This study performed to determine whether OX40L overexpressed by recombinant rabies virus(LBNSE-OX40L)can enhance the innate immune response through activation of dendritic cells and thus activate early antibody production.Bone marrow dendritic cells(BMDCs)were extracted from the femur of Balb/c mice and cultured for 6 days,and the cultured BMDCs were infected with the parental virus LBNSE and the recombinant virus LBNSE-OX40L with the multiplicity of infections(MOI)=1.The effect of each virus on the maturation of BMDCs was analyzed by flow cytometry;ELISA was used to detect the expression of innate immunity-related cytokines such as interferon-α(IFN-α)and interleukin-12p40(IL-12p40)in the supernatants of the infected BMDCs.For in vivo study,Balb/c female mice were injected intramuscularly with 106 FFU of parental virus LBNSE and recombinant virus LBNSE-OX40L in both hind limbs,and the inguinal lymph nodes of mice were collected on day 6 after immunization,and the proportion of mature DCs was detected by flow cytometry.The serum was collected on day 6 after immunization,and the content of virus-neutralizing antibody(VNA)was detected by antiviral neutralizing antibody titration.Mouse serum was collected on day 6 after immunization,and virus neutralizing antibody content was measured by titration of antiviral neutralizing antibody,while IgG antibody in mouse serum was detected by ELISA.IgM antibody subclasses were detected by ELISA on days 2,4,and 6 after immunization.Compared with the parental virus LBNSE,the recombinant virus LBNSE-OX40L was able to activate more BMDCs in vitro and produce significantly higher levels of IFN-α and IL-12p40.Furthermore,the recombinant virus LBNSE-OX40L stimulated the maturation and differentiation of the DCs in vivo,which led to the rapid production of high levels of VNA and RABV-specific IgG and IgM antibodies.Taken together,LBNSE-OX40L activates dendritic cells to promote the body's innate immune response,and in turn enhances early antibody production,thus can be an early effective rabies vaccine candidate.