Publications by authors named "Victoria L Hansen"

8 Publications

  • Page 1 of 1

The molecular assembly of the marsupial γμ T cell receptor defines a third T cell lineage.

Science 2021 03;371(6536):1383-1388

Infection and Immunity Program and Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia.

αβ and γδ T cell receptors (TCRs) are highly diverse antigen receptors that define two evolutionarily conserved T cell lineages. We describe a population of γμTCRs found exclusively in non-eutherian mammals that consist of a two-domain (Vγ-Cγ) γ-chain paired to a three-domain (Vμ-Vμj-Cμ) μ-chain. γμTCRs were characterized by restricted diversity in the Vγ and Vμj domains and a highly diverse unpaired Vμ domain. Crystal structures of two distinct γμTCRs revealed the structural basis of the association of the γμTCR heterodimer. The Vμ domain shared the characteristics of a single-domain antibody within which the hypervariable CDR3μ loop suggests a major antigen recognition determinant. We define here the molecular basis underpinning the assembly of a third TCR lineage, the γμTCR.
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http://dx.doi.org/10.1126/science.abe7070DOI Listing
March 2021

The effects of tributyrin supplementation on weight gain and intestinal gene expression in broiler chickens during Eimeria maxima-induced coccidiosis.

Poult Sci 2021 Apr 18;100(4):100984. Epub 2021 Jan 18.

Animal Biosciences and Biotechnology Laboratory, Henry A. Wallace Beltsville Agricultural Research Center, Beltsville, MD 20705, USA. Electronic address:

Butyrate is a feed additive that has been shown to have antibacterial properties and improve gut health in broilers. Here, we examined the performance and gene expression changes in the ileum of tributyrin-supplemented broilers infected with coccidia. Ninety-six, Ross 708 broilers were fed either a control corn-soybean-based diet (-BE) or a diet supplemented with 0.25% (w/w) tributyrin (+BE). Birds were further divided into groups that were inoculated with Eimeria maxima oocysts (EM) or sham-inoculated (C) on day 21 posthatch. At 7 d postinfection (7 d PI), the peak of pathology in E. maxima infection, tributyrin-supplemented birds had significantly improved feed conversion ratios (FCR, P < 0.05) and body weight gain (BWG, P < 0.05) compared with -BE-infected birds, despite both groups having similar feed intake (FI, P > 0.05). However, at 10 d post-infection (10 d PI) no significant effects of feed type or infection were observed. Gene expression in the ileum was examined for insights into possible effects of infection and tributyrin supplementation on genes encoding proteins related to immunity, digestion, and gut barrier integrity. Among immune-related genes examined, IL-1B and LEAP2 were only significantly affected at 7 d PI. Transcription of genes related to digestion (APN, MCT1, FABP2, and MUC2) were primarily influenced by infection at 7 d PI and tributyrin supplementation (FABP2 and MUC2) at 10 d PI. With exception of ZO1, tight junction genes were affected by either infection or feed type at 7 d PI. At 10 d PI, only CLDN1 was not affected by either infection or feed type. Overall tributyrin shows promise as a supplement to improve performance during coccidiosis in broiler chickens; however, its effect on gene expression and mode of action requires further research.
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http://dx.doi.org/10.1016/j.psj.2021.01.007DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7921011PMC
April 2021

Uterine epithelial remodelling during pregnancy in the marsupial Monodelphis domestica (Didelphidae): Implications for mammalian placental evolution.

J Anat 2020 06 12;236(6):1126-1136. Epub 2020 Feb 12.

School of Life and Environmental Sciences, University of Sydney, Sydney, NSW, Australia.

Mammalian pregnancy involves remodelling of the uterine epithelium to enable placentation. In marsupials, such remodelling has probably played a key role in the transition from ancestral invasive placentation to non-invasive placentation. Identifying uterine alterations that are unique to marsupials with non-invasive placentation can thus elucidate mechanisms of marsupial placental evolution. We identified apical alterations to uterine epithelial cells prior to implantation in Monodelphis domestica, a member of the least derived living marsupial clade (Didelphidae) with invasive (endotheliochorial) placentation. We then compared these traits with those of Macropus eugenii (Macropodidae) and Trichosurus vulpecula (Phalangeridae), both with non-invasive placentation, to identify which alterations to the uterine epithelium are ancestral and which facilitate secondarily evolved non-invasive placentation. In M. domestica, remodelling of the uterine epithelium involves reduced cellular heterogeneity and development of uterodome-like cells, suggesting that similar alterations may also have occurred in the marsupial common ancestor. These alterations also overlap with those of both T. vulpecula and Ma. eugenii, suggesting that the placental shift from invasive to non-invasive placentation in marsupials involves essential, conserved characteristics, irrespective of placental mode. However, unique apical alterations of both T. vulpecula and Ma. eugenii, relative to M. domestica, imply that lineage-specific alterations underpin the evolutionary shift to non-invasive placentation in marsupials.
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http://dx.doi.org/10.1111/joa.13162DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7219617PMC
June 2020

Evidence for regulation of the complement system during pregnancy being ancient and conserved in mammals.

Dev Comp Immunol 2020 03 27;104:103562. Epub 2019 Nov 27.

