CARD 2023: expanded curation, support for machine learning, and resistome prediction at the Comprehensive Antibiotic Resistance Database.

The Comprehensive Antibiotic Resistance Database (CARD; card.mcmaster.ca) combines the Antibiotic Resistance Ontology (ARO) with curated AMR gene (ARG) sequences and resistance-conferring mutations to provide an informatics framework for annotation and interpretation of resistomes. As of version 3.2.4, CARD encompasses 6627 ontology terms, 5010 reference sequences, 1933 mutations, 3004 publications, and 5057 AMR detection models that can be used by the accompanying Resistance Gene Identifier (RGI) software to annotate genomic or metagenomic sequences. Focused curation enhancements since 2020 include expanded ß-lactamase curation, incorporation of likelihood-based AMR mutations for Mycobacterium tuberculosis, addition of disinfectants and antiseptics plus their associated ARGs, and systematic curation of resistance-modifying agents. This expanded curation includes 180 new AMR gene families, 15 new drug classes, 1 new resistance mechanism, and two new ontological relationships: evolutionary_variant_of and is_small_molecule_inhibitor. In silico prediction of resistomes and prevalence statistics of ARGs has been expanded to 377 pathogens, 21,079 chromosomes, 2,662 genomic islands, 41,828 plasmids and 155,606 whole-genome shotgun assemblies, resulting in collation of 322,710 unique ARG allele sequences. New features include the CARD:Live collection of community submitted isolate resistome data and the introduction of standardized 15 character CARD Short Names for ARGs to support machine learning efforts.

Chronic COVID-19 infection in an immunosuppressed patient shows changes in lineage over time: a case report.

BACKGROUND: The COVID-19 pandemic, caused by the Severe Acute Respiratory Syndrome Coronavirus 2 virus, emerged in late 2019 and spready globally. Many effects of infection with this pathogen are still unknown, with both chronic and repeated COVID-19 infection producing novel pathologies. CASE PRESENTATION: An immunocompromised patient presented with chronic COVID-19 infection. The patient had history of Hodgkin's lymphoma, treated with chemotherapy and stem cell transplant. During the course of their treatment, eleven respiratory samples from the patient were analyzed by whole-genome sequencing followed by lineage identification. Whole-genome sequencing of the virus present in the patient over time revealed that the patient at various timepoints harboured three different lineages of the virus. The patient was initially infected with the B.1.1.176 lineage before coinfection with BA.1. When the patient was coinfected with both B.1.1.176 and BA.1, the viral populations were found in approximately equal proportions within the patient based on sequencing read abundance. Upon further sampling, the lineage present within the patient during the final two timepoints was found to be BA.2.9. The patient eventually developed respiratory failure and died. CONCLUSIONS: This case study shows an example of the changes that can happen within an immunocompromised patient who is infected with COVID-19 multiple times. Furthermore, this case demonstrates how simultaneous coinfection with two lineages of COVID-19 can lead to unclear lineage assignment by standard methods, which are resolved by further investigation. When analyzing chronic COVID-19 infection and reinfection cases, care must be taken to properly identify the lineages of the virus present.

Understanding Myeloma-Related Information Needs and Communication Preferences Within Black American Communities: An Exploratory Study.

Myeloma is the third most common blood cancer and one of the most complex and expensive cancers to treat. Black Americans face health disparities related to myeloma incidence, age at diagnosis, access to novel treatments, and mortality. To help reduce health disparities among Black Americans through education and outreach, the Leukemia & Lymphoma Society has implemented its Myeloma Link initiative. In 2022, a formative, qualitative evaluation was conducted across the 15 U.S. cities that implemented Myeloma Link to better understand the information and communication needs and preferences of three groups: patients, community members, and primary care providers (PCPs). Data collection included interviews with eight patients, two focus groups with a total of ten community members, and interviews with six PCPs. Patients expressed wanting information about treatment experiences, including clinical trials, and emotional and peer support services, particularly from other Black American patients. Community members were largely unfamiliar with myeloma and desired outreach via trusted community organizations about disease signs and symptoms. Both groups discussed the importance of self-advocacy within the current healthcare system and wanted actionable messaging, rather than messaging leading with disparities statistics. PCPs described systemic capacity and time challenges in the context of needing to address more frequently encountered health conditions; nonetheless, PCPs welcomed information and brief trainings about myeloma diagnosis and treatment options, referrals to specialists, and how to improve care, prognosis, and caregiver support. Findings underscore the importance of outreach initiatives such as Myeloma Link to help meet these needs and reduce health disparities.

