Regulation and functions of the IL-10 family of cytokines in inflammation and disease.

The IL-10 family of cytokines consists of nine members: IL-10, IL-19, IL-20, IL-22, IL-24, IL-26, and the more distantly related IL-28A, IL-28B, and IL-29. Evolutionarily, IL-10 family cytokines emerged before the adaptive immune response. These cytokines elicit diverse host defense mechanisms, especially from epithelial cells, during various infections. IL-10 family cytokines are essential for maintaining the integrity and homeostasis of tissue epithelial layers. Members of this family can promote innate immune responses from tissue epithelia to limit the damage caused by viral and bacterial infections. These cytokines can also facilitate the tissue-healing process in injuries caused by infection or inflammation. Finally, IL-10 itself can repress proinflammatory responses and limit unnecessary tissue disruptions caused by inflammation. Thus, IL-10 family cytokines have indispensable functions in many infectious and inflammatory diseases.

Signaling via the IL-20 receptor inhibits cutaneous production of IL-1ß and IL-17A to promote infection with methicillin-resistant Staphylococcus aureus.

Staphylococcus aureus causes most infections of human skin and soft tissue and is a major infectious cause of mortality. Host defense mechanisms against S. aureus are incompletely understood. Interleukin 19 (IL-19), IL-20 and IL-24 signal through type I and type II IL-20 receptors and are associated with inflammatory skin diseases such as psoriasis and atopic dermatitis. We found here that those cytokines promoted cutaneous infection with S. aureus in mice by downregulating IL-1ß- and IL-17A-dependent pathways. We noted similar effects of those cytokines in human keratinocytes after exposure to S. aureus, and antibody blockade of the IL-20 receptor improved outcomes in infected mice. Our findings identify an immunosuppressive role for IL-19, IL-20 and IL-24 during infection that could be therapeutically targeted to alter susceptibility to infection.

IL-22 bridges the lymphotoxin pathway with the maintenance of colonic lymphoid structures during infection with Citrobacter rodentium.

Colonic patches (CLPs) and isolated lymphoid follicles (ILFs) are two main lymphoid structures in the colon. Lymphoid tissue-inducer cells (LTi cells) are indispensable for the development of ILFs. LTi cells also produce interleukin 17 (IL-17) and IL-22, signature cytokines secreted by IL-17-producing helper T cells. Here we report that IL-22 acted downstream of the lymphotoxin pathway and regulated the organization and maintenance of mature CLPs and ILFs in the colon during infection with Citrobacter rodentium. Lymphotoxin (LTα(1)ß(2)) regulated the production of IL-22 during infection with C. rodentium, but the lymphotoxin-like protein LIGHT did not. IL-22 signaling was sufficient to restore the organization of CLPs and ILFs and host defense against infection with C. rodentium in mice lacking lymphotoxin signals, which suggests that IL-22 connects the lymphotoxin pathway to mucosal epithelial defense mechanisms.

Prostaglandin E2 suppresses antifungal immunity by inhibiting interferon regulatory factor 4 function and interleukin-17 expression in T cells.

T helper 17 (Th17) cells play an important role in mucosal host defense through production of the signature cytokines IL-17 and IL-22. Prostaglandin E2 (PGE2) has been shown to enhance IL-17 production by mature Th17 cells. However, when present during Th17 cell differentiation, we found that PGE2 inhibited the transcription factor IRF4 and suppressed production of IL-17 but not IL-22. We show that IRF4 was required for IL-17 expression but inhibited IL-22 expression, highlighting the potential for discordant regulation of these two cytokines in Th17 cells. The pathogenic fungus Cryptococcus neoformans produces PGE2, and we found that it uses PGE2- and IRF4-dependent mechanisms to specifically inhibit induction of IL-17 during Th17 cell differentiation. Blockade of host PGE2 during infection led to increased IL-17 production from CD4(+) T cells and increased survival of mice. These findings suggest that host- or pathogen-derived PGE2 can act directly on Th17 cells during differentiation to inhibit IL-17-dependent antimicrobial responses.

NRROS negatively regulates reactive oxygen species during host defence and autoimmunity.

