L. Courtney Smith

L. Courtney Smith
George Washington University | GW · Department of Biological Sciences

PhD, UCLA

About

223
Publications
29,149
Reads
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Introduction
L. Courtney Smith works at the Department of Biological Sciences, George Washington University. She does research in Cell Biology, Immunology and Marine Biology. The research foci in the lab are 1) functions of the SpTransformer proteins from the purple sea urchin and 2) the sequence diversity and expression regulation of the SpTransformer gene family.
Additional affiliations
September 1995 - present
George Washington University
Position
  • Professor
February 1985 - August 1995
California Institute of Technology
Position
  • PostDoc Position
Description
  • Sea Urchin Immunology
Education
September 1980 - March 1985
University of California, Los Angeles
Field of study
  • Microbiology and Immunology
September 1974 - December 1976
September 1970 - May 1974
Drake University
Field of study
  • Biology

Publications

Publications (223)
Article
Full-text available
Molecular cloning, gene manipulation, gene expression, protein function, and gene regulation all depend on the introduction of nucleic acids into target cells. Multiple methods have been developed to facilitate such delivery including instrument based microinjection and electroporation, biological methods such as transduction, and chemical methods...
Chapter
Full-text available
Textbooks on immunology rarely spend more than a few pages describing the principles of invertebrate immunology. Coming away from these often gives the reader the impression that this immune system is simple and non-specific in nature yet with over 1.3 million extant species of invertebrates, there is inevitably a great diversity of strategies to d...
Article
Full-text available
The sea urchin, Strongylocentrotus purpuratus, possesses at least seven distinguishable cell populations in the coelomic fluid, which vary in morphology, size, and function. Of these, the large phagocytes, small phagocytes, and red spherule cells are thought to be key to the echinoid immune response. Because there are currently no effective and rap...
Article
Full-text available
The generation of large immune gene families is often driven by evolutionary pressure exerted on host genomes by their pathogens, which has been described as the immunological arms race. The SpTransformer (SpTrf) gene family from the California purple sea urchin, Strongylocentrotus purpuratus, is upregulated upon immune challenge and encodes the Sp...
Article
Full-text available
The appearance of adaptive immunity in jawed vertebrates is termed the immunological 'Big Bang' because of the short evolutionary time over which it developed. Underlying it is the recombination activating gene (RAG)-based V(D)J recombination system, which initiates the sequence diversification of the immunoglobulins and lymphocyte antigen receptor...
Article
Full-text available
The adaptive immune response in jawed vertebrates is marked by the ability to diversify somatically specific immune receptor genes. Somatic recombination and hypermutation of gene segments are used to generate extensive repertoires of T and B cell receptors. In contrast, jawless vertebrates utilize a distinct diversification system based on copy ch...
Article
Full-text available
Background: The location of coelomocyte proliferation in adult sea urchins is unknown and speculations since the early 1800s have been based on microanatomy and tracer uptake studies. In adult sea urchins (Strongylocentrotus purpuratus) with down-regulated immune systems, coelomocyte numbers increase in response to immune challenge, and whether som...
Chapter
Sea urchin coelomocytes can be collected in large numbers from adult sea urchins of the species, Strongylocentrotus purpuratus, which typically has 12–40 mL of coelomic fluid. Coelomocytes are used for analysis of immune reactions and immune gene expression in addition to basic functions of cells, in particular for understanding structure and modif...
Chapter
Full-text available
Correction to: Chapter 13 in: E. L. Cooper (ed.), Advances in Comparative Immunology, https://doi.org/10.1007/978-3-319-76768-0_13
Chapter
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The Echinodermata are an ancient phylum of benthic marine invertebrates with a dispersal-stage planktonic larva. These animals have innate immune systems characterized initially by clearance of foreign particles, including microbes, from the body cavity of both larvae and adults, and allograft tissue rejection in adults. Immune responsiveness is me...
Article
Full-text available
The purple sea urchin, Strongylocentrotus purpuratus, has a complex and robust immune system that is mediated by a number of multi-gene families including the SpTransformer (SpTrf) gene family (formerly Sp185/333). In response to immune challenge from bacteria and various pathogen-associated molecular patterns, the SpTrf genes are up-regulated in s...
