Treatment Of Rabies With Adeno-associated Virus Expressing Virus-neutralizing Antibody

Rabies is a fatal zoonotic disease caused by rabies virus(RABV).Approximately 59,000 people die of rabies every year worldwide,posing a serious threat to human life and health and the global economy.Rabies virus has a long incubation period and proliferates after entering the central nervous system(CNS).At present,there is no effective treatment method for rabies.Once the symptom occurs,the mortality rate is close to 100%,posing a major threat to human life and health.Current recommended therapy is the combination therapy of rabies immunoglobulin(RIG),rabies vaccine,antiviral drugs and interferon alpha.However,depending on the patient’s infection status,treatment time after onset,and different clinical symptoms,the therapy is still in the exploratory stage.The major difficulty in treatment is that the flow rate of cerebrospinal fluid is relatively fast,and RIG stays in the brain for a limited time and requires multiple consecutive administrations.Focused on the shortcomings of the existing treatment method,this study proposes to use the long-acting expression AAV system to overexpress the rabies antibodies CR57 and CR4098 to help patients clearing RABV from the human body.(1)We constructed and packaged the AAV recombinant virus that overexpressed the rabies antibodies CR57 and CR4098,and verified the expression of the antibodies in vivo and in vitro.And through flow cytometry analysis,AAV-CR57 does not need to undergo a humoral immune response,and can directly express long-term rabies antibodies in the body,providing a new vaccine immunization program for patients with congenital immunodeficiency.(2)A mouse infection model was constructed to simulate natural infection.After 4 days of intramuscular injection of the RABV street virus strain DRV-mexico into the hind limbs,the AAV recombinant virus was delivered to the mouse brain by a single intracranial injection.The survival rate of mice in the AAV-CR57 group was increased to 70%,and the survival rate of mice in the control group was 0%.Since the intracranial treatment plan cannot be realized on the human body,the treatment plan is further explored.(3)It has been reported in the literature that inserting 9 amino acid sequences at positions 587 and 588 of the AAV capsid protein can enhance the ability of AAV to cross the blood-brain barrier(BBB)through tail vein injection.However,in the mouse infection model,tail vein injection on the 4th day did not improve the survival rate of mice.(4)A rat cerebrospinal fluid treatment model was constructed,and DRV-mexico was injected into the hind limbs of the rats.On the 4th day after infection,AAV-CR57 was delivered into the rat brain by a single injection through cerebrospinal fluid.The survival rate of rats was increased to 60%,and the survival rate of rats in the control group was 0%.This thesis has developed a rabies antibody treatment plan based on the AAV expression system,which provides new ideas for the treatment of rabies.