Host Cell Poly(ADP-ribose) glycohydrolase Is Crucial for Trypanosoma cruzi Infection Cycle

Trypanosoma cruzi, etiological agent of Chagas´ disease, has a complex life cycle which involves the invasion of mammalian host cells, differentiation and intracellular replication. Here we report the first insights into the biological role of a poly(ADPribose) glycohydrolase in a trypanosomatid (TcPARG). In silico analysis of the TcPARG gene pointed out the conservation of key residues involved in the catalytic process and, by Western blot, we demonstrated that it is expressed in a life stagedependant manner. Indirect immunofluorescense assays and electron microscopy using an anti-TcPARG antibody showed that this enzyme is localized in the nucleus independently of the presence of DNA damage or cell cycle stage. The addition of poly(ADP-ribose) glycohydrolase inhibitors ADP-HPD (adenosine diphosphate (hydroxymethyl)pyrrolidinediol) or DEA (6,9-diamino-2-ethoxyacridine lactate monohydrate) to the culture media, both at a 1 μM concentration, reduced in vitro epimastigote growth by 35% and 37% respectively, when compared to control cultures. We also showed that ADP-HPD 1 μM can lead to an alteration in the progression of the cell cycle in hydroxyurea synchronized cultures of T. cruzi epimastigotes. Outstandingly, here we demonstrate that the lack of poly(ADP-ribose) glycohydrolase activity in Vero and A549 host cells, achieved by chemical inhibition or iRNA, produces the reduction of the percentage of infected cells as well as the number of amastigotes per cell and trypomastigotes released, leading to a nearly complete abrogation of the infection process. We conclude that both, T. cruzi and the host, poly(ADP-ribose) glycohydrolase activities are important players in the life cycle of Trypanosoma cruzi, emerging as a promising therapeutic target for the treatment of Chagas´ disease.Fil: Vilchez Larrea, Salomé Catalina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular; ArgentinaFil: Schlesinger, Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular; ArgentinaFil: Kevorkian, María Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular; ArgentinaFil: Flawia, Mirtha Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Fisiología, Biología Molecular y Celular; ArgentinaFil: Alonso, Guillermo Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Fisiología, Biología Molecular y Celular; ArgentinaFil: Fernandez Villamil, Silvia Hebe. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Química Biológica; Argentin

Disrupted ADP-ribose metabolism with nuclear Poly (ADP-ribose) accumulation leads to different cell death pathways in presence of hydrogen peroxide in procyclic Trypanosoma brucei

TbPARG in Trypanosoma brucei. A) TbPARG localization in untreated (control) and in procyclic cultures exposed to 500 μM H2O2 for 10 min. IFI was carried out as reported in our previous work [33]. TbPARG was identified with our home-made antibody against TcPARG [33]; and PAR was identified with a commercial antibody against PAR (BD). White bar represents 50 μm. B) Western blot analysis of 40 μg protein per lane revealed with a commercial anti-PARG antibody (Antibody Verify) in T. brucei procyclic (PC) and bloodstream (BST) forms. The arrow indicates the band with the expected molecular weight (approximately 60 kDa). The membrane stained with Red Ponceau was used as a loading control. (TIF 4272 kb

Human isotype‐dependent inhibitory antibody responses against Mycobacterium tuberculosis

Accumulating evidence from experimental animal models suggests that antibodies play a protective role against tuberculosis (TB). However, little is known about the antibodies generated upon Mycobacterium tuberculosis (MTB) exposure in humans. Here, we performed a molecular and functional characterization of the human B‐cell response to MTB by generating recombinant monoclonal antibodies from single isolated B cells of untreated adult patients with acute pulmonary TB and from MTB‐exposed healthcare workers. The data suggest that the acute plasmablast response to MTB originates from reactivated memory B cells and indicates a mucosal origin. Through functional analyses, we identified MTB inhibitory antibodies against mycobacterial antigens including virulence factors that play important roles in host cell infection. The inhibitory activity of anti‐MTB antibodies was directly linked to their isotype. Monoclonal as well as purified serum IgA antibodies showed MTB blocking activity independently of Fc alpha receptor expression, whereas IgG antibodies promoted the host cell infection. Together, the data provide molecular insights into the human antibody response to MTB and may thereby facilitate the design of protective vaccination strategies

