IMMUNOREGULATION OF MYELOMA CELL DIFFERENTIATION

B淋巴细胞通过增殖和分化为 分泌抗体的浆细胞 这种反应可以被增强或抑制 通过抗原特异性T辅助（TH）或T抑制（TS）细胞， 分别 TNP特异性IgA315- 分泌MOPC-315骨髓瘤血浆 细胞由恶性的小的，非分泌的 淋巴细胞样干细胞这些细胞的增殖和分化 干细胞可以由载体特异性TH的不同亚群调节， TS细胞。 我感兴趣的是确定其中的生化变化 MOPC-315细胞分泌分化的激活和抑制。 直到纯化的辅助和抑制调节因子可从 我的单克隆分化辅助和抑制T细胞系， 研究;（1）MOPC-315分化是否可以通过 胸腺非依赖性抗原TNP-LPS（E. coli055：B5脂多糖）， 以及（2）这种调节的代谢要求是什么。 我发现，虽然未结合或FITC结合的LPS对315 当以低于10微克/ml的剂量加入时， 在体外，观察到315细胞PFC频率显著增加， 从0.001 - 0.1微克/毫升TNP-LPS和315细胞的显著抑制 在1.0微克/ml TNP-LPS下诱导抗TNP IgA PFC频率。 这些 如果单克隆抗独特型抗体315 抗体或 培养液中含有DNP-glycine，表明TNP-LPS 表面膜IgA结合315 是必需的。 刺激剂量 的TNP-LPS必须仅存在于前2小时以获得最大的 培养开始后48小时测量增强。 抑制剂量 TNP-LPS作用24小时后，PFC的抑制作用达到最大 频率和对辅助性T细胞刺激的最大无反应性 分泌分化这种无反应性一旦诱导，持续5 - 7 天 在用刺激剂量的 TNP-LPS，一种丝氨酸酯酶被激活，这是PFC所必需的 频率增强 这种丝氨酸酯酶活性需要磷脂 在TNP-LPS温育的前15分钟内，诱导甲基化。 抑制剂量的TNP-LPS不会引起这些变化，但会改变细胞的功能。 315细胞代谢，使得随后的培养物中含有0.01微克/ml TNP-LPS不增加PFC频率和丝氨酸酯酶， 磷脂甲基化不发生。 我正在继续这些研究， 我开始确定细胞核、细胞质和 使用2D凝胶电泳检测膜蛋白磷酸化。 （LB）

B lymphocytes respond to antigen by proliferating and differentiating into antibody-secreting plasmacytes. That response can be enhanced or inhibited by antigen-specific T-helper (TH) or T-suppressor (TS) cells, respectively. The TNP-specific IgA315-secreting MOPC-315 myeloma plasma cells arise by differentiation from malignant small, nonsecretory lymphocytoid stem cells. The proliferation and differentiation of those stem cells can be regulated by distinct subsets of carrier-specific TH and TS cells. I was interested in determining the biochemical changes involved in activation and suppression of MOPC-315 cell secretory differentiation. Until purified helper and suppressor regulatory factors were available from my monoclonal differentiation helper and suppressor T-cell lines, I investigated; (1) whether MOPC-315 differentiation could be modulated by the thymus-independent antigen TNP-LPS (E. coli 055:B5 lipopolysaccharide), and (2) what some of the metabolic requirements were for that modulation. I found that while unconjugated or FITC-conjugated LPS had no effect on 315 cell differentiation when added at doses lower than 10 micrograms/ml in vitro, significant enhancement of 315 cell PFC frequency was observed with from 0.001-0.1 micrograms/ml TNP-LPS and significant inhibition of 315 cell anti-TNP IgA PFC frequency was induced at 1.0 micrograms/ml TNP-LPS. These low dose effects were blocked if monoclonal anti-idiotype315 antibody or DNP-glycine were included in the culture media implying that TNP-LPS engagement of surface membrane IgA315 was required. The stimulatory dose of TNP-LPS had to be present for only the first 2 hrs to get maximal enhancement measured 48 hrs after culture initiation. The inhibitory dose of TNP-LPS had to be present 24 hrs to get maximal inhibition of PFC frequency and maximal unresponsiveness to helper T-cell stimulation of secretory differentiation. This unresponsiveness once induced lasted 5-7 days. Within the first 1 hr of culture with the stimulatory dose of TNP-LPS, a serine esterase is activated which is required for the PFC frequency enhancement. This serine esterase activity requires phospholipid methylation within the first 15 min of TNP-LPS incubation to be induced. The inhibitory dose of TNP-LPS does not induce these changes but alters the 315 cell metabolism such that subsequent culture with 0.01 micrograms/ml TNP-LPS does not enhance PFC frequency and the serine esterase and phospholipid methylation does not occur. I am continuing these studies and am beginning to determine temporal changes in nuclear, cytoplasmic, and membrane protein phosphorylation using 2D gel electrophoresis. (LB)