Studies on the host-parasite relationship of Nematospiroides dubius in the mouse

Hagan, Paul (1980) Studies on the host-parasite relationship of Nematospiroides dubius in the mouse. PhD thesis, University of Glasgow.

Abstract

The work presented in this thesis has shown that N. dubius has a marked immunosuppressive effect on the expulsion of T. spiralis from mice which was manifested by a delay in the rejection of T. spiralis. Using cell transfer techniques it was shown that both priming and expression of mesenteric lymph node cells was affected by N. dubius. Experiments designed to detect suppressor cell activity in this system provided equivocal results. The localization of labelled lymphoblasts was also examined in N. dubius and T. spiralis infected mice and it was found that the enhanced homing of lympho-blasts to the small intestine of T. spiralis infected mice was delayed by 8 days when a concurrent N. dubius infection was present. The ability of mice to mount a peripheral (subcutaneous) inflammatory response to a biologically inert filter was also investigated. No differences were detected in the numbers or rate of accumulation of macrophages or polymorphs onto the filters. An attempt to examine macrophage activity histochemically during N. dubius infection was found to be of little value. Responses of mesenteric lymph node cells from M. dubius infected mice to PHA were depressed throughout the first forty days of infection but it proved impossible to link these results to the measurements obtained from 'in vivo' blastogenesis. Concentrated ES-products from N. dubius adult worms were not toxic for lymphoid cells. In the second section the immune response against N. dubius was examined. Attempts to transfer immunity with serum obtained from multiply immunized mice were relatively unsuccessful giving a maximum protection against challenge infection of only 26%. Mesenteric lymph node cell and spleen cell transfers also gave limited protection. Splenectomy had little effect on the survival of a primary infection of N. dubius and did not alter the response to a challenge infection. As a result of the problems encountered with cell and serum transfers other methods of stimulating a transferable immunity were undertaken. The survival of irradiated larvae was examined and it was found that female worm fecundity was abolished by irradiation at 6.5k.rads and that a reduction in worm recoveries could be brought about by doses of 10k.rads and above. At 25k.rads virtually no larvae reached the adult stage. Irradiated larvae were shown to stimulate high levels of protection against challenge infection and their effectiveness was found to be mouse strain independent. N. dubius adult worms are not normally expelled from the intestine of NIH mice during infection. However, N. dubius adult worms, surgically implanted in low numbers (50 worms) were expelled from the intestines of mice which were in the process of eliminating a T. spiralis infection. The field strain of N. dubius isolated from A. sylvaticus was not capable of surviving in NIH mice without immunosuppressive treatment. However field strain parasites immunized mice against a challenge infection of normal larvae more effectively than did normal larvae.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Additional Information: Adviser: Dr. D. Wakelin
• Keywords: Parasitology, immunology.
• Subjects: Q Science > QL Zoology; Q Science > QR Microbiology
• Colleges/Schools: College of Medical Veterinary and Life Sciences
• Date of Award: 1980
• Depositing User: Enlighten Team
• Unique ID: glathesis:1980-72053
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 17 May 2019 13:13
• Last Modified: 02 Aug 2022 13:58
• URI: https://theses.gla.ac.uk/id/eprint/72053