Neutrophil Phagocytosis Research Articles

Phytoadaptogen reverses the adverse effects of Naftussya bioactive water on dynamic muscle performance in healthy rats

Background.. Muscular performance is considered one of the attributes of health and non-specific resistance. Phytoadaptogens occupy an important place in the arsenal of means of increasing non-specific resistance and stress resistance. Many years of research of the Truskavetsian Scientific School of Balneology have demonstrated the adaptogenic properties of the main therapeutic factor of the resort, Naftussya bioactive water, as well as ozokerite and mineral baths. However, in contrast to the beneficial effect of the latter on stress resistance and the neuro-endocrine-immune complex, the effect on the physical performance is ambiguous. The purpose of this study is to test the ability of phytocomposition to prevent the adverse actotropic effect of Naftussya bioactive water at rats. Material and methods. The experimentt have been carried out at 42 female rats. Rats of the control group for 7 days loaded through a tube with tap daily water (2 mL once), while the animals of the other groups received according to a similar scheme daily water with the addition of 0,1 mL of Balm; bioactive Naftussya water per se or with the addition of 0,1 mL of Balm. The day after completion the course of water loads in the animal determined the urinary excretion of 17-ketosteroids, assessed the mineralocorticoid activity (MCA) by the urine K/Na ratio as well as the state of neutrophil phagocytosis by the number of absorbed latex particles. Results. It was found that the weekly use of Naftyssya bioactive water reduces the duration of swimming of rats to exhaustion by 30% compared to the daily water control. Addition of phytoadaptogen to Naftyssya softens its negative actotropic effect by up to -9%, and adding Balsam to daily water prolongs the maximum duration of swimming compared to the control by 11%. A positive correlation of the swimming test with 17-KS excretion and water diuresis was revealed, but a negative correlation with MCA, spontaneous diuresis and neutrophils phagocytosis. Conclusion. Phytoadaptogen reverses the adverse effects of Naftussya bioactive water on dynamic muscle performance in healthy rats by mitigating the decrease in the excretion of 17-ketosteroids and increased mineralocorticoid activity.

Phytoadaptogen reverses the adverse effects of Naftussya bioactive water on dynamic muscle performance in healthy rats

Background.. Muscular performance is considered one of the attributes of health and non-specific resistance. Phytoadaptogens occupy an important place in the arsenal of means of increasing non-specific resistance and stress resistance. Many years of research of the Truskavetsian Scientific School of Balneology have demonstrated the adaptogenic properties of the main therapeutic factor of the resort, Naftussya bioactive water, as well as ozokerite and mineral baths. However, in contrast to the beneficial effect of the latter on stress resistance and the neuro-endocrine-immune complex, the effect on the physical performance is ambiguous. The purpose of this study is to test the ability of phytocomposition to prevent the adverse actotropic effect of Naftussya bioactive water at rats. Material and methods. The experimentt have been carried out at 42 female rats. Rats of the control group for 7 days loaded through a tube with tap daily water (2 mL once), while the animals of the other groups received according to a similar scheme daily water with the addition of 0,1 mL of Balm; bioactive Naftussya water per se or with the addition of 0,1 mL of Balm. The day after completion the course of water loads in the animal determined the urinary excretion of 17-ketosteroids, assessed the mineralocorticoid activity (MCA) by the urine K/Na ratio as well as the state of neutrophil phagocytosis by the number of absorbed latex particles. Results. It was found that the weekly use of Naftyssya bioactive water reduces the duration of swimming of rats to exhaustion by 30% compared to the daily water control. Addition of phytoadaptogen to Naftyssya softens its negative actotropic effect by up to -9%, and adding Balsam to daily water prolongs the maximum duration of swimming compared to the control by 11%. A positive correlation of the swimming test with 17-KS excretion and water diuresis was revealed, but a negative correlation with MCA, spontaneous diuresis and neutrophils phagocytosis. Conclusion. Phytoadaptogen reverses the adverse effects of Naftussya bioactive water on dynamic muscle performance in healthy rats by mitigating the decrease in the excretion of 17-ketosteroids and increased mineralocorticoid activity.

Lack of SIRP-alpha reduces lung cancer growth in mice by promoting anti-tumour ability of macrophages and neutrophils.

