Prophylactic Efficacy of Equine Immunoglobulin F(ab′)2 Fragments Against Feline Parvovirus

Abstract

Feline parvovirus (FPV), a type of parvovirus prevalent worldwide, can cause foetal death and acute enteritis in adult cats with severe leukopenia, and yet there are no effective drugs to prevent or treat FPV. Here, the immune effects of two FPV vaccines on horses were compared. IgG was extracted from FPV-immunized horse sera. Equine F(ab′) 2 fragments were obtained from pepsin-digested IgG and then purified by protein-G column chromatography. The results showed that the inactivated FPV oil vaccine was more effective than the inactivated FPV propolis vaccine in helping healthy horses to produce hyper-immune serum. Four methods were tested, among which the optimized octanoic acid-ammonium sulphate precipitation method was proved to be the best process for extracting IgG. The optimal condition for preparing F(ab′) 2 by pepsin digestion was 30°C for 3.5 h, and the content, purity and recovery of F(ab′) 2 were 8.64 mg/mL, 90.36% and 93.24%, respectively. Our equine immunoglobulin F(ab′) 2 fragments effectively neutralized activity in vitro against FPV, alleviated the clinical symptoms of FPVinfected cats, reduced the viral loads in the intestine and had prophylactic effects in FPV-infected cats. These results indicate that the F(ab′) 2 fragment prepared from inactivated FPV-immunized horses may be used as a prophylactic agent for diseases caused by FPV.

Research on Rapid Detection Technology for β2-Agonists: Multi-Residue Fluorescence Immunochromatography Based on Dimeric Artificial Antigen

“…Animals were exsanguinated 10 days after the last immunization. The serum was separated, and the antibody was extracted by the octanoic acid–ammonium sulfate method [ 34 ], subpackaged, and stored at −20 °C. The titer of the antibody detected by indirect competitive ELISA was determined to be positive if the OD 450 nm/negative OD 450 nm of the well tested ≥2.1 (P/N ≥ 2.1).…”

Therapeutic Effects of Propionibacterium acnes and Lipopolysaccharide from Escherichia coli in Cats with Feline Panleukopenia

“…Feline parvovirus (FPV) is a small, non-enveloped single-stranded DNA virus that belongs to the Parvoviridae family, specifically the parvovirus genus and feline parvovirus subgroup. Transmission of the virus from an infected cat to a susceptible cat occurs easily through the fecal–oral route [ 1 ]. Following FPV infection, viral replication takes place in the oropharyngeal epithelium within 18 to 24 h post-infection, followed by dissemination during the viremic phase within 2 to 7 days post-infection.…”

“…Recombinant feline interferon omega (IFN-ω) has also shown inhibitory effects on the replication of feline parvovirus in cats in vivo [ 7 ]. Recently, horse anti-FPV IgG has been employed in certain European countries as a preventive measure against feline parvovirus infection [ 1 ]. In cases where exposure to the virus has occurred but clinical signs have not yet manifested, the administration of antiserum or high-titer parvoviral antiserum from vaccinated or recovered cats can be advantageous [ 8 ].…”