Lymphocytes were obtained from tumor and spleen tissues for phenotype analysis. Spleen and tumor lymphocytes were isolated from fresh spleen and tumor biopsies obtained from three mice per group. Spleen and tumor biopsies were briefly homogenized mechanically in PBS, filtered (100 µm cell strainer; BD PharMingen) and then placed in lysis buffer (ACK lysing buffer, LONZA) to remove red blood cells. One million splenocytes were washed once in PBS containing 1% bovine serum albumin (BSA) and re-suspended in 100 µl of PBS/BSA buffer. Meanwhile, one million cells obtained from tumor tissues were placed in RPMI medium, incubated to obtain suspension cell for 1hour at 37°C, centrifuged (1200 rpm, 3 min) and then washed in PBS. Next, the lymphocytes were incubated with various conjugated monoclonal antibodies, including CD4-APC, CD8-FITC and CD19-PE for 20min at 4°C, washed twice in PBS, and re-suspended in 400 µl of PBS. A flow cytometric analysis was performed on a FACSAria flow cytometry (BD Biosciences), and the data were analyzed using the WinMDI statistical software (Scripps, La Jolla, CA, USA). Forward and side scatter parameters were used to gate on lymphocytes.