Analysis of isotype-specific antibody responses to bovine herpesviruses 1.1 and 1.2a allows to estimate the stage of infection

Abstract

Specific IgM, IgA, IgG1, IgG2, as well as neutralizing antibody responses were evaluated in sera of calves experimentally infected with two isolates of bovine herpesvirus type 1 (BoHV1) of distinct subtypes (subtype 1, BoHV1.1; subtype 2a, BoHV-1.2a). No significant differences were observed in the antibody responses induced by each BoHV-1 subtype. The antibody responses following primary acute infection were characterized by an increase in specific IgM and IgA levels between days 2 and 14 post inoculation (pi). IgG1 was detected from days 11 to 30 pi. IgG2 was detected on the sample taken on day 30 pi. Reactivation of infection following dexamethasone administration induced a significant rise in IgA levels, whereas IgG1 and IgG2 levels, which were at high levels from the beginning of the reactivation process, showed a slight alteration after corticosteroid treatment. These results suggest that it is possible to estimate the dynamics of BoHV-1 infections with basis on the analysis of class- and subclass-specific antibody responses. Such information may be particularly useful for the study of the kinetics of the infection in a herd and to aid in the adoption of appropriate control measures..

Field Evaluation of Commercial Vaccines against Infectious Bovine Rhinotracheitis (Ibr) Virus Using Different Immunization Protocols

“…For the quantification of BoHV-1-specific total IgG, IgG1 and IgG2, three indirect ELISAs were developed. A stock ELISA antigen was prepared on MDBK cells infected with BoHV-1 LA strain at a multiplicity of infection (MOI) between 0.1 and 1 and further treated with 0.2% N-octyl-glucopyranoside (OGP) following previously described methods [ 11 ]. Class and subclass-specific peroxidase conjugates (anti-bovine IgG, IgG1 and IgG2 antibodies) were purchased commercially and employed following the manufacturers’ instructions (Jackson Immunoresearch Laboratories INC, West Grove, PA, USA).…”

“…After 1 h incubation at 37 • C, plates were washed three times with PBST-20. Class or subclass-specific peroxidase conjugates (diluted in PBS as previously titrated) were then added to wells and the plates were again incubated for 1 h at 37 • C. After another series of washings with PBST-20, 100 µL of the substrate ortho-phenylenediamine (OPD; Sigma, Darmstadt, Germany) with 0.03% H 2 O 2 were added to plates [11]. After 30-min incubation at room temperature, the optical density (OD) was determined at 405 nm in a Multiskan (Titertek, Waltham, Massachusetts, EUA) ELISA reader.…”

“…Primary BoHV-1 infection induces strong humoral and cell-mediated immune responses in cattle, as would be expected under normal conditions [ 10 , 11 ]. The serum neutralization (SN) test used to quantify BoHV-1 neutralizing antibodies in sera of cattle is recommended by the World Organization for Animal Health (OIE).…”

“…The serum neutralization (SN) test used to quantify BoHV-1 neutralizing antibodies in sera of cattle is recommended by the World Organization for Animal Health (OIE). SN has been used extensively to evaluate vaccines [ 11 , 12 , 13 , 14 ], although there is a difference in the titers obtained according to the sample used [ 15 ]. Moreover, it has been shown that the efficacy of the immune response against BoHV-1 depends on increased Th1-type cell-mediated responses [ 16 ].…”