Biomarkers of therapeutic responses in chronic Chagas disease: state of the art and future perspectives

The definition of a biomarker provided by the World Health Organization is any substance, structure, or process that can be measured in the body, or its products and influence, or predict the incidence or outcome of disease. Currently, the lack of prognosis and progression markers for chronic Chagas disease has posed limitations for testing new drugs to treat this neglected disease. Several molecules and techniques to detect biomarkers in Trypanosoma cruzi-infected patients have been proposed to assess whether specific treatment with benznidazole or nifurtimox is effective. Isolated proteins or protein groups from different T. cruzi stages and parasite-derived glycoproteins and synthetic neoglycoconjugates have been demonstrated to be useful for this purpose, as have nucleic acid amplification techniques. The amplification of T. cruzi DNA using the real-time polymerase chain reaction method is the leading test for assessing responses to treatment in a short period of time. Biochemical biomarkers have been tested early after specific treatment. Cytokines and surface markers represent promising molecules for the characterisation of host cellular responses, but need to be further assessed.RICET RD12/0018/0010. RICET RD12/0018/0021. AGAUR 2014SGR26. Plan Nacional de I+D+I SAF2012-35777. Plan Nacional de I+D+I SAF2013-48527-R. NIMHD/NIH 2G12MD007592. Financial support: CRESIB and IPBLN research members were partially supported by the RICET (RD12/0018/0010, RD12/0018/0021), M-JP and JG received research funds from AGAUR (2014SGR26) and Fundación Mundo Sano, M-CT and M-CL were supported by Plan Nacional de I+D+I (MINECO-Spain) (SAF2012-35777, SAF2013-48527-R and FEDER), ICA was partially supported by NIMHD/NIH (2G12MD007592). Financial support: CRESIB and IPBLN research members were partially supported by the RICET (RD12/0018/0010, RD12/0018/0021), M-JP and JG received research funds from AGAUR (2014SGR26) and Fundación Mundo Sano, M-CT and M-CL were supported by Plan Nacional de I+D+I (MINECO-Spain) (SAF2012-35777, SAF2013-48527-R and FEDER), ICA was partially supported by NIMHD/NIH (2G12MD007592).Peer reviewe

The Trypomastigote Small Surface Antigen (TSSA) regulates Trypanosoma cruzi infectivity and differentiation

Background: TSSA (Trypomastigote Small Surface Antigen) is an antigenic, adhesion molecule displayed on the surface of Trypanosoma cruzi trypomastigotes. TSSA displays substantial sequence identity to members of the TcMUC gene family, which code for the trypomastigote mucins (tGPI-mucins). In addition, TSSA bears sequence polymorphisms among parasite strains; and two TSSA variants expressed as recombinant molecules (termed TSSA-CL and TSSA-Sy) were shown to exhibit contrasting features in their host cell binding and signaling properties. Methods/Principle findings: Here we used a variety of approaches to get insights into TSSA structure/function. We show that at variance with tGPI-mucins, which rely on their extensive O-glycoslylation to achieve their protective function, TSSA seems to be displayed on the trypomastigote coat as a hypo-glycosylated molecule. This has a functional correlate, as further deletion mapping experiments and cell binding assays indicated that exposition of at least two peptidic motifs is critical for the engagement of the ‘adhesive’ TSSA variant (TSSA-CL) with host cell surface receptor(s) prior to trypomastigote internalization. These motifs are not conserved in the ‘non-adhesive’ TSSA-Sy variant. We next developed transgenic lines over-expressing either TSSA variant in different parasite backgrounds. In strict accordance to recombinant protein binding data, trypomastigotes over-expressing TSSA-CL displayed improved adhesion and infectivity towards non-macrophagic cell lines as compared to those over-expressing TSSA-Sy or parental lines. These phenotypes could be specifically counteracted by exogenous addition of peptides spanning the TSSA-CL adhesion motifs. In addition, and irrespective of the TSSA variant, over-expression of this molecule leads to an enhanced trypomastigote-to-amastigote conversion, indicating a possible role of TSSA also in parasite differentiation. Conclusion/Significance: In this study we provided novel evidence indicating that TSSA plays an important role not only on the infectivity and differentiation of T. cruzi trypomastigotes but also on the phenotypic variability displayed by parasite strains.Fil: Camara, María de los Milagros. Universidad Argentina de la Empresa; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas; ArgentinaFil: Canepa, Gaspar Exequiel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas; ArgentinaFil: Lantos, Andrés Bernardo Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas; ArgentinaFil: Balouz, Virginia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas; ArgentinaFil: Yu, Hai. University of California at Davis; Estados UnidosFil: Chen, Xi. University of California at Davis; Estados UnidosFil: Campetella, Oscar Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas; ArgentinaFil: Mucci, Juan Sebastián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas; ArgentinaFil: Buscaglia, Carlos Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas; Argentin

