Protection against challenge infection in the offspring mice born to immunized mother mice with schistosomulum cells

LIU Tao; WU Ning; CAI Lingting; HU Liping

doi:10.13431/j.cnki.immunol.j.20180116

Abstract：To explore the resistance against challenge infection in the two susceptible strains of the offspring mice born to mother mice immunized with schistosomulum cells. Both susceptible female Kunming strain and Balb/c strain of mice to schiostosome were immunized with Schistosomulum japonicum cells for 3 time, respectively. After mating with the corresponding strain of male mice, the offspring mice either born to immunized mothers or to untreated mothers were divided into 4 groups, A1:experiment offspring mice born to immunized Kunming strain of mother mice, B1: control offspring mice born to untreated Kunming strain of mothers, A2: experiment offspring mice born to immunized Balb/c strain of mother mice, B2: control offspring mice born to untreated Balb/c strain of mothers. About 6-8 weeks post neutralization rearing (both strains of mice in weight of 16-20 g), the two strains of offspring mice either born to immunized mothers (A1 and A2 group) or born to untreated normal mothers (B1 and B2 group) were challenged with S. j cercariae and the protection efficiency was evaluated with parasitological and immunological indicators. The worm burdens and liver egg loads collected from above 4 groups were counted and compared; The liver sections were prepared and stained with HE, and the diameters and areas of liver egg granulomas were estimated; The levels of Ig G against soluble juvenile worm antigen (SJWA) in the sera of the progenies collected at different time points were detected by ELISA. Compared with two strains of control groups B1 and B2, both strains of experiment offspring mice (A1 and A2) possessed certain level of protection against challenge infection with either Kunming strain of offspring mice exhibiting 35.6％ reduction in worm burden and 59.4％ reduction of liver egg burden or Balb/c strain of offspring mice showing 29.8％ reduction in worm burden and 47.4％ reduction in liver egg burden. The liver appearances of A1 and A2 mice were relatively normal as compared with that of control mice. At the same time, the mean diamaters and areas of granulomas in the sections of livers from A1 and A2 groups were significantly smaller than that in the sections of livers from B1 and B2 groups. Furthermore, ELISA results showed that the levels of specific Ig G against SJWA in the sera from A1 and A2 group of mice were higher than the Ig G levels in the sera from corresponding strain of control groups. By employing two susceptible strains of mice to S. j infection as models, the experiment results indicated that the mother mice immunized with live schistosomulum cells could deliver the protective immunity to next generation and make them to inherit immune protection against initial acquired challenge of Schistosoma japonicum.