Fundación Instituto Leloir

About: Fundación Instituto Leloir is a facility organization based out in Buenos Aires, Argentina. It is known for research contribution in the topics: Dentate gyrus & Neurogenesis. The organization has 702 authors who have published 1052 publications receiving 39299 citations.

Class III peroxidases PRX01, PRX44, and PRX73 potentially target extensins during root hair growth in Arabidopsis thaliana

Abstract: Fil: Marzol, Eliana. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Parque Centenario. Instituto de Investigaciones Bioquimicas de Buenos Aires. Fundacion Instituto Leloir. Instituto de Investigaciones Bioquimicas de Buenos Aires; Argentina

Heterologous booster response after inactivated virus BBIBP-CorV vaccination in older people

Abstract: Whole-virion inactivated SARS-CoV-2 vaccines are one of the most widely used vaccines worldwide. However, compared with the mRNA-based and adenovirus-based platforms,1Menni C May A Polidori L et al.COVID-19 vaccine waning and effectiveness and side-effects of boosters: a prospective community study from the ZOE COVID Study.Lancet Infect Dis. 2022; 22: 1002-1010Summary Full Text Full Text PDF PubMed Scopus (39) Google Scholar little information is available about the immune response that is induced by inactivated virus vaccines2Costa Clemens SA Weckx L Clemens R et al.Heterologous versus homologous COVID-19 booster vaccination in previous recipients of two doses of CoronaVac COVID-19 vaccine in Brazil (RHH-001): a phase 4, non-inferiority, single blind, randomised study.Lancet. 2022; 399: 521-529Summary Full Text Full Text PDF PubMed Scopus (96) Google Scholar and the convenience of applying heterologous boosters to reach an improved response against variants of concern, including omicron (B.1.1.529). Particularly scarce are data for older people (ie, age >60 years). In this study, we performed a longitudinal analysis of serum samples from an older population of volunteers (n=26 for prime vaccination and n=98 for booster vaccination; mean age 79 years [SD 11·8]), obtained 21 days, 100 days, 160 days, and 220 days after the second dose of a two-dose primary immunisation schedule with the inactivated virus BBIBP-CorV (Sinopharm) vaccine, and 21 days and 90 days after application of a booster with ChAdOx1 nCoV-19 (Oxford-AstraZeneca), Sputnik V (Gamaleya Research Institute of Epidemiology and Microbiology), or BNT162b2 (Pfizer-BioNTech). Because of the low seroconversion rates observed after BBIBP-CorV primary vaccination, a homologous booster dose was not included in this study. We evaluated serum concentrations of IgG anti-spike antibodies3Ojeda DS Gonzalez Lopez Ledesma MM Pallarés HM et al.Emergency response for evaluating SARS-CoV-2 immune status, seroprevalence and convalescent plasma in Argentina.PLoS Pathog. 2021; 17e1009161 Crossref PubMed Scopus (43) Google Scholar and neutralising capacity against the original B.1 lineage and the omicron variant of concern.4Sanchez L Oviedo Rouco S Pifano M et al.Antibody durability at 1 year after Sputnik V vaccination.Lancet Infect Dis. 2022; 22: 589-590Summary Full Text Full Text PDF PubMed Scopus (2) Google Scholar Both the concentration of IgG anti-spike antibodies and the seropositivity rate greatly declined over time after vaccination with two doses of BBIBP-CorV (figure). After 220 days, the seropositivity rate was reduced from 81% to 54%. Application of a booster dose of ChAdOx1 nCoV-19, Sputnik V, or BNT162b2 raised the concentrations of IgG anti-spike antibodies on day 21 more than 350-fold (from 11·8 binding antibody units [BAU]/mL to 4397 BAU/mL for ChAdOx1 nCoV-19, 4285 BAU/mL for Sputnik V, and 9391 BAU/mL for BNT162b2) and seropositivity was detected in 98 (100%) participants (figure). This response was sustained at 90 days after the booster dose (figure). Neutralising antibodies against B.1 and omicron also decreased over time since primary immunisation (appendix p 1). Neutralising activity against the B.1 virus was detected in six (23%) of 26 participants at 220 days after vaccination with two doses of BBIBP-CorV (appendix p 1). Application of a heterologous booster dose of ChAdOx1 nCoV-19, Sputnik V, or BNT162b2 greatly increased neutralising activity against B.1, with activity detected in 97–100% of participants who received a booster. Only two (8%) of 26 participants showed detectable concentrations of neutralising antibodies against omicron 220 days after the application of the primary BBIBP-CorV scheme. This percentage increased to 74–91% after a booster dose of ChAdOx1 nCoV-19, Sputnik V, or BNT162b2 (appendix p 1). Few data are available on effectiveness of a booster dose for individuals who are immunised with inactivated COVID-19 vaccines.2Costa Clemens SA Weckx L Clemens R et al.Heterologous versus homologous COVID-19 booster vaccination in previous recipients of two doses of CoronaVac COVID-19 vaccine in Brazil (RHH-001): a phase 4, non-inferiority, single blind, randomised study.Lancet. 2022; 399: 521-529Summary Full Text Full Text PDF PubMed Scopus (96) Google Scholar The results presented here indicate that a heterologous booster dose with ChAdOx1 nCoV-19, Sputnik V, or BNT162b2 vaccines markedly increases the neutralising activity against the omicron variant in older people who have received two doses of BBIBP-CorV. We declare no competing interests. SOR, PER, EAM, PR, and MMGLL contributed equally. Download .pdf (.18 MB) Help with pdf files Supplementary appendix COVID-19 vaccine waning and effectiveness and side-effects of boosters: a prospective community study from the ZOE COVID StudyAfter 5 months, vaccine effectiveness remained high among individuals younger than 55 years. Booster doses restore vaccine effectiveness. Adverse reactions after booster doses were similar to those after the second dose. Homologous booster schedules had fewer reported systemic side-effects than heterologous boosters. Full-Text PDF Open Access

Impact of the interplay between stemness features, p53 and pol iota on replication pathway choices.

Abstract: Using human embryonic, adult and cancer stem cells/stem cell-like cells (SCs), we demonstrate that DNA replication speed differs in SCs and their differentiated counterparts. While SCs decelerate DNA replication, differentiated cells synthesize DNA faster and accumulate DNA damage. Notably, both replication phenotypes depend on p53 and polymerase iota (POLι). By exploring protein interactions and newly synthesized DNA, we show that SCs promote complex formation of p53 and POLι at replication sites. Intriguingly, in SCs the translocase ZRANB3 is recruited to POLι and required for slow-down of DNA replication. The known role of ZRANB3 in fork reversal suggests that the p53-POLι complex mediates slow but safe bypass of replication barriers in SCs. In differentiated cells, POLι localizes more transiently to sites of DNA synthesis and no longer interacts with p53 facilitating fast POLι-dependent DNA replication. In this alternative scenario, POLι associates with the p53 target p21, which antagonizes PCNA poly-ubiquitination and, thereby potentially disfavors the recruitment of translocases. Altogether, we provide evidence for diametrically opposed DNA replication phenotypes in SCs and their differentiated counterparts putting DNA replication-based strategies in the spotlight for the creation of therapeutic opportunities targeting SCs.

ISCB-Student Council Narratives: Strategical development of the ISCB-Regional Student Groups in 2016

Abstract: Regional Student Groups are groups established and managed by the ISCB-Student Council in different regions of the world. The article highlights some of the initiatives and management lessons from our 'top-performing' Spotlight Regional Student Groups (RSGs), RSG-Argentina and RSG-UK, for the current year (2016). In addition, it details some of the operational hurdles faced by RSGs and possible solutions.