ABSTRACT
Objective To explore the immunoregulatory and lethal effects of natural killer T lymphocytes(NKTs) in vitro .Meth‐ods The mixed lymphocyte cultured(MLC) system was established ,in which the B16F10‐luc‐G5 cells were set as target cells ,the total lymphocyte cells were set as effector cells .(1)In the experiment on immunoregulatory effects ,NKT lymphocytes or CD4+CD25+ T lymphocytes were set as regulating cells ,there was three groups ,including the NKT group ,CD4+CD25+ T group and pure target cell control group .Otherewise ,the 1640 blank control group was set by only adding RPMI1640 solution .(2)In the ex‐periment on antitumor effects ,the NKT or natural killer(NK) lymphocytes were set as killer cells ,there was three groups ,inclu‐ding the NKT group ,NK group and pure target cell control group .Mixed culturing 24 ,48 and 72 hours ,the bioluminescence of target cells in MCL system was detected by using the in vivo imaging system .Results (1)In the experiment on immunoregulatory effects ,there were statistically significant differences in measured average photon numbers between NKT group ,CD4+ CD25+ T group and the two control groups(P<0 .05) .The statistically significant differences were also found in the NKT group between 24 hours and 72 hours (P<0 .05) .(2)In the experiment on antitumor effects ,there were statistically significant differences in meas‐ured average photon numbers ,when the NKT group and NK group were compared to the pure target cell control group(P<0 .05) . After culturing 24 and 72 hours ,statistically significant differences were found between NKT group and NK group(P<0 .05) .Con‐clusion The NKT cells could inhibit the lethal effects of lymphocyte cells on target cells ,and the inhibitory effects are changed by the length of culturing .Compared with the CD4+CD25+ T lymphocytes ,NKT lymphocytes have strongger regulatory effects .Addi‐tionally ,the NKT cells have lethal effects on target cells ,which might be weaker than that of NK cells .