Feline infectious peritonitis virus (FIPV) is a feline coronavirus that causes feline infectious peritonitis. Infection is ubiquitous in domestic cats, especially where conditions are crowded. FIPV can survive in for 7 weeks in a dry environment and may be transmitted indirectly via fomites. FPIV is an enveloped single stranded RNA virus. Most FIPV-infected cats either stay healthy or show only a mild enteritis. Only a proportion of FPIV-infected cats will develop FIP, a pyogranulomatous vasculitis (Addie et al., 2009).
4. Microbial Pathogenesis
The pathogenesis of FIP may be explained by an increased number of mutants, stochastically arising during bursts of replication (eg, under immune suppression), some of them growing to high concentrations in monocytes and macrophages. Mutations have been identified in non-structural genes, and more may remain to be identified. These highly virulent FPIV mutants have consistently induced FIP under experimental conditions, but their virulence has not been traced to a molecular source. The viral load and the cat’s immune response determine whether FIP will develop. Both viral genetics and host immunity are likely to play a role in the development of FIP. The pathology of FIP has been classified into two forms: an effusive (wet) FIP characterised by polyserositis (eg, thoracic and abdominal effusion)and vasculitis, and a non-effusive (dry) FIP characterised by granulomatous lesions in organs (Addie et al., 2009).
5. Host Ranges and Animal Models
Domestic cats
6. Host Protective Immunity
It has been suggested that cats mounting a strong cell-mediated immune response do not develop FIP, whereas cats showing a predominantly humoral response progress to disease. Hypergammaglobulinaemia is common in cats with FIP. Also, a drastic depletion of T cells from blood and lymphoid tissues has been described (Addie et al., 2009).
>gi|315192965|ref|YP_004070195.1| putative 3a protein [Feline infectious peritonitis virus]
MDIVKSIDIFVDAVLDELDRAYFAVTLKVEFKTGKLLVCIGFGDTLLEAKDKAYAKLGLSFIEEVNSHTV
V
Molecule Role :
Virmugen
Molecule Role Annotation :
A 3abc deletion mutant in Feline infectious peritonitis virus (FIPV) was attenuated and provided protection against virulent FIPV strain 79-1146 challenge in kittens (Haijema et al., 2004).
>gi|315192966|ref|YP_004070196.1| putative 3b protein [Feline infectious peritonitis virus]
MLSLVSPLLKKSIVIQLFSITVYKFKAKFWYKLPFETRLCIIKHTRPKALSVTKQVKRDYRKIAILNSMR
K
Molecule Role :
Virmugen
Molecule Role Annotation :
A 3abc deletion mutant in Feline infectious peritonitis virus (FIPV) was attenuated and provided protection against virulent FIPV strain 79-1146 challenge in kittens (Haijema et al., 2004).
Molecule Role Annotation :
A 3abc deletion mutant in Feline infectious peritonitis virus (FIPV) was attenuated and provided protection against virulent FIPV strain 79-1146 challenge in kittens (Haijema et al., 2004).
>gi|315192970|ref|YP_004070200.1| non-structural protein 7a [Feline infectious peritonitis virus]
MLVFVHAVLVTALILLLIGRIQLLERLLLSHLLNLTTVSNVLGVPDSSLRVNCLQLLKPDCLDFNILHKV
LAETRLLVVVLRVIFLVLLGFSCYTLLGALF
Molecule Role :
Virmugen
Molecule Role Annotation :
A 7ab deletion mutant in Feline infectious peritonitis virus is attenuated and provides protection against virulent FIPV strain 79-1146 challenge in kittens (Haijema et al., 2004).
Molecule Role Annotation :
A 7ab deletion mutant in Feline infectious peritonitis virus is attenuated and provides protection against virulent FIPV strain 79-1146 challenge in kittens (Haijema et al., 2004).
A healthy 5-month-old kitten with an F1PV serum antibody titer greater than 1:1600 served as the immune serum donor. This animal was an SPF kitten who had seroconverted by natural exposure to FIPV-shedding contact cats and had remained asymptomatic.(Weiss and Scott, 1981)
f. Immunization Route
Intravenous injection (i.v.)
g. Description
A serum containing anti-FIBV produced by an asymptomatic cat was injected into other cats.(Weiss and Scott, 1981)
h.
