PREVALENCE OF THE ABCB1-1Δ GENE IN NONDOMESTIC SPECIES OF THE CANIDAE FAMILY.

The ABCB1 gene is responsible for encoding the P-glycoprotein (P-gp) efflux transporter that prevents accumulation of exogenous substances in the body by utilizing ATP hydrolysis to transport these substances against their concentration gradient. In dogs, homozygous or heterozygous mutations for the previously described ABCB1-1Δ mutation lead to ineffective P-gp efflux transport function and puts the animal at risk for potentially devastating adverse drug effects. The purpose of this study was to evaluate ABCB1-1Δ gene mutation status in species belonging to the Canidae family, including each of the following: maned wolf (Chrysocyon brachyurus), gray wolf (Canis lupus), red wolf (Canis rufus), coyote (Canis latrans), dingo (Canis lupus dingo), New Guinea singing dog (Canis lupus dingo), arctic fox (Vulpes lagopus), and fennec fox (Vulpes zerda). These species were chosen based on an evolutionary study conducted by Belyaev that noted foxes, bred for temperament, tended to have similar behaviors seen in the modern-day dog. Wolves, known predecessors to the modern dog, were also included. In the current study, a buccal swab was performed on each animal and then tested at Washington State University's Veterinary Clinical Pharmacology Lab, where they were tested according to previously published methods validating buccal swab samples and polymerase chain reaction (PCR) -based genetic analysis. Knowledge of Canidae species ABCB1-1Δ gene mutation status allows for safe and effective therapeutic treatment of nondomestic animals, ensuring any anticipated adverse drug events are prevented. All eight species were found to have the wild-type ABCB1 gene and thus, expected to have normally functioning P-gp efflux transporters. Although these data can be used to guide clinical decision making, because of a small sample size, a more robust study is necessary to assess Canidae ABCB1-1Δ mutation status comprehensively.

Presence of cerebrospinal fluid antibodies associated with autoimmune encephalitis of humans in dogs with neurologic disease.

BACKGROUND: Presumed autoimmune diseases affecting the central nervous system (CNS) of dogs are common. In people, antibodies against neuronal cell surface antigens that are associated with a wide variety of neurological syndromes have been identified. The presence of cerebrospinal fluid (CSF) autoantibodies that target neuronal cell surface proteins has not been reported in dogs with neurologic disorders. OBJECTIVES: Autoantibodies to neuronal cell surface antigens can be found in the CSF of dogs with inflammatory CNS disease. Our aim was to determine whether 6 neuronal cell surface autoantibodies were present in the CSF of dogs diagnosed with inflammatory and noninflammatory CNS disease. ANIMALS: Client-owned dogs with CNS disease and complete diagnostic evaluation including magnetic resonance imaging and CSF analysis were included. One healthy dog was included as a negative control. METHODS: Cerebrospinal fluid was tested for 6 antigenic targets with a commercially available indirect immunofluorescence assay test kit. RESULTS: There were 32 dogs with neurological disease, 19 diagnosed with inflammatory disease (encephalitis and meningitis), 10 with noninflammatory disease (neoplasia, intervertebral disk disease, degenerative myelopathy, and epilepsy), 2 with no diagnosis, and 1 with neoplasia and meningoencephalitis. Anti-N-methyl-d-aspartate receptor 1 (NMDAR1) antibodies were detected in 3 dogs (3/32; 9.38%). All 3 dogs responded to treatment of meningoencephalomyelitis of unknown etiology (MUE). CONCLUSIONS AND CLINICAL IMPORTANCE: Further evaluation of the prevalence and clinical relevance of CSF and serum antibodies to neuronal cell surface antigens is warranted. Defining antigenic targets associated with encephalitis in dogs might allow diagnostic categorization of MUE antemortem.

Disruption of Trim9 function abrogates macrophage motility in vivo.

The vertebrate immune response comprises multiple molecular and cellular components that interface to provide defense against pathogens. Because of the dynamic complexity of the immune system and its interdependent innate and adaptive functionality, an understanding of the whole-organism response to pathogen exposure remains unresolved. Zebrafish larvae provide a unique model for overcoming this obstacle, because larvae are protected against pathogens while lacking a functional adaptive immune system during the first few weeks of life. Zebrafish larvae were exposed to immune agonists for various lengths of time, and a microarray transcriptome analysis was executed. This strategy identified known immune response genes, as well as genes with unknown immune function, including the E3 ubiquitin ligase tripartite motif-9 (Trim9). Although trim9 expression was originally described as "brain specific," its expression has been reported in stimulated human Mϕs. In this study, we found elevated levels of trim9 transcripts in vivo in zebrafish Mϕs after immune stimulation. Trim9 has been implicated in axonal migration, and we therefore investigated the impact of Trim9 disruption on Mϕ motility and found that Mϕ chemotaxis and cellular architecture are subsequently impaired in vivo. These results demonstrate that Trim9 mediates cellular movement and migration in Mϕs as well as neurons.

