Rickettsia typhi, the etiologic agent of murine typhus, is regarded as one of the major causes of acute febrile disease in Korea. Together with Rickettsia prowazekii, R. typhi is classified into typhus group, and the antigenic profiles of these
microbes
are very similar to each other. However, the species specific protein antigens of both species were reported to possess protective immunity. Accordingly, this antigen is thought as a candadato in the development of a recombinant vaccine.
To produce monoclonal antibodies to the species specific protein antigen of R. typhi, BALB/c mice were immunized with purified R. typhi and the culture supernatants of the hybrid cells were screened by indirect immuofluoresscence test. Among the
monoclonal antibodies produced, eight monoclonal antibodies were specific to R. typhi and two monoclonal antibodies reacted both with R. tyhpi and R. prowazekii. On western blotting, the former recognized the antigen with apparent size of 135kDa,
and
the latter, 33kDa. With these results, the molecular weight of species specific protein antigen of R. typhi was estimated approximately as 135kDa. And probably, the monoclonal antibodies to this protein could be used in the cloning of protective
antigens of R. typhi.
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