＣ１分泌的化学趋化因子对胸腺细胞亚群的趋化作用。方法以抗体加补体杀伤结合免疫磁珠及ｐａｎｎｉｎｇ法，将小鼠胸腺细胞分离纯化，获得ＣＤ４＋ＣＤ８＋（ＤＰ），ＣＤ４－ＣＤ８－（ＤＮ），ＣＤ４＋ＣＤ８－（ＣＤ４ＳＰ）及ＣＤ４－ＣＤ８＋（ＣＤ８ＳＰ）四亚群细胞，用Ｂｏｙｄｅｎ小室分析ＭＴＥＣ１┐ＳＮ对四群胸腺细胞的趋化作用。结果ＭＴＥＣ１┐ＳＮ对ＤＰ及ＣＤ４ＳＰ胸腺细胞有趋化活性（ＣＩ＝６．６±１．０及６．１±１．８）；对ＣＤ８ＳＰ细胞有中度趋化活性（ＣＩ＝３．２±１．０）；对ＤＮ趋化活性微弱（ＣＩ＝１．３±０．６）。化学趋化因子ＭＣＰ┐１纯品对ＣＤ４ＳＰ胸腺细胞显示强趋化活性（ＣＩ＝５．６），对ＤＮ胸腺细胞则无可测出趋化活性。结论ＭＴＥＣ１分泌的化学趋化因子对ＤＰ，ＣＤ４ＳＰ及ＣＤ８ＳＰ胸腺细胞有显著趋化作用，对ＤＮ胸腺细胞几乎无趋化作用。提示此类化学趋化因子有趋使胸腺发育中后期阶段的细胞向胸腺髓质区迁移和定位的作用。     

The RhoA- and CDC42-specific exchange factor Dbs promotes expansion of immature thymocytes and deletion of double-positive and single-positive thymocytes

Specific members of the Rho family of GTPases exert unique influences on thymocyte proliferation, differentiation and deletion. Dbs is a guanine nucleotide exchange factor which is expressed throughout thymocyte development and is able to activate the Rho family GTPases CDC42, RhoA and RhoG. Transgenic mice expressing an activated form of Dbs had increased numbers of double-negative thymocytes. The Dbs transgene promoted expansion of double-negative thymocytes in the absence of pre-TCR, but had no effect on pre-TCR-dependent differentiation of double-negative thymocytes into double-positive thymocytes. Transgenic double-positive thymocytes were proliferative in vivo, but were also susceptible to apoptosis in vivo and in vitro. The transgenic single-positive thymocytes had attenuated proliferative responses following TCR ligation, and were depleted rather than expanded during culture in the presence of anti-CD3. When expressing a positively selectable TCR, transgenic double-positive thymocytes were increased in number and activated, but the output of single-positive thymocytes was reduced. Transgenic double-positive thymocytes were acutely sensitive to deletion by TCR ligation in vivo. These results indicate that activation of Dbs has the potential to promote proliferation throughout thymocyte development, but also sensitizes double-positive and single-positive thymocytes to deletion.     

WUT6-抗人胸腺细胞共同性分化抗原来交瘤细胞系的建立

本文报导了用人胎儿胸腺细胞免疫BALB/c小鼠,取其脾细胞与小鼠骨髓瘤细胞系NS-1融合,获得一株能稳定分泌抗人共同性胸腺细胞单克隆抗体的杂交瘤细胞株,W_(?)T_(?)。它与72％胸腺细胞、皮肤Langerhan's细胞及部分T细胞系呈阳性反应;外周血T、D细胞、粒细胞、红细胞、血小板及B细胞系、Null细胞系均阴性。FACS检测结果及W_(?)T_(?)阳性细胞的组织分布特点均同HIT_6相似。在胸腺、皮质细胞及髓质中少数胞体较大呈树突状的细胞呈阳性反应。在扁桃体实质中少数散在细胞阳性。上皮基底层中的Langerhan's细胞则呈强阳性反应。用W_(?)T_(?)亲和层析柱提取胸腺细胞膜上相应的靶抗原分子,证明W_(?)T_(?)识别分子量为51KDa的抗原。免疫竞争抑制试验表明,W_(?)T_(?)同抗原的结合可被HIT_6完全阻断。说明W_(?)T_(?)与HIT_6识别相同的抗原决定簇。     

Differential expression of APO-1 on human thymocytes: Implications for negative selection?

Negative selection during T cell ontogeny involves selective induction of apoptosis in thymocytes. In peripheral lymphoid cells, apoptosis may be mediated via the APO-1 pathway. Here we report that APO-1 is constitutively expressed on the vast majority of human thymocytes but down-regulated at a mature stage of thymocyte development (TCR^hi). This stage of development is characterized by CD28^hi, CD44^hi, CD69^hi and up-regulation of Bcl-2 protein. We define a new thymocyte subpopulation that expresses high levels of APO-1 and intermediate levels of T cell receptor α/β (TCR^im/APO-1^hi). The TCR^im/APO-1^hi population contains a large fraction of dead cells, suggesting that the APO-1 pathway may be involved in negative selection of at least a fraction of thymocytes after intrathymic activation.     

胸腺细胞凋亡的研究进展

就目前在胸腺细胞凋亡这一方面的国内外研究进展作一简要综述。     

原位末端标记检测实验性变态反应性神经炎胸腺细胞的凋亡

目的为了探讨地塞米松对实验性变态反应性神经炎（ＥＡＮ）小鼠胸腺细胞的影响。方法应用原位末端标记法和电镜检测ＥＡＮ小鼠胸腺细胞的凋亡。结果以上两种方法均发现地塞米松处理组胸腺细胞凋亡率明显高于自然病程组和正常对照组。结论地塞米松可明显增强ＥＡＮ小鼠胸腺细胞凋亡。