Chemical Softness in Aromatic Adsorption: Benzene, Nitrobenzene and Anisole on Pt{111}.

We describe a method for the calculation of chemical softness at metal surfaces, demonstrating its utility in understanding the adsorption of benzene, nitrobenzene and anisole at the Pt{111} surface. Based on this method, we show that directing effects due to either of the substituent groups are mostly swamped by substrate influences, while significant variations in softness within the groups themselves are readily apparent.

Presenting Symptoms in Newly Diagnosed Myeloma, Relation to Organ Damage, and Implications for Symptom-Directed Screening: A Secondary Analysis from the Tackling Early Morbidity and Mortality in Myeloma (TEAMM) Trial.

Multiple myeloma (MM) patients risk diagnostic delays and irreversible organ damage. In those with newly diagnosed myeloma, we explored the presenting symptoms to identify early signals of MM and their relationships to organ damage. The symptoms were recorded in patients' own words at diagnosis and included diagnostic time intervals. Those seen by a haematologist >6 months prior to MM diagnosis were classified as precursor disease (PD). Most (962/977) patients provided data. Back pain (38%), other pain (31%) and systemic symptoms (28%) predominated. Patients rarely complain of 'bone pain', simply 'pain'. Vertebral fractures are under-recognised as pathological and are the predominant irreversible organ damage (27% of patients), impacting the performance status (PS) and associated with back pain (odds ratio (OR) 6.14 [CI 4.47-8.44]), bone disease (OR 3.71 [CI 1.88-7.32]) and age >65 years (OR 1.58 [CI 1.15-2.17]). Renal failure is less frequent and associated with gastrointestinal symptoms (OR 2.23 [CI1.28-3.91]), age >65 years (OR 2.14 [CI1.28-3.91]) and absence of back pain (OR 0.44 [CI 0.29-0.67]). Patients with known PD (n = 149) had fewer vertebral fractures (p = 0.001), fewer adverse features (p = 0.001), less decline in PS (p = 0.001) and a lower stage (p = 0.04) than 813 with de novo MM. Our data suggest subgroups suitable for trials of 'symptom-directed' screening: those with back pain, unexplained pain, a general decline in health or low-impact vertebral compression fractures.

Mucins Shed from the Laminated Layer in Cystic Echinococcosis Are Captured by Kupffer Cells via the Lectin Receptor Clec4F.

Cystic echinococcosis is caused by the larval stages (hydatids) of cestode parasites belonging to the species cluster Echinococcus granulosus sensu lato, with E. granulosus sensu stricto being the main infecting species. Hydatids are bladderlike structures that attain large sizes within various internal organs of livestock ungulates and humans. Hydatids are protected by the massive acellular laminated layer (LL), composed mainly of mucins. Parasite growth requires LL turnover, and abundant LL-derived particles are found at infection sites in infected humans, raising the question of how LL materials are dealt with by the hosts. In this article, we show that E. granulosus sensu stricto LL mucins injected into mice are taken up by Kupffer cells, the liver macrophages exposed to the vascular space. This uptake is largely dependent on the intact mucin glycans and on Clec4F, a C-type lectin receptor which, in rodents, is selectively expressed in Kupffer cells. This uptake mechanism operates on mucins injected both in soluble form intravenously (i.v.) and in particulate form intraperitoneally (i.p.). In mice harboring intraperitoneal infections by the same species, LL mucins were found essentially only at the infection site and in the liver, where they were taken up by Kupffer cells via Clec4F. Therefore, shed LL materials circulate in the host, and Kupffer cells can act as a sink for these materials, even when the parasite grows in sites other than the liver.

Immunology of a unique biological structure: the Echinococcus laminated layer.