Signal regulatory protein-alpha (SIRPα) is a transmembrane glycoprotein specifically expressed on myeloid cells. Blockade of SIRPα/CD47 interaction is effective in combinational therapy of some cancers. This study aimed to explore into the role and underlying molecular mechanisms of SIRPα in lung cancer growth. A mouse model with lung cancer in wild-type (WT) and SIRPα-knockout mouse (KO) mice was established by subcutaneous injection of Lewis murine lung cancer cells (LLC). Circulating monocytes and neutrophils were depleted in mice by intraperitoneal administration of clodronate liposomes and anti-Ly6G antibody, respectively. Phenotypes and phagocytosis of macrophages and neutrophils were analysed by flow cytometry. Transwell assay was used to analyse LLC cells migration and invasion. Lack of SIRPα inhibited LLC cells growth in KO mice, associated with reduced infiltrating PD-1+ CD8+ T cells and production of IL-6 from infiltrating macrophages and neutrophils in tumour tissues. Depletion of circulating monocytes and neutrophils reduced LLC cells growth in WT mice, which was abolished in KO mice. Studies in vitro showed that lack of SIRPα increased M1/M2 ratio, and reduced LLC cell migration and invasion via attenuated IL-6 secretion. Lack of SIRPα expression in neutrophils effectively increased the cytotoxic activity to LLC cells in vitro. Lack of SIRPα suppressed lung cancer cell growth in mice, dependent on circulating macrophages and neutrophils, in association with improved phagocytosis and reduced IL-6 expression.

αDβ2 as a novel target of experimental polymicrobial sepsis.

Since sepsis was defined three decades ago, it has been a target of intensive study. However, there is no specific sepsis treatment available, with its high mortality and morbidity. αDβ2 (CD11d/CD18) is one of the four β2 integrin members. Its role in sepsis has been limitedly studied. Using an experimental polymicrobial sepsis model, we found that the deficiency of αDβ2 was associated with less lung injury and better outcome, which was in sharp contrast to other β2 integrin member αLβ2 (CD11a/CD18), and αMβ2 (CD11b/CD18). This phenotype was supported by a reduction of bacterial loads in αDβ2 knockout mice. Further analysis showed that the deficiency of αDβ2 led to a reduction of neutrophil cell death as well as an increase in neutrophil phagocytosis in both murine and human systems. Our data showed a unique role of αDβ2 among the β2 integrin members, which would serve as a potential target to improve the outcome of sepsis.

Neutrophil extracellular traps and complications of liver transplantation.

Many end-stage liver disease etiologies are attributed to robust inflammatory cell recruitment. Neutrophils play an important role in inflammatory infiltration and neutrophil phagocytosis, oxidative burst, and degranulation. It has also been suggested that neutrophils may release neutrophil extracellular traps (NETs) to kill pathogens. It has been proven that neutrophil infiltration within the liver contributes to an inflammatory microenvironment and immune cell activation. Growing evidence implies that NETs are involved in the progression of numerous complications of liver transplantation, including ischemia-reperfusion injury, acute rejection, thrombosis, and hepatocellular carcinoma recurrence. NETs are discussed in this comprehensive review, focusing on their effects on liver transplantation complications. Furthermore, we discuss NETs as potential targets for liver transplantation therapy.

Platelet p110β mediates platelet-leukocyte interaction and curtails bacterial dissemination in pneumococcal pneumonia.

Phosphatidylinositol 3-kinase catalytic subunit p110β is involved in tumorigenesis and hemostasis. However, it remains unclear if p110β also regulates platelet-mediated immune responses, which could have important consequences for immune modulation during anti-cancer treatment with p110β inhibitors. Thus, we investigate how platelet p110β affects inflammation and infection. Using a mouse model of Streptococcus pneumoniae-induced pneumonia, we find that both platelet-specific p110β deficiency and pharmacologic inhibition of p110β with TGX-221 exacerbate disease pathogenesis by preventing platelet-monocyte and neutrophil interactions, diminishing their infiltration and enhancing bacterial dissemination. Platelet p110β mediates neutrophil phagocytosis of S.pneumoniae invitro and curtails bacteremia invivo. Genetic deficiency or inhibition of platelet p110β also impairs macrophage recruitment in an independent model of sterile peritonitis. Our results demonstrate that platelet p110β dysfunction exacerbates pulmonary infection by impeding leukocyte functions. Thereby, our findings provide important insights into the immunomodulatory potential of PI3K inhibitors in bacterial infection.