Reactive oxygen species (ROS) produced by phagocytes are essential for host defence against bacterial and fungal infections. Individuals with defective ROS production machinery develop chronic granulomatous disease. Conversely, excessive ROS can cause collateral tissue damage during inflammatory processes and therefore needs to be tightly regulated. Here we describe a protein, we termed negative regulator of ROS (NRROS), which limits ROS generation by phagocytes during inflammatory responses. NRROS expression in phagocytes can be repressed by inflammatory signals. NRROS-deficient phagocytes produce increased ROS upon inflammatory challenges, and mice lacking NRROS in their phagocytes show enhanced bactericidal activity against Escherichia coli and Listeria monocytogenes. Conversely, these mice develop severe experimental autoimmune encephalomyelitis owing to oxidative tissue damage in the central nervous system. Mechanistically, NRROS is localized to the endoplasmic reticulum, where it directly interacts with nascent NOX2 (also known as gp91(phox) and encoded by Cybb) monomer, one of the membrane-bound subunits of the NADPH oxidase complex, and facilitates the degradation of NOX2 through the endoplasmic-reticulum-associated degradation pathway. Thus, NRROS provides a hitherto undefined mechanism for regulating ROS production--one that enables phagocytes to produce higher amounts of ROS, if required to control invading pathogens, while minimizing unwanted collateral tissue damage.

Impact of a pharmacy technician on an interprofessional antithrombotic stewardship program at an academic medical center.

PURPOSE: The need for monitoring and standardization of anticoagulation management has garnered the attention of national organizations, driving the implementation of antithrombotic stewardship programs (ASPs). Established ASPs have highlighted interdisciplinary collaboration between physicians, nurses, and pharmacists and demonstrated financial benefits and positive patient care outcomes. While pharmacy technicians are key members of the pharmacy profession, they are rarely utilized to expand clinical programs. The aim of this report is to describe the impact of adding a pharmacy technician to an ASP at an academic medical center. SUMMARY: The departments of pharmacy and quality at West Virginia University Hospitals (WVUH) developed a business plan and financially justified an ASP. The ASP was implemented in January 2022 and consisted of 2 full-time clinical pharmacist specialists, 1 full-time clinical pharmacy technician, 2 full-time clinical nurse specialists, and 1 part-time physician medical director. The clinical pharmacy technician's primary role was to review patients' sequential compression device (SCD) compliance and newly started oral anticoagulants prior to discharge. The clinical nurse specialists educated patients newly started on oral anticoagulants within 24 hours of discharge and triaged any postdischarge medication access issues. The medical director provided high-level program oversight and acted as a clinical consultant on complex patient cases. In the first 6 months after the program's implementation, the clinical pharmacy technician made 174 recommendations to the clinical pharmacist specialists regarding discharge transitions of care and assessed SCD compliance in 246 patients. Of the 246 patients assessed, 217 patients (88%) were deemed to be noncompliant. CONCLUSION: The pharmacy department at WVUH successfully justified and implemented an interprofessional ASP at an academic medical center, which is the first ASP to date to incorporate a clinical pharmacy technician.

Interleukin-22, a T(H)17 cytokine, mediates IL-23-induced dermal inflammation and acanthosis.

Psoriasis is a chronic inflammatory skin disease characterized by hyperplasia of the epidermis (acanthosis), infiltration of leukocytes into both the dermis and epidermis, and dilation and growth of blood vessels. The underlying cause of the epidermal acanthosis in psoriasis is still largely unknown. Recently, interleukin (IL)-23, a cytokine involved in the development of IL-17-producing T helper cells (T(H)17 cells), was found to have a potential function in the pathogenesis of psoriasis. Here we show that IL-22 is preferentially produced by T(H)17 cells and mediates the acanthosis induced by IL-23. We found that IL-23 or IL-6 can directly induce the production of IL-22 from both murine and human naive T cells. However, the production of IL-22 and IL-17 from T(H)17 cells is differentially regulated. Transforming growth factor-beta, although crucial for IL-17 production, actually inhibits IL-22 production. Furthermore, IL-22 mediates IL-23-induced acanthosis and dermal inflammation through the activation of Stat3 (signal transduction and activators of transcription 3) in vivo. Our results suggest that T(H)17 cells, through the production of both IL-22 and IL-17, might have essential functions in host defence and in the pathogenesis of autoimmune diseases such as psoriasis. IL-22, as an effector cytokine produced by T cells, mediates the crosstalk between the immune system and epithelial cells.

