Quantitative Trait Loci Associated with the Immune Response to a Bovine Respiratory Syncytial Virus Vaccine

Infectious disease is an important problem for animal breeders, farmers and governments worldwide. One approach to reducing disease is to breed for resistance. This linkage study used a Charolais-Holstein F2 cattle cross population (n = 501) which was genotyped for 165 microsatellite markers (covering all autosomes) to search for associations with phenotypes for Bovine Respiratory Syncytial Virus (BRSV) specific total-IgG, IgG1 and IgG2 concentrations at several time-points pre- and post-BRSV vaccination. Regions of the bovine genome which influenced the immune response induced by BRSV vaccination were identified, as well as regions associated with the clearance of maternally derived BRSV specific antibodies. Significant positive correlations were detected within traits across time, with negative correlations between the pre- and post-vaccination time points. The whole genome scan identified 27 Quantitative Trait Loci (QTL) on 13 autosomes. Many QTL were associated with the Thymus Helper 1 linked IgG2 response, especially at week 2 following vaccination. However the most significant QTL, which reached 5% genome-wide significance, was on BTA 17 for IgG1, also 2 weeks following vaccination. All animals had declining maternally derived BRSV specific antibodies prior to vaccination and the levels of BRSV specific antibody prior to vaccination were found to be under polygenic control with several QTL detected

Lack of antibody affinity maturation due to poor Toll-like receptor stimulation leads to enhanced respiratory syncytial virus disease

Respiratory syncytial virus (RSV) is a leading cause of hospitalization in infants. A formalin-inactivated RSV vaccine was used to immunize children and elicited nonprotective, pathogenic antibody. Immunized infants experienced increased morbidity after subsequent RSV exposure. No vaccine has been licensed since that time. A widely accepted hypothesis attributed the vaccine failure to formalin disruption of protective antigens. Here we show that the lack of protection was not due to alterations caused by formalin but instead to low antibody avidity for protective epitopes. Lack of antibody affinity maturation followed poor Toll-like receptor (TLR) stimulation. This study explains why the inactivated RSV vaccine did not protect the children and consequently led to severe disease, hampering vaccine development for 42 years. It also suggests that inactivated RSV vaccines may be rendered safe and effective by inclusion of TLR agonists in their formulation, and it identifies affinity maturation as a key factor for the safe immunization of infants.Fil: Delgado, Maria Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Fundación para la Investigación en Infectología Infantil; ArgentinaFil: Coviello, Silvina Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Fundación para la Investigación en Infectología Infantil; ArgentinaFil: Monsalvo, Ana Clara. Fundación para la Investigación en Infectología Infantil; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Melendi, Guillermina Amanda. Fundación para la Investigación en Infectología Infantil; Argentina. University Johns Hopkins; Estados UnidosFil: Hernandez, Johanna Zea. Fundación para la Investigación en Infectología Infantil; Argentina. University Johns Hopkins; Estados UnidosFil: Batalle, Juan Pio. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Fundación para la Investigación en Infectología Infantil; ArgentinaFil: Diaz, Leandro. Fundación para la Investigación en Infectología Infantil; ArgentinaFil: Trento, Alfonsina. Universidad Carlos III de Madrid. Instituto de Salud; EspañaFil: Chang, Herng-Yu. University Johns Hopkins; Estados UnidosFil: Mitzner, Wayne. University Johns Hopkins; Estados UnidosFil: Ravetch, Jeffrey. The Rockefeller University; Estados UnidosFil: Melero, José A.. Universidad Carlos III de Madrid. Instituto de Salud; EspañaFil: Irusta, Pablo M.. University Of Georgetown; Estados Unidos. Fundación para la Investigación en Infectología Infantil; ArgentinaFil: Polack, Fernando Pedro. Fundación para la Investigación en Infectología Infantil; Argentina. University Johns Hopkins; Estados Unido