Ghoneum M, Vojdani A, Banionis A, Oppenheimer S, Lagos N, Gill G
Drew University of Medicine and Science, Department of Otolaryngology, Los Angeles, CA 90059, USA.
Toxicol Ind Health. 1997 Nov-Dec;13(6):727-41. doi: 10.1177/074823379701300603.
The present study examines the effect of methylcholanthrene (MCA), a a carcinogenic polycyclic hydrocarbon, on the carbohydrate receptor determinants (RD) on natural killer (NK) cell surface using the bead-coupled lectin assay. Murine NK cells exhibited different degrees of preferential binding to the specific lectins tested. Of the ten lectins tested, five exhibited a positive binding affinity while the remaining five exhibited no or insignificant binding. NK cells bind to beads derivatized with mannose specific lectins: Concanavalin A (Con A), Lens culinaris, and Pisum sativum. NK cells also bind to other lectin beads such as Triticum vulgaris (GalNac) and Vicia villosa (D-GlcNAc). All these lectin beads exhibited greater than 90% adhesion. The underivatized control beads exhibited no NK binding. The NK cells that were exposed to MCA for 2 h demonstrated a significant decrease in lectin bead-cell coupling in a dose dependent manner. MCA (10 micrograms/mL) caused a 17.8%, 40% and 4.7% decrease in binding affinity when introduced to the mannose specific lectins; Con A, L. culinaris and P. sativum beads, respectively. The binding of T. vulgaris and V. villosa to NK cells was inhibited (23.4% and 28%) by MCA treatment. An increase in the dose to 20 micrograms/mL resulted in a greater inhibition in binding affinity towards lectin beads. Con A, 35.3%, L. culinaris, 62.6%, P. sativum, 30.9%, T. vulgaris, 44.2% and V. villosa, 46.2%. The effect of MCA activation and cytotoxic response. Hydrolysis of PI metabolites (PIP and PIP2) cause generation of secondary messenger: inositol-1,4,5-triphosphate and diacylglycerol, both of which elicit an immune response through their products (Ca2+ and PKC) respectively. Identification of the relationship between receptor level, induction of second messenger and cytotoxic activity may resolve the molecular basis of suppression of NK cytotoxicity by MCA and other PAH compounds.
本研究使用磁珠偶联凝集素测定法，检测致癌性多环烃甲基胆蒽（MCA）对自然杀伤（NK）细胞表面碳水化合物受体决定簇（RD）的影响。小鼠NK细胞对所检测的特定凝集素表现出不同程度的优先结合。在所检测的10种凝集素中，5种表现出阳性结合亲和力，其余5种则无结合或结合不明显。NK细胞与用甘露糖特异性凝集素衍生化的磁珠结合：刀豆球蛋白A（Con A）、扁豆凝集素和豌豆凝集素。NK细胞也与其他凝集素磁珠结合，如普通小麦（GalNac）和绒毛豌豆（D-GlcNAc）。所有这些凝集素磁珠的黏附率均大于90%。未衍生化的对照磁珠未显示NK细胞结合。暴露于MCA 2小时的NK细胞，其凝集素磁珠与细胞的偶联呈剂量依赖性显著降低。当加入甘露糖特异性凝集素Con A、扁豆凝集素和豌豆凝集素磁珠时，MCA（10微克/毫升）分别导致结合亲和力下降17.8%、40%和4.7%。MCA处理抑制了普通小麦和绒毛豌豆与NK细胞的结合（分别为23.4%和28%）。剂量增加到20微克/毫升导致对凝集素磁珠的结合亲和力受到更大抑制。Con A为35.3%，扁豆凝集素为62.6%，豌豆凝集素为30.9%，普通小麦为44.2%，绒毛豌豆为46.2%。MCA激活和细胞毒性反应的影响。磷脂酰肌醇代谢产物（PIP和PIP2）的水解产生第二信使：肌醇-1,4,5-三磷酸和二酰甘油，二者分别通过其产物（Ca2+和蛋白激酶C）引发免疫反应。确定受体水平、第二信使的诱导与细胞毒性活性之间的关系，可能会揭示MCA和其他多环芳烃化合物抑制NK细胞毒性的分子基础。
