Construction And Immunogenicity Investigation Of Recombinant Rabies Virus Expressing Mice CXCL13

Rabies, a fatal zoonosis, occurs in more than 150 countries and regions. Currently, vaccination is still the most convenient and effective way to prevent and control rabies,therefore exploring a rabies vaccine with high safety, efficiency and low price is urgently needed.CXCL13, a chemokine interacting with its receptor CXCR5, can attract mature B lymphocytes and T follicular helper cells(T_FH) into the secondary lymphoid follicles.It can promote the developing of the Germinal center（GC） and Germinal center B cell（GC B） as well as the production of high affinity antibodies, and participate in the immune response.As the importance of the CXCL13, we research the role in developing the immune response in RABV infection by rescuing the LBNSE-CXCL13 and constructing the mouse infection model.The results are shown as follows:1. No significant difference was observed between the growth kinetics of LBNSE-CXCL13 and LBNSE on BSR or NA cells, indicating the expression of CXCL13 did not affect the LBNSE-CXCL13’s proliferation in vitro;2. Pathogenicity and clinical signs of the mice infected with LBNSE-CXCL13 by the i.m. route was similar to the LBNSE, and there is no death in the experiment;3. The mice immunized with LBNSE-CXCL13 have a significantly higher level VNA than those immunized with LBNSE-GM-CSF or LBNSE during 2-6 weeks, and the level of the VNA still higher than 0.5 IU/ml at 9th week in all three groups;4. Compared with LBNSE, LBNSE-CXCL13 could significantly stimulate the activation of bmDC in vitro, but failed to activate more DCs than that immunized with LBNSE-GM-CSF either in the blood or lymph nodes at 3 or 6 days post immunization in vivo;5. GC B and T_FH cells in the spleens and lymph nodes of the mice challenged with LBNSE-CXCL13 were significantly activated at the 7th or 14 th day post immunization compared with that immunized with LBNSE-GM-CSF6. LBNSE-CXCL13 could provide a better protection for mice（95%） than that of LBNSE（50%） or LBNSE-GM-CSF（70%） after challenged with 50 LD50 CVS-24 at 2th week.In summary, our study demonstrated that LBNSE-CXCL13 could significantly stimulate the mice to produce a higher level of VNA and provided a better protection, indicating that LBNSE-CXCL13 could be an promising rabies vaccine candidate.