Elevated serum gamma-glutamyltransferase activity and immunohistochemistry in two dogs with renal carcinoma.

During a 3-year time period, a 15-year-old male castrated Terrier mix (dog 1) and a 6-year-old female spayed Labrador Retriever (dog 2) presented to the North Carolina State Veterinary Hospital with similar blood work abnormalities and no significant physical examination findings. A CBC, chemistry panel, and urinalysis performed on both dogs were relatively unremarkable, other than a marked increase in serum gamma-glutamyltransferase (GGT) activity. Through imaging, both patients were diagnosed with a renal mass, and histopathology of both masses revealed a carcinoma.

Niche-DE: niche-differential gene expression analysis in spatial transcriptomics data identifies context-dependent cell-cell interactions.

Existing methods for analysis of spatial transcriptomic data focus on delineating the global gene expression variations of cell types across the tissue, rather than local gene expression changes driven by cell-cell interactions. We propose a new statistical procedure called niche-differential expression (niche-DE) analysis that identifies cell-type-specific niche-associated genes, which are differentially expressed within a specific cell type in the context of specific spatial niches. We further develop niche-LR, a method to reveal ligand-receptor signaling mechanisms that underlie niche-differential gene expression patterns.

A Kmer-based paired-end read assembler and genotyper for canine MHC class I genotyping.

The major histocompatibility complex class I (MHC-I) genes are highly polymorphic. MHC-I genotyping is required for determining the peptide epitopes available to an individual's T-cell repertoire. Current genotyping software tools do not work for the dog, due to very limited known canine alleles.

Doxorubicin for treatment of histiocytic sarcoma in dogs: 31 cases (2003-2017).

Objective: To evaluate the efficacy of doxorubicin for treatment of histiocytic sarcoma (HS) in dogs, whether administered as the sole treatment or as an adjunct to surgery or radiation therapy.

Animals: 31 client-owned dogs with localized or disseminated HS examined between 2003 and 2017.

Procedures: Medical records were reviewed retrospectively, and data were collected.

High-resolution characterization of the structural features and genetic variation of six feline leukocyte antigen class I loci via single molecule, real-time (SMRT) sequencing.

Of the 12 full-length feline leukocyte antigen class I (FLAI) loci, 3 are presumed to be classical: FLAI-E, FLAI-H, and FLAI-K. As diversity is a class Ia hallmark, multi-allelism is an important surrogate supporting a classical designation, in the absence of direct demonstration of T-cell restriction. Conversely, limited polymorphism at an expressed locus suggests regulation of immune effectors with invariant receptors, and non-classical status.

Dog leukocyte antigen-88*034:01 presents nonamer peptides from canine distemper virus hemagglutinin, large polymerase, and matrix proteins.

Canine spontaneous cancers may offer greater fidelity than rodent models in advancing clinical immunotherapies. Boxers in particular are distinguished as study subjects by their popularity, and high incidence of human-relevant cancers. Further, the MHC class I allele DLA-88*034:01, with a known motif, dominates the breed, facilitating discovery of shared CTL responses against mutation-origin neoepitopes by standard prediction methods.

Cancer-testis antigens in canine histiocytic sarcoma and other malignancies.

Cancer-testis antigens (CTAs) are a category of self proteins aberrantly expressed in diverse malignancies, mostly solid tumours, due to epigenetic de-repression. Normally expressed only in fetal or gametogenic tissues, CTAs are tantalizing immunotherapy targets, since autoimmunity risks appear minimal. Few prevalent CTAs have been identified in human hematologic cancers, and just two in their veterinary counterparts.

Incidence and risk factors associated with development of clinical cardiotoxicity in dogs receiving doxorubicin.

Background: Doxorubicin (DOX) can cause cumulative cardiotoxicity in dogs, but the incidence of clinical cardiotoxicity in dogs receiving DOX has not been determined.

Hypothesis/objectives: To determine if the duration of DOX infusion influences the incidence of cardiotoxicity, to characterize the incidence of clinical cardiotoxicity in dogs during or after DOX chemotherapy, and to identify any risk factors associated with cardiotoxicity.

Animals: Four-hundred ninety-four dogs that received at least 1 dose of DOX for the treatment of cancer.

The prevalent Boxer MHC class Ia allotype dog leukocyte antigen (DLA)-88*034:01 preferentially binds nonamer peptides with a defined motif.