PDGFRA defines the mesenchymal stem cell Kaposi's sarcoma progenitors by enabling KSHV oncogenesis in an angiogenic environment

Kaposi’s sarcoma (KS) is an AIDS-defining cancer caused by the KS-associated herpesvirus (KSHV). Unanswered questions regarding KS are its cellular ontology and the conditions conducive to viral oncogenesis. We identify PDGFRA(+)/SCA-1(+) bone marrow-derived mesenchymal stem cells (Pα(+)S MSCs) as KS spindle-cell progenitors and found that pro-angiogenic environmental conditions typical of KS are critical for KSHV sarcomagenesis. This is because growth in KS-like conditions generates a de-repressed KSHV epigenome allowing oncogenic KSHV gene expression in infected Pα(+)S MSCs. Furthermore, these growth conditions allow KSHV-infected Pα(+)S MSCs to overcome KSHV-driven oncogene-induced senescence and cell cycle arrest via a PDGFRA-signaling mechanism; thus identifying PDGFRA not only as a phenotypic determinant for KS-progenitors but also as a critical enabler for viral oncogenesis.Fil: Naipauer, Julian. Miami University; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Sylvester Comprehensive Cancer Center and Miami Center for AIDS Research; Estados UnidosFil: Rosario, Santas. Miami University; Estados Unidos. Sylvester Comprehensive Cancer Center and Miami Center for AIDS Research; Estados UnidosFil: Gupta, Sachin. Miami University; Estados Unidos. Sylvester Comprehensive Cancer Center and Miami Center for AIDS Research; Estados UnidosFil: Premer, Courtney. Miami University; Estados UnidosFil: Méndez Solís, Omayra. Miami University; Estados Unidos. Sylvester Comprehensive Cancer Center and Miami Center for AIDS Research; Estados UnidosFil: Schlesinger, Mariana. Miami University; Estados Unidos. Sylvester Comprehensive Cancer Center and Miami Center for AIDS Research; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Ponzinibbio, Maria Virginia. Miami University; Estados Unidos. Sylvester Comprehensive Cancer Center and Miami Center for AIDS Research; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Jain, Vaibhav. University of Florida; Estados UnidosFil: Gay, Lauren. University of Florida; Estados UnidosFil: Renne, Rolf. University of Florida; Estados UnidosFil: Chan, Ho Lam. Miami University; Estados UnidosFil: Morey, Lluis. Miami University; Estados UnidosFil: Salyakina, Daria. Miami University; Estados Unidos. Sylvester Comprehensive Cancer Center and Miami Center for AIDS Research; Estados UnidosFil: Abba, Martín Carlos. Miami University; Estados Unidos. Universidad Nacional de La Plata. Facultad de Ciencias Médicas. Centro de Investigaciones Inmunológicas Básicas y Aplicadas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Williams, Sion. Miami University; Estados UnidosFil: Hare, Joshua M.. Miami University; Estados UnidosFil: Goldschmidt Clermont, Pascal. Miami University; Estados UnidosFil: Mesri, Enrique Alfredo. Sylvester Comprehensive Cancer Center and Miami Center for AIDS Research; Estados Unidos. Miami University; Estados Unido

PDGFRA defines the mesenchymal stem cell Kaposi's sarcoma progenitors by enabling KSHV oncogenesis in an angiogenic environment

Kaposi’s sarcoma (KS) is an AIDS-defining cancer caused by the KS-associated herpesvirus (KSHV). Unanswered questions regarding KS are its cellular ontology and the conditions conducive to viral oncogenesis. We identify PDGFRA(+)/SCA-1(+) bone marrow-derived mesenchymal stem cells (Pα(+)S MSCs) as KS spindle-cell progenitors and found that pro-angiogenic environmental conditions typical of KS are critical for KSHV sarcomagenesis. This is because growth in KS-like conditions generates a de-repressed KSHV epigenome allowing oncogenic KSHV gene expression in infected Pα(+)S MSCs. Furthermore, these growth conditions allow KSHV-infected Pα(+)S MSCs to overcome KSHV-driven oncogene-induced senescence and cell cycle arrest via a PDGFRA-signaling mechanism; thus identifying PDGFRA not only as a phenotypic determinant for KS-progenitors but also as a critical enabler for viral oncogenesis.Centro de Investigaciones Inmunológicas Básicas y Aplicada

SDSS-III: Massive Spectroscopic Surveys of the Distant Universe, the Milky Way Galaxy, and Extra-Solar Planetary Systems

