GEM-PA-Based Subunit Vaccines of Crimean Congo Hemorrhagic Fever Induces Systemic Immune Responses in Mice.

The Crimean Congo Hemorrhagic Fever Virus (CCHFV) is a tick-borne bunyavirus of the Narovirus genus, which is the causative agent of Crimean Congo Hemorrhagic Fever (CCHF). CCHF is endemic in Africa, the Middle East, Eastern Europe and Asia, with a high case-fatality rate of up to 50% in humans. Currently, there are no approved vaccines or effective therapies available for CCHF. The GEM-PA is a safe, versatile and effective carrier system, which offers a cost-efficient, high-throughput platform for recovery and purification of subunit proteins for vaccines. In the present study, based on a GEM-PA surface display system, a GEM-PA based vaccine expressing three subunit vaccine candidates (G-GP, including G-eGN, G-eGC and G-NAb) of CCHFV was developed, displaying the ectodomains of the structural glycoproteins eGN, eGC and NAb, respectively. According to the immunological assays including indirect-ELISA, a micro-neutralization test of pseudo-virus and ELISpot, 5 µg GPBLP3 combined with Montanide ISA 201VG plus Poly (I:C) adjuvant (A-G-GP-5 µg) elicited GP-specific humoral and cellular immunity in BALB/c mice after three vaccinations via subcutaneous injection (s.c.). The consistent data between IgG subtype and cytokine detection, ELISpot and cytokine detection indicated balanced Th1 and Th2 responses, of which G-eGN vaccines could elicit a stronger T-cell response post-vaccination, respectively. Moreover, all three vaccine candidates elicited high TNF-α, IL-6, and IL-10 cytokine levels in the supernatant of stimulated splenocytes in vitro. However, the neutralizing antibody (nAb) was only detected in A-G-eGC and A-G-eGC vaccination groups with the highest neutralizing titer of 128, suggesting that G-eGC could elicit a stronger humoral immune response. In conclusion, the GEM-PA surface display system could provide an efficient and convenient purification method for CCHFV subunit antigens, and the G-GP subunit vaccine candidates will be promising against CCHFV infections with excellent immunogenicity.

[Comparative Observation on Electroacupuncture and Manual Acupuncture in Rabbits with Facial Nerve Injury by Electron Microscope].

OBJECTIVE: To observe the effect of manual acupuncture and electroacupuncture (EA) on ultrastructure of facial nerve Schwann cells, myelin sheath and mitochondria in facial nerve injury rabbits, so as to explore its mechanism underlying improving facial palsy. METHODS: A total of 50 New Zealand rabbits were randomly divided into normal, sham-operation, model, MA and EA groups (n=10 in each group). Facial nerve injury model was made by clamping the facial nerve for 5 min using a pair of forceps. Manual needle stimulation (mild reinforcing-reducing) or EA (continuous wave, 20 Hz) was applied to "Dicang" (ST 4), "Xiaguan" (ST 7), "Taiyang" (EX-HN 5) and "Yangbai" (GB 14) on the injured sides for 4 weeks, 30 min each day. The facial nerve motion score was performed every 7 days. The ultrastructure of facial nerve was observed by electron microscope after 28 days' treatment. RESULTS: There were no significant differences in behavioral score and ultrastructure in normal and sham-operation groups (P<0.05). Compared with the normal group, facial nerve motion scores, ultrastructural morphological changes and the number of axons per unit area, myelin sheath thickness and axon area were worse in the model group (P<0.05). After treatment, facial nerve motion scores, ultrastructural morphological changes and the number of axons per unit area, myelin sheath thickness and axon area in the two treatment groups were better than those in the model group (P<0.05), and EA worked better than MA (P<0.05). CONCLUSIONS: In the treatment of facial nerve injury, EA can promote axoplasmic mitochondrial proliferation, myelin sheath recovery and axonal regeneration more effectively than MA, which may be one of the mechanisms that EA therapy is superior to MA.