Effects of avian infectious bronchitis with Newcastle disease and Marek's disease vaccinations on the expression of toll-like receptors and avian β-defensins in the kidneys of broiler chicks

Abstract

The aim of this study was to determine the effect of vaccinations for avian infectious bronchitis/Newcastle disease ( IB/ND ) and Marek's disease ( MD ) on the expression of Toll-like receptors ( TLR s) that recognize viral RNA and microbial DNA, and avian β-defensins ( AvBD s) in chick kidneys. Day-old chicks were vaccinated with MD or IB/ND vaccines, or received no treatment (control group). The gene expression of TLRs and AvBDs in the kidneys of 3-day-old chicks and 10-day-old chicks was examined using real-time PCR. The localization of AvBD2 and AvBD4 was examined by immunohistochemistry at day three only. At 3 days of age the expression of TLR7 and TLR21 was significantly higher in the IB/ND group (but not in the MD group) when compared to the control group. Conversely, at 10 days of age there was no significant difference in the expression of the three TLRs between groups. In the 3-day-old chicks the expression levels of AvBD4, 5, 6, and 7 were higher in the MD group when compared to the control group. Furthermore, at this age, the expression levels of other AvBDs were not significantly different between the control and vaccination (MD and IB/ND) groups. At 10 days of age, no AvBD expression was affected by MD and IB/ND vaccinations. Immunohistochemistry results localized AvBD2 in the leukocytes in the interstitial tissue and AvBD4 in the surface of microvillus epithelial cells of renal tubules, and in the epithelial cells of the collecting ducts and ureter. The localization of AvBD2 and AvBD4 was identified in all chicks. We suggest that the expression of innate immune molecules (including TLRs and AvBDs) in kidneys could be modulated by MD and IB/ND vaccination when performed at the day-old stage. Although the effects of both vaccinations may subside within 10 days, the enhanced expression of those innate immune molecules may support the innate immuno-defense function in the kidneys of young chicks.

Modulation of the innate immune system by lipopolysaccharide in the proventriculus of chicks inoculated with or without Newcastle disease and infectious bronchitis vaccine

“…The expression of TLR21 was higher in the proventriculus of chicks administered with the ND/IB vaccine (V+L-) than in nonvaccinated chicks (V-L-). Recently, we reported that ND/IB vaccination increased the expression of TLR7 and TLR21 in chick kidneys ( Shimizu et al, 2020 ). Thus, it is likely that the inoculation of chicks with ND/IB vaccine upregulates the expression of TLR21 that recognize unmethylated CpG-DNA of DNA virus and bacteria in both the proventriculus and kidney.…”

“…The antibodies against AvBD1, AvBD2, and CATH1 were used in our previous studies involving immunohistochemistry and western blot analysis ( Elhamouly et al, 2018 ; Elhamouly et al, 2019 ; Shimizu et al, 2020 ; Terada et al, 2020a ). Antisera against AvBD1, AvBD2, and CATH1 was raised by immunization of rabbits with keyhole limpet hemocyanin-conjugated synthetic peptide (anti-AvBD1 was obtained from Operon Biotechnologies K.K., Tokyo Japan; anti-AvBD2 was obtained from Medical & Biological Laboratories, Nagoya, Japan; and CATH1 was obtained from Sigma-Aldrich Japan K.K., Tokyo, Japan).…”

“…We reported that routine multiple vaccinations, including vaccines for Marek's disease ( MD ), avian infectious bronchitis virus ( IB ), Newcastle disease and IB virus ( ND/IB ), and infectious bursal disease, caused the increase in the expression of TLR2 and 21 and the decrease in the AvBDs expression in the ovary of 21-day-old chicks ( Kang et al, 2019 ). Meanwhile, our recent study showed that ND/IB vaccination upregulated the expression of TLR7 and 21 among 3 TLRs (TLR3, 7, and 21), and MD vaccination modulated the expression of AvBDs in the kidney of 3-day-old chicks ( Shimizu et al, 2020 ). Thus, we hypothesize that training of the innate immunities by vaccination may be possible in the different organs in chicks as reported in mammals.…”

“…The LPS challenge was performed because many pathogenic microbes infecting the gut include gram-negative bacteria such as Salmonella bacteria and Campylobacter. The ND/IB vaccine was expected to affect the innate immunity because our previous study showed that the expression of two of three TLRs was upregulated by that vaccine in the chick kidney ( Shimizu et al, 2020 ).…”

Avian Beta Defensin 2 (AvBD2) Gene Polymorphism Identification in IPB-D1 Chicken

“…Several molecules have also been reported to suppress the action of AvBD2 in defense against NDV, one of which is p38 MAPK (Liu et al 2018). In addition, localization of AvBD2 and AvBD4 was found in chickens that were vaccinated against ND and Marek's disease (Shimizu et al 2020).…”