tetano
Editor, Senior Moderator
Vet Microbiol. 2017 Jun;205:117-123. doi: 10.1016/j.vetmic.2017.05.021. Epub 2017 May 29.
[h=1]Preexisting Salmonella-specific immunity interferes with the subsequent development of immune responses against the Salmonella strains delivering H9N2 hemagglutinin.[/h] Hajam IA[SUP]1[/SUP], Lee JH[SUP]2[/SUP].
[h=3]Author information[/h]
[h=3]Abstract[/h] Recombinant Salmonella strains expressing foreign heterologous antigens have been extensively studied as promising live vaccine delivery vehicles. In this study, we constructed attenuated smooth (S-HA) and rough (R-HA) Salmonella strains expressing hemagglutinin (HA) of H9N2, a low pathogenic avian influenza A virus. We then investigated the HA-specific immune responses following oral immunization with either S-HA or R-HA strain in chicken model. We further examined the effects of the preexisting anti-Salmonella immunity on the subsequent elicitation of the HA and the Salmonella ompA specific immune responses. Our results showed that primary immunization with either the S-HA or the R-HA strain elicited comparable HA-specific immune responses and the responses were significantly (p<0.05) higher compared to the Salmonella vector control. When chickens were pre-immunized with the smooth Salmonella carrier alone and then vaccinated with either S-HA or R-HA strain 3, 6 and 9 weeks later, respectively, significant reductions were seen for HA-specific immune responses at week 6, a point which corresponded to the peak of the primary Salmonella-specific antibody responses. No reductions were seen at week 3 and 9, albeit, the HA-specific immune responses were boosted at week 9, a point which corresponded to the lowest primary Salmonella-specific antibody responses. The ompA recall responses remain refractory at week 3 and 6 following deliberate immunization with the carrier strain, but were significantly (p<0.05) increased at week 9 post-primary immunization. We conclude that preexisting anti-Salmonella immunity inhibits antigen-specific immune responses and this effect could be avoided by carefully selecting the time point when carrier-specific immune responses are relatively low.
Copyright ? 2017 Elsevier B.V. All rights reserved.
[h=4]KEYWORDS:[/h] H9N2; Immune interference; O antigen; Preexisting immunity; Salmonella
PMID: 28622853 DOI: 10.1016/j.vetmic.2017.05.021
[h=1]Preexisting Salmonella-specific immunity interferes with the subsequent development of immune responses against the Salmonella strains delivering H9N2 hemagglutinin.[/h] Hajam IA[SUP]1[/SUP], Lee JH[SUP]2[/SUP].
[h=3]Author information[/h]
[h=3]Abstract[/h] Recombinant Salmonella strains expressing foreign heterologous antigens have been extensively studied as promising live vaccine delivery vehicles. In this study, we constructed attenuated smooth (S-HA) and rough (R-HA) Salmonella strains expressing hemagglutinin (HA) of H9N2, a low pathogenic avian influenza A virus. We then investigated the HA-specific immune responses following oral immunization with either S-HA or R-HA strain in chicken model. We further examined the effects of the preexisting anti-Salmonella immunity on the subsequent elicitation of the HA and the Salmonella ompA specific immune responses. Our results showed that primary immunization with either the S-HA or the R-HA strain elicited comparable HA-specific immune responses and the responses were significantly (p<0.05) higher compared to the Salmonella vector control. When chickens were pre-immunized with the smooth Salmonella carrier alone and then vaccinated with either S-HA or R-HA strain 3, 6 and 9 weeks later, respectively, significant reductions were seen for HA-specific immune responses at week 6, a point which corresponded to the peak of the primary Salmonella-specific antibody responses. No reductions were seen at week 3 and 9, albeit, the HA-specific immune responses were boosted at week 9, a point which corresponded to the lowest primary Salmonella-specific antibody responses. The ompA recall responses remain refractory at week 3 and 6 following deliberate immunization with the carrier strain, but were significantly (p<0.05) increased at week 9 post-primary immunization. We conclude that preexisting anti-Salmonella immunity inhibits antigen-specific immune responses and this effect could be avoided by carefully selecting the time point when carrier-specific immune responses are relatively low.
Copyright ? 2017 Elsevier B.V. All rights reserved.
[h=4]KEYWORDS:[/h] H9N2; Immune interference; O antigen; Preexisting immunity; Salmonella
PMID: 28622853 DOI: 10.1016/j.vetmic.2017.05.021