المؤلفون: Villafañe, Luciana^1,2 (AUTHOR), Rocha, Rosana Valeria^1,2 (AUTHOR), Bigi, María Mercedes³ (AUTHOR), Klepp, Laura Inés^1,2 (AUTHOR), Taboga, Oscar Alberto^1,2 (AUTHOR), Forrellad, Marina Andrea^1,2 (AUTHOR), López, María Gabriela^1,2 (AUTHOR), Bigi, Fabiana^1,2 (AUTHOR) bigi.fabiana@inta.gob.ar

المصدر: Veterinary Immunology & Immunopathology. Jul2024, Vol. 273, pN.PAG-N.PAG. 1p.

مصطلحات موضوعية: *MYCOBACTERIUM bovis, *TUBERCULOSIS in cattle, *RECOMBINANT proteins, *TUBERCULIN test, *ANTIGENS, *LIVESTOCK productivity

مستخلص: Bovine tuberculosis (bTB) represents a threat to livestock production. Mycobacterium bovis is the main causative agent of bTB and a pathogen capable of infecting wildlife and humans. Eradication programs based on surveillance in slaughterhouses with mandatory testing and culling of reactive cattle have failed to eradicate bTB in many regions worldwide. Therefore, developing effective tools to control this disease is crucial. Using a computational tool, we identified proteins in the M. bovis proteome that carry predictive binding peptides to BoLADRB3.2 and selected Mb0309, Mb1090, Mb1810 and Mb3810 from all the identified proteins. The expression of these proteins in a baculovirus-insect cell expression system was successful only for Mb0309 and Mb3810. In parallel, we expressed the ESAT-6 family proteins EsxG and EsxH in this system. Among the recombinant proteins, Mb0309 and EsxG exhibited moderate performance in distinguishing between cattle that test positive and negative to bTB using the official test, the intradermal tuberculin test (IDT), when used to stimulate interferon-gamma production in blood samples from cattle. However, when combined as a protein cocktail, Mb0309 and EsxG were reactive in 50 % of positive cattle. Further assessments in cattle that evade the IDT (false negative) and cattle infected with M ycobacterium avium paratuberculosis are necessary to determine the potential utility of this cocktail as an additional tool to assist the accurate diagnosis of bTB. • Mb0309 exhibits predictive binding to alleles of BoLADRB3.2. • Both EsxG and Mb0309 were effectively expressed using a baculovirus-insect cell system. • In an IFN-γ release assay, EsxG and Mb0309 displayed reactivity in 50 % of cattle with bovine tuberculosis (bTB). [ABSTRACT FROM AUTHOR]

المؤلفون: Villafañe, Luciana¹ (AUTHOR) villafane.luciana@inta.gob.ar, Vaulet, Lucía Gallo^1,2,3 (AUTHOR), Viere, Florencia M.⁴ (AUTHOR), Klepp, Laura I.¹ (AUTHOR) klepp.laura@inta.gob.ar, Forrellad, Marina A.¹ (AUTHOR) forrellad.marina@inta.gob.ar, Bigi, María M.⁵ (AUTHOR) mbigi@conicet.gov.ar, Romano, María I.¹ (AUTHOR) romano.mariaisabel@inta.gob.ar, Magistrelli, Giovanni⁶ (AUTHOR) giovanni.magistrelli@lightchainbio.com, Fermepin, Marcelo Rodríguez^2,3 (AUTHOR) mrfchlam@ffyb.uba.ar, Bigi, Fabiana¹ (AUTHOR) bigi.fabiana@inta.gob.ar

المصدر: Journal of Immunological Methods. Jan2022, Vol. 500, pN.PAG-N.PAG. 1p.

مصطلحات موضوعية: *COVID-19, *COVID-19 pandemic, *VACCINE effectiveness, *SERODIAGNOSIS, *SARS-CoV-2

مستخلص: Serology tests for SARS-CoV-2 have proven to be important tools to fight against the COVID-19 pandemic. These serological tests can be used in low-income and remote areas for patient contact tracing, epidemiologic studies and vaccine efficacy evaluations. In this study, we used a semi-stable mammalian episomal expression system to produce high quantities of the receptor-binding domain-RBD of SARS-CoV-2 in a simple and very economical way. The recombinant antigen was tested in an in-house IgG ELISA for COVID-19 with a panel of human sera. A performance comparison of this serology test with a commercial test based on the full-length spike protein showed 100% of concordance between tests. Thus, this serological test can be an attractive and inexpensive option in scenarios of limited resources to face the COVID-19 pandemic. • Highly efficient expression of RBD domain from episomal plasmid in mammalian cells. • Low cost RBD-ELISA yielded results 100% concordant to Spike-ELISA. • All sera from vaccinated people recognized RBD protein in the in-house ELISA. [ABSTRACT FROM AUTHOR]