动物造模 z-bio 2022-07-25 343

　　Objective: To investigate the regulatory effect of human alpha interferon (IFN-α) gene on the immune function of mice after oral administration of Bifidobacterium transformed.

　　Methods: The E. coli-Bifidobacterium shuttle expression vector pBADX-hIFNα2b containing human IFN-α gene was constructed, and the IFN-α gene was obtained by electroporation to transform the bifidobacteria, and the cells after L-arabinose-induced hIFN-α2b expression were collected and prepared The viable bacterial suspension was gavaged into Balb/C mice. The mice in the experimental group (IFN) were treated with bifidobacteria transformed with hIFN-α2b after inducible expression by 0.2% L-arabinose, and each mouse was intragastrically administered with 0.1 ml of 1010/ml viable bacteria; the negative control group (NC) was treated with the same amount, etc. The volume of empty vector pBADX transformed the viable bifidobacteria by intragastric administration; the blank control group (BC) was intragastrically administered with an equal volume of normal saline. Gavage once every other day, continuous treatment for 2 weeks. The lymphocyte subsets and proportions in the thymus, spleen and blood of mice were detected by flow cytometry, and the contents of IFN-γ, IL-4 and other immune factors were detected by flow cytometry.

　　Results: Compared with the NS group and the BC group, the proportions of CD3+CD8+ and CD4+CD8+ cells in the thymus of mice in the IFN group were significantly increased (P<0.01); the proportions of CD3+CD4+, CD3+CD8+ and CD4+CD8+ cells in the spleen were significantly increased (P<0.01); only the proportion of CD3+CD8+ cells in the blood was significantly increased (P<0.01). The content of IFN-γ in the blood of the IFN group was significantly higher than that of the BC group and the NS group (P<0.01); in addition, the content of IFN-γ in the NS group was significantly higher than that in the BC group (P<0.05). there="" was="" no="" significant="" difference="" in="" the="" concentrations="" of="" 2b="" and="" il-4="" blood="" p="">0.05).

　　Conclusion: Oral administration of hIFN-α-transformed bifidobacteria can promote the proliferation and maturation of mouse thymus and spleen lymphocytes, and increase the level of Th1 cytokines in blood.