The dynamic observation of the levels of IL-2,IL-5 and IL-6 produced by Balb/c mice infected with Dengue Virus type II clinic strain

Objective To observe the dynamic levels of IL-2,IL-5 and IL-6 produced by Balb/ c mice infected with DEN_2 clinical strains and to study their relation.Methods The Balb/c mouse in- feetion model was established by multiple-site subcutaneous injection with various doses of DEN_2 clini- cal strain.Mouse plasma samples collected from different experiment groups at various time after in fection were tested for IL-2,IL-5 and IL-6 levels with sandwich ELISA.Results After primary in- feeted with DEN_2 B strain,the levels of IL-2,IL-5 and IL-6 of all experimental groups were not sig- nificantly higher than the normal control group while the levels of experimental groups increased sig- nificantly after re-infection.The level of IL-2 reached to peak[average value of(101 522.44±10 465.375)pg/ml]at the 4th day after re-infection(the 20th day after the primary infection),and then the level gradually reduced.The levels of IL-5 in the Balb/c mice of the group 1 and 2 reached to peak at the 1st day after re infection(the 16th day after the primary infection),and there was signifi- cant difference between these two groups and the control group(P＜0.05).The levels of IL-6 in all experimental groups reached to peak at the 1st and the 2nd day after re-infection.The peak value of the third group is the highest comparing with the normal control group(P＜0.05).Conclusion Th2 response was predominant in the second infection phase.