A hyperactive Mpl-based cell growth switch drives macrophage-associated erythropoiesis through an erythroid-megakaryocytic precursor.

Several approaches for controlling hematopoietic stem and progenitor cell expansion, lineage commitment, and maturation have been investigated for improving clinical interventions. We report here that amino acid substitutions in a thrombopoietin receptor (Mpl)--containing cell growth switch (CGS) extending receptor stability improve the expansion capacity of human cord blood CD34(+) cells in the absence of exogenous cytokines. Activation of this CGS with a chemical inducer of dimerization (CID) expands total cells 99-fold, erythrocytes 70-fold, megakaryocytes 0.5-fold, and CD34(+) stem/progenitor cells 4.4-fold by 21 days of culture. Analysis of cells in these expanded populations identified a CID-dependent bipotent erythrocyte-megakaryocyte precursor (PEM) population, and a CID-independent macrophage population. The CD235a(+)/CD41a(+) PEM population constitutes up to 13% of the expansion cultures, can differentiate into erythrocytes or megakaryocytes, exhibits very little expansion capacity, and exists at very low levels in unexpanded cord blood. The CD206(+) macrophage population constitutes up to 15% of the expansion cultures, exhibits high-expansion capacity, and is physically associated with differentiating erythroblasts. Taken together, these studies describe a fundamental enhancement of the CGS expansion platform, identify a novel precursor population in the erythroid/megakaryocytic differentiation pathway of humans, and implicate an erythropoietin-independent, macrophage-associated pathway supporting terminal erythropoiesis in this expansion system.

JAK2 expression is associated with tumor-infiltrating lymphocytes and improved breast cancer outcomes: implications for evaluating JAK2 inhibitors.

Janus kinase-2 (JAK2) supports breast cancer growth, and clinical trials testing JAK2 inhibitors are under way. In addition to the tumor epithelium, JAK2 is also expressed in other tissues including immune cells; whether the JAK2 mRNA levels in breast tumors correlate with outcomes has not been evaluated. Using a case-control design, JAK2 mRNA was measured in 223 archived breast tumors and associations with distant recurrence were evaluated by logistic regression. The frequency of correct pairwise comparisons of patient rankings based on JAK2 levels versus survival outcomes, the concordance index (CI), was evaluated using data from 2,460 patients in three cohorts. In the case-control study, increased JAK2 was associated with a decreasing risk of recurrence (multivariate P = 0.003, n = 223). Similarly, JAK2 was associated with a protective CI (<0.5) in the public cohorts: NETHERLANDS CI = 0.376, n = 295; METABRIC CI = 0.462, n = 1,981; OSLOVAL CI = 0.452, n = 184. Furthermore, JAK2 was strongly correlated with the favorable prognosis LYM metagene signature for infiltrating T cells (r = 0.5; P < 2 × 10(-16); n = 1,981) and with severe lymphocyte infiltration (P = 0.00003, n = 156). Moreover, the JAK1/2 inhibitor ruxolitinib potently inhibited the anti-CD3-dependent production of IFN-γ, a marker of the differentiation of Th cells along the tumor-inhibitory Th1 pathway. The potential for JAK2 inhibitors to interfere with the antitumor capacities of T cells should be evaluated.

Differential expression and ligand binding indicate alternative functions for zebrafish polymeric immunoglobulin receptor (pIgR) and a family of pIgR-like (PIGRL) proteins.

The polymeric immunoglobulin (Ig) receptor (pIgR) is an integral transmembrane glycoprotein that plays an important role in the mammalian immune response by transporting soluble polymeric Igs across mucosal epithelial cells. Single pIgR genes, which are expressed in lymphoid organs including mucosal tissues, have been identified in several teleost species. A single pigr gene has been identified on zebrafish chromosome 2 along with a large multigene family consisting of 29 pigr-like (PIGRL) genes. Full-length transcripts from ten different PIGRL genes that encode secreted and putative inhibitory membrane-bound receptors have been characterized. Although PIGRL and pigr transcripts are detected in immune tissues, only PIGRL transcripts can be detected in lymphoid and myeloid cells. In contrast to pIgR which binds Igs, certain PIGRL proteins bind phospholipids. PIGRL transcript levels are increased after infection with Streptococcus iniae, suggesting a role for PIGRL genes during bacterial challenge. Transcript levels of PIGRL genes are decreased after infection with Snakehead rhabdovirus, suggesting that viral infection may suppress PIGRL function.