Abstract
The effect of peritoneal macrophages and serum from mice infected with Babesia microti, Schistosoma mansoni and B. microti plus S. mansoni on the growth of B. microti was assessed in short term in vitro cultures using the criterium of rate of incorporation of (3H)Hypoxan-thine. In the absence of serum, macrophages and supernatants from macrophage cultures failed to affect the in vitro growth of B. microti. In contrast, in the absen-de of macrophages, serum from mice infected with B. microti and with B. microti plus S. mansoni induced a marked inhibition of the in vitro growth of B. Microti. The level of inhibition induced by serum from mice infected with both S. mansoni and B. microti exceeded consistently that induced by serum from mice infected with B. microti only. Serum from mice only infected with S. mansoni induced a marked increase in the in vitro growth of B. microti. These findings suggest a suppression of B. microti in concurrently S. mansoni-infected mice induced by an immunological specific anti-2?. microti factor potentiated by the concurrent S. mansoni infection. The results do not indicate that activation of the mononuclear phagocytic system is of primary importance in suppression of B. microti in-concurrently S. mansoni infected mice.
Keywords: rodent model, concurrent infection, in vitro cultures, peritoneal macrophages, (3H)Hypoxanthine incorporation, growth inhibition, potentiation of immunological response, immunological specific anti-B. microti factor.
Sammendrag
Effekten aΓ peritoneale makrofager og serum fra mus inficerede med Babesia microti, Schistosoma mansoni, og B. microti plus S. mansoni pæ væksten af B. microti blev undersøgt i korttids in vitro-kultur-er under anvendelse af (3H)Hypoxanthine inkorporering som vækstkriterium. I fravær af serum påvirkede hverken makrofager eller supernatanten fra makrofagkulturer in vitro væksten af B. microti. I modsætning hertil forårsagede serum fra mus inficerede med B. microti og med B. microti plus S. mansoni i fravær af makrofager en markant hæmning af væksten af B. microti in vitro. Graden af hæmning forårsaget af serum fra S. mansoni plus B. microti inficerede mus overgik konsekvent graden af hæmning forårsaget af serum fra B. microti inficerede mus. Serum fra S. mansoni inficerede mus forårsagede en markant forøgelse i in vitro væksten af B. microti. Disse resultater peger på at in vivo suppression af B. microti i mus med en samtidig S. mansoni infection kan være forårsaget af en immunologisk specifik anti-B, microti faktor der potentieres gennem samtidig tilstedeværelse af S. mansoni infektion. Resultaterne tyder ikke på at non-specifik aktivering af det mononukleære fagocytiske system er af primær betydning for suppression af B. microti i mus med samtidig S. mansoni infektion.
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Acknowledgments
This study was supported by grants from the Carls-berg Foundation and the Danish Natural Science Research Council.
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