The role of microglia in 67NR mammary tumor-induced suppression of brain responses to immune challenges in female mice.

It is poorly understood how solid peripheral tumors affect brain neuroimmune responses despite the various brain-mediated side effects and higher rates of infection reported in cancer patients. We hypothesized that chronic low-grade peripheral tumor-induced inflammation conditions microglia to drive suppression of neuroinflammatory responses to a subsequent peripheral immune challenge. Here, Balb/c murine mammary tumors attenuated the microglial inflammatory gene expression responses to lipopolysaccharide (LPS) and live Escherichia coli (E. coli) challenges and the fatigue response to an E. coli infection. In contrast, the inflammatory gene expression in response to LPS or a toll-like receptor 2 agonist of Percoll-enriched primary microglia cultures was comparable between tumor-bearing and -free mice, as were the neuroinflammatory and sickness behavioral responses to an intracerebroventricular interleukin (IL)-1ß injection. These data led to the hypothesis that Balb/c mammary tumors blunt the neuroinflammatory responses to an immune challenge via a mechanism involving tumor suppression of the peripheral humoral response. Balb/c mammary tumors modestly attenuated select circulating cytokine responses to LPS and E. coli challenges. Further, a second mammary tumor/mouse strain model (E0771 tumors in C57Bl/6 mice) displayed mildly elevated inflammatory responses to an immune challenge. Taken together, these data indicate that tumor-induced suppression of neuroinflammation and sickness behaviors may be driven by a blunted microglial phenotype, partly because of an attenuated peripheral signal to the brain, which may contribute to infection responses and behavioral side effects reported in cancer patients. Finally, these neuroimmune effects likely vary based on tumor type and/or host immune phenotype.

Sensitivity to Neutralizing Antibodies and Resistance to Type I Interferons in SARS-CoV-2 R.1 Lineage Variants, Canada.

Isolating and characterizing emerging SARS-CoV-2 variants is key to understanding virus pathogenesis. In this study, we isolated samples of the SARS-CoV-2 R.1 lineage, categorized as a variant under monitoring by the World Health Organization, and evaluated their sensitivity to neutralizing antibodies and type I interferons. We used convalescent serum samples from persons in Canada infected either with ancestral virus (wave 1) or the B.1.1.7 (Alpha) variant of concern (wave 3) for testing neutralization sensitivity. The R.1 isolates were potently neutralized by both the wave 1 and wave 3 convalescent serum samples, unlike the B.1.351 (Beta) variant of concern. Of note, the R.1 variant was significantly more resistant to type I interferons (IFN-α/ß) than was the ancestral isolate. Our study demonstrates that the R.1 variant retained sensitivity to neutralizing antibodies but evolved resistance to type I interferons. This critical driving force will influence the trajectory of the pandemic.

ADAMTS1 is regulated by the EP4 receptor in the zebrafish ovary.

Prostaglandins (PGs) are a class of fatty-acid derived hormones that are essential in ovulation of teleosts, but their exact role remains unknown. One putative target of PGs in ovulation is regulation of the expression of members of the A Disintegrin and Metalloproteinase with Thrombospondin motifs (ADAMTS) family, which are implicated in follicular rupture. This study investigated the regulation of ADAMTS, other proteases, and their inhibitors in response to treatment with PGE2 or PGF2α. Four members of the ADAMTS family, ADAMTS1, ADAMTS5, ADAMTS9, and ADAMTS16 were shown to be expressed in the ovary of zebrafish, but only adamts1 was upregulated in full-grown follicles following treatment with PGE2. Inhibitors of the PG receptors EP1 and EP2 had no effect on PGE2-stimulated adamts1 expression, while treatment of full-grown follicles with both PGE2 and GW627368x, an inhibitor of EP4 function, prevented the PGE2-induced increase in adamts1 expression. Treatment of full-grown follicles with the maturation-inducing hormone 17α,20ß-dihydroxy-4-pregnen-3-one (17,20ß-P) in vitro had no effect on the expression of adamts1 mRNA. These findings suggest that expression of ADAMTS1 in zebrafish ovarian follicles is regulated by the prostaglandin PGE2 via the EP4 series prostaglandin receptor.

Nuclear progesterone receptor regulates ptger4b and PLA2G4A expression in zebrafish (Danio rerio) ovulation.