The larval stages of the cestode parasites belonging to the genus Echinococcus grow within internal organs of humans and a range of animal species. The resulting diseases, collectively termed echinococcoses, include major neglected tropical diseases of humans and livestock. Echinococcus larvae are outwardly protected by the laminated layer (LL), an acellular structure that is unique to this genus. The LL is based on a fibrillar meshwork made up of mucins, which are decorated by galactose-rich O-glycans. In addition, in the species cluster termed E. granulosus sensu lato, the LL features nano-deposits of the calcium salt of myo-inositol hexakisphosphate (Insp6). The main purpose of our article is to update the immunobiology of the LL. Major recent advances in this area are (i) the demonstration of LL "debris" at the infection site and draining lymph nodes, (ii) the characterization of the decoy activity of calcium Insp6 with respect to complement, (iii) the evidence that the LL mucin carbohydrates interact specifically with a lectin receptor expressed in Kupffer cells (Clec4F), and (iv) the characterization of what appear to be receptor-independent effects of LL particles on dendritic cells and macrophages. Much information is missing on the immunology of this intriguing structure: we discuss gaps in knowledge and propose possible avenues for research.

Daratumumab, bortezomib and dexamethasone at first relapse for patients with multiple myeloma: A real-world multicentre UK retrospective analysis.

Daratumumab, bortezomib and dexamethasone (DVd) is approved for patients with relapsed multiple myeloma following the CASTOR phase 3 clinical trial. This retrospective multicentre analysis assesses the overall response rate (ORR) and progression-free survival (PFS) in routine clinical practice for patients at first relapse treated with DVd incorporating weekly bortezomib. Data were collected from 296 sequential patients treated across 15 UK centres. After a median follow-up of 21 months, the ORR was 82% (26% partial response, 56% very good partial response or better) and the median PFS was 16 months [95% confidence interval (CI) 12-20 months]. Results were similar regardless of prior lenalidomide exposure. The median time to next treatment was 20 months (95% CI 15-25 months) and the estimated overall survival at two years was 74%. Patients with high-risk features (by cytogenetics, International Staging System or extramedullary disease) and those treated within 18 months of initiation of progression-free treatment, or within 12 months of autologous stem cell transplant, had significantly inferior outcomes. The grade 2 and 3 peripheral neuropathy rate was 7%. DVd with weekly bortezomib was effective in a heterogenous real-world population at first relapse with a low rate of peripheral neuropathy. However, high-risk patients had inferior outcomes and should be considered for alternative treatments.

Hypoxia shapes the immune landscape in lung injury and promotes the persistence of inflammation.

Hypoxemia is a defining feature of acute respiratory distress syndrome (ARDS), an often-fatal complication of pulmonary or systemic inflammation, yet the resulting tissue hypoxia, and its impact on immune responses, is often neglected. In the present study, we have shown that ARDS patients were hypoxemic and monocytopenic within the first 48 h of ventilation. Monocytopenia was also observed in mouse models of hypoxic acute lung injury, in which hypoxemia drove the suppression of type I interferon signaling in the bone marrow. This impaired monopoiesis resulted in reduced accumulation of monocyte-derived macrophages and enhanced neutrophil-mediated inflammation in the lung. Administration of colony-stimulating factor 1 in mice with hypoxic lung injury rescued the monocytopenia, altered the phenotype of circulating monocytes, increased monocyte-derived macrophages in the lung and limited injury. Thus, tissue hypoxia altered the dynamics of the immune response to the detriment of the host and interventions to address the aberrant response offer new therapeutic strategies for ARDS.

Cell origin and niche availability dictate the capacity of peritoneal macrophages to colonize the cavity and omentum.

The relationship between macrophages of the peritoneal cavity and the adjacent omentum remains poorly understood. Here, we describe two populations of omental macrophages distinguished by CD102 expression and use an adoptive cell transfer approach to investigate whether these arise from peritoneal macrophages, and whether this depends upon inflammatory status, the origin of peritoneal macrophages and availability of the omental niches. We show that whereas established resident peritoneal macrophages largely fail to migrate to the omentum, monocyte-derived resident cells readily migrate and form a substantial component of omental CD102+ macrophages in the months following resolution of peritoneal inflammation. In contrast, both populations had the capacity to migrate to the omentum in the absence of endogenous peritoneal and omental macrophages. However, inflammatory macrophages expanded more effectively and more efficiently repopulated both CD102+ and CD102- omental populations, whereas established resident macrophages partially reconstituted the omental niche via recruitment of monocytes. Hence, cell origin determines the migration of peritoneal macrophages to the omentum and predisposes established resident macrophages to drive infiltration of monocyte-derived cells.

