1. State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou, China;
2. Department of Experimental Research, Sun Yat-sen University Cancer Center, Guangzhou, China;
3. Department of Biotherapy, Sun Yat-sen University Cancer Center, Guangzhou, China;
4. Department of Nasopharyngeal Carcinoma, Sun Yat-sen University Cancer Center, Guangzhou, China.
* Co-first author
Background: Adoptive immunotherapy with EBV-specific CTLs (EBV-CTL) has been used to treat EBV-associated nasopharyngeal carcinoma (NPC) but only a fraction of the patients shows noticeable clinical response.
Patients and Methods: Sixty-seven newly diagnosed NPC patients from 2005 to 2007 and 21 healthy donors were collected. Immunological parameters and immune function of PBMCs and EBV-CTL were analyzed by flow cytometer analysis (FACS) and 51Cr releasing experiment; Molecular characteristics on NPC tumor cells were investigated by immunochemical staining and statistic analysis.
Results: NPC patients can be classified into two groups based on the percentage of CD3+ T cells in peripheral blood before accepted any treatment, (>52.6%, mean-2SE from healthy controls, NPC Group 1; <52.6%, NPC Group 2). The patients in Group 2 showed a significant decrease of CD3+CD8+ T-cells, CD3+CD4+ T-cells and CD3+CD45RO+ memory T cells, and increase of CD3-CD16+ NK cells compared to Group 1 patients and healthy controls (P<0.001). EBV-specific T cell responses, were weaker in this group of patients and their tumor cells expressed lower levels of the EBV encoded latent membrane protein (LMP)-1 and HLA class II protein compared with the patients of NPC Group 1 (P<0.05) .
Conclusion: These findings demonstrate that NPC patients could be distinguished on the basis of their immune status which will affect the efficacy of EBV-CTL immunotherapy.
Keywords: NPC, EBV-specific CTL, immunotherapy, LMP1, immunophenotype