Phosphatidylserine receptor Tim-4 is essential for the maintenance of the homeostatic state of resident peritoneal macrophages.

Tim-4 is a phosphatidylserine (PS) receptor that is expressed on various macrophage subsets. It mediates phagocytosis of apoptotic cells by peritoneal macrophages. The in vivo functions of Tim-4 in phagocytosis and immune responses, however, are still unclear. In this study, we show that Tim-4 quickly forms punctate caps on contact with apoptotic cells, in contrast to its normal diffused expression on the surface of phagocytes. Despite its expression in marginal zone and tingible body macrophages, Tim-4 deficiency only minimally affects outcomes of several acute immune challenges, including the trapping of apoptotic cells in the marginal zone, the clearance apoptotic cells by tingible body macrophages, and the formation of germinal centers and elicitation of antibody responses against sheep red blood cells (SRBCs). In addition, Tim-4(-/-) resident peritoneal macrophages (rPMs) phagocytose necrotic cells and other opsonized targets normally. However, their ability to bind and engulf apoptotic cells is significantly compromised both in vitro and in vivo. Most importantly, Tim-4 deficiency results in increased cellularity in the peritoneum. Resting rPMs produce higher TNF-alpha in culture. Their response to LPS, on the contrary, is dampened. Our data support an indispensible role of Tim-4 in maintaining the homeostasis of rPMs.

Mucosal adjuvant activity of cholera toxin requires Th17 cells and protects against inhalation anthrax.

Cholera toxin (CT) elicits a mucosal immune response in mice when used as a vaccine adjuvant. The mechanisms by which CT exerts its adjuvant effects are incompletely understood. We show that protection against inhalation anthrax by an irradiated spore vaccine depends on CT-mediated induction of IL-17-producing CD4 Th17 cells. Furthermore, IL-17 is involved in the induction of serum and mucosal antibody responses by CT. Th17 cells induced by CT have a unique cytokine profile compared with those induced by IL-6 and TGF-beta, and their induction by CT requires cAMP-dependent secretion of IL-1beta and beta-calcitonin gene-related peptide by dendritic cells. These findings demonstrate that Th17 cells mediate mucosal adjuvant effects of CT and identify previously unexplored pathways involved in Th17 induction that could be targeted for development of unique mucosal adjuvants.

The hemodynamic effects of diazepam versus dexmedetomidine in the treatment of alcohol withdrawal syndrome: A randomized clinical trial.

BACKGROUND: Dexmedetomidine (DEX) is an alpha-2 adrenergic drug used for short sedation and as an alternative to diazepam (DZP) in the treatment of alcohol withdrawal syndrome (AWS). PURPOSE: This study aims to compare the hemodynamic effect of DZP versus DEX on heart rate (HR) and blood pressure in patients with AWS. METHODS: Prospective randomized clinical trial that includes 40 patients with AWS from Mérida, Yucatán, México. RESULTS: Forty patients were randomly divided into two groups: one group DZP (n=20) patients received diazepam (doses 5-20mg IV) and the other group (n=20) received DEX (dexmedetomidine infusion .2-.7mcg/kg/min). We obtained statistical significance in sedation with the DEX group in the degree of traumatic brain injury I/II (p=.003). The DEX group remained haemodynamically stable in the first 24h, the mean HR (73.85±8.39) was significant comparing both groups (p=.002). In the comparison of the figures for the DEX group with the DZP (143.85±2.30-137.95±5.62) the SBP was significant with a (p=.0001). Furthermore, DEX treatment was shorter. CONCLUSION: Although DEX is not indicated for the routine treatment of AWS, this study proposes a positive effect on HR, SBP and fewer days of treatment compared to the standard DZP treatment for AWS. Clinical Trials.gov ID: NCT03877120-https://clinicaltrials.gov/ct2/show/NCT03877120.

Epidemiological study of prevalent pathogens in the Northwest region of Argentina (NWA).

