A. Binder et al., THE MYCOPLASMA ARTHRITIDIS INFECTION IN CONGENITALLY ATHYMIC NUDE RATS, Journal of experimental animal science, 35(4), 1993, pp. 177-185
Fifteen young (47-81 days old) and 5 adult (360 days old) Rowett nude
rats (rnu/rnu) and 12 euthymic littermates (rnu/+) (56 days old) were
infected with Mycoplasma (M.) arthritidis ISR1. The polyarthritis deve
loping after the infection was more severe in the athymic than in the
euthymic rats. In the nude rats the disease was progressive and led to
the death of 6 animals whereas in the euthymic littermates the diseas
e was resolved within 70 days after infection. In contrast to euthymic
rats athymic animals did not develop antibodies against M. arthritidi
s within 6 weeks (young nude rats) or 23 weeks (adult nude rats) after
infection, indicating that M. arthritidis is a thymus dependent antig
en. However, low antibody titers were found in the nude rats infected
at an age between 47 and 81 days at 340 days after infection, probably
due to the development of T-cells which occur in older nude rats. The
euthymic as well as the young athymic rats showed an increase in anti
body titers after a challenge infection 345 days after the first infec
tion and both were resistant to challenge infection. On the contrary t
he adult nude rats infected with M. arthritidis did not develop antibo
dies against the mycoplasmas and were highly susceptible to a second i
nfection after 198 days. This indicates that antibodies play an import
ant role in the defence of the M. arthritidis infection in rats.