Dexamethasone affects the chemotaxis and phagocytic activity of neutrophils for boar spermatozoa and the quality of liquid preserved boar semen in vitro

This study aimed to investigate the effect of dexamethasone (DEX) on chemotaxis and phagocytic activity of neutrophils for spermatozoa and semen quality of preserved boar semen. The different concentrations of dexamethasone were added to boar semen dilutions to detect its effects on the chemotaxis of neutrophils and phagocytosis of neutrophils and sperm motility sperm malformation rate, plasma membrane integrity, mitochondrial activity, and spermatozoa motility parameters. The study results showed that the experimental groups of DEX significantly inhibited the phagocytosis and chemotaxis of PMNs for spermatozoa. With the increased concentration of DEX, there was an inhibition effect on PMNs activity. In addition, under 17 °C storage conditions, the addition of DEX 1 × 10−6 mol/mL concentration has the best preservation effect on boar semen, which can effectively improve the sperm motility, movement parameters, plasma membrane integrity, mitochondrial activity, T-AOC activity, and significantly reduce the sperm malformation rate and H2O2 content. Therefore, the most suitable concentration of DEX to preserve boar semen at 17 °C is 1 × 10−6 mol/mL. The significant increase of conception rate of sows and litter size of piglets proved that DEX has practical application value. Thus, it is shown that the use of DEX to inhibit uterine inflammation is effective and feasible for sperm damage providing new methods for developing low-dose artificial insemination technology.

Local immune state in the women with miscarriage

Functional state of immunity provides maintenance of immunological tolerance for allogeneic fetus, and high level of local protection against antigenic stimulation. Increased functional activity of phagocytic cells at systemic and local levels may cause impairment of complete fetoplacental complex, thus leading to abortion. The purpose of our study was to assess the state of local immunity in women with pregnancy loss.
 The study involved 174 women in their reproductive age. The first group consisted of 65 patients (37.4%) with a diagnosis of miscarriage, the history of 2 abortions over the period from conception to the 20th week of gestation. The second group included 37 patients (21.2%) with documented recurrent pregnancy loss, with a history of 3 miscarriages. The control group consisted of 72 conditionally healthy women (41.4%) who had 2 or more term pregnancies with the same partner, without a history of obstetric and gynecological complications. Their mean age was 366 years old. Total number and viability of leukocytes, the indices of functional neutrophil activity, their functional reserve and neutrophil stimulation index were determined in cervical mucosal samples over the first phase of the menstrual cycle.
 In the first phase of menstrual cycle, the women with miscarriage and recurrent pregnancy loss exhibited a statistically significant increase of phagocytosis by the neutrophils from cervical mucus as compared to the group of conditionally healthy women. Intensity of neutrophil phagocytosis in cervical mucus reached higher values in the women with recurrent pregnancy loss more often, compared to the control group. Evaluation of the functional reserve of cervical mucus neutrophils in the subjects with recurrent pregnancy loss and miscarriage showed a trend towards statistically significant differences: this parameter was higher in the patients than in control group. The ability of cervical mucosal neutrophils to produce reactive oxygen species (both spontaneous and induced) did not show statistically significant differences between the patients and controls.
 Hence, we have observed aberrant functional activity of neutrophilic granulocytes from cervical mucosa in the groups of women with 2 or more abortions, without changing ability of the cells to produce reactive oxygen species. This finding may be explained by prevalence of oxygen-independent mechanisms of intracellular killing, thus suggesting a role of neutrophils for impaired balance of immunological tolerance in pregnant women at the local level.

Immunogenic cell death as driver of autoimmunity in granulomatosis with polyangiitis.

