The attachment and entry of Trypanosoma dionisii to mouse peritoneal macrophages in vitro were studied. Both occurred to a similar extent whether parasites were alive or heat-killed, and whether macrophages were obtained from normal or immunized mice. Attachment occurred equally at 4 and 37 C, but entry only occurred at the higher temperature. Neither was affected by pretreatment of parasites with active or inactivated complement. Entry, but not attachment, was inhibited by cytochalasin B; both were inhibited by trypsin. Immune mouse plasma (if inactivated) stimulated attachment but not entry (within 24 h). It also stimulated intracellular replication of T. dionisii by multiple fission and subsequent differentiation (probably within macrophages) to small extracellular trypomastigotes. No extracellular parasite and only scanty intracellular forms survived 120 h in cultures containing non-inactivated immune mouse plasma. It was concluded that attachment (in the absence of antibody) occurred to non-specific receptors in the macrophage membrane and was followed by phagocytosis of the parasites rather than their active penetration of the cell.
BakerJ. R.1976; Species of the subgenus Schizotrypanum other than Trypanosoma cruzi and their potential usefulness in the laboratory. Transactions of the Royal Society of Tropical Medicine and Hygiene 70:126–127
BakerJ. R., GreenS. M., ChalonerL. A., GaborakM.1972; Trypanosoma (Schizotrypanum) dionisii of Pipistrellus pipistrellus (Chiroptera): intra- and extra-cellular development in vitro. Parasitology 65:251–263
BakerJ. R., ListonA. J., SeldenL. F.1976; Trypomastigote dimorphism and satellite deoxyribonucleic acid in a clone of Trypanosoma (Schizotrypanum) dionisii. Journal of General Microbiology 97:113–115
BudzkoD. B., PizzimentiM. C., KierszenbaumF.1975; Effects of complement depletion in experimental Chagas’ disease: immune lysis of virulent blood forms of Trypanosoma cruzi. Infection and Immunity 11:86–91
DvorakJ. A., HydeT. P.1973; Trypanosoma cruzi: interaction with vertebrate cells in vitro. I. Individual reactions at the cellular and subcellular level. Experimental Parasitology 34:268–283
GriffinF. M., BiancoC., SilversteinS. C.1975; Characterization of the macrophage receptor for complement and demonstration of its functional independence from the receptor for the Fc portion of immunoglobulin G. Journal of Experimental Medicine 141:1269–1277
HoffR.1975; Killing in vitro of Trypanosoma cruzi by macrophages from mice immunized with T. cruzi or BCG, and absence of cross-immunity on challenge in vivo. Journal of Experimental Medicine 142:299–311
KloetzelJ., DeaneM. P.1970; Adherence of sensitized trypanosomes to peritoneal cells. Revista do Instituto de medicina tropical de São Paulo 12:383–387
KongtongP., InokiS.1975; Scanning electron microscopic studies on penetration of Trypanosoma cruzi into fibroblast cells. Japanese Journal of Parasitology 24:284–293
KreierJ. P., Al-AbassyS. M., SeedT. M.1976; Trypanosoma cruzi: observations on entry, development, release and ultrastructure of para-sites grown in cell cultures. Ohio Journal of Science 76:243–253
ListonA. J., BakerJ. R.1977; Trypanosoma dionisii: attachment and entry to mouse peritoneal macrophages in vitro and the involvement of membrane receptors. Journal of Protozoology (in the Press). [Abstract]
ListonA. J., BakerJ. R., SeldenL. F.1977; Specific delayed-type hypersensitivity footpad response in mice artificially immunized with two Trypanosoma (Schizotrypanum) species. Journal of General Microbiology 98:615–617
MilderR. V., KloetzelJ., DeaneM. P.1973; Observation on the interaction of peritoneal macrophages with Trypanosoma cruzi. I. Initial phase of the relationship with blood stream and culture forms in vitro. Revista do Instituto de medicina tropical de São Paulo 15:386–392
NogueiraN., CohnZ.1976; Trypanosoma cruzi: mechanism of entry and intracellular fate in mammalian cells. Journal of Experimental Medicine 143:1402–1420
StraussP. R.1971; The effect of homologous rabbit antiserum on the growth of Leishmania tarentolae - a fine structure study. Journal of Protozoology 18:147–156
TanowitzH., WittnerM., KressY., BloomB.1975; Studies of in vitro infection by Trypanosoma cruzi. I. Ultrastructural studies on the invasion of macrophages and L-cells. American Journal of Tropical Medicine 34:25–33
UnkelessJ. C.1977; The presence of two Fc receptors on mouse macrophages: evidence from a variant cell line and differential trypsin sensitivity. Journal of Experimental Medicine 145:931–947