RESUMO
The process of interaction between macrophages and Tritrichomonas foetus and Trichomonas vaginalis was analysed using light microscopy, scanning and transmission electron microscopy. The parasites attach to the macrophage surface and are ingested through a phagocytic process. Parasite-macrophage association index was higher for activated than for resident macrophages. Previous incubation of the parasites in the presence of Concanavalin A rendered their surface less negative and more hydrophobic, as evaluated by measurement of the zeta potential and contact angle, respectively. This treatment significantly increased parasite ingestion by resident, but not activated macrophages.
Assuntos
Macrófagos/parasitologia , Tritrichomonas/metabolismo , Animais , Concanavalina A/farmacologia , Macrófagos/fisiologia , Macrófagos/ultraestrutura , Camundongos , Microscopia Eletrônica , Microscopia Eletrônica de Varredura , Fagocitose/efeitos dos fármacos , Fagocitose/fisiologia , Tritrichomonas/fisiologia , Tritrichomonas/ultraestruturaRESUMO
The pathogenic protozoan Tritrichomonas foetus is able to ingest polystyrene particles with a diameter up to 1.0 micron. Trichomonas vaginalis, however, ingest particles as large as 4.4 microns in diameter. The particles are found within cytoplasmic membrane-bounded vacuoles. Morphometrical analysis showed that T. vaginalis presents a higher endocytic activity than T. foetus. Coating of the polystyrene particles with cationized ferritin increases their binding to the parasite surface but does not interfere with their ingestion. In contrast, coating with laminin significantly increased the uptake of the particles by both parasites while coating with fibronectin potentiates the ingestion of the particles only by T. foetus. These observations suggest the presence of laminin- and fibronectin-binding sites on the surface of trichomonads, an observation which is in agreement with the recent description of a receptor for laminin on the surface of trichomonads.
Assuntos
Endocitose/fisiologia , Trichomonas vaginalis/fisiologia , Tritrichomonas/fisiologia , Animais , Sítios de Ligação , Fibronectinas/fisiologia , Laminina/fisiologia , Microscopia Eletrônica , Microscopia Eletrônica de Varredura , Receptores de Fibronectina , Receptores Imunológicos/fisiologia , Receptores de Laminina , Trichomonas vaginalis/ultraestrutura , Tritrichomonas/ultraestruturaRESUMO
Four Tritrichomonas foetus strains were successfully preserved in liquid nitrogen at -196 degrees C in the presence of 10% dimethylsulfoxide (DMSO) for 7 months (Strain 1) and 6 months (Strain 2, 3 and 4). The percentage of viable organisms after thawing ranged between 65 and 85%, depending upon the strain. The method used is described in detail.