| dc.description.abstract | The gene expression of two immunoregulatory cytokines, IL-10 and IFN-y, during
infection of bovine leukocytes with T. parva was investigated at the single cell level.
Initial results obtained from in vitro studies with infected cells using RT-PCR showed
that both Il.TO and IFN-y messages were present. The ability of Theileria-infected cells
to produce Ils-l Otranscripts was a consistent feature. However, their ability to exhibit
IFN-y messages was less consistent. On application of in situ hybridisation technique
using bovine Il.s lO and IFN-y-specific riboprobes, it was demonstrated that most
infected lymphocytes produced ll.,-l 0 and that few of these cells displayed expression of
IFN~y transcripts. Thus, judging from the relative abundance of Il.>I0 and lack of IFN-y
mRNA, the expression of Ilv lO, a cytokine known to inhibit IFN-y production and
functions, was shown to be upregulated in leukocytes responding to T. parva infection
in cattle. These experiments did not demonstrate the production of biologically active
Il.s IO during the infection. However, the accompanying relative absence of IFN-y
mRNA in situ may suggests that biologically active Il--I 0 was produced and blocked the
production of IFN-y, an important effector TH I cytokine. The apparent upregulated
expression of Ilv lOduring infection with T. parva is indicative of a regulatory role for
this cytokine in the mediation of susceptibi"lity to acute disease. This parasite-instigated
induction and upregulation of ll.,-I 0 expression may represent an important strategy by
which intracellular T. parva eludes IFN-y-dependent cell-mediated immune destruction.
Through its induction of tissue-damaging metalloproteinase, Il.s lOpresence also offers
a biochemical explanation ·to - the possible mechanism of propagating the
lymphoproliferative, immunopathologic and tissue destructive phenomena observed in
ECF. | en |