Northwest Argentina (NWA) is a poor economic-geographical region, with the highest rate of diarrhea diseases. At the moment, there are no reports showing the epidemiological status of this region that would allow to establish methods for prevention and control of these infections and to indicate of the prevalent pathogen that produces them. Therefore we carried out an epidemiological study of the gastroenteritis etiological agents and their incidence in the pediatric population. A total of 17 823 fecal samples were collected, 14 242 from HNJ-Tuc, 2,257 from CePSI-Stgo and 1,324 from HINEP-Cat. In 2,595 samples a bacterial agent was identified, the 93.64% corresponded to Shigella/Salmonella clinical isolates. Shigella genus was the prevalent pathogen, being Shigella flexneri 2 the most frequent serotype. Most of the Shigella clinical isolates presented themselves as multidrug-resistant (MDR), harboring 2 to 3 genetic resistance determinants. 50% of the affected patients were children under 4 years old. Here, we demonstrate that bacterial gastrointestinal diseases strongly affect the health of NWA population. The appearance of epidemic outbreaks, as happened during 2014, suggest that they may be related to the socio-economic poverty of NWA. Recently, Shigella flexneri 2 has become the highest NWA´s incidence infectious agent. The acquisition of new antibiotic resistance determinants may play an important role in their adaptation and persistence.

Preclinical antilymphoma activity of a humanized anti-CD40 monoclonal antibody, SGN-40.

SGN-40 is a humanized IgG1 antihuman CD40 that is currently in a phase I clinical trial for the treatment of multiple myeloma. As surface CD40 expression on B-lineage cells is maintained from pro-B cells to plasma cells, SGN-40 may be applicable to treatment of other B-cell neoplasias, including non-Hodgkin's lymphoma. In this study, we examined potential in vitro and in vivo anti-B-lineage lymphoma activity of SGN-40. Recombinant SGN-40 was expressed and purified from Chinese hamster ovary cells and characterized based on binding affinity, specificity, and normal B-cell stimulation. The ability of SGN-40 to target neoplastic B cells was examined in vitro by proliferation inhibition, cytotoxicity, and antibody-dependent cell cytotoxicity assays and in vivo by human lymphoma xenograft models. Recombinant SGN-40 showed high affinity, Kd of approximately 1 nmol/L, and specific binding to CD40. Whereas SGN-40 was a weak agonist in stimulating normal B-cell proliferation in the absence of IL-4 and CD40L, it delivered potent proliferation inhibitory and apoptotic signals to, and mediated antibody-dependent cytotoxicity against, a panel of high-grade B-lymphoma lines. These in vitro antilymphoma effects were extended to disseminated and s.c. xenograft CD40 tumor models. In these xenograft models, the antitumor activity of SGN-40 was comparable with that of rituximab. The preclinical in vitro and in vivo antilymphoma activity of SGN-40 observed in this study provides a rationale for the clinical testing of SGN-40 in the treatment of CD40+ B-lineage lymphomas.

Preserving immunogenicity of lethally irradiated viral and bacterial vaccine epitopes using a radio- protective Mn2+-Peptide complex from Deinococcus.

Although pathogen inactivation by γ-radiation is an attractive approach for whole-organism vaccine development, radiation doses required to ensure sterility also destroy immunogenic protein epitopes needed to mount protective immune responses. We demonstrate the use of a reconstituted manganous peptide complex from the radiation-resistant bacterium Deinococcus radiodurans to protect protein epitopes from radiation-induced damage and uncouple it from genome damage and organism killing. The Mn(2+) complex preserved antigenic structures in aqueous preparations of bacteriophage lambda, Venezuelan equine encephalitis virus, and Staphylococcus aureus during supralethal irradiation (25-40 kGy). An irradiated vaccine elicited both antibody and Th17 responses, and induced B and T cell-dependent protection against methicillin-resistant S. aureus (MRSA) in mice. Structural integrity of viruses and bacteria are shown to be preserved at radiation doses far above those which abolish infectivity. This approach could expedite vaccine production for emerging and established pathogens for which no protective vaccines exist.

Interleukin-22 mediates early host defense against attaching and effacing bacterial pathogens.