Previous studies have implicated the nuclear progesterone receptor (Pgr or nPR) as being critical to ovulation in fishes. This study investigated the expression of Pgr in zebrafish ovarian follicles throughout development as well as putative downstream targets of Pgr by searching the promoter regions of selected genes for specific DNA sequences to which Pgr binds and acts as a transcription factor. Expression of Pgr mRNA increases dramatically as follicles grow and mature. In silico analysis of selected genes linked to ovulation showed that the prostaglandin receptors ptger4a and ptger4b contained the progesterone responsive element (PRE) GRCCGGA in their promoter regions. Studies using full-grown follicles incubated in vitro revealed that ptger4b was upregulated in response to 17,20ß-P. Our studies also showed that the expression of phospholipase A2 (PLA2G4A) mRNA and protein, a key enzyme in prostaglandin synthesis, was upregulated in response to 17,20ß-P treatment. pla2g4a was not found to contain a PRE, indicating that it is regulated indirectly by 17,20ß-P or that it may contain an as-of-yet unidentified PRE in its promoter region. Collectively, these studies provide further evidence of the importance of Pgr during the periovulatory periods through its involvement in prostaglandin production and function by controlling expression of PLA2G4A and the receptor EP4b and that these genes appear to be regulated through the actions of 17,20ß-P.

Effect of enclosure expansion on the activity budgets of eastern black-and-white colobus monkeys, Colobus guereza.

Behavior is one of the most observable and informative indicators of animal welfare. This study used behavioral observation methodologies to evaluate the impact of an enclosure expansion on the activity budgets of a group of three eastern black-and-white colobus monkeys, Colobus guereza, housed at the Adelaide Zoo in South Australia. Instantaneous scan sampling methods were used to record the monkeys' behavior before and after they were given access to new aerial walkways at 2-min intervals between 8:30 a.m. and 4:30 p.m., over a total of 109 h (66 baseline hours, 43 post-expansion hours). Broad state behaviors (e.g., social, moving, resting, interacting, and feeding) were recorded and were used to generate activity budgets. Locomotion, feeding, and social behaviors increased following the addition of the aerial walkways, along with an overall increase in activity, attributed to the larger area and increased complexity of the environment. Results indicate that the addition of aerial walkways was effective for increasing the behavioral repertoire in colobus monkeys, aligning activity budgets more closely with their wild counterparts, and increasing active and affiliative behaviors.

G protein-coupled receptors differentially regulate glycosylation and activity of the inwardly rectifying potassium channel Kir7.1.

Kir7.1 is an inwardly rectifying potassium channel with important roles in the regulation of the membrane potential in retinal pigment epithelium, uterine smooth muscle, and hypothalamic neurons. Regulation of G protein-coupled inwardly rectifying potassium (GIRK) channels by G protein-coupled receptors (GPCRs) via the G protein ßγ subunits has been well characterized. However, how Kir channels are regulated is incompletely understood. We report here that Kir7.1 is also regulated by GPCRs, but through a different mechanism. Using Western blotting analysis, we observed that multiple GPCRs tested caused a striking reduction in the complex glycosylation of Kir7.1. Further, GPCR-mediated reduction of Kir7.1 glycosylation in HEK293T cells did not alter its expression at the cell surface but decreased channel activity. Of note, mutagenesis of the sole Kir7.1 glycosylation site reduced conductance and open probability, as indicated by single-channel recording. Additionally, we report that the L241P mutation of Kir7.1 associated with Lebers congenital amaurosis (LCA), an inherited retinal degenerative disease, has significantly reduced complex glycosylation. Collectively, these results suggest that Kir7.1 channel glycosylation is essential for function, and this activity within cells is suppressed by most GPCRs. The melanocortin-4 receptor (MC4R), a GPCR previously reported to induce ligand-regulated activity of this channel, is the only GPCR tested that does not have this effect on Kir7.1.

Microglial recruitment of IL-1ß-producing monocytes to brain endothelium causes stress-induced anxiety.

