Increased frequency of Foxp3+ regulatory T cells in mice with hepatocellular carcinoma

• Published in: Asian Pacific journal of cancer prevention : APJCP Vol. 13; no. 8; pp. 3815 - 3819
• Main Authors: Du, Yong, Chen, Xin, Huang, Zhi-Ming, Ye, Xiao-Hua, Niu, Qing
• Format: Journal Article
• Language: English
• Published: Thailand 01.01.2012
• Subjects: Animals; Carcinoma, Hepatocellular - immunology; Carcinoma, Hepatocellular - metabolism; Carcinoma, Hepatocellular - pathology; Cells, Cultured; Flow Cytometry; Forkhead Transcription Factors - metabolism; Granzymes - metabolism; Liver Neoplasms - immunology; Liver Neoplasms - metabolism; Liver Neoplasms - pathology; Lymphocytes, Tumor-Infiltrating - immunology; Lymphocytes, Tumor-Infiltrating - metabolism; Lymphocytes, Tumor-Infiltrating - pathology; Male; Mice; Mice, Inbred BALB C; Spleen - immunology; Spleen - metabolism; Spleen - pathology; T-Lymphocyte Subsets - immunology; T-Lymphocyte Subsets - metabolism; T-Lymphocyte Subsets - pathology; T-Lymphocytes, Regulatory - immunology; T-Lymphocytes, Regulatory - metabolism; T-Lymphocytes, Regulatory - pathology
• ISSN: 1513-7368; 2476-762X
• DOI: 10.7314/APJCP.2012.13.8.3815

The CD4+CD25+ regulatory T cell (Treg) is a special kind of T cell subset. Studies have showed that Treg cells are involved in a number of physiological processes and pathologic conditions such as autoimmune diseases, transplantation tolerance and cancer. Tregs with unique capacity for immune inhibition can impair anti-tumour immunity and help tumor cells to escape from immune surveillance. The aim of our study was to investigate whether Tregs are involved in hepatocellular carcinoma (HCC). A BABL/C mouse with HCC in situ model was established to evaluate the Treg existence in carcinoma tissues and the changes of Tregs in spleen using flow cytometry and immunohistochemistry methods. Granzyme B expression in carcinoma tissues was analyzed by immunohistochemistry to investigate the tumor local immune status. The proportion of CD4+CD25+/CD4+ spleen lymphocytes of tumor bearing mice (18.8% ± 1.26%) was found to be significantly higher than that in normal mice (9.99% ± 1.90%) (P<0.01 ). Immunohistochemistry of spleen tissue also confirmed that there was an increase in Treg in tumor-bearing mice, while in carcinomas it showed Treg cells to be present in tumor infiltrating lymphocyte areas while Granzyme B was rarely observed. Anti-tumour immunity was suppressed, and this might be associated with the increase of Tregs. Our observations suggest that the CD4+CD25+Treg/ CD4+ proportion in spleen lymphocytes can be a sensitive index to evaluate the change of Tregs in hepatocellular carcinoma mice and the Treg may be a promising therapeutic target for cancer.