Three-step Anti-aMPV IgA Expression Profile Evaluation in Turkeys of Different Immunological Status after TRT Vaccination

Abstract

Maternally derived antibodies (MDA) don not protect turkeys against rhinotracheitis (TRT) but high MDA influences upper respiratory tract (URT) immunity stimulation after avian Metapneumovirus (aMPV) vaccination. Humoral immunity can not be considered as an indicator of protection against TRT, but specific antibodies inhibit aMPV replication and alleviate the course of TRT. Scarce reports indicate the role of IgA in protection against TRT. The aim of our study was to investigate the impact of MDA on stimulation, antigen specificity acquisition of B lymphocytes, and the production of specific IgA after TRT vaccination of turkeys.The results of our study indicate that MDA on the day of TRT vaccination causes disturbances at different levels of specific humoral immunity expression including antigen specificity acquisition of B IgA + lymphocytes as well as production and secretion of IgA. Vaccine immunity against aMPV associated with sIgA is well expressed in birds not possessing MDA on the day of TRT vaccination, whereas it is inhibited in MDA + birds.These results corroborate our previous findings and indicate that MDA could be responsible for TRT vaccination failure. These findings could explain the observed frequency of TRT field outbreaks despite aMPV vaccination of turkey flocks.

IFNγ production profile in turkeys of different immunological status after TRT vaccination

“…As demonstrated in our previous studies, the presence of MDA has a very strong impact on the stimulation of both humoral and cellular immunity after bird vaccination against TRT with the aMPV/A subtype (13,14). In the present experiment, we evaluated the effect of MDA on the stimulation of T lymphocytes and splenocytes for IFNγ gene production after vaccination against TRT.…”

“…We observed similar phenomena in our previous study with B cells isolated from the upper respiratory tract of birds after vaccination against TRT. In the case of vaccinated MDA+ birds, the population of IgA + B cells expanded, while no change was noted in the population of cells capable of producing specific IgA in confrontation with vaccine aMPV nor in the level of specific IgA in the URT (13,14).…”

“…ELISpot assay. An enzyme-linked immunospot (ELISpot) assay was performed as described previously (14,18) with modifications. After membrane activation in 70% ethanol at 50 μL/well for 45 s, MultiScreen ELISPOT plates (Millipore, Burlington, MA, USA) were coated with Rabbit Anti-Chicken IFNγ antibody (as above; Bio-Rad) and incubated at 4°C for 24 h. Splenic lymphocytes in a 1.5 × 10 4 quantity were added in triplicate directly to the wells of previously prepared ELISpot plates with BD FACSAria II (BD) and prior to incubation at 39.5°C in 5% CO2 for 24 h, 100 µL of Iscove's modified Dulbecco's medium (Sigma Aldrich) with previously titrated vaccine aMPV/A suspension was added to each well.…”

“…Few studies have been performed so far to determine the effect of MDA on the efficacy of vaccination against TRT. Śmiałek et al (13,14) demonstrated that MDA-possessing (MDA+) turkeys did not produce specific IgY or IgA after the vaccination against TRT. Additionally, the authors found abnormalities in the specificity of IgA + B lymphocyte response in MDA+ turkeys after vaccination using aMPV subtype A (aMPV/A).…”

Immunogenicity of Pigeon Circovirus Recombinant Capsid Protein in Pigeons

“…ELISPOT was performed, as described previously [ 36 ], with modifications. After membrane activation (70% ethanol, 50 μL/well, 1 min) and 4 PBS (Sigma Aldrich, Schnelldorf, Germany) rinsing cycles (300 µL/well), MultiScreen plates (Merck Millipore, Burlington, MA, USA) were coated with 100 µL/ well of the PBS solution of PiCV rCP (conc.…”