Psychosocial stress contributes to the development of anxiety and depression. Recent clinical studies have reported increased inflammatory leukocytes in circulation of individuals with stress-related psychiatric disorders. Parallel to this, our work in mice shows that social stress causes release of inflammatory monocytes into circulation. In addition, social stress caused the development of prolonged anxiety that was dependent on inflammatory monocytes in the brain. Therefore, we hypothesize that chronic stress drives the production of inflammatory monocytes that are actively recruited to the brain by microglia, and these monocytes augment neuroinflammatory signaling and prolong anxiety. Here we show that repeated social defeat stress in mice activated threat appraisal centers in the brain that spatially coincided with microglial activation and endothelial facilitation of monocyte recruitment. Moreover, microglial depletion with a CSF1R antagonist prior to stress prevented the recruitment of monocytes to the brain and abrogated the development of anxiety. Cell-specific transcriptional profiling revealed that microglia selectively enhanced CCL2 expression, while monocytes expressed the pro-inflammatory cytokine interleukin-1ß (IL-1ß). Consistent with these profiles, the recruited inflammatory monocytes with stress adhered to IL-1R1+ neurovascular endothelial cells and this interaction was blocked by microglial depletion. Furthermore, disruption of IL-1ß signaling by caspase-1KO specifically within bone marrow-derived cells revealed that monocytes promoted anxiogenesis through stimulation of neurovascular IL-1R1 by IL-1ß. Collectively, the development of anxiety during stress was caused by microglial recruitment of IL-1ß-producing monocytes, which stimulated brain endothelial IL-1R1. Thus, monocyte IL-1ß production represents a novel mechanism that underlies behavioral complications associated with stress-related psychiatric disorders.

Investigating the role of prostaglandin receptor isoform EP4b in zebrafish ovulation.

Prostaglandins (PGs) are a class of fatty acid-derived hormones that play an essential role in the regulation of ovulation of teleosts. This study investigated the various isoforms of ovarian PG receptors in the zebrafish ovary and their role in ovulation. Using real time qPCR, six PG receptor isoforms (ptger1a, ptger1b, ptger2a, ptger4a, ptger4b, and ptgfr) were shown to be expressed in the ovary. Only the PG receptor isoform ptger4b was upregulated at the time of ovulation in vivo, or following treatment in vivo with Ovaprim, which contains a gonadotropin releasing hormone analogue and a dopamine receptor antagonist and stimulates ovulation. Treatment of full-grown follicles with the maturation-inducing hormone 17α,20ß-dihydroxy-4-pregnen-3-one (17,20ßP) in vitro also induced expression of EP4b mRNA. Females ovulate in vivo after injection with Ovaprim, or injection with Ovaprim and inhibitors of EP1 (ONO-8130) or EP2 (TG4-155) function; they do not ovulate when injected with Ovaprim and an EP4 inhibitor (GW237368x). These findings suggest that the EP4 receptor, in particular the EP4b isoform, is essential for ovulation.

Increased non-melanoma skin cancer risk in young patients with inflammatory bowel disease on immunomodulatory therapy: a retrospective single-centre cohort study.

BACKGROUND: Recent studies report an increased risk of non-melanoma skin cancer (NMSC) in immunosuppressed patients with inflammatory bowel disease (IBD). Concurrently, paediatric IBD incidence is rising, with more patients now exposed to immunomodulators from a younger age. OBJECTIVES: To investigate NMSC incidence and to examine the risk associated with immunomodulators in the development of NMSC in patients with IBD. METHODS: This was a retrospective single-centre cohort study. Patients with IBD attending a tertiary adult hospital from 1994 to 2013 were included. Skin cancer incidence was compared with population data from the National Cancer Registry of Ireland (NCRI) to calculate standardized incidence ratio (SIR). Logistic regression was utilized for risk factor analysis. RESULTS: Two thousand and fifty-three patients with IBD were studied. The SIR for NMSC in patients with IBD taking immunomodulators overall was 1.8 (95% CI: 1.0-2.7) with age-specific rates significantly elevated across certain age categories. Exposure to thiopurines (OR: 5.26, 95% CI: 2.15-12.93, P < 0.001) and in particular thiopurines and/or tumour necrosis factor alpha (TNF-α) inhibitors (OR: 6.45, 95% CI: 2.69-15.95, P < 0.001) was significantly associated with NMSC. The majority (82%) of those exposed to a TNF-α inhibitor also had thiopurine exposure. CONCLUSIONS: Compliance with skin cancer preventative measures should be highlighted to all patients with IBD. There should be a low threshold for dermatology referral for immunosuppressed patients, particularly those with a history of exposure to dual immunomodulators from a young age.

Two diffusion photopolymer for sharp diffractive optical elements recording.

Photopolymers as recording media are widely used in optical applications. In such materials, changes in the phase of the transmittance function are generated during exposure due to refractive index and thickness modulations. These changes arise primarily as a consequence of photopolymerization and mass transport processes. Characterizing polymers' performance, for example, quantifying the value of monomer diffusion, is therefore very important. Applying index matching, the volume and surface optical effect are separated in an acrylamide/polyvinylalcohol (AA/PVA) material. Using a simplified model that includes the effects of the holes produced during polymerization, both hole and monomer diffusion are analyzed. The analysis presented indicates higher material sensitivity than previously estimated. The results also indicate the possibility of recording sharper diffractive optical elements profiles, like blazed gratings, having diffraction efficiencies higher than 80%.