Development of effective immunotherapy for chemoresistant malignancies can be advanced by studies in spontaneous cancer models, such as the dog. A crucial first step, T-cell epitope discovery, can be assisted by determination of binding motifs of common dog leukocyte antigen (DLA) class Ia allotypes. Boxers are popular, inbred dogs with increased risks of relevant target cancers and restricted MHC diversity.

Canine scent detection of canine cancer: a feasibility study.

The scent detection prowess of dogs has prompted interest in their ability to detect cancer. The purpose of this study was to determine whether dogs could use olfactory cues to discriminate urine samples collected from dogs that did or did not have urinary tract transitional cell carcinoma (TCC), at a rate greater than chance. Dogs with previous scent training (n=4) were initially trained to distinguish between a single control and a single TCC-positive urine sample.

JAK2 V617F-positive acute myeloid leukaemia (AML): a comparison between de novo AML and secondary AML transformed from an underlying myeloproliferative neoplasm. A study from the Bone Marrow Pathology Group.

The JAK2 V617F mutation is characteristic of most Philadelphia chromosome-negative myeloproliferative neoplasms (MPNs) and occurs rarely in de novo acute myeloid leukaemia (AML). We sought to characterize AMLs that harbour this mutation and distinguish those that arise de novo (AML-DN) from those that reflect transformation of an underlying MPN (AML-MPN). Forty-five patients with JAK2 V617F-mutated AML were identified; 15 were AML-DN and 30 were AML-MPN.

The canine MHC class Ia allele DLA-88*508:01 presents diverse self- and canine distemper virus-origin peptides of varying length that have a conserved binding motif.

Ideally, CD8+ T-cell responses against virally infected or malignant cells are defined at the level of the specific peptide and restricting MHC class I element, a determination not yet made in the dog. To advance the discovery of canine CTL epitopes, we sought to determine whether a putative classical MHC class Ia gene, Dog Leukocyte Antigen (DLA)-88, presents peptides from a viral pathogen, canine distemper virus (CDV). To investigate this possibility, DLA-88*508:01, an allele prevalent in Golden Retrievers, was expressed as a FLAG-tagged construct in canine histiocytic cells to allow affinity purification of peptide-DLA-88 complexes and subsequent elution of bound peptides.

Saporin-conjugated tetramers identify efficacious anti-HIV CD8+ T-cell specificities.

Antigen-specific T-cells are highly variable, spanning potent antiviral efficacy and damaging auto-reactivity. In virus infections, identifying the most efficacious responses is critical to vaccine design. However, current methods depend on indirect measures or on ex vivo expanded CTL clones.

Lymph flow regulates collecting lymphatic vessel maturation in vivo.

Fluid shear forces have established roles in blood vascular development and function, but whether such forces similarly influence the low-flow lymphatic system is unknown. It has been difficult to test the contribution of fluid forces in vivo because mechanical or genetic perturbations that alter flow often have direct effects on vessel growth. Here, we investigated the functional role of flow in lymphatic vessel development using mice deficient for the platelet-specific receptor C-type lectin-like receptor 2 (CLEC2) as blood backfills the lymphatic network and blocks lymph flow in these animals.

Lymphatic function is required prenatally for lung inflation at birth.

Mammals must inflate their lungs and breathe within minutes of birth to survive. A key regulator of neonatal lung inflation is pulmonary surfactant, a lipoprotein complex which increases lung compliance by reducing alveolar surface tension (Morgan, 1971). Whether other developmental processes also alter lung mechanics in preparation for birth is unknown.

Platelet immunoreceptor tyrosine-based activation motif (ITAM) signaling and vascular integrity.

Platelets are well-known for their critical role in hemostasis, that is, the prevention of blood loss at sites of mechanical vessel injury. Inappropriate platelet activation and adhesion, however, can lead to thrombotic complications, such as myocardial infarction and stroke. To fulfill its role in hemostasis, the platelet is equipped with various G protein-coupled receptors that mediate the response to soluble agonists such as thrombin, ADP, and thromboxane A2.

Platelets mediate lymphovenous hemostasis to maintain blood-lymphatic separation throughout life.

Mammals transport blood through a high-pressure, closed vascular network and lymph through a low-pressure, open vascular network. These vascular networks connect at the lymphovenous (LV) junction, where lymph drains into blood and an LV valve (LVV) prevents backflow of blood into lymphatic vessels. Here we describe an essential role for platelets in preventing blood from entering the lymphatic system at the LV junction.

Deletion of naïve T cells recognizing the minor histocompatibility antigen HY with toxin-coupled peptide-MHC class I tetramers inhibits cognate CTL responses and alters immunodominance.

