A large panel of mouse monoclonal antibodies was produced and tested against field isolates of the equine H7N7 influenza A virus subtype. Only a limited degree of H7 haemagglutinin variation was detected. At least four antigenic sites were identified by selecting variant viruses in eggs. The limited variation in the field did not correlate with the frequency of variant viruses detected in eggs; this frequency was similar to those reported for other influenza viruses. We sought to determine whether the limited amount of variation could be correlated with an epitope-restricted antibody response in vaccinated horses. To this end, limiting dilution cultures were established with peripheral blood leukocytes from vaccinated ponies and the antibodies released into culture supernatants were assayed for binding to variant H7 viruses in ELISA. Three neutralizable antigenic sites mapped by mouse anti-bodies were also recognized by antibodies in pony limiting dilution culture supernatants, indicating that the equine antibody response against the influenza virus H7 haemagglutinin is diverse, and should be effective in selecting variant viruses.
AppletonJ. A.,
AntczakD. F.,
LopesA. D.1987; Characterization of the equine influenza virus H3 with monoclonal antibodies. Archives of Virology 94:339–346
AppletonJ. A.,
GagliardoL. F.,
AntczakD. F.,
PolemanJ. C.1989; Production of an equine monoclonal antibody specific for the H7 hemagglutinin of equine influenza virus. Veterinary Immunology and Immunopathology 23:257–266
GibsonC. A.,
DanielsR. S.,
McCauleyJ. W.,
SchildG. C.1988; Hemagglutinin gene sequencing studies of equine-1 influenza A viruses. In Equine Infectious Diseases vol 5 pp 51–59 Edited by
PowellD. G.
Lexington: University of Kentucky Press;
KudoH.,
OhdeH.,
YamanakaT.1986; Hemagglutination-inhibiting antibodies to equine influenza viruses in Japanese horses and antigenic variation of the viruses. Kitasato Archives of Experimental Medicine 59:49–55
LaverW. G.,
AirG. M.,
WebsterR. G.,
GerhardW.,
WardC. W.,
DopheideT. A. A.1979; Antigenic drift in type A influenza virus: sequence differences in the hemagglutinin of Hong Kong (H3N2) variants selected with monoclonal hybridoma antibodies. Virology 98:226–237
LubeckM. D.,
SchulmanJ. L.,
PaleseP.1980; Antigenic variants of influenza viruses: marked differences in the frequencies of variants selected with different monoclonal antibodies. Virology 102:458–462
WoodJ. M.,
MumfordJ.,
FolkersC.,
ScottA. M.,
SchildG. C.1983; Studies with inactivated equine influenza vaccine 1. Serological responses of ponies to graded doses of vaccine. Journal of Hygiene90371–384