Daclizumab reduces CD25 levels on T cells through monocyte-mediated trogocytosis.

Daclizumab is a humanized monoclonal antibody that prevents interleukin-2 (IL-2) binding to CD25, blocking IL-2 signaling by cells that require high-affinity IL-2 receptors to mediate IL-2 signaling. The phase 2a CHOICE study evaluating daclizumab as a treatment for multiple sclerosis (MS) included longitudinal analysis of activated T cell counts. Whereas an exposure-dependent relationship was observed between daclizumab and reductions in HLA-DR(+)-activated T cells, a similar relationship was not observed for reductions in CD25 levels. The objective of this report is to determine the mechanism by which daclizumab reduces CD25 levels on peripheral blood mononuclear cells (PBMCs) using cytometric techniques. Daclizumab reduced T cell CD25 levels through a mechanism that required the daclizumab-Fc domain interaction with Fc receptors (FcR) on monocytes, but not on natural killer (NK) cells, and was unrelated to internalization or cell killing. Activated CD4(+) T cells and FoxP3(+) Treg cells showed evidence of trogocytosis of the CD25 antigen in the presence of monocytes. A daclizumab variant that retained affinity for CD25 but lacked FcR binding did not induce trogocytosis and was significantly less potent as an inhibitor of IL-2-induced proliferation of PBMCs. In conclusion, Daclizumab-induced monocyte-mediated trogocytosis of CD25 from T cells appears to be an additional mechanism contributing to daclizumab inhibition of IL-2 signaling.

Psychosocial stress and inflammation in cancer.

Stress-induced immune dysregulation results in significant health consequences for immune related disorders including viral infections, chronic autoimmune disease, and tumor growth and metastasis. In this mini-review we discuss the sympathetic, neuroendocrine and immunologic mechanisms by which psychosocial stress can impact cancer biology. Both human and animal studies have shown the sympathetic and neuroendocrine responses to psychosocial stress significantly impacts cancer, in part, through regulation of inflammatory mediators. Psychosocial stressors stimulate neuroendocrine, sympathetic, and immune responses that result in the activation of the hypothalamic-pituitary-adrenal (HPA)-axis, sympathetic nervous system (SNS), and the subsequent regulation of inflammatory responses by immune cells. Social disruption (SDR) stress, a murine model of psychosocial stress and repeated social defeat, provides a novel and powerful tool to probe the mechanisms leading to stress-induced alterations in inflammation, tumor growth, progression, and metastasis. In this review, we will focus on SDR as an important model of psychosocial stress in understanding neural-immune mechanisms in cancer.

Further exploration of M1 allosteric agonists: subtle structural changes abolish M1 allosteric agonism and result in pan-mAChR orthosteric antagonism.

This letter describes the further exploration of two series of M(1) allosteric agonists, TBPB and VU0357017, previously reported from our lab. Within the TPBP scaffold, either electronic or steric perturbations to the central piperidine ring led to a loss of selective M(1) allosteric agonism and afforded pan-mAChR antagonism, which was demonstrated to be mediated via the orthosteric site. Additional SAR around a related M(1) allosteric agonist family (VU0357017) identified similar, subtle 'molecular switches' that modulated modes of pharmacology from allosteric agonism to pan-mAChR orthosteric antagonism. Therefore, all of these ligands are best classified as bi-topic ligands that possess high affinity binding at an allosteric site to engender selective M(1) activation, but all bind, at higher concentrations, to the orthosteric ACh site, leading to non-selective orthosteric site binding and mAChR antagonism.

Stigma, public awareness about intellectual disability and attitudes to inclusion among different ethnic groups.