Cat Response
Vaccination Protocol:
Serum was administered by slow intravenous injection and given at a dosage of 11 ml/kg per cat.(Weiss and Scott, 1981)
Challenge Protocol:
Six hr after administration of serum, the experimental kittens were inoculated intraperitoneally with 0.5 ml of FIPV- infected liver homogenate.
Efficacy:
Not protected, higher fatality rate than unvaccinated cats. (Weiss and Scott, 1981)
SF-9 cells cultured for 2 days were inoculated with the recombinant baculovirus. After absorption for 1 h, serum-free TC-100 medium was added to the cells and the cells were cultured at 27 °C. After culture for 96 h, the infected cells were recovered and washed with PBS. One milliliter of RSB buffer containing 0.2% NP-40 (0.01 M NaCl, 0.0015 M MgCl2, 0.01 M Tris–HCl, pH 7.4) was added to 1×107 cells and the cell suspension was kept at 4 °C for 30 min with occasional shaking. The cells were centrifuged at 800×g for 10 min. The precipitate was resuspended in PBS and used as recombinant N protein. Feline inactivated trivalent vaccine (Felidovac PCR; Intervet, The Netherlands), which is commercially available in Japan, was added to the recombinant N protein as an adjuvant. This feline inactivated trivalent vaccine contains 2% aluminum hydroxide gels and L80 as an adjuvant. (Hohdatsu et al., 2003)
g. Immunization Route
subcutaneous injection
h. Description
Cell lysate with baculovirus-expressed N protein of the Type I FIPV strain KU-2 recombinant vaccine was effective in preventing the progression of FIP without inducing antibody-dependent enhancement of FIPV infection in cats. (Hohdatsu et al., 2003)
i.
Cat Response
Vaccination Protocol:
Eight SPF cats aged 6 months and eight SPF cats aged 7–9 months were used in the first and second experiments, respectively. In both experiments, four cats were subcutaneously vaccinated three times with 3-week intervals. The same vaccination/challenge experiment was repeated twice. (Hohdatsu et al., 2003)
Immune Response:
In all vaccinated cats, the ELISA value against N protein began to increase on Day 6 after the challenge and the antibody responded earlier than that in the control cats. The anti-challenge virus (strain 79-1146) neutralizing antibody production converted to positive on Day 12 after the challenge in the vaccination and control groups, showing no significant difference between the two groups. (Hohdatsu et al., 2003)
Challenge Protocol:
As a challenge control, four cats received a subcutaneous administration of the SF-9 cell-derive d antigen, which was prepared as the recombinant N protein described above, with the adjuvant. Four weeks after the third vaccination, all cats were challenged oronasally with 105 TCID50 FIPV strain 79-1146. (Hohdatsu et al., 2003)
Efficacy:
Combining the results of the first and second experiments, the survival rates were 75% (6/8) and 12.5% (1/8) for the immunized and control groups, respectively. These survival rates were analyzed using the X2-test, and there was a significant difference (P<0.05). (Hohdatsu et al., 2003)
IV. References
1. Addie et al., 2009: Addie D, Belák S, Boucraut-Baralon C, Egberink H, Frymus T, Gruffydd-Jones T, Hartmann K, Hosie MJ, Lloret A, Lutz H, Marsilio F, Pennisi MG, Radford AD, Thiry E, Truyen U, Horzinek MC. Feline infectious peritonitis. ABCD guidelines on prevention and management. Journal of feline medicine and surgery. 2009; 11(7); 594-604. [PubMed: 19481039].
2. Haijema et al., 2004: Haijema BJ, Volders H, Rottier PJ. Live, attenuated coronavirus vaccines through the directed deletion of group-specific genes provide protection against feline infectious peritonitis. Journal of virology. 2004; 78(8); 3863-3871. [PubMed: 15047802].
3. Satoh et al., 2011: Satoh R, Furukawa T, Kotake M, Takano T, Motokawa K, Gemma T, Watanabe R, Arai S, Hohdatsu T. Screening and identification of T helper 1 and linear immunodominant antibody-binding epitopes in the spike 2 domain and the nucleocapsid protein of feline infectious peritonitis virus. Vaccine. 2011; 29(9); 1791-1800. [PubMed: 21216312].
4. Takano et al., 2014: Takano T, Tomizawa K, Morioka H, Doki T, Hohdatsu T. Evaluation of protective efficacy of the synthetic peptide vaccine containing the T-helper 1 epitope with CpG oligodeoxynucleotide against feline infectious peritonitis virus infection in cats. Antiviral therapy. 2014; 19(7); 645-650. [PubMed: 24458025].