Systemic Influences of Mammary Cancer on Monocytes in Mice.

There is a growing body of evidence that cancer causes systemic changes. These influences are most evident in the bone marrow and the blood, particularly in the myeloid compartment. Here, we show that there is an increase in the number of bone marrow, circulating and splenic monocytes by using mouse models of breast cancer caused by the mammary epithelial expression of the polyoma middle T antigen. Cancer does not affect ratios of classical to non-classical populations of monocytes in the circulation nor does it affect their half-lives. Single cell RNA sequencing also indicates that cancer does not induce any new monocyte populations. Cancer does not change the monocytic progenitor number in the bone marrow, but the proliferation rate of monocytes is higher, thus providing an explanation for the expansion of the circulating numbers. Deep RNA sequencing of these monocytic populations reveals that cancer causes changes in the classical monocyte compartment, with changes evident in bone marrow monocytes and even more so in the blood, suggesting influences in both compartments, with the down-regulation of interferon type 1 signaling and antigen presentation being the most prominent of these. Consistent with this analysis, down-regulated genes are enriched with STAT1/STAT2 binding sites in their promoter, which are transcription factors required for type 1 interferon signaling. However, these transcriptome changes in mice did not replicate those found in patients with breast cancer. Consequently, this mouse model of breast cancer may be insufficient to study the systemic influences of human cancer.

The expanding world of tissue-resident macrophages.

The term 'macrophage' encompasses tissue cells that typically share dependence on the same transcriptional regulatory pathways (e.g. the transcription factor PU.1) and growth factors (e.g. CSF1/IL-34). They share a core set of functions that largely arise from a uniquely high phagocytic capacity manifest in their ability to clear dying cells, pathogens and scavenge damaged, toxic or modified host molecules. However, macrophages demonstrate a remarkable degree of tissue-specific functionality and have diverse origins that vary by tissue site and inflammation status. With our understanding of this diversity has come an appreciation of the longevity and replicative capacity of tissue-resident macrophages and thus the realisation that macrophages may persist through tissue perturbations and inflammatory events with important consequences for cell function. Here, we discuss our current understanding of the parameters that regulate macrophage survival and function, focusing on the relative importance of the tissue environment versus cell-intrinsic factors, such as origin, how long a cell has been resident within a tissue and prior history of activation. Thus, we reconsider the view of macrophages as wholly plastic cells and raise many unanswered questions about the relative importance of cell life-history versus environment in macrophage programming and function.

Colonization With Fluoroquinolone-Resistant Enterobacterales Decreases the Effectiveness of Fluoroquinolone Prophylaxis in Hematopoietic Cell Transplant Recipients.

