IMMUNOREGULATION OF MYELOMA CELL DIFFERENTIATION

B淋巴细胞对抗原的反应是通过增殖和分化为 分泌抗体的浆细胞。这种反应可以增强或抑制 通过抗原特异性T辅助细胞(TH)或T抑制细胞(TS)， 分别进行了分析。分泌TNP特异性IgA315的骨髓瘤MOPC-315血浆 细胞是由恶性的无分泌性小细胞分化而来的 淋巴样干细胞。成纤维细胞的增殖和分化 干细胞可以由不同的携带者特异性TH和TH亚群调节 TS细胞。我对确定其中涉及的生化变化很感兴趣 激活和抑制MOPC-315细胞的分泌分化。 直到纯化的辅助因子和抑制因子可从 我的单克隆性分化辅助和抑制T细胞系 研究；(1)MOPC-315分化是否受 胸腺非依赖性抗原TNP-LPS(E.Coli055：B5脂多糖)， 以及(2)这种调节的某些代谢需求是什么。 我发现，虽然未结合或FITC结合的内毒素对315细胞没有影响 当添加剂量低于10微克/毫升时，细胞分化 在体外，观察到315细胞的PFC频率显著增加 0.001-0.1微克/mlTNP-内毒素对315细胞的明显抑制作用 1.0微克/mlTNP-内毒素可诱导产生抗TNP-IgA PFC频率。这些 如果抗独特型315的单抗或 培养基中含有DNP-甘氨酸，表明TNP-内毒素 需要结合表面膜IgA315。刺激性剂量 只需在最初的2小时内存在即可达到最大 在培养开始48小时后测量增强。抑制剂量 TNP-LPS必须存在24小时才能最大限度地抑制PFC 辅助性T细胞刺激的频率和最大无反应性 分泌分化。这种曾经引起的无反应持续了5-7天 几天。在培养的第一个小时内，用刺激量 TNP-LPS，PFC所需的丝氨酸酯酶被激活 频率增强。这种丝氨酸酯酶活性需要磷脂 在TNP-LPS孵育的前15分钟内诱导甲基化。 抑制剂量的TNP-内毒素不会引起这些变化，但会改变 315细胞代谢使后续培养浓度为0.01微克/毫升 TNP-内毒素不增加PFC频率和丝氨酸酯酶和 磷脂甲基化不会发生。我正在继续这些研究，并且 AM开始确定细胞核、细胞质和 膜蛋白的二维凝胶电泳法磷酸化。(磅)

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)