Characteristic Of The Immune Response Induced By HSV-1 Mutant Strain M3

Herpes simplex virus type 1(HSV-1)is a ubiquitous virus,which forms a life-long latent infection in human nervous system tissues,and leads to various syndromes by its sporicidal reactivation from these tissues.Primary infection and reactivation of HSV-1 cause cold sore,genital herpes,herpetic stromal keratitis and herpes simplex encephalitis.Specific anti-virus medicine can alleviate the symptoms,however,hardly eliminate the latent virus.Thus,a therapeutic or prophylactic HSV-1 vaccine is urgently needed.Subunit vaccine containing envelop glycoproteins is the main focus of Herpes simplex virus vaccine development for a long period,whereas several clinical trials showed that subunit vaccines failed to elicit a satisfied protective immunity.These failures indicate that a limited variety of virus antigen in subunit vaccine may not sufficient to induce effective immune response.In contrast,a live attenuated vaccine represents ample virus antigens,and its replication in the host can mimic virus infection to stimulate immune system.Thus,live attenuated vaccine has broad application prospects in the development of HSV-1 vaccine.Traditional production of attenuated virus strain relies on consecutive passage of virus on cells or ’animals,which is time and fortune demanding.We previously utilized the novel CRISPR/Cas9 technology to edit the HSV-1 genome,and constructed an u17,u141 and LAT gene partial delete mutant strain,namely M3.M3 was showed to be genetically stable and phenotypically attenuated in vivo and in vitro.However,the characteristic of immune response induced by M3 in vivo remains unclear,while a systematic knowledge of the infection dynamics and the host immune response is the key to a comprehensive recognition of vaccine safety and efficiency.To investigate the characteristics of immune response induced by this mutant strain,here we performed a discrepancy analysis of the gene expression profile,and the pathological changes induced by the mutant strain M3 compared to that induced by the wild type strain Mckrae,and we characterized the innate and adaptive immune response induced by M3 strain.Further,we evaluated the protective efficiency and its mechanism of M3 immunity.Via discrepancy analysis,we found that M3 and Mckrae induce a distinct gene expression pattern,with Mckrae induce an inflammatory dominated immune response which is accompanied by a high level of pro-inflammatory cytokine production,severe pathological changes,and high mortality,whereas M3 infection stimulated innate immune response,antigen presentation,cellular and humoral immunity associated gene expression,and M3 showed a distinct attenuated phenotype in mice.Analysis of the characteristics of the immune response induced by M3 showed that,M3 induce a broad,persistent,self-controlled and non-tissue damage immune response.Meanwhile,through virus challenge test,we showed that M3 immunity increases mice survival,alleviates clinical symptoms and tissue damages,and restricts virus proliferation in vivo and viral shedding in tears.The protective immunity induced by M3 also impaires viral latency in mice.Further,we identified the pivotal role of T cells in this protective immunity.Our research revealed the wide variations in immune response induced by HSV-1 mutant strain and wild type strain,and systematically analyzed the characteristics of the immune response induced by mutant strain M3.The finding of our research will provide profitable evidence to support the development of HSV-1 live attenuated vaccine via directional genome mutation.