Involvement of dsRNA virus in the protein compositionand growth kinetics of host Trichomonas vaginalis

Summary

Trichomonas vaginalis harbors a double-stranded (ds)-RNA virus, and the presence of virus is related to upregulated expression and phenotypic variation of a prominent immunogen (Khoshnan A, Alderete JF (1994) J Virol 68: 4 035–4 038). To further test the influence of virus on T. vaginalis, virus-infected (V⁺) isolates were compared to virus-free (V^-), agar-cloned progeny trichomonads derived from the parental isolates for accumulation of total proteins and cysteine proteinases. Comparative high resolution two dimensional (2D)-SDS-PAGE was performed of trichomonads grown in a chemostat under identical conditions. At least 47 proteins were identified as specifically expressed by representative V⁺ isolate 347, and ∼41 spots were specific to the corresponding V^- progeny, showing an association between virus and the presence and absence of parasite proteins. Qualitatively and quantitatively dissimilar cysteine proteinase patterns were detected from numerous V⁺ isolates and the V^- progeny. A 2D analysis for isolate 347 showed the appearance of unique proteinase activities for parental parasites and presence of at least one proteinase in the V^- progeny. Finally, the V⁺ T. vaginalis isolate 347, but not the V^- isolate 347 progeny nor other V⁺ isolates, underwent fluctuations in density during chemostat growth allowing for purification of virus particles from the V⁺ isolate 347 supernatants during decreased parasite density.