BACKGROUND: Levofloxacin prophylaxis is recommended to prevent gram-negative bloodstream infections (BSIs) in patients with prolonged chemotherapy-induced neutropenia. However, increasing fluoroquinolone resistance may decrease the effectiveness of this approach. METHODS: We assessed the prevalence of colonization with fluoroquinolone-resistant Enterobacterales (FQRE) among patients admitted for hematopoietic cell transplantation (HCT) from November 2016 to August 2019 and compared the risk of gram-negative BSI between FQRE-colonized and noncolonized patients. All patients received levofloxacin prophylaxis during neutropenia. Stool samples were collected upon admission for HCT and weekly thereafter until recovery from neutropenia, and underwent selective culture for FQRE. All isolates were identified and underwent antimicrobial susceptibility testing by broth microdilution. FQRE isolates also underwent whole-genome sequencing. RESULTS: Fifty-four of 234 (23%) patients were colonized with FQRE prior to HCT, including 30 of 119 (25%) allogeneic and 24 of 115 (21%) autologous HCT recipients. Recent antibacterial use was associated with FQRE colonization (P = .048). Ninety-one percent of colonizing FQRE isolates were Escherichia coli and 29% produced extended-spectrum ß-lactamases. Seventeen (31%) FQRE-colonized patients developed gram-negative BSI despite levofloxacin prophylaxis, compared to only 2 of 180 (1.1%) patients who were not colonized with FQRE on admission (P < .001). Of the 17 gram-negative BSIs in FQRE-colonized patients, 15 (88%) were caused by FQRE isolates that were genetically identical to the colonizing strain. CONCLUSIONS: Nearly one-third of HCT recipients with pretransplant FQRE colonization developed gram-negative BSI while receiving levofloxacin prophylaxis, and infections were typically caused by their colonizing strains. In contrast, levofloxacin prophylaxis was highly effective in patients not initially colonized with FQRE.

Macrophages inhibit and enhance endometriosis depending on their origin.

Macrophages are intimately involved in the pathophysiology of endometriosis, a chronic inflammatory disorder characterized by the growth of endometrial-like tissue (lesions) outside the uterus. By combining genetic and pharmacological monocyte and macrophage depletion strategies we determined the ontogeny and function of macrophages in a mouse model of induced endometriosis. We demonstrate that lesion-resident macrophages are derived from eutopic endometrial tissue, infiltrating large peritoneal macrophages (LpM) and monocytes. Furthermore, we found endometriosis to trigger continuous recruitment of monocytes and expansion of CCR2+ LpM. Depletion of eutopic endometrial macrophages results in smaller endometriosis lesions, whereas constitutive inhibition of monocyte recruitment significantly reduces peritoneal macrophage populations and increases the number of lesions. Reprogramming the ontogeny of peritoneal macrophages such that embryo-derived LpM are replaced by monocyte-derived LpM decreases the number of lesions that develop. We propose a putative model whereby endometrial macrophages are "proendometriosis" while newly recruited monocyte-derived macrophages, possibly in LpM form, are "antiendometriosis." These observations highlight the importance of monocyte-derived macrophages in limiting disease progression.

Local proliferation of monocytes.

Discussion on how monocytes may contribute to the expansion of Mϕ populations at the site of inflammation.

Impact of a Multiplexed Polymerase Chain Reaction Panel on Identifying Diarrheal Pathogens in Hematopoietic Cell Transplant Recipients.

BACKGROUND: Diarrhea is common and associated with substantial morbidity among hematopoietic cell transplant (HCT) recipients, but the etiology is often not identified. Multiplexed polymerase chain reaction (PCR) assays increase the detection of diarrheal pathogens, but the impact of this technology in this population has not been evaluated. METHODS: Our center replaced stool cultures and other conventional microbiologic methods with the FilmArray Gastrointestinal Panel (GI PCR) in June 2016. We reviewed all adult patients who received an HCT from June 2014-May 2015 (pre-GI PCR, n = 163) and from June 2016-May 2017 (post-GI PCR, n = 182) and followed them for 1 year after transplantation. Clostridioides difficile infection was diagnosed by an independent PCR test in both cohorts. RESULTS: The proportion of patients with ≥1 identified infectious diarrheal pathogen increased from 25% to 37% after implementation of GI PCR (P = .01). Eight patients (5%) in the pre-GI PCR cohort tested positive for a pathogen other than C. difficile versus 49 patients (27%) in the post-GI PCR cohort (P < .001). The most common non-C. difficile diarrheal pathogens in the post-GI PCR cohort were enteropathogenic Escherichia coli (n = 14, 8%), norovirus (n = 14, 8%), and Yersinia enterocolitica (n = 7, 4%). The percentage of diarrheal episodes with an identified infectious etiology increased from 14% to 23% (P = .001). Median total costs of stool testing per patient did not increase (pre: $473; post: $425; P = .25). CONCLUSIONS: Infectious etiologies of diarrhea were identified in a higher proportion of HCT recipients after replacing conventional stool testing with a multiplexed PCR assay, without an increase in testing costs.

