T. cruzi trypomastigotes

An important discovery about T. cruzi life cycle occurred in the 1980s. Deane et al. (1986) have shown that the entire developmental cycle of T. cruzi (trypomastigotes-epimastigotes-metacyclic infective trypomastigotes) may take place within the lumen of the anal odoriferous glands of... 

Purified GPIs, obtained by proteinase K digestion from the mucins of T. cruzi trypomastigotes (tGPIs), are potent inducers of nitric oxide, tumor necrosis factor-a and interleukin-12. The unsaturated fatty acid of the GPI alkylacyl-PI moiety is essential for bioactivity, but other features of the intact GPI are also necessary since the PI obtained by nitrous acid treatment was inactive.32 Correlation between GPI structure and proinflammatory activity in macrophages has been reviewed.52... 

SCHEME 4. Retrosynthetic scheme for the synthesis of the GPI-anchor of T. cruzi trypomastigote glycoproteins, lacking Gal/ in the glycan, showing key building blocks and D-mannose monosaccharide intermediates. 

A partially characterized sulfoglycosphingolipid is also present in T. cruzi trypomastigotes (60). Besides neutral and sulfoglycosphingolipids, sialoglycolipids have been characterized in trypomastigote forms of T. cruzi (61). 

GPI fraction purified from T. cruzi trypomastigote mucins has a level of proin-flammatory activity that is comparable with bacterial hpopolysaccharide [9]. Given that neither the glycan structure alone nor the lyso-aUcyl- or acyl-alkyl-phosphatidylinositol moieties are able to induce the production of NO, interleukin 12 (IL-12), and tumor necrosis factor-a (TNF-a) in macrophages, it is hypothesized that the full GPI structure, containing the unsaturated fatty acids, is necessary for the observed proinflammatory activity. 

The enzymatically active protein isolated from T. cruzi trypomastigotes through cleavage of the glycophosphoinositol anchor, comprises several distinct domains [28] (Figure 4) ... 

In the first week after T. cruzi infection, trypomastigotes are detected in blood samples by microscopic examination, but parasitemia is rapidly controlled and becomes extremely low. The infection persists for the lifetime of humans and laboratory animals as either latent or pathogenic parasitism. It is extremely difficult to demonstrate circulating parasites during the chronic disease (Krettli, 2009). 

States, Roellig et al. (2009) presented the first demonstration of the oral transmission of T. cruzi to raccoons (Procyon lotor), a natural reservoir host in the United States, by ingestion of trypomastigotes and infected insects. 

According to Dias (2006), cooking above 45 °C and pasteurization are capable of killing T. cruzi cells. However, the meat of wild animals should be cooked above 60 °C, since T. cruzi amastigotes cells can survive in the tissues of these animals at such a temperature (Neto et al., 2000). Ferreira et al. (2001) working with experimentally contaminated human milk found that heating at 62.5 °C for 30 min was sufficient for inactivation of trypomastigote forms of T. cruzi. 

The use of microwaves was also suggested as a hypothesis for inactivation of T. cruzi in human milk. Ferreira et al. (2003) were able to inactivate trypomastigotes present in human milk when heating to 63 °C (7 min, 45% power) in a domestic microwave oven (2450 MHz, 700 W). 

T. cruzi exhibits two cell types in vertebrate hosts, a blood form termed a trypomastigote, and in the tissues (mainly heart, skeletal and smooth muscle, and reticulo-endothelial cells) the parasite occurs as an amastigote (Fig. 6.3). Trypomastigotes... 

T. cruzi small mucin-like gene family TcTS, Trypanosoma cruzi trans-sialidase THF, tetrahydrofuran TMSOTf, trimethylsilyl trifluoromethanesulfonate TRR, Thr-rich region TSSA, trypomastigote small surface antigen UDP, uridine diphosphate VSG, variant surface glycoprotein. 

It was shown that the IPC synthase was induced upon differentiation,47 providing an important target for antiprotozoal therapy, since no equivalent mammalian enzyme is known. In this respect, biosynthesis of radioactive IPC by metabolic labeling of T. cruzi epimastigotes,66 trypomastigotes,69 and amastigotes47 could be used to study the action of potential inhibitors. Properties of the IPC synthase have been described,70 but in contrast to earlier results,47 the authors report no inhibition of the enzyme by aureobasidin. Elucidation of the structure of the T. cruzi enzyme would clarify its analogy with the yeast enzyme. 

A 45-kDa mucin, expressed only in invasive trypomastigotes and shed to the medium, is involved in adhesion to mammalian cells.126 It was recognized by the anU-T-cruzi mucin monoclonal antibody MabC20, although no structural data are included to support its classification as a mucin. 

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