Contributions of Farm Animals to Immunology

By their very nature, great advances in immunology are usually underpinned by experiments carried out in animal models and inbred lines of mice. Also, their corresponding knock-out or knock-in derivatives have been the most commonly used animal systems in immunological studies. With much credit to their usefulness, laboratory mice will never provide all the answers to fully understand immunological processes. Large animal models offer unique biological and experimental advantages that have been and continue to be of great value to the understanding of biological and immunological processes. From the identification of B cells to the realization that γδ T cells can function as professional antigen presenting cells, farm animals have contributed significantly to a better understanding of immunity

Determinants of labor informality in colombia : an approach from venezuelan immigration.

Vol. 27, No. 2 (2019)Este documento estudia la incidencia que ha tenido la inmigración venezolana en los últimos años con respecto a la informalidad vivida en Colombia para el periodo 2015-2018. Par ello se empleó un modelo logístico para determinar el grado de probabilidad que tiene un trabajador en Colombia de ser informal. Se utilizaron los microdatos de la Gran Encuesta Integrada de Hogares (GEIH) del Departamento Administrativo Nacional de Estadística (DANE), además de datos proporcionados por Migración Colombia, desagregados por las 23 principales ciudades del país. Los resultados indican que el ingreso de inmigrantes venezolanos, afecta los niveles de informalidad en el país, donde la probabilidad que un trabajador en Colombia sea informal aumenta en un 0,49% por cada 10.000 inmigrantes que habían ingresado a una determinada ciudad.This document studies the incidence that Venezuelan immigration has had in recent years with respect to the informality experienced in Colombia for the period 2015-2018. For this, a logistic model determined the degree of probability that a worker in Colombia has been informal. Micro data from the Large Integrated Household Survey (GEIH) of the National Administrative Department of Statistics (DANE) helped in addition to data provided by Migración Colombia, disaggregated by the 23 main cities of the country. The results indicate that the income of Venezuelan immigrants affects informality levels in the country, where the probability that a worker in Colombia is informal increases by 0.49% for every 10,000 immigrants who have entered a certain city

Bovine Derived in vitro Cultures Generate Heterogeneous Populations of Antigen Presenting Cells

Antigen presenting cells (APC) of the mononuclear phagocytic system include dendritic cells (DCs) and macrophages (Macs) which are essential mediators of innate and adaptive immune responses. Many of the biological functions attributed to these cell subsets have been elucidated using models that utilize in vitro-matured cells derived from common progenitors. However, it has recently been shown that monocyte culture systems generate heterogeneous populations of cells, DCs, and Macs. In light of these findings, we analyzed the most commonly used bovine in vitro-derived APC models and compared them to bona fide DCs. Here, we show that bovine monocyte-derived DCs and Macs can be differentiated on the basis of CD11c and MHC class II (MHCII) expression and that in vitro conditions generate a heterologous group of both DCs and Macs with defined and specific biological activities. In addition, skin-migrating macrophages present in the bovine afferent lymph were identified and phenotyped for the first time. RNA sequencing analyses showed that these monophagocytic cells have distinct transcriptomic profiles similar to those described in other species. These results have important implications for the interpretation of data obtained using in vitro systems

Transduction of skin-migrating dendritic cells by human adenovirus 5 occurs via an actin-dependent phagocytic pathway

Dendritic cells (DC) are central to the initiation of immune responses, and various approaches have been used to target vaccines to DC in order to improve immunogenicity. Cannulation of lymphatic vessels allows for the collection of DC that migrate from the skin. These migrating DC are involved in antigen uptake and presentation following vaccination. Human replication-deficient adenovirus (AdV) 5 is a promising vaccine vector for delivery of recombinant antigens. Although the mechanism of AdV attachment and penetration has been extensively studied in permissive cell lines, few studies have addressed the interaction of AdV with DC. In this study, we investigated the interaction of bovine skin-migrating DC and replication-deficient AdV-based vaccine vectors. We found that, despite lack of expression of Coxsackie B–Adenovirus Receptor and other known adenovirus receptors, AdV readily enters skin-draining DC via an actin-dependent endocytosis. Virus exit from endosomes was pH independent, and neutralizing antibodies did not prevent virus entry but did prevent virus translocation to the nucleus. We also show that combining adenovirus with adjuvant increases the absolute number of intracellular virus particles per DC but not the number of DC containing intracellular virus. This results in increased trans-gene expression and antigen presentation. We propose that, in the absence of Coxsackie B–Adenovirus Receptor and other known receptors, AdV5-based vectors enter skin-migrating DC using actin-dependent endocytosis which occurs in skin-migrating DC, and its relevance to vaccination strategies and vaccine vector targeting is discussed

Bovine gammadelta T Cells Are a Major Regulatory T Cell Subset

In humans and mice, γδ T cells represent <5% of the total circulating lymphocytes. In contrast, the γδ T cell compartment in ruminants accounts for 15–60% of the total circulating mononuclear lymphocytes. Despite the existence of CD4(+)CD25(high) Foxp3(+) T cells in the bovine system, these are neither anergic nor suppressive. We present evidence showing that bovine γδ T cells are the major regulatory T cell subset in peripheral blood. These γδ T cells spontaneously secrete IL-10 and proliferate in response to IL-10, TGF-β, and contact with APCs. IL-10–expressing γδ T cells inhibit Ag-specific and nonspecific proliferation of CD4(+) and CD8(+) T cells in vitro. APC subsets expressing IL-10 and TFG-β regulate proliferation of γδ T cells producing IL-10. We propose that γδ T cells are a major regulatory T cell population in the bovine system

Protection of calves by a prefusion-stabilized bovine RSV F vaccine

Bovine respiratory syncytial virus, a major cause of respiratory disease in calves, is closely related to human RSV, a leading cause of respiratory disease in infants. Recently, promising human RSV-vaccine candidates have been engineered that stabilize the metastable fusion (F) glycoprotein in its prefusion state; however, the absence of a relevant animal model for human RSV has complicated assessment of these vaccine candidates. Here, we use a combination of structure-based design, antigenic characterization, and X-ray crystallography to translate human RSV F stabilization into the bovine context. A “DS2” version of bovine respiratory syncytial virus F with subunits covalently fused, fusion peptide removed, and pre-fusion conformation stabilized by cavity-filling mutations and intra- and inter-protomer disulfides was recognized by pre-fusion- specific antibodies, AM14, D25, and MPE8, and elicited bovine respiratory syncytial virus- neutralizing titers in calves >100-fold higher than those elicited by post-fusion F. When challenged with a heterologous bovine respiratory syncytial virus, virus was not detected in nasal secretions nor in respiratory tract samples of DS2-immunized calves; by contrast bovine respiratory syncytial virus was detected in all post-fusion- and placebo-immunized calves. Our results demonstrate proof-of-concept that DS2-stabilized RSV F immunogens can induce highly protective immunity from RSV in a native host with implications for the efficacy of prefusion- stabilized F vaccines in humans and for the prevention of bovine respiratory syncytial virus in calves

Molecular and functional characterization of the group B rotavirus enterotoxin non-structural protein 4

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Molecular and functional characterization of the group B rotavirus enterotoxin non-structural protein 4

EThOS - Electronic Theses Online ServiceGBUnited Kingdo