Data
rSpTrf-E1 binds to Vibrio diazotrophicus and Saccharomyces cerevisiae with saturable kinetics. (A) Vibrio diazotrophicus (2.9 X 108 cells) or (B) Saccharomyces cerevisiae (1.48 X 104 cells) were incubated in three trials each with increasing concentrations biotinylated rSpTrf-E1 for 30 min at 14°C. Control bacteria were incubated in standard PBS wi...
Article
Full-text available
The complex innate immune system of sea urchins is underpinned by several multigene families including the SpTransformer family (SpTrf; formerly Sp185/333) with estimates of ~50 members, although the family size is likely variable among individuals of Strongylocentrotus purpuratus. The genes are small with similar structure, are tightly clustered,...
Data
Giant unilamellar vesicles (GUVs) show fusion, budding, and invagination in the presence of recombinant SpTransformer protein, rSpTransformer-E1 (rSpTrf-E1). The movie is composed of a series of confocal microscopy images captured every 15 s starting at ~12 min after the addition of rSpTrf-E1 to the upper right edge of the well that likely diffuses...
Article
Full-text available
The purple sea urchin, Strongylocentrotus purpuratus, possesses a sophisticated innate immune system that functions without adaptive capabilities and responds to pathogens effectively by expressing the highly diverse SpTransformer gene family (formerly the Sp185/333 gene family). The swift gene expression response and the sequence diversity of SpTr...
Article
Full-text available
The purple sea urchin, Strongylocentrotus purpuratus, expresses a diverse immune response protein family called Sp185/333. A recombinant Sp185/333 protein, previously called rSp0032, shows multitasking antipathogen binding ability, suggesting that the protein family mediates a flexible and effective immune response to multiple foreign cells. Bioinf...
Article
Full-text available
Diversification of immune genes in host organisms that are in deadly arms races with pathogens has resulted in a wide range of approaches by which the host survives. Well known examples of adaptive immunity in vertebrates include somatic recombination of the immunoglobulin gene family and assembly of the variable lymphocyte receptors. The CRISPR-Ca...
Article
Full-text available
Background Genomic regions with repetitive sequences are considered unstable and prone to swift DNA diversification processes. A highly diverse immune gene family of the sea urchin (Strongylocentrotus purpuratus), called Sp185/333, is composed of clustered genes with similar sequence as well as several types of repeats ranging in size from short ta...
Chapter
Full-text available
Innate immune systems in both animals and plants that lack somatic recombination and assembly mechanisms rely on a limited, preset number of genes encoding pathogen-recognition proteins that target universal pathogen-associated molecular patterns and/or monitor pathogen effector activity. To keep up with the ever-expanding diversity and virulence o...
Article
Full-text available
The 13th Congress of the International Society of Developmental and Comparative Immunology took place in Murcia Spain from June 28 to July 3, 2015 at the Victor Villegas Auditorium and Convention Center. There were two or three parallel sessions during the Congress that covered a wide range of immunological topics and brought researchers together f...
Article
Full-text available
Effective protection against pathogens requires the host to produce a wide range of immune effector proteins. The Sp185/333 gene family, which is expressed by the California purple sea urchin Strongylocentrotus purpuratus in response to bacterial infection, encodes a highly diverse repertoire of anti-pathogen proteins. A subset of these proteins ca...
Article
Full-text available
In response to bacterial and fungal infections in insects and mammals, distinct families of innate immune pattern recognition receptors (PRRs) initiate highly complex intracellular signaling cascades. Those cascades induce a variety of immune functions that restrain the spread of microbes in the host. Insect and mammalian innate immune receptors in...
Article
Full-text available
Immune systems in animals rely on fast and efficient responses to a wide variety of pathogens. The Sp185/333 gene family in the purple sea urchin, Strongylocentrotus purpuratus, consists of an estimated 50 (±10) members per genome that share a basic gene structure but show high sequence diversity, primarily due to the mosaic appearance of short blo...
Article
Full-text available
Development of protocols and media for culturing immune cells from marine invertebrates has not kept pace with advancements in mammalian immune cell culture, the latter having been driven by the need to understand the causes of and develop therapies for human and animal diseases. However, expansion of the aquaculture industry and the diseases that...
