A. Kukreja et al., STUDY OF THE PROTECTIVE IMMUNITY OF COEXPRESSED GLYCOPROTEIN-H AND GLYCOPROTEIN-L OF EQUINE HERPESVIRUS-1 IN A MURINE INTRANASAL INFECTION MODEL, Veterinary microbiology, 60(1), 1998, pp. 1-11
Equine herpesvirus-1 (EHV-1) glycoproteins H, and L (gH and gL) expres
sed individually or co-expressed by recombinant baculoviruses were use
d to immunise BALB/c mice prior to intranasal challenge in a murine mo
del of respiratory infection. Only the co-expressed material (EHV-1 gH
/gL) induced neutralising antibody (low levels). The same immunogen al
so produced the strongest cellular responses. Immunisation with gH/gL
and, to a lesser extent, with gH alone was associated with a reduction
of virus load in nasal turbinates and olfactory bulbs after challenge
infection. Viraemia, detected by polymerase chain reaction, was also
reduced. No such protective effects were observed for gL alone. Adopti
ve transfer of lymphocytes from gH/gL-immunised mice to naive mice sub
sequently challenged with EHV-1 indicated that both CD4(+) and CD8(+)
cells had a role in protective immunity. Although clearance of EHV-1 f
rom respiratory tissue was not as effective as previously found for gl
ycoproteins D or C, these experiments provide evidence that the co-exp
ression of EHV-1 gL with gH generates a conformational neutralising ep
itope which is not present in either molecule alone, and suggests that
gH/gL antigen may have a better potential as a component of an EHV-1
vaccine than gH alone. (C) 1998 Elsevier Science B.V.