Antibodies against Crandell Rees feline kidney (CRFK) cell line antigens, alpha-enolase, and annexin A2 in vaccinated and CRFK hyperinoculated cats.
BACKGROUND
Cats inoculated with feline herpesvirus 1, calicivirus, and panleukopenia (FVRCP) vaccines grown on the Crandell Rees feline kidney (CRFK) cell line have been shown to develop anti-CRFK antibodies. The identities of common CRFK antigens are unknown.


OBJECTIVE
Cats inoculated with CRFK lysates and FVRCP vaccines will develop autoantibodies measurable by Western blot immunoassay. Antigens associated with these antibodies can be isolated for further study.


METHODS
One CRFK hyperinoculated rabbit, 44 age-matched unvaccinated kittens purchased from a commercial vendor.


METHODS
Commonly recognized CRFK antigens were identified by comparison of Western blot immunoassays using sera from a hyperinoculated rabbit and kittens inoculated with CRFK lysate or 1 of 4 commercially available FVRCP vaccines. Antigens were purified from CRFK lysates and sequenced. Antigen recognition was confirmed by Western blot immunoassay and indirect ELISA for 2 proteins using sera from CRFK and FVRCP inoculated kittens.


RESULTS
CRFK antigens 47, 40, and 38 kD in size were identified. Protein isolation and sequencing identified 3 CRFK proteins as alpha-enolase, annexin A2, and macrophage capping protein (MCP). Sera from FVRCP and CRFK inoculated cats were confirmed to recognize annexin A2 and alpha-enolase by Western blot immunoassay and indirect ELISA.


CONCLUSIONS
This study validated the use of Western blot immunoassay for detection of antibodies against CRFK proteins and identified 3 CRFK antigens. In humans, alpha-enolase antibodies are nephritogenic; alpha-enolase and annexin A2 antibodies have been associated with autoimmune diseases. Further research will be necessary to determine the clinical relevance of these findings.
Department of Clinical Sciences, Veterinary Medical Center, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, USA. jwhittemore@utk.edu
J C
JC
Whittemore
J R
JR
Hawley
W A
WA
Jensen
M R
MR
Lappin
D000595:Amino Acid Sequence; D000818:Animals; D017306:Annexin A2 / Q000097:blood* / Q000737:chemistry / Q000378:metabolism; D000906:Antibodies / Q000097:blood*; D000917:Antibody Formation / Q000276:immunology; D000941:Antigens / Q000276:immunology*; D017927:Calicivirus, Feline / Q000276:immunology; D002415:Cats; D002460:Cell Line; D028301:Feline Panleukopenia Virus / Q000276:immunology; D006564:Herpesviridae / Q000276:immunology; D008969:Molecular Sequence Data; D010751:Phosphopyruvate Hydratase / Q000097:blood* / Q000737:chemistry / Q000378:metabolism; D011817:Rabbits; D014765:Viral Vaccines / Q000276:immunology*
D017306:Annexin A2; D000906:Antibodies; D000941:Antigens; D014765:Viral Vaccines; D010751:Phosphopyruvate Hydratase