Immune response of the harderian gland in chickens to infectious bronchitis coronavirus

  • S. Guralska Polissia National University, 7, Stary Boulevard, Zhytomyr, Ukraine, 10008
  • T. Kot Polissia National University, 7, Stary Boulevard, Zhytomyr, Ukraine, 10008
  • N. Dyshliuk National University of Life and Environmental Sciences of Ukraine, 15, Heroyiv Oborony Str, Kyiv, Ukraine, 03041
  • S. Zaika Polissia National University, 7, Stary Boulevard, Zhytomyr, Ukraine, 10008
  • Z. Khomenko Polissia National University, 7, Stary Boulevard, Zhytomyr, Ukraine, 10008
Keywords: B-lymphocytes, humoral immunity, immunosuppression, avian infectious bronchitis, naive T-helpers, natural T-helpers, T-cytotoxic cells, foreign antigen

Abstract

Aim. To determine the difference in immune responses of the harderian gland in clinically healthy chickens and the ones with infectious bronchitis based on the content, localization and morphometric estimation of the surface markers of Т- and В-lymphocytes and to determine the differentiation index as an indicator of assessing body defenses. Methods. Histological, immunohistochemical, optical, morphometric and statistical. Results. The histological study of the harderian gland of chickens with infectious bronchitis determined the swelling and proliferation of the connective tissue as well as infiltration of secretory lobules by lymphoid cells. It was found that the immunity of chickens with infectious bronchitis, in which the harderian gland plays a relevant role, depends considerably on the differentiation index of immunocompetent cells. There was a reliable 1.77- and 1.36-fold decrease in this indicator for 40- and 90-day-old chickens, respectively, in case of nephroso-nephritic form of infectious bronchitis which demonstrated a weaker function of the defense cells of this organ. According to the cytomorphometric analysis, the number of cells, expressing CD4+, CD8+, CD20+, CD45RA+ markers in the harderian gland of sick 20-, 40-, and 90-day-old chickens with respiratory and nephroso-nephritic forms of infectious bronchitis was reliably (P < 0.05) increasing compared to the clinically healthy chickens. For instance, the number of mature В-lymphocytes increased in sick 20-day-old chickens – 2.44 times, 40-day-old chickens – 1.88 times, and 90-day-old ones – 2.62 times compared to clinically healthy chickens. Conclusions. The data were obtained about the changes in quantitative and qualitative composition of lymphocytes with surface markers CD4+, CD8+, CD20+, CD45RA+ in the harderian gland of chickens with infectious bronchitis. Our results will supplement current knowledge about the feasibility of immunohistochemical methods in the diagnostics of avian infectious bronchitis.
Published
2021-06-10
How to Cite
Guralska, S., Kot, T., Dyshliuk, N., Zaika, S., & Khomenko, Z. (2021). Immune response of the harderian gland in chickens to infectious bronchitis coronavirus. Agricultural Science and Practice, 8(1), 58-66. https://doi.org/10.15407/agrisp8.01.049