Mice depleted for Exchange Proteins Directly Activated by cAMP (Epac) exhibit irregular liver regeneration in response to partial hepatectomy.

The exchange proteins directly activated by cAMP 1 and 2 (Epac1 and Epac2) are expressed in a cell specific manner in the liver, but their biological functions in this tissue are poorly understood. The current study was undertaken to begin to determine the potential roles of Epac1 and Epac2 in liver physiology and disease. Male C57BL/6J mice in which expression of Epac1 and/or Epac2 are deleted, were subjected to partial hepatectomy and the regenerating liver was analyzed with regard to lipid accumulation, cell replication and protein expression. In response to partial hepatectomy, deletion of Epac1 and/or Epac2 led to increased hepatocyte proliferation 36 h post surgery, and the transient steatosis observed in wild type mice was virtually absent in mice lacking both Epac1 and Epac2. The expression of the protein cytochrome P4504a14, which is implicated in hepatic steatosis and fibrosis, was substantially reduced upon deletion of Epac1/2, while a number of factors involved in lipid metabolism were significantly decreased. Moreover, the number of Küpffer cells was affected, and Epac2 expression was increased in the liver of wild type mice in response to partial hepatectomy, further supporting a role for these proteins in liver function. This study establishes hepatic phenotypic abnormalities in mice deleted for Epac1/2 for the first time, and introduces Epac1/2 as regulators of hepatocyte proliferation and lipid accumulation in the regenerative process.

Deletion of a Csf1r enhancer selectively impacts CSF1R expression and development of tissue macrophage populations.

The proliferation, differentiation and survival of mononuclear phagocytes depend on signals from the receptor for macrophage colony-stimulating factor, CSF1R. The mammalian Csf1r locus contains a highly conserved super-enhancer, the fms-intronic regulatory element (FIRE). Here we show that genomic deletion of FIRE in mice selectively impacts CSF1R expression and tissue macrophage development in specific tissues. Deletion of FIRE ablates macrophage development from murine embryonic stem cells. Csf1rΔFIRE/ΔFIRE mice lack macrophages in the embryo, brain microglia and resident macrophages in the skin, kidney, heart and peritoneum. The homeostasis of other macrophage populations and monocytes is unaffected, but monocytes and their progenitors in bone marrow lack surface CSF1R. Finally, Csf1rΔFIRE/ΔFIRE mice are healthy and fertile without the growth, neurological or developmental abnormalities reported in Csf1r-/- rodents. Csf1rΔFIRE/ΔFIRE mice thus provide a model to explore the homeostatic, physiological and immunological functions of tissue-specific macrophage populations in adult animals.

Colonization With Levofloxacin-resistant Extended-spectrum ß-Lactamase-producing Enterobacteriaceae and Risk of Bacteremia in Hematopoietic Stem Cell Transplant Recipients.