BACKGROUND: Attitudes to the inclusion of people with intellectual disabilities (IDs) have been studied extensively, yet evidence on public awareness about ID and stigma is limited. The relationship between attitudes, knowledge and stigma associated with ID is poorly understood. The present study examined these factors and the relationships between them in the context of a multicultural society. METHOD: UK residents of working age (n = 1002) were presented with a diagnostically unlabelled vignette of someone with a mild ID. They were asked to label the difficulties presented and to complete measures of social distance and attitudes to the inclusion of people with IDs. RESULTS: While attitudes to the inclusion of people with IDs were relatively positive overall, social contact was viewed with ambivalence. Inclusion attitudes and social distance were only moderately correlated. Across the whole sample 28% recognised typical symptoms of mild ID. Recognition of ID was associated with lower stigma and more positive attitudes than attribution of the difficulties presented to other causes. White Westerners showed increased knowledge, lower stigma and favoured inclusion more than participants from ethnic minorities. Among the latter group, Asians showed lower stigma and attitudes more in line with inclusion policies than participants of Black African/Caribbean backgrounds. Once a host of contextual factors were considered jointly, only contact was consistently associated with the variables measured. CONCLUSIONS: Stigma associated with ID is of concern across all ethnic groups, although it appears to be increased among the public from ethnic minorities. Given that contact and awareness are associated with reduced stigma, they should be considered as prime foci for efforts to tackle ID stigma. The current findings serve as baseline for attempts to increase public awareness and tackle stigma.

SARS-CoV-2 Outbreak Investigation Using Contact Tracing and Whole-Genome Sequencing in an Ontario Tertiary Care Hospital.

Genomic epidemiology can facilitate an understanding of evolutionary history and transmission dynamics of a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) outbreak. We used next-generation sequencing techniques to study SARS-CoV-2 genomes isolated from patients and health care workers (HCWs) across five wards of a Canadian hospital with an ongoing SARS-CoV-2 outbreak. Using traditional contact tracing methods, we show transmission events between patients and HCWs, which were also supported by the SARS-CoV-2 lineage assignments. The outbreak predominantly involved SARS-CoV-2 B.1.564.1 across all five wards, but we also show evidence of community introductions of lineages B.1, B.1.1.32, and B.1.231, falsely assumed to be outbreak related. Altogether, our study exemplifies the value of using contact tracing in combination with genomic epidemiology to understand the transmission dynamics and genetic underpinnings of a SARS-CoV-2 outbreak. IMPORTANCE Our manuscript describes a SARS-CoV-2 outbreak investigation in an Ontario tertiary care hospital. We use traditional contract tracing paired with whole-genome sequencing to facilitate an understanding of the evolutionary history and transmission dynamics of this SARS-CoV-2 outbreak in a clinical setting. These advancements have enabled the incorporation of phylogenetics and genomic epidemiology into the understanding of clinical outbreaks. We show that genomic epidemiology can help to explore the genetic evolution of a pathogen in real time, enabling the identification of the index case and helping understand its transmission dynamics to develop better strategies to prevent future spread of SARS-CoV-2 in congregate, clinical settings such as hospitals.

Beta adrenergic blockade decreases the immunomodulatory effects of social disruption stress.

During physiological or psychological stress, catecholamines produced by the sympathetic nervous system (SNS) regulate the immune system. Previous studies report that the activation of ß-adrenergic receptors (ßARs) mediates the actions of catecholamines and increases pro-inflammatory cytokine production in a number of different cell types. The impact of the SNS on the immune modulation of social defeat has not been examined. The following studies were designed to determine whether SNS activation during social disruption stress (SDR) influences anxiety-like behavior as well as the activation, priming, and glucocorticoid resistance of splenocytes after social stress. CD-1 mice were exposed to one, three, or six cycles of SDR and HPLC analysis of the plasma and spleen revealed an increase in catecholamines. After six cycles of SDR the open field test was used to measure behaviors characteristic of anxiety and indicated that the social defeat induced increase in anxiety-like behavior was blocked by pre-treatment with the ß-adrenergic antagonist propranolol. Pre-treatment with the ß-adrenergic antagonist propranolol did not significantly alter corticosterone levels indicating no difference in activation of the hypothalamic-pituitary-adrenal axis. In addition to anxiety-like behavior the SDR induced splenomegaly and increase in plasma IL-6, TNFα, and MCP-1 were each reversed by pre-treatment with propranolol. Furthermore, flow cytometric analysis of cells from propranolol pretreated mice reduced the SDR-induced increase in the percentage of CD11b(+) splenic macrophages and significantly decreased the expression of TLR2, TLR4, and CD86 on the surface of these cells. In addition, supernatants from 18h LPS-stimulated ex vivo cultures of splenocytes from propranolol-treated SDR mice contained less IL-6. Likewise propranolol pre-treatment abrogated the glucocorticoid insensitivity of CD11b(+) cells ex vivo when compared to splenocytes from SDR vehicle-treated mice. Together, this study demonstrates that the immune activation and priming effects of SDR result, in part, as a consequence of SNS activation.