Journal Article

Pathogenicity and immunogenicity of gI/gE/TK-gene-deleted Felid herpesvirus 1 variants in cats

Tang, Aoxing, Zhu, Meng, Li, Chuangfeng, Zhang, Da, Zhu, Shiqiang, Liu, Guangqing, Meng, Chunchun, Wang, Xiao, Zhu, Jie

2023

Overview

Background Felid herpesvirus 1 (FHV-1) is a major pathogenic agent of upper respiratory tract infections and eye damage in felines worldwide. Current FHV-1 vaccines offer limited protection of short duration, and therefore, do not reduce the development of clinical signs or the latency of FHV-1. Methods To address these shortcomings, we constructed FHV ∆gIgE-eGFP, FHV ∆TK mCherry, and FHV ∆gIgE/TK eGFP-mCherry deletion mutants (ΔgI/gE, ΔTK, and ΔgIgE/TK, respectively) using the clustered regularly interspaced palindromic repeats (CRISPR)/CRISP-associated protein 9 (Cas9) system (CRISPR/Cas9), which showed safety and immunogenicity in vitro. We evaluated the safety and efficacy of the deletion mutants administered with intranasal (IN) and IN + subcutaneous (SC) vaccination protocols. Cats in the vaccination group were vaccinated twice at a 4-week interval, and all cats were challenged with infection 3 weeks after the last vaccination. The cats were assessed for clinical signs, nasal shedding, and virus-neutralizing antibodies (VN), and with postmortem histological testing. Results Vaccination with the gI/gE-deleted and gI/gE/TK-deleted mutants was safe and resulted in significantly lower clinical disease scores, fewer pathological changes, and less nasal virus shedding after infection. All three mutants induced virus-neutralizing antibodies after immunization. Conclusions In conclusion, this study demonstrates the advantages of FHV-1 deletion mutants in preventing FHV-1 infection in cats.

• Publisher: BioMed Central,BioMed Central Ltd,Springer Nature B.V,BMC
• Subject: Animals / Antibodies / Antibodies, Neutralizing / Biomedical and Life Sciences / Biomedicine / Cat / Cat Diseases - prevention & control / Cats / Cloning / CRISPR / CRISPR-Cas systems / CRISPR/Cas9 / Cytomegalovirus / Deletion mutant / Diseases / eyes / Felid alphaherpesvirus 1 / Felid herpesvirus 1 / Genes / Genetic aspects / Genetic engineering / Genomes / Herpes viruses / Herpesviridae Infections - prevention & control / Herpesviridae Infections - veterinary / Herpesviruses / histology / Identification and classification / Immunogenicity / Infections / Kinases / Latency / Membranes / Mutants / nose / Pathogenicity / pathogens / Plasmids / Proteins / Recombinant virus / Respiratory tract diseases / Vaccination / Vaccine / Vaccines / Varicellovirus - genetics / Virology / Virulence / Viruses