Cell death and dysregulated clearance of dead cells play essential roles in the induction of chronic inflammatory processes and autoimmune diseases. Granulomatosis with polyangiitis (GPA), a neutrophil-driven autoimmune disorder, is characterized by necrotizing inflammation predominantly of the respiratory tract and an anti-neutrophil cytoplasmic autoantibody (ANCA)-associated systemic necrotizing vasculitis. Defective regulation of neutrophil homeostasis and cell death mechanisms have been demonstrated in GPA. Disturbed efferocytosis (i.e., phagocytosis of apoptotic neutrophils by macrophages) as well as cell death-related release of damage-associated molecular patterns (DAMP) such as high mobility group box 1 (HMGB1) contribute to chronic non-resolving inflammation in GPA. DAMP have been shown to induce innate as well as adaptive cellular responses thereby creating a prerequisite for the development of pathogenic autoimmunity. In this review, we discuss factors contributing to as well as the impact of regulated cell death (RCD) accompanied by DAMP-release as early drivers of the granulomatous tissue inflammation and autoimmune responses in GPA.

The Influence of Age and Gender on the Serum XOR Activity, Leukocyte Gene Expression of XOR and MPO, and Biochemical Parameters in Newborn Foals

One of the initial responses of the host's innate immunity of newborns against pathogens is the use of oxidative enzymes. This study aimed to evaluate changes in serum xanthine oxidoreductase (XOR) activity, the leukocyte myeloperoxidase (MPO) and XOR genes expression, and some biochemical parameters in healthy Darehshuri newborn foals up to 60 days of life. Blood samples were collected from 16 foals at 1, 7, 15, 30, and 60 days and used for detecting XOR activity, biochemical parameters, and also gene expression by real-time RT-PCR. High activity of XOR was observed at birth, explained by physiologic hypoxia during the birth without sex difference. The significant decrease in XOR activity during the following days is probably related to the decreased levels of substrate and feedback inhibition of XOR by uric acid. No correlations were found between XOR activity and uric acid. A positive correlation was observed between XOR mRNA and serum XOR activity in 15 days. The results also indicate higher levels of MPO gene expression at 30 days, which may be associated with their capacity for neutrophil phagocytosis. The concentrations of creatinine, total protein, and albumin were higher at birth, whereas uric acid level was lower (P < 0.05). It can be concluded that XOR activity decreases with age and there is no significant change in its gene expression and MPO expression increases with age and is sex-dependent. There is an influence of age on XOR activity, leukocyte expression of MPO, and biochemical parameters in healthy newborn foals up to 60 days of life.

Symposium review: Environmental effects on mammary immunity and health.

Environmental effects on pathogen abundance and access are precursors to mastitis. Indeed, high heat and humidity, and unsanitary housing and equipment, are associated with greater pathogen load and exposure. Although less is known about effects of environment on a cow's ability to resist infection, several indicators suggest that it can affect pathogen responses. Mastitis incidence and bulk tank somatic cell count vary with season, typically peaking in summer. Recent controlled studies have revealed that heat stress exposure results in changes in the microbiome of the cow and her environment, which may relate to negative effects on milk quality and cow health. Alternatively, specific pathogen loads may vary based on housing dynamics rather than associations with physical environment. Indeed, housing-related stressors, such as overcrowding and social group challenge, influence secretion of glucocorticoids, thus affecting pathogen resistance in the cow. Two key seasonal variables are photoperiod and temperature, specifically the heat stress consequent to elevated temperature and humidity. Shifts in light duration regulate immune function in other species, but apparently have limited effect on udder health of lactating cows. In contrast, in dry cows, short days increase peripheral blood mononuclear cell number and are associated with lower somatic cell count in the next lactation, compared with long days. With heat stress, elevated body temperature directly affects expression of immune-related genes in mammary tissue. Responses depend on duration of exposure and feature acute upregulation of immune-signaling pathways, followed by enrichment of other immune-related pathways after prolonged exposure. Most responses are transient and recover within 1 wk. Functionally, heat stress impairs some aspects of acquired immunity in dry cows, including antigen responses and lymphocyte proliferation, but apparently not innate immune function. However, heat stress in late gestation reduces neutrophil phagocytosis and killing in vitro, and neutrophils in circulation are reduced in vivo as are responses to pathogen challenge in the subsequent lactation. A holistic understanding of the complex interplay of environment, pathogens, and host is needed to inform advances in this area.

Transcellular biosynthesis of leukotriene B4 orchestrates neutrophil swarming to fungi

SummaryNeutrophil swarming is an