An investigation of factors involved in the development of eosinophilic responses in rodents

Entrican, Gary (1985) An investigation of factors involved in the development of eosinophilic responses in rodents. PhD thesis, University of Glasgow.

Abstract

Elevated numbers of blood and tissue eosinophils were induced in mice and rats by parasitic and non-parasitic means. Mice infected with the nematode Trichinella spiralis developed a peripheral blood eosinophilia which peaked approximately 21 days post infection. Histological examination of various tissues showed that the blood does not always reflect total body changes in eosinophil distribution. The numbers of eosinophils in skeletal muscle continued to increase at a time when the numbers of eosinophils in the blood were decreasing. The involvement of T. spiralis antigens in eliciting this eosinophilia was investigated using an artificial method to localize parasitic material in tissue. A homogenate of T. spiralis larvae was shown to be antigenic by precipitation with serum from a T. spiralis- infected rabbit. This antigenic preparation, designated TSAG, was also capable of eliciting a humoral response when injected into a rabbit. Although not a pure antigenic preparation, the TSAG did contain antigenic components which could bind to inert latex particles. This was demonstrated in vitro by agglutination and fluorescent techniques. When these TSAG-coated particles were injected into mice in such a manner as to result in their embolization in the pulmonary vasculature, they elicited a greater peripheral blood eosinophilic response than mcoated particles. However, similar studies on mice injected with latex particles coated with a non-parasite antigen (BGG) induced a comparable eosinophilia to that induced by parasite antigen- coated particles. The eosinophilia could not, therefore, be directly related to TSAG. Histological measurements of pulmonary cellular accumulations around the embolized particles also showed that TSAG was not more effective than BGG at inducing pulmonary cell accumulations, and furthermore, that uncoated particles also induced cell accumulations. The response to uncoated particles suggested a non-specific mechanism for the induction of eosinophilic responses. This latex model was used to investigate the ability of athymic (Rnu/Rnu) nude rats to develop an eosinophilia following pulmonary embolization of BGG-coated or uncoated latex particles. The number of circulating eosinophils increased in both cases, with the greater response occurring in rats injected with latex-BGG. A similar response was observed in euthymic (Rnu/+) littermates. Pretreatment of both Rnu/Rnu and Rnu/+ rats with antithymocyte serum altered the magnitude of the response but did not totally abrogate it. Studies on interleukin-1 activity in lung lavages recovered from these rats showed that injection of latex particles did not enhance alveolar macrophage activity 48 hours after their pulmonary embolization. The level of activity was similar in both Rnu/Rnu and Rnu/+ rats suggesting that macrophages were not involved in the response in Rnu/Rnu rats which are T cell deficient. The results show that the possibility of a residual T cell population in these rats cannot be excluded. In addition to these responses to physical manipulations, evidence is provided for inherent fluctuations in the number of circulating eosinophils, emphasizing the importance of careful experimental design when investigating haematological phenomena.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Keywords: Pathology, parasitology.
• Colleges/Schools: College of Medical Veterinary and Life Sciences
• Supervisor's Name: Parrott, Prof. D.M.V., Bruce, Dr. R.G. and Eady, Dr. R.P.
• Date of Award: 1985
• Depositing User: Enlighten Team
• Unique ID: glathesis:1985-73740
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 14 Jun 2019 08:56
• Last Modified: 15 Jun 2021 11:13
• URI: https://theses.gla.ac.uk/id/eprint/73740