An alpha-Gal-containing neoglycoprotein-based vaccine partially protects against murine cutaneous leishmaniasis caused by Leishmania major

Submitted by Sandra Infurna ([email protected]) on 2018-02-08T14:28:28Z No. of bitstreams: 1 otacilio_moreira_etal_IOC_2017.pdf: 4048766 bytes, checksum: 739bd60ac93001eb3f167318d867f73c (MD5)Approved for entry into archive by Sandra Infurna ([email protected]) on 2018-02-08T14:43:56Z (GMT) No. of bitstreams: 1 otacilio_moreira_etal_IOC_2017.pdf: 4048766 bytes, checksum: 739bd60ac93001eb3f167318d867f73c (MD5)Made available in DSpace on 2018-02-08T14:43:57Z (GMT). No. of bitstreams: 1 otacilio_moreira_etal_IOC_2017.pdf: 4048766 bytes, checksum: 739bd60ac93001eb3f167318d867f73c (MD5) Previous issue date: 2017University of Texas at El Paso. Department of Biological Sciences. Border Biomedical Research Center. El Paso, Texas, USA.University of Texas at El Paso. Department of Chemistry. Border Biomedical Research Center. El Paso, Texas, USA.Liverpool School of Tropical Medicine. Department of Parasitology. Pembroke Place, Liverpool, United Kingdom.University of Texas at El Paso. Department of Biological Sciences. Border Biomedical Research Center. El Paso, Texas, USA.University of Texas at El Paso. Department of Chemistry. Border Biomedical Research Center. El Paso, Texas, USA.Liverpool School of Tropical Medicine. Department of Parasitology. Pembroke Place, Liverpool, United Kingdom.University of Texas at El Paso. Department of Biological Sciences. Border Biomedical Research Center. El Paso, Texas, USA.University of Texas at El Paso. Department of Biological Sciences. Border Biomedical Research Center. El Paso, Texas, USA.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia Molecular e Doenças Endêmicas. Rio de Janeiro, RJ. Brasil.Liverpool School of Tropical Medicine. Department of Parasitology. Pembroke Place, Liverpool, United Kingdom / Liverpool School of Tropical Medicine. Department of Vector Biology. Pembroke Place, Liverpool, United Kingdom.University of Texas at El Paso. Department of Chemistry. Border Biomedical Research Center. El Paso, Texas, USA.University of Texas at El Paso. Department of Biological Sciences. Border Biomedical Research Center. El Paso, Texas, USA.University of Texas at El Paso. Department of Biological Sciences. Border Biomedical Research Center. El Paso, Texas, USA.Protozoan parasites from the genus Leishmania cause broad clinical manifestations known as leishmaniases, which affect millions of people worldwide. Cutaneous leishmaniasis (CL), caused by L. major, is one the most common forms of the disease in the Old World. There is no preventive or therapeutic human vaccine available for L. major CL, and existing drug treatments are expensive, have toxic side effects, and resistant parasite strains have been reported. Hence, further therapeutic interventions against the disease are necessary. Terminal, non-reducing, and linear α-galactopyranosyl (α-Gal) epitopes are abundantly found on the plasma membrane glycolipids of L. major known as glycoinositolphospholipids. The absence of these α-Gal epitopes in human cells makes these glycans highly immunogenic and thus potential targets for vaccine development against CL