Scientific Publications by FDA Staff

Int J Parasitol 2004 Feb;34(2):205-17

Generation of Leishmania donovani axenic amastigotes: their growth and biological characteristics.

Debrabant A, Joshi MB, Pimenta PF, Dwyer DM

Dwyer DM, NIAID, Cell Biol Sect, Parasit Dis Lab, Div Intramural Res,NIH, Bldg 4,Room 126, Bethesda, MD 20892 USA NIAID, Cell Biol Sect, Parasit Dis Lab, Div Intramural Res,NIH, Bethesda, MD 20892 USA US FDA, Ctr Biol Evaluat & Res, Div Emerging & Transfus Transmitted Dis, Bethesda, MD USA Fdn Oswaldo Cruz, Ctr Pesquisas Rene Rachou, Lab Med Entomol, Belo Horizonte, MG, Brazil

In this report, we describe an in vitro culture system for the generation and propagation of axenic amastigotes from the well characterised 1S-CL2D line of Leishmania donovani. Fine structure analyses of these in vitro-grown amastigotes demonstrated that they possessed morphological features characteristic of L. donovani tissue-derived amastigotes. Further, these axenic amastigotes (LdAxAm) were shown to synthesise and release a secretory acid phosphatase isoform similar to that produced by intracellular amastigotes. Such LdAxAm also expressed surface membrane 3'-nucleotidase enzyme activity similar to that of tissue-derived amastigotes. Moreover, LdAxAm, in contrast to promastigotes, expressed significant levels of the amastigote-specific A2 proteins. In addition, LdAxAm, derived from long term cultures of Ld 1S-CL2D promastigotes, had significant infectivity for both human macrophages in vitro and for hamsters in vivo. Thus, the in vitro culture system described herein provides a useful tool for the generation of large quantities of uniform populations of axenic amastigotes of the L. donovani 1S-CL2D line. The availability of such material should greatly facilitate studies concerning the cell and molecular biology of this parasite developmental stage.