Sarker Md Moklesur Rahman, Zhong Ming
Department of Immunochemistry, Division of Pharmaceutical Sciences, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Tsushima-naka, Kita-ku, Okayama, Japan ; Clinical Investigation Centre, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia.
Department of Immunochemistry, Division of Pharmaceutical Sciences, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Tsushima-naka, Kita-ku, Okayama, Japan.
Indian J Pharmacol. 2014 Jan-Feb;46(1):40-5. doi: 10.4103/0253-7613.125164.
Keyhole limpet hemocyanin (KLH) is a popular tumor vaccine carrier protein and an immunostimulant. The present study aimed to investigate the immunoregulatory activity of KLH on cytotoxicity, cytokines production, and proliferation of natural killer (NK) cells. Moreover, antiproliferative activity of KLH on Meth A sarcoma cells was studied.
Cytotoxicity was determined with killing ability of NK cells against yeast artificial chromosome (YAC)-1 cells. Interferon-gamma (IFN-γ) and tumor necrosis factor-alpha (TNF-α) productions by NK cells were measured by enzyme-linked immunosorbent assay (ELISA). Proliferations of NK and Meth A cells were determined by [(3)H]thymidine incorporated proliferation and 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) methods, respectively.
KLH at 6.25, 12.5, and 25 μg/well augmented cytotoxicity of NK cells against YAC-1 cells by 2.5, three, and five-times, respectively. KLH at 25 μg/well enhanced IFN-γ and TNF-α productions by 17- and 23-folds, respectively. The proliferation of NK cells was three times stimulated by KLH. The proliferation of Meth A cells was markedly inhibited by all the doses; the highest (4-folds higher) inhibition was observed at a dose of KLH (25 μg/well).
The study demonstrated the anticancer activity of KLH acting through the induction of NK cells and inhibition of cancer cells. KLH, therefore, may be a good candidate for an anticancer agent alone or in combination with other chemotherapeutic agents.
匙孔血蓝蛋白（KLH）是一种常用的肿瘤疫苗载体蛋白和免疫刺激剂。本研究旨在探讨KLH对自然杀伤（NK）细胞的细胞毒性、细胞因子产生及增殖的免疫调节活性。此外，还研究了KLH对Meth A肉瘤细胞的抗增殖活性。
通过NK细胞对酵母人工染色体（YAC）-1细胞的杀伤能力测定细胞毒性。采用酶联免疫吸附测定（ELISA）法检测NK细胞产生的γ干扰素（IFN-γ）和肿瘤坏死因子-α（TNF-α）。分别采用[³H]胸腺嘧啶掺入增殖法和3-[4,5-二甲基噻唑-2-基]-2,5-二苯基四氮唑溴盐（MTT）法测定NK细胞和Meth A细胞的增殖。
每孔6.25、12.5和25 μg的KLH分别使NK细胞对YAC-1细胞的细胞毒性增强2.5倍、3倍和5倍。每孔25 μg的KLH分别使IFN-γ和TNF-α的产生增加17倍和23倍。KLH使NK细胞的增殖受到3倍的刺激。所有剂量的KLH均显著抑制Meth A细胞的增殖；在KLH剂量为每孔25 μg时观察到最高抑制率（高4倍）。
该研究证明了KLH通过诱导NK细胞和抑制癌细胞发挥抗癌活性。因此，KLH单独或与其他化疗药物联合使用可能是一种很好的抗癌药物候选物。