Center for Evolutionary and Theoretical Immunology, Department of Biology, University of New Mexico, Albuquerque, NM, USA. Electronic address:

Here we demonstrate that regulation of the Complement (C') components of the immune system is an ancient and conserved feature of mammalian pregnancy. Transcript levels were reduced for complement components C3 and C4 throughout pregnancy in a marsupial, Monodelphis domestica. Downstream C' component transcripts were significantly less abundant relative to non-pregnant controls at the start of pregnancy but increased during late pregnancy, in some cases peaking close to parturition. These results are consistent with observations in human pregnancy that deposition of C5 through C9 on fetal membranes is associated with labor and parturition. Complement regulators CD46 and CD59 are present at the fetomaternal interface during M. domestica pregnancy as well, implying regulation of C' effector mechanisms is necessary for maintenance of normal marsupial pregnancy. Collectively these results support regulating the complement system may have contributed to the transition from oviparity to viviparity in mammals over 165 million years ago.
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http://dx.doi.org/10.1016/j.dci.2019.103562DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6937380PMC
March 2020

A 'devil' of a problem.

Elife 2018 08 14;7. Epub 2018 Aug 14.

Center for Evolutionary & Theoretical Immunology, Department of Biology, University of New Mexico, Albuquerque, United States.

The discovery of a second facial tumor disease in the Tasmanian devil has provided insights into the emergence of contagious cancers.
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http://dx.doi.org/10.7554/eLife.39976DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6092114PMC
August 2018

A pronounced uterine pro-inflammatory response at parturition is an ancient feature in mammals.

Proc Biol Sci 2017 Oct;284(1865)

Center for Evolutionary and Theoretical Immunology, Department of Biology, University of New Mexico, Albuquerque, NM 87131, USA.

Regulating maternal immunity is necessary for successful human pregnancy. Whether this is needed in mammals with less invasive placentation is subject to debate. Indeed, the short gestation times in marsupials have been hypothesized to be due to a lack of immune regulation during pregnancy. Alternatively, the maternal marsupial immune system may be unstimulated in the absence of a highly invasive placenta. Transcripts encoding pro-inflammatory cytokines were found to be overrepresented in the whole uterine transcriptome at terminal pregnancy in the opossum, To investigate this further, immune gene transcripts were quantified throughout opossum gestation. Transcripts encoding pro-inflammatory cytokines remained relatively low during pre- and peri-attachment pregnancy stages. Levels dramatically increased late in gestation, peaking within 12 h prior to parturition. These results mirror the spike of inflammation seen at eutherian parturition but not at attachment or implantation. Our results are consistent with the role of pro-inflammatory cytokines at parturition being an ancient and conserved birth mechanism in therian mammals.
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http://dx.doi.org/10.1098/rspb.2017.1694DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5666101PMC
October 2017

On the prenatal initiation of T cell development in the opossum Monodelphis domestica.

J Anat 2017 Apr 4;230(4):596-600. Epub 2017 Jan 4.

Department of Biology, Center for Evolutionary and Theoretical Immunology, University of New Mexico, Albuquerque, NM, USA.

Thymus-dependent lymphocytes (T cells) are a critical cell lineage in the adaptive immune system of all jawed vertebrates. In eutherian mammals the initiation of T cell development takes place prenatally and the offspring of many species are born relatively immuno-competent. Marsupials, in contrast, are born in a comparatively altricial state and with a less well developed immune system. As such, marsupials are valuable models for studying the peri- and postnatal initiation of immune system development in mammals. Previous results supported a lack of prenatal T cell development in a variety of marsupial species. In the gray short-tailed opossum, Monodelphis domestica, however, there was evidence that αβT cells were present on postnatal day 1 and likely initiated development prenatally. Demonstrated here is the presence of CD3ε lymphocytes in late-stage embryos at a site in the upper thoracic cavity, the site of an early developing thymus. CD3ε cells were evident as early as 48 h prior to parturition. In day 14 embryos, where there is clear organogenesis, CD3ε cells were only found at the site of the early thymus, consistent with no extra-thymic sites of T cell development in the opossum. These observations are the first evidence of prenatal T cell lineage commitment in any marsupial.
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http://dx.doi.org/10.1111/joa.12587DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5345628PMC
April 2017

The Evolution and Structure of Atypical T Cell Receptors.

Results Probl Cell Differ 2015 ;57:265-78

Department of Biology, Center for Evolutionary and Theoretical Immunology, University of New Mexico, Albuquerque, NM, 87131, USA.

The T cell receptor structure and genetic organization have been thought to have been stable in vertebrate evolution relative to the immunoglobulins. For the most part, this has been true and the content and organization of T cell receptor genes has been fairly conserved over the past 400 million years of gnathostome evolution. Analyses of TCRδ chains in a broad range of vertebrate lineages over the past decade have revealed a remarkable and previously unrealized degree of plasticity. This plasticity can generally be described in two forms. The first is broad use of antibody heavy chain variable genes in place of the conventional Vδ. The second form containing an unusual three extracellular domain structures has evolved independently in both cartilaginous fishes and mammals. Two well-studied vertebrate lineages, the eutherian mammals such as mice and humans and teleost fishes, lack any of these alternative TCR forms, contributing to why they went undiscovered for so long after the initial description of the conventional TCR chains three decades ago. This chapter describes the state of knowledge of these unusual TCR forms, both their structure and genetics, and current ideas on their function.
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http://dx.doi.org/10.1007/978-3-319-20819-0_11DOI Listing
April 2016