Building on the legacy of the Sloan Digital Sky Survey (SDSS-I and II), SDSS-III is a program of four spectroscopic surveys on three scientific themes: dark energy and cosmological parameters, the history and structure of the Milky Way, and the population of giant planets around other stars. In keeping with SDSS tradition, SDSS-III will provide regular public releases of all its data, beginning with SDSS DR8 (which occurred in Jan 2011). This paper presents an overview of the four SDSS-III surveys. BOSS will measure redshifts of 1.5 million massive galaxies and Lya forest spectra of 150,000 quasars, using the BAO feature of large scale structure to obtain percent-level determinations of the distance scale and Hubble expansion rate at z<0.7 and at z~2.5. SEGUE-2, which is now completed, measured medium-resolution (R=1800) optical spectra of 118,000 stars in a variety of target categories, probing chemical evolution, stellar kinematics and substructure, and the mass profile of the dark matter halo from the solar neighborhood to distances of 100 kpc. APOGEE will obtain high-resolution (R~30,000), high signal-to-noise (S/N>100 per resolution element), H-band (1.51-1.70 micron) spectra of 10^5 evolved, late-type stars, measuring separate abundances for ~15 elements per star and creating the first high-precision spectroscopic survey of all Galactic stellar populations (bulge, bar, disks, halo) with a uniform set of stellar tracers and spectral diagnostics. MARVELS will monitor radial velocities of more than 8000 FGK stars with the sensitivity and cadence (10-40 m/s, ~24 visits per star) needed to detect giant planets with periods up to two years, providing an unprecedented data set for understanding the formation and dynamical evolution of giant planet systems. (Abridged)Comment: Revised to version published in The Astronomical Journa

Cloning, characterization and functional studies of poly (ADP-ribose) polymerase and poly (ADP-ribose) glycohydrolase enzimes of Trypanosoma brucei

El metabolismo de polímeros de ADP-ribosa (PAR) está involucrado en múltiples funciones celulares, como la señalización y reparación del ADN, el mantenimiento de la integridad genómica, la decisión entre la supervivencia y muerte celular y el mecanismo de muerte. Poli(ADP-ribosa)polimerasa (PARP) y poli(ADPribosa) glicohidrolasa (PARG) son las proteínas involucradas en esta vía metabólica. PARP es la enzima encargada de sintetizar al polímero, mientras que PARG es responsable de su degradación. En Trypanosoma brucei ambas proteínas, denominadas TbPARP y TbPARG, son codificadas por un gen de copia única. En la presente tesis se muestra la caracterización de la actividad de TbPARP in vitro en la reacción de PARilación. Estudios funcionales de TbPARP y TbPARG en el contexto del parásito permitieron identificar su localización subcelular en condiciones normales y de estrés oxidativo. También se describe aquí la cinética de aparición de PAR en el núcleo. Mediante la obtención de líneas transgénicas de parásitos procíclicos sobreexpresantes de TbPARP y silenciados (ARNi) para ambas enzimas se realizaron ensayos de supervivencia a distintas concentraciones del agente genotóxico H2O2. Los mismos presentaron diferentes grados de citotoxicidad y variaciones en el mecanismo de muerte celular de acuerdo a la presencia o ausencia de polímero en el núcleo. También se estudió el efecto de la acumulación nuclear del polímero sobre la progresión del ciclo celular en cultivos transgénicos sincronizados. Palabras claves: Trypanosoma brucei, PARP, PARG, PAR, ciclo celular, estrés oxidativo, Enfermedad del sueño.Poly(ADP-ribose)polymerase (PAR) metabolism is involved in multiple cellular functions such as DNA signaling and repair, maintenance of genomic integrity, switching between cell survival and death, and decision of death pathways. Poly(ADPribose) polymerase (PARP) and poly(ADP-ribose)glycohydrolase (PARG) are proteins involved in this metabolic pathway. PARP synthesizes the polymer while PARG is in charge of its hydrolysis. In Trypansoma brucei both proteins, named TbPARP and TbPARG, are codified by a single copy gene. The present thesis shows the characterization of in vitro activity of TbPARP carried out in the PARylation reaction. Functional studies of TbPARP and TbPARG in the context of the parasite allowed the identification of their subcelular localization in normal conditions and under oxidative stress. Kinetics of PAR appearance in the nucleus is also described here. We obtained transgenic lines of procyclic parasites which over-expressed TbPARP or downregulated both enzymes to perform survival assays at different concentrations of the genotoxic agent H2O2. They presented variation in the cytotoxicity levels and in the death pathway involved according to the presence or absence of PAR in the nucleus. It has also been studied the effect of PAR nuclear accumulation on cell cycle progression in synchronized transgenic cultures. Key words: Trypanosoma brucei, PARP, PARG, PAR, cell cycle, oxidative stress, African trypanosomiasis.Fil:Schlesinger, Mariana. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina

