GU Yujie;WANG Ruibai;JIANG Jingwei;ZHAO Xiuqin;LIU Haican;WAN Kanglin;XU Da;National Institute for Communicable Disease Control and Prevention,Chinese Center for Disease Control and Prevention;Objective To preliminarily analyze the immunogenicity of Mycobacterium massiliense(M. massiliense) whole-cell lysate proteins in order to provide a basis for the application of M. massiliense-based immunology.Methods The whole-cell protein of M. massiliense was extracted by ultrasonic disruption and used to immunize BALB/c mice subcutaneously,either alone or mixed with DP adjuvant [a mixture of dimethyl dioctadecyl ammonium bromide(DDA) and polyinosinic-polycytidylic acid(PolyI:C)],and the control mice were injected with an equal amount of sterile PBS for a total of three times with an interval of 14 d,with eight mice for each group.Two weeks after the final immunization,the blood and spleen samples were collected and the antibody levels of IgG,IgG1,and IgG2a in serum were analyzed by ELISA.The levels of IL-2,IFN-γ,TNF-α,IL-12,granulocyte-macrophage colony stimulating factor(GM-CSF),IL-17A,IL-4,IL-6 and IL-10 secreted by mouse sensitized spleen lymphocytes were detected by Luminex technique,and the effect on TCM(central memory T cells)/IFN-γ~+cells in mouse spleen lymphocytes was measured by flow cytometry.A growth inhibition experiment was performed to evaluate the effect of bacterial protein immunization on the replication of Mycobacterium tuberculosis(M. tuberculosis) H37Rv in mouse spleen lymphocytes.Results IgG,IgG1 and IgG2a serum antibodies in mice were induced by both the bacterial protein and protein-adjuvant complexes.Compared with the control group,IL-12 secretion levels by spleen lymphocytes of mice immunized with bacterial protein and protein-adjuvant complexes had no significant change(0.60≤t≤2.41,each P>0.05).The levels of IFN-γ,TNF-α,IL-2,IL-4,IL-6,IL-10,GM-CSF and IL-17 secreted by spleen lymphocytes of mice immunized with protein-adjuvant complexes increased significantly(3.77≤t≤23.46,each P <0.05) after bacterial protein and purified protein derivative(PPD) stimulation.In mice immunized with bacterial protein,stimulation with bacterial protein and PPD resulted in a significant rise in IL-2 and IL-4 secretion(5.36≤t≤13.26,each P <0.05),whereas TNF-α secretion increased significantly only after PPD stimulation(t=4.15,P <0.05).IL-10 secretion decreased significantly after stimulation(t=3.04 and 4.10,respectively,each P <0.05),and IL-6 secretion increased significantly only after bacterial protein stimulation(t=8.34,P <0.05).Compared with the control group,the proportion of CD4~+TCM/IFN-γ~+ and CD8~+TCM/IFN-γ~+ cells in spleen lymphocytes of mice immunized with protein-adjuvant complexes increased significantly after being stimulated by PPD and bacterial protein(2.63≤t≤5.96,each P<0.05).Compared with the control group,there was no significant difference in the proliferation of M. tuberculosis H37Rv in the spleen lymphocytes of mice immunized with bacterial protein and protein-adjuvant complexes(t=2.29 and 1.10,respectively,each P> 0.05).Conclusion The bacterial protein of M. massiliense has good immunogenicity,which can induce the tendency of Th2-type immune response,and combined with adjuvant to enhance cellular immune response,it can improve the level of induced cellular immune response.
2025 06 v.38 [Abstract][OnlineView][Download 984K]