Infections by attaching and effacing (A/E) bacterial pathogens, such as Escherichia coli O157:H7, pose a serious threat to public health. Using a mouse A/E pathogen, Citrobacter rodentium, we show that interleukin-22 (IL-22) has a crucial role in the early phase of host defense against C. rodentium. Infection of IL-22 knockout mice results in increased intestinal epithelial damage, systemic bacterial burden and mortality. We also find that IL-23 is required for the early induction of IL-22 during C. rodentium infection, and adaptive immunity is not essential for the protective role of IL-22 in this model. Instead, IL-22 is required for the direct induction of the Reg family of antimicrobial proteins, including RegIIIbeta and RegIIIgamma, in colonic epithelial cells. Exogenous mouse or human RegIIIgamma substantially improves survival of IL-22 knockout mice after C. rodentium infection. Together, our data identify a new innate immune function for IL-22 in regulating early defense mechanisms against A/E bacterial pathogens.

The effects of IL-20 subfamily cytokines on reconstituted human epidermis suggest potential roles in cutaneous innate defense and pathogenic adaptive immunity in psoriasis.

IL-19, IL-20, IL-22, IL-24, and IL-26 are members of the IL-10 family of cytokines that have been shown to be up-regulated in psoriatic skin. Contrary to IL-10, these cytokines signal using receptor complex R1 subunits that are preferentially expressed on cells of epithelial origin; thus, we henceforth refer to them as the IL-20 subfamily cytokines. In this study, we show that primary human keratinocytes (KCs) express receptors for these cytokines and that IL-19, IL-20, IL-22, and IL-24 induce acanthosis in reconstituted human epidermis (RHE) in a dose-dependent manner. These cytokines also induce expression of the psoriasis-associated protein S100A7 and keratin 16 in RHE and cause persistent activation of Stat3 with nuclear localization. IL-22 had the most pronounced effects on KC proliferation and on the differentiation of KCs in RHE, inducing a decrease in the granular cell layer (hypogranulosis). Furthermore, gene expression analysis performed on cultured RHE treated with these cytokines showed that IL-19, IL-20, IL-22, and IL-24 regulate many of these same genes to variable degrees, inducing a gene expression profile consistent with inflammatory responses, wound healing re-epithelialization, and altered differentiation. Many of these genes have also been found to be up-regulated in psoriatic skin, including several chemokines, beta-defensins, S100 family proteins, and kallikreins. These results confirm that IL-20 subfamily cytokines are important regulators of epidermal KC biology with potentially pivotal roles in the immunopathology of psoriasis.

Loss of TACI causes fatal lymphoproliferation and autoimmunity, establishing TACI as an inhibitory BLyS receptor.

BLys , a key cytokine that sustains B cell maturation and tolerance, binds three receptors: BR3, BCMA, and TACI. Results from knockout mice implicate a major functional role for BR3 and a redundant one for BCMA in B cell function. TACI's role is controversial based on defects in TI antibody responses accompanied by B cell hyperplasia in knockout mice. We have presently characterized a precise role for TACI in vivo. TACI(-/-) mice develop fatal autoimmune glomerulonephritis, proteinurea, and elevated levels of circulating autoantibodies. Treatment of B cells with TACI agonistic antibodies inhibits proliferation in vitro and activation of a chimeric receptor containing the TACI intracellular domain induces apoptosis. These results demonstrate the critical requirement for TACI in regulating B cell homeostasis.

NTB-A, a new activating receptor in T cells that regulates autoimmune disease.

The CD28 co-stimulatory pathway is well established for T cell activation; however, results from CD28 -/- mice suggest the existence of additional co-stimulatory pathways. Here we report the further characterization of a new member of the CD2 superfamily, NTB-A, important in T cell co-stimulation. NTB-A is expressed on T cells, and its expression is up-regulated on activated cells. Triggering of NTB-A with monoclonal antibodies in the absence of CD28 signals leads to T cell proliferation and interferon-gamma secretion but not interleukin-4. Cross-linking of NTB-A also induces phosphorylation of NTB-A and the association of SAP (SLAM-associated protein), the protein absent in X-linked lymphoproliferative disease. T helper cells differentiated by cross-linking NTB-A and CD3 developed predominantly into Th1 cells not Th2 cells. In vivo blocking of NTB-A interactions with its ligands by using soluble NTB-A-Fc fusion protein inhibits B cell isotype switching to IgG2a and IgG3, commonly induced by Th1-type cytokines. Most important, treatment of mice with NTB-A-Fc delays the onset of antigen-induced experimental allergic encephalomyelitis in myelin basic protein-T cell receptor transgenic mice, suggesting a role in T cell-mediated autoimmune disease. Regulation of interferon-gamma secretion, and not interleukin-4 in vitro, as well as inhibition of Th1 cell-induced isotype switching and attenuation of experimental allergic encephalomyelitis indicate that NTB-A is important for Th1 responses. The observation that cross-linking of NTB-A induces T cell activation, expansion, and Th1-type cytokine production suggests NTB-A is a novel co-stimulatory receptor. The identification of NTB-A as a regulator of T cell response paves the way to provide novel therapeutic approaches for modulation of the immune response.

