Y Liu1, M Xu1, Z Su1, Y Cai1, G Zhang1, H Zhang1. 1. Microbiology Resources, Institute of Applied Ecology, Chinese Academy of Science, Shenyang, China College of Resource and Environment, Graduate University of Chinese Academy of Sciences, Beijing, China Center for Drug Evaluation and Research, Tianjin Institute of Pharmaceutical Research, Tianjin, China.
Abstract
AIMS: To investigate the improved antitumour activity of SAM-3 compared with recombinant staphylococcal enterotoxins C2 (rSEC2). METHODS AND RESULTS: Methylthiazol tetrazolium and flow cytometry assays showed that the antitumour activity of SAM-3 in vivo was improved because of enhanced T-cell stimulating potency, resulting in massive activation of T cells, particularly CD4(+) and CD8(+) T cells, and subsequent cytokine release. Quantitative real-time PCR assay showed that despite similar Vβ specificities induced by rSEC2 and SAM-3, the quantities of activated T cells bearing specific Vβin vitro were different. CONCLUSIONS: The results strongly suggested that the increased SAM-3-T-cell receptor (TCR) binding affinity contributed to massive T-cell activation and cytokine release, substantially amplifying antitumour immune response in vivo. SIGNIFICANCE AND IMPACT OF THE STUDY: This study provided evidence for the mechanism of SAM-3 antitumour activity improvement compared with rSEC2. Results indicated that SAM-3 could be used as a potent powerful candidate agent for tumour treatment in clinics.
AIMS: To investigate the improved antitumour activity of SAM-3 compared with recombinant staphylococcal enterotoxins C2 (rSEC2). METHODS AND RESULTS:Methylthiazol tetrazolium and flow cytometry assays showed that the antitumour activity of SAM-3 in vivo was improved because of enhanced T-cell stimulating potency, resulting in massive activation of T cells, particularly CD4(+) and CD8(+) T cells, and subsequent cytokine release. Quantitative real-time PCR assay showed that despite similar Vβ specificities induced by rSEC2 and SAM-3, the quantities of activated T cells bearing specific Vβin vitro were different. CONCLUSIONS: The results strongly suggested that the increased SAM-3-T-cell receptor (TCR) binding affinity contributed to massive T-cell activation and cytokine release, substantially amplifying antitumour immune response in vivo. SIGNIFICANCE AND IMPACT OF THE STUDY: This study provided evidence for the mechanism of SAM-3 antitumour activity improvement compared with rSEC2. Results indicated that SAM-3 could be used as a potent powerful candidate agent for tumour treatment in clinics.