TcTASV-C, a Protein Family in Trypanosoma cruzi that Is Predominantly Trypomastigote-Stage Specific and Secreted to the Medium

Abstract

Among the several multigene families codified by the genome of T. cruzi, the TcTASV family was the latest discovered. The TcTASV (Trypomastigote, Alanine, Serine, Valine) family is composed of ∼40 members, with conserved carboxi- and amino-termini but with a variable central core. According to the length and sequence of the central region the family is split into 3 subfamilies. The TcTASV family is conserved in the genomes of – at least – lineages TcI and TcVI and has no orthologues in other trypanosomatids. In the present work we focus on the study of the TcTASV-C subfamily, composed by 16 genes in the CL Brener strain. We determined that TcTASV-C is preferentially expressed in trypomastigotes, but it is not a major component of the parasite. Both immunoflourescence and flow cytometry experiments indicated that TcTASV-C has a clonal expression, i.e. it is not expressed by all the parasites of a certain population at the same time. We also determined that TcTASV-C is phosphorylated and glycosylated. TASV-C is attached to the parasite surface by a GPI anchor and is shed spontaneously into the medium. About 30% of sera from infected hosts reacted with TcTASV-C, confirming its exposition to the immune system. Its superficial localization and secretory nature suggest a possible role in host-parasite interactions.

Sialic Acid Glycobiology Unveils Trypanosoma cruzi Trypomastigote Membrane Physiology

“…The puzzling non-colocalizing patterns found for the different proteins analyzed, together with other reports of trypomastigote proteins that also displayed dotted patterns [ 18 , 25 , 48 ] suggest a particular membrane topology with defined domains. To obtain highly solved topological information, we then assayed atomic force microscopy (AFM), a suitable tool that has been used in epimastigotes [ 49 , 50 ].…”

“…Despite their complexity and variations in amino acid sequence, TcMUC II deduced products share a common structure made up of a highly conserved N -terminal signal peptide, a variable and central region showing highly biased amino acid composition, in which Thr, Ser, Pro, Gly, and Ala residues together might add up to 60–80% of the total count, and a C -terminal GPI attachment signal. Besides the TcMUC genes, other families of glycosylated proteins families such as TcTASV [ 18 ] and MASP [ 7 ] are being discovered. To date, the structure of the O -linked oligosaccharides has only been determined for the mucins from the non-infective insect epimastigote stage (known as Gp35/50 mucins) of different strains of T .…”

Trypanosoma cruzi 80 kDa prolyl oligopeptidase (Tc80) as a novel immunogen for Chagas disease vaccine

“…Although a vesicular location near the flagellar pocket has been described in trypomastigotes [ 6 ], its location on the surface cannot be ruled out since many T . cruzi protein has been shown to be temporary located on the membrane [ 45 – 47 ].…”

Towards High-throughput Immunomics for Infectious Diseases: Use of Next-generation Peptide Microarrays for Rapid Discovery and Mapping of Antigenic Determinants

“…Peptides from the same protein were synthesized at randomized positions within a single sector. The chip contains additional 2386 unique peptides corresponding to eight proteins not accounted within the protein groups defined above (and of which 2 proteins resulted seropositive), including members of the T. cruzi TASV protein family ( 30 , 31 ) and 21 epitopes of high prevalence in healthy humans (not associated to Chagas disease, identified in the IEDB with a search for linear B-cell epitopes from any source with sero-prevalence > = 50%, assayed in at least 20 subjects). The sequences of these 532 proteins (457 T. cruzi proteins, 54 neo-proteins and the additional 21 short peptidic epitopes of high prevalence in healthy humans) are available in supplemental Table S4 .…”