Changes of DNT number in B16P10 melanoma mice and its relationship with growth

Objective To study the relationship between the changes of double negative T cells (DNT) in peripheral blood and the growth of tumor in B16F10 melanoma mice.Methods (1) Tumor-bearing mice (Babl/C) were established by inoculation of melanoma cells as experimental group,with (BI6-F10-luc-GS) (1×105 in 100 μl) injected subcutaneously into the right dorsal region near the thigh.Flow cytometry was used to detect the composition changes of lymphocyte in peripheral blood from experimental group (tumor-bearing mice,n=10) and control group (normal Babl/C mice,n=10) on Day0,Day3,Day5 and Day9,and tumor growth in experimental group were monitored by in vivo imaging [luminescence detection by In Vivo Imaging System(IVIS)]on Day0,Day3,Day5,Day7 and Day9.(2) Twenty tumor-bearing mice were randomly divided into DNT effect group (experimental group,n=10) and tumor control group (control group,n=10).DNT was separated by Aria Cell Sorter and then injected in experimental group (DNT 1×106 in 100 μl),but 100 μl PBS in control group.Then tumor growth of two groups were observed by IVIS in vivo on Day0,Day3,Day5,Day7 and Day9.Results Contrast to normal mice,in tumor-bearing (B16-F10-luc-G5) mice,DNT increased (P 0.05) of mean photon count [photon/(cm2.ser.s)]on Day0 [(6.35E+05)+7 655.4 vs (6.27E+05)±6320.0],but significant difference (P<0.05) between each two days from Day3 to Day9 [(1.22E+05)±1 820.1 vs (2.36E+05)±2 270.8,(1.10E+05)±2090.7 vs (2.67E+05)±3070.0,(2.40E+05)±3515.2vs(3.40E+05)±4352.8,(1.18E+06)±1 1530.8 vs(1.31E+06)±11 852.3].Conclusions The growth of melanoma in mice can boost the amount of DNT.The amount of DNT is positively related to tumor size,indicating that DNT could he used as one target in cancer treatment in future. Key words: T-lymphocytes; regulatory; Melanoma; Mice; inbred BALBC