Background: Bacteremia caused by extended-spectrum ß-lactamase (ESBL)-producing Enterobacteriaceae (ESBL-E) is associated with inadequate empirical therapy and substantial mortality in neutropenic patients. Strategies are needed to identify neutropenic patients at high risk of these infections. Methods: From April 2014 to September 2016, we collected perianal swabs, both at admission and weekly thereafter, from patients undergoing hematopoietic stem cell transplantation (HSCT). Patients received prophylactic levofloxacin while neutropenic. Swabs were plated onto selective agar, colonies were identified and underwent antimicrobial susceptibility testing, and phenotypic ESBL testing and polymerase chain reaction for ß-lactamase genes were performed on ceftriaxone-resistant Enterobacteriaceae. We then determined the prevalence of pre-transplant ESBL-E colonization and risk of ESBL-E bacteremia. Colonizing and bloodstream isolates from patients with ESBL-E bacteremia underwent multilocus sequence typing and pulsed-field gel electrophoresis. Results: We analyzed 312 patients, including 212 allogeneic and 100 autologous HSCT recipients. Ten percent (31/312) of patients had pre-transplant ESBL-E colonization. Susceptibility rates of colonizing ESBL-E were: levofloxacin, 25%; cefepime, 9%; piperacillin-tazobactam, 84%; and meropenem, 97%. Of 31 patients colonized with ESBL-E pre-transplant, 10 (32%) developed ESBL-E bacteremia during their transplant admission, compared to 1 (0.4%) of 281 patients not colonized with ESBL-E (P < .001). All bloodstream ESBL-E were levofloxacin-resistant and colonizing and bloodstream isolates from individual patients had identical genotypic profiles. Conclusions: HSCT recipients who are colonized with levofloxacin-resistant ESBL-E pre-transplant and receive levofloxacin prophylaxis have high rates of bacteremia from their colonizing strain during neutropenia. Assessing for ESBL-E colonization in neutropenic patients could lead to optimization of empirical antibacterial therapy.

Interleukin-4 activated macrophages mediate immunity to filarial helminth infection by sustaining CCR3-dependent eosinophilia.

Eosinophils are effectors in immunity to tissue helminths but also induce allergic immunopathology. Mechanisms of eosinophilia in non-mucosal tissues during infection remain unresolved. Here we identify a pivotal function of tissue macrophages (Mϕ) in eosinophil anti-helminth immunity using a BALB/c mouse intra-peritoneal Brugia malayi filarial infection model. Eosinophilia, via C-C motif chemokine receptor (CCR)3, was necessary for immunity as CCR3 and eosinophil impairments rendered mice susceptible to chronic filarial infection. Post-infection, peritoneal Mϕ populations proliferated and became alternatively-activated (AAMϕ). Filarial AAMϕ development required adaptive immunity and interleukin-4 receptor-alpha. Depletion of Mϕ prior to infection suppressed eosinophilia and facilitated worm survival. Add back of filarial AAMϕ in Mϕ-depleted mice recapitulated a vigorous eosinophilia. Transfer of filarial AAMϕ into Severe-Combined Immune Deficient mice mediated immunological resistance in an eosinophil-dependent manner. Exogenous IL-4 delivery recapitulated tissue AAMϕ expansions, sustained eosinophilia and mediated immunological resistance in Mϕ-intact SCID mice. Co-culturing Brugia with filarial AAMϕ and/or filarial-recruited eosinophils confirmed eosinophils as the larvicidal cell type. Our data demonstrates that IL-4/IL-4Rα activated AAMϕ orchestrate eosinophil immunity to filarial tissue helminth infection.

Evaluation of a human adenovirus viral load assay using the Altona RealStar® PCR test.

This study evaluated the performance of the Altona Diagnostics RealStar® Adenovirus Research Use Only (RUO) real-time PCR reagents for HAdV quantitation in plasma samples from immunodeficient patients. The assay was linear from 2.30-9.17 log10 copies/mL (coefficient of determination; R2=0.998) with limits of detection and quantification of 2.19 log10 and 2.30 log10 copies/mL (>95% positivity rate), respectively. Assay precision was highly reproducible with coefficients of variance ranging from 0% to 4.7%. A comparison of 66 matched samples showed good agreement (R2=0.845) between the Altona and the reference laboratory assay, with an average negative bias (-0.24 log10 copies/mL). Genotyping analysis demonstrated that HAdV species B and C accounted for 77% of the positive samples. A significant (≥0.9 log10) difference in quantitation between both tests was found for three HAdV types (HAdV types A12, B14 and F41). In conclusion, the Altona RealStar® test is a reliable and sensitive assay for HAdV DNA quantitation.