RESUMEN
Feline coronavirus (FCoV) infection is a leading cause of death in cats. In this study, we produced FCoV-I virus-like particles (VLPs) containing E, M, N, and S proteins using a baculovirus expression system and mixed VLPs with the adjuvants MF59 and CpG 55.2 to prepare an VLP/MF59/CpG vaccine. After immunization of mice with the vaccine, IgG specific antibodies titers against S and N proteins increased to 1:12,800, and IFN-γ+ and IL-4+ splenocytes were significantly increased. Following immunization of FCoV-negative cats, the S protein antibodies in immunized cats (5/5) increased significantly, with a peak of 1:12,800. Notably, after booster vaccination in FCoV-positive cats, a significant reduction in viral load was observed in the feces of partial cats (4/5), and the FCoV-I negative conversion was found in two immunized cats (2/5). Therefore, the VLP/MF59/CpG vaccine is a promising candidate vaccine to prevent the FCoV infection.
Asunto(s)
Adyuvantes Inmunológicos , Anticuerpos Antivirales , Coronavirus Felino , Inmunoglobulina G , Vacunas de Partículas Similares a Virus , Carga Viral , Animales , Gatos , Vacunas de Partículas Similares a Virus/inmunología , Vacunas de Partículas Similares a Virus/administración & dosificación , Anticuerpos Antivirales/sangre , Anticuerpos Antivirales/inmunología , Ratones , Coronavirus Felino/inmunología , Inmunoglobulina G/sangre , Adyuvantes Inmunológicos/administración & dosificación , Vacunas Virales/inmunología , Vacunas Virales/administración & dosificación , Interleucina-4/metabolismo , Interferón gamma/metabolismo , Ratones Endogámicos BALB C , Heces/virología , Adyuvantes de Vacunas , Polisorbatos/administración & dosificación , Femenino , Infecciones por Coronavirus/prevención & control , Infecciones por Coronavirus/inmunología , Infecciones por Coronavirus/veterinaria , Inmunogenicidad Vacunal , Glicoproteína de la Espiga del Coronavirus/inmunología , Glicoproteína de la Espiga del Coronavirus/genética , Bazo/inmunología , Enfermedades de los Gatos/prevención & control , Enfermedades de los Gatos/inmunología , Enfermedades de los Gatos/virología , Baculoviridae/genética , Vacunación , Inmunización Secundaria , EscualenoRESUMEN
Bovine parainfluenza virus type 3 (BPIV3) is a viral respiratory pathogen of cattle that causes substantial economic losses. A replicating-defective recombinant human adenovirus type 5 (HAd5), carrying a fusion protein of BPIV3 genotype C (HAd5-F), was constructed and evaluated for its immunogenicity and protective efficacy in mice. After intramuscular injection with the HAd5-F, the IgG titers against F proteins increased to 1:102,400, and virus-neutralizing titers increased to 1:256, significantly higher than those in the group injected with inactivated BPIV3C in mice (p<0.05). The splenic CD4+/CD8+T lymphocytes and IFN-γ+/IL-4+ cytokine percentages were more significant in the HAd5-F group than those in the control group. A BPIV3C challenge in a mouse model was used to assess protective efficacy of the HAd5-F. The viral loads in the lungs and tracheas of mice immunized with the HAd5-F were significantly lower than those in the control group (p<0.0001). There were no significant histopathological alterations in the lungs of mice vaccinated with the HAd5-F. These findings suggested that the HAd5-F elicited excellent immunity against BPIV3C infection.