Antibody recognition of the glycoprotein g of viral haemorrhagic septicemia virus (VHSV) purified in large amounts from insect larvae

Table 1 pH-dependence of the recognition of G21-465 by sera from hyperimmunized (pool 1) and VHSV-infected (pool 2 and pool 3) rainbow trout as shown by immunoblotting

Trout sera	Immunization with VHSV-07.71	Number of sera	Neutralization titer	pH 6.7/pH 7.7, ratio
Pool 1	Hyperimmunized	3	800	2.85 ± 1.36 (n = 3)
Pool 2	Surviving infection	3	< 40	3.45 ± 0.23 (n = 2)
Pool 3	Surviving infection	4	> 5120	3.12 ± 0.58 (n = 2)

G21-465 was electrophoresed in 5-20% polyacrylamide gels (gradient PAGE), transferred to nitrocellulose and derived strips were used for reaction with each of the pooled trout sera at pH 6.7 and 7.7 as described, except that diaminobenzidine (DAB) was used for staining the reaction. Pool 1 included 3 sera from trout hyperimmunized by injection of purified VHSV with neutralization titers of 800 (dilution of the sera causing a 50% decrease in the in vitro VHSV titer). Pool 2 included 3 sera from trout surviving infection with VHSV with neutralization titers < 40 (gift of Dr.Castric). Pool 3 included 4 sera from trout surviving infection with VHSV with neutralization titers > 5120 (gift from Dr. Castric). The intensity of the stained bands were estimated by densitometry (Image J 1.38x, http://rsb.info.nih.gov/ij) and ratios were then calculated by the formula: intensity of the stained bands at 6.7/intensity of the stained bands at pH 7.7. Means and standard deviations were calculated from at least 2 experiments (n).

ISSN: 1756-0500