The Journal of Medical Microbiology, Vol 13, Issue 2 313-318, Copyright © 1980 by Society for General Microbiology
Immunosuppression in toxoplasmosis: further studies on mice infected with louping-ill virus
H. W. Reid, D. Buxton, I. Pow and J. Finlayson
Mice were infected with an avirulent cyst-producing strain of Toxoplasma
gondii and given injections of louping-ill virus 7 days later; control mice
were given virus but not Toxoplasma. Test and control mice were then
killed, in groups, 2, 4, 6, 8 and 10 days later. In the dually infected
mice viraemia was later, greater and more prolonged; titres of virus
recovered from brain and spleen were greater; production and
haemagglutinating antibody to louping-ill virus was later and less, and
inflammation in the brain was more severe, than in mice given virus alone.
We suggest that T. gondii suppressed the immunity of mice, making them more
susceptible to the virus, and that a significant proportion of the
increased number of inflammatory cells observed in the brain could have
been toxoplasma specific and not virus-specific and hence contributed to
the increased susceptibility of the dually infected mice to louping-ill
virus.