Alloreactive T-cell responses directed against minor histocompatibility (H) antigens, which arise from diverse genetic disparities between donor and recipient outside the MHC, are an important cause of rejection of MHC-matched grafts. Because clinically significant responses appear to be directed at only a few antigens, the selective deletion of naïve T cells recognizing donor-specific, immunodominant minor H antigens in recipients before transplantation may be a useful tolerogenic strategy. We have previously demonstrated that peptide-MHC class I tetramers coupled to a toxin can efficiently eliminate specific TCR-transgenic T cells in vivo.

Podoplanin maintains high endothelial venule integrity by interacting with platelet CLEC-2.

Circulating lymphocytes continuously enter lymph nodes for immune surveillance through specialized blood vessels named high endothelial venules, a process that increases markedly during immune responses. How high endothelial venules (HEVs) permit lymphocyte transmigration while maintaining vascular integrity is unknown. Here we report a role for the transmembrane O-glycoprotein podoplanin (PDPN, also known as gp38 and T1α) in maintaining HEV barrier function.

Characterization and allelic variation of the transporters associated with antigen processing (TAP) genes in the domestic dog (Canis lupus familiaris).

The function of the transporters associated with antigen processing (TAP) complex is to shuttle antigenic peptides from the cytosol to the endoplasmic reticulum to load MHC class I molecules for CD8(+) T-cell immunosurveillance. Here we report the promoter and coding regions of the canine TAP1 and TAP2 genes, which encode the homologous subunits forming the TAP heterodimer. By sampling genetically divergent breeds, polymorphisms in both genes were identified, although there were few amino acid differences between alleles.

Polymorphisms and tissue expression of the feline leukocyte antigen class I loci FLAI-E, FLAI-H, and FLAI-K.

Cytotoxic CD8+ T-cell immunosurveillance for intracellular pathogens, such as viruses, is controlled by classical major histocompatibility complex (MHC) class Ia molecules, and ideally, these antiviral T-cell populations are defined by the specific peptide and restricting MHC allele. Surprisingly, despite the utility of the cat in modeling human viral immunity, little is known about the feline leukocyte antigen class I complex (FLAI). Only a few coding sequences with uncertain locus origin and expression patterns have been reported.

Comparison of automated versus manual neutrophil counts for the detection of cellular abnormalities in dogs receiving chemotherapy: 50 cases (May to June 2008).

Objective: To determine the frequency of clinically relevant abnormalities missed by failure to perform a blood smear evaluation in a specific subset of dogs receiving chemotherapy and to compare automated and manual neutrophil counts in the same population.

Design: Retrospective case series.

Animals: 50 dogs receiving chemotherapy with a total nucleated cell count > 4,000 nucleated cells/μL.

Platelet ITAM signaling is critical for vascular integrity in inflammation.

Platelets play a critical role in maintaining vascular integrity during inflammation, but little is known about the underlying molecular mechanisms. Here we report that platelet immunoreceptor tyrosine activation motif (ITAM) signaling, but not GPCR signaling, is critical for the prevention of inflammation-induced hemorrhage. To generate mice with partial or complete defects in these signaling pathways, we developed a protocol for adoptive transfer of genetically and/or chemically inhibited platelets into thrombocytopenic (TP) mice.

TAK1 (MAP3K7) signaling regulates hematopoietic stem cells through TNF-dependent and -independent mechanisms.

A cytokine/stress signaling kinase Tak1 (Map3k7) deficiency is known to impair hematopoietic progenitor cells. However, the role of TAK1 signaling in the stem cell function of the hematopoietic system is not yet well defined. Here we characterized hematopoietic stem cells (HSCs) harboring deletion of Tak1 and its activators, Tak1 binding proteins 1 and 2 (Tab1 and Tab2) using a competitive transplantation assay in a mouse model.

A cell-based MHC stabilization assay for the detection of peptide binding to the canine classical class I molecule, DLA-88.

Identifying immunodominant CTL epitopes is essential for studying CD8+ T-cell responses in populations, but remains difficult, as peptides within antigens typically are too numerous for all to be synthesized and screened. Instead, to facilitate discovery, in silico scanning of proteins for sequences that match the motif, or binding preferences, of the restricting MHC class I allele - the largest determinant of immunodominance - can be used to predict likely candidates. The high false positive rate with this analysis ideally requires binding confirmation, which is obtained routinely by an assay using cell lines such as RMA-S that have defective transporter associated with antigen processing (TAP) machinery, and consequently, few surface class I molecules.