Shigella SPP., asociada a enfermedad diarreica aguda, aisladas en el Hospital de Niños de Catamarca, Argentina

Con el fin de evaluar prevalencia, frecuencia de serogrupos, serotipos y susceptibilidad antimicrobiana de cepas de Shigella spp aisladas de niños con síndrome diarreico agudo en la Ciudad de Catamarca, se realizó un estudio epidemiológico observacional descriptivo de corte transversal entre Octubre 2011 y Mayo 2012. El criterio de inclusión fue el niño con síndrome diarreico agudo. Las muestras de materia fecal (n= 433), fueron procesadas en el Laboratorio de Bacteriología del Hospital de Niños de Catamarca. En 141/433 (32,56%) se aislaron bacterias enteropatógenas cuyas frecuencias correspondieron: 6/141 (4,26%) Es cherichiacoli, 10/141 (7,09%) Salmonella spp. y 125/141 (88,65%) Shigella spp. (p<0,001 ,x2 Pearson). Fue mayor la chance del aislamiento de Shigellaspp. (Odds Ratio 61,04, 95% IC= 29,54- 126,13) en referencia a los otros enteropatógenos. Respecto a los aislamientos del Género Shigella 39/125(31%) correspondió a Shigellasonnei (serog D) y 86/125 (69%) a Shigellaflexneri (serog B). Las distintas frecuencias observadas fueron estadísticamente significativas (p<0,001 x2 Pearson). De los 86 aislamientos de Shigellaflexneri ,7 (8%) correspondieron al serotipo 1, 30 (35%) al 2, 3 (3,5%) al 3 y 46 (53,5%) al AA479 (p<0,001; x2 Pearson ) . Los aislamientos de S.flexneri fueron más frecuentes en los meses de Diciembre 2011 y Enero 2012 (39,2%), mientras que para E. coli y Salmonella spp. se distribuyeron de modo uniforme durante el período estudiado.Los valores de la media de las edades de la población en la que se aisló Shigella fueron:4 años (IC 95% 3-5 años) para S. flexneri AA479, 6 años (IC 95% 4-7 años) para S.sonneiy 5 años (IC 95% 4-6 años) para S. flexneri 2.

SUMMARY: In order to evaluate the prevalence, serotypes and antimicrobial susceptibility of Shigella spp. isolated from children with acute diarrheic syndrome an epidemiological cross sectional, descriptive study was performed in Catamarca City between October to May 2012. The inclusion criterion was the child with acute diarrhea. All samples (n=433) were processed in Bacteriological Laboratory of Catamarca Children Hospital. Enteropathogenic bacteria were found in 141/433 samples (32.56 %) which correspond to: 6/141 (4 %) toEscherichia coli, 10/141 (7.09%) to Salmonella spp., and 125/141 (88.65 %) to Shigella spp. (p<0.001, x2Pearson; Odds Ratio 61.04, 95% IC= 29.54- 126.13).The detection of Shigellaflexneri serotypes corresponded to: 7 (8%) to serotype 1, 30 (35 %) to serotype 2, 3 (3.5%) to serotype 3 and 46 (53.5%)to AA479 (p<0.001; x2Pearson). S. flexneri was the most frequent bacterial agent isolated between December 2011 and January 2012 (39.2%) while Escherichia coli y Salmonella spp. were uniformly found during the considered period. The median age of the population of children which was isolated the different serotypes Shigellaflexneri was: 4 years old (CI 95% 3-5 years) for S. flexneri AA479, 5 years old (CI 95% 4-6 years) for S.flexneri 2 and for S.sonnei 6 years old (IC 95% 4-7 years).