Article
Full-text available
Purple sea urchins (Strongylocentrotus purpuratus) express a highly variable set of immune genes called Sp185/333 by two subtypes of coelomocytes: the polygonal and small phagocytes. We report that the Sp185/333 genes and their encoded proteins are also expressed in all of the major organs in the adult sea urchin, including the axial organ, pharynx...
Article
Full-text available
The purple sea urchin has a complex immune system that is likely mediated by gene expression in coelomocytes (blood cells). A broad array of potential immune receptors and immune response proteins has been deduced from their gene models. Here we use shotgun mass spectrometry to describe 307 proteins with possible immune function in sea urchins incl...
Article
Full-text available
The California purple sea urchin, Strongylocentrotus purpuratus, is a long-lived echinoderm with a complex and sophisticated innate immune system. Several large gene families that function in immunity in this species includes the Sp185/333 gene family with ~50 (±10) members. The family shows intriguing sequence diversity and encodes a broad array o...
Article
Full-text available
The arms race between hosts and pathogens (and other non-self) drives the molecular diversification of immune response genes in the host. Over long periods of evolutionary time, many different defense strategies have been employed by a wide variety of invertebrates. We review here penaeidins and crustins in crustaceans, the allorecognition system e...
Article
Full-text available
The immune system of the purple sea urchin, Strongylocentrotus purpuratus, is complex and sophisticated. An important component of sea urchin immunity is the Sp185/333 gene family, which is significantly upregulated in immunologically challenged animals. The Sp185/333 genes are less than 2 kb with two exons and are members of a large diverse family...
Article
Full-text available
A full length cDNA sequence expressed in coelomocytes shows significant sequence match to vertebrate Tie1 and Tie2/TEK. Vertebrate Tie2/TEK is the receptor for the angiopoietins and plays an important role in angiogenesis and hematopoiesis, whereas Tie1 regulates the activity of Tie2. The deduced sequence of the SpTie1/2 protein has a similar order...
Article
Full-text available
The Sp185/333 system of genes, messages and proteins are expressed in the coelomocytes of the purple sea urchin, Strongylocentrotus purpuratus, and is an extraordinary example of diversification of a putative innate immune response system in an invertebrate. Reviewed here, is the current understanding of this complex system as illustrated by sequen...
Article
Full-text available
Pathogen diversification can alter infection virulence, which in turn drives the evolution of host immune diversification, resulting in countermeasures for survival in this arms race. Somatic recombination of the immunoglobulin gene family members is a very effective mechanism to diversify antibodies and T-cell receptors that function in the adapti...
Article
Full-text available
A survey for immune genes in the genome for the purple sea urchin has shown that the immune system is complex and sophisticated. By inference, immune responses of all echinoderms maybe similar. The immune system is mediated by several types of coelomocytes that are also useful as sensors of environmental stresses. There are a number of large gene f...
Article
Full-text available
The cysteine-rich strongylocins were the first antimicrobial peptides (AMPs) discovered from the sea urchin species, Strongylocentrotus droebachiensis. Homologous putative proteins (called SpStrongylocin) were found in the sister species, S. purpuratus. To demonstrate that they exhibit the same antibacterial activity as strongylocins, cDNAs encodin...
Data
Echinoderm sequence accession numbers. An Excel spreadsheet containing the accession numbers of the experimentally validated echinoderm sequences used to evaluate the splicing models.
Data
Purpuratus splicer. A PERL script to implement the Purpuratus splicing model.
Data
Vertebrate splicer. A PERL script to implement the Vertebrate splicing model.
Article
Full-text available
185/333 genes and transcripts from the purple sea urchin, Strongylocentrotus purpuratus, predict high levels of amino acid diversity within the encoded proteins. Based on their expression patterns, 185/333 proteins appear to be involved in immune responses. In the present study, one- and two-dimensional Western blots show that 185/333 proteins exhi...
Article
Full-text available
As the amount of genome sequencing data grows, so does the problem of computational gene identification, and in particular, the splicing signals that flank exon borders. Traditional methods for identifying splicing signals have been created and optimized using sequences from model organisms, mostly vertebrate and yeast species. However, as genome s...