Avian paramyoxvirus-8 immunization reduces viral shedding after homologous APMV-8 challenge but fails to protect against Newcastle disease

Abstract

BackgroundProtection against infection by Newcastle disease virus (NDV), also designated as avian paramyxovirus subtype-1 (APMV-1), is mediated by immune responses to the two surface glycoproteins, hemagglutinin-neuraminidase (HN) and fusion (F) protein. Thus, a chimeric APMV-1 based vaccine that encodes APMV-8 HN- and F-proteins and expresses the hemagglutinin of avian influenza virus (AIV) H5N1, is able to protect against HPAIV H5N1 but fails to protect against NDV [PLoS One8:e72530, 2013]. However, it is unclear whether avirulent APMV-subtypes, like APMV-8 can induce subtype-specific immunity and protect from a homologous challenge.FindingsAPMV-8 infections of 3- and 6-weeks-old specific pathogen free (SPF)-chickens did not induce any clinical signs but was associated with virus shedding for up to 6 days. Viral replication was only detected in oropharyngeal- and never in cloacal swabs. Upon reinfection with homologous APMV-8, viral shedding was restricted to day 2 and in contrast to naive SPF-chickens, only RNA but no infectious virus was recovered. No protection was induced against virulent NDV challenge, although morbidity and mortality was delayed in APMV-8 primed chickens. This lack of protection is in line with a lack of reactivity of APMV-8 specific sera to APMV-1 HN-protein: Neither by hemagglutin-inhibition (HI) test nor immunoblot analyses, cross-reactivity was detected, despite reactivity to internal proteins.ConclusionsImmune responses mounted during asymptomatic APMV-8 infection limit secondary infection against homologues reinfection and facilitates a delay in the onset of disease in a subtype independent manner but is unable to protect against Newcastle disease, a heterologous APMV-subtype.Electronic supplementary materialThe online version of this article (doi:10.1186/1743-422X-11-179) contains supplementary material, which is available to authorized users.

Engineered recombinant protein products of the avian paramyxovirus type-1 nucleocapsid and phosphoprotein genes for serological diagnosis

“…FJ619036) one day after hatch and challenged with APMV-8 on day 21 post vaccination. as described in detail by Grund et al [ 46 ]. Samples used here for serological analyzes were taken on days 21 post vaccination and 14 post challenge.…”

Monoclonal antibodies specific for the hemagglutinin-neuraminidase protein define neutralizing epitopes specific for Newcastle disease virus genotype 2.VII from Egypt

“…Despite the genetic variation, antigenically NDV still forms a single homogenous serotype [ 20 , 21 ]. Based on the haemagglutination inhibition test (HI) that detects HN-specific antibodies that block virus binding to sialic acid receptors on erythrocytes or serum neutralization tests, polyclonal sera can differentiate between serotypes of the subfamily Avulavirinae [ 22 , 23 ] but cannot distinguish between NDV genotypes [ 21 ]. However, by monoclonal antibodies (MAbs) differences in specific epitopes have been recognized [ 24 – 26 ].…”

Monoclonal Antibodies Specific for the Hemagglutinin-Neuraminidase Protein Define Neutralizing Epitopes Specific for Newcastle Disease Virus Genotype 2.VII from Egypt.

“…Despite the genetic variation, antigenically NDV still forms a single homogenous serotype [18,19]. Based on the haemagglutination inhibition test (HI) that detects HN-speci c antibodies that block virus binding to sialic acid receptors on erythrocytes or serum neutralization tests, polyclonal sera can differentiate between serotypes of the subfamily Avulavirinae [20,21] but cannot distinguish between NDV gentoypes [19]. However, by monoclonal antibodies (MAbs) differences in speci c epitopes have been recognized [22][23][24].…”