The plasma membrane H+-ATPase gene family in Solanum tuberosum L. Role of PHA1 in tuberization

This study presents the characterization of the plasma membrane (PM) H+-ATPases in potato, focusing on their role in stolon and tuber development. Seven PM H+-ATPase genes were identified in the Solanum tuberosum genome, designated PHA1?PHA7. PHA genes show distinct expression patterns in different plant tissues and under different stress treatments. Application of PM H+-ATPase inhibitors arrests stolon growth, promotes tuber induction, and reduces tuber size, indicating that PM H+-ATPases are involved in tuberization, acting at different stages of the process. Transgenic potato plants overexpressing PHA1 were generated (PHA1-OE). At early developmental stages, PHA1-OE stolons elongate faster and show longer epidermal cells than wild-type stolons; this accelerated growth is accompanied by higher cell wall invertase activity, lower starch content, and higher expression of the sucrose?H+ symporter gene StSUT1. PHA1-OE stolons display an increased branching phenotype and develop larger tubers. PHA1-OE plants are taller and also present a highly branched phenotype. These results reveal a prominent role for PHA1 in plant growth and development. Regarding tuberization, PHA1 promotes stolon elongation at early stages, and tuber growth later on. PHA1 is involved in the sucrose?starch metabolism in stolons, possibly providing the driving force for sugar transporters to maintain the apoplastic sucrose transport during elongation.Fil: Stritzler, Margarita. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Muñiz García, María Noelia. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Schlesinger, Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Cortelezzi, Juan Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Capiati, Daniela Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; Argentin

1650. Knowledge and Attitudes Toward Influenza Vaccination Among Hispanics: A Survey Conducted in Latin American Consulates in South Florida

Abstract Background Each year Influenza causes between 12,000 and 56,000 deaths, and over half a million of hospitalizations in the United States. Despite the widespread availability of vaccination, immunization coverage is low. Less than half of American adults receive the influenza vaccine, and there is a disparity between Hispanic and non-Hispanics, with only 35.9% of Hispanic compared with 45.9% of white non-Hispanics receiving the vaccine. In Miami, South Florida, over two-thirds of the population is Hispanic, and rates of influenza vaccination are low. This study aims to identify the knowledge and attitudes toward influenza vaccination among members of the adult Hispanic community in Miami, and to identify barriers to vaccination in this population. Methods This is a cross-sectional study conducted during the influenza season in 2017 and 2019 (October to December). A survey was administered in the waiting rooms of participating Latin American Consulates (Argentina, Colombia, Ecuador, Guatemala, Honduras, Mexico, Peru, and Uruguay) in Miami. Participants included were older than 18 years, Hispanic, and with residence in the United States for more than 6 months. The participants accepted the inform consent orally. The survey was voluntary and anonymous. Results We enrolled 970 adults. The median age was 43 years, 50% were male, 60% had health insurance, and 67% had completed education of high school or higher. Knowledge regarding influenza and vaccination was low (78% believed asymptomatic individuals could transmit influenza, 14% knew that vaccination is recommended during the winter months, 50% felt not everyone should be vaccinated, 25% believed the vaccine causes influenza, and 7% autism). About one quarter (27%) received the influenza vaccine annually, 35% sometimes, and 38% never. Using multinomial logistic regression, we identified age χ2(2) = 19.38, P < 0.001, consulate χ2(6) = 160.21, P < 0.001, and insurance status χ2(2) = 23.04, P < 0.001 as predictors of receiving vaccination. Neither gender, nor education level found to be associated with vaccination behavior. Conclusion Immunization rates in the adult Hispanic population are low. Interventions to improve vaccination among Hispanics who are older and lack of health insurance are urgently needed in the diverse Hispanic community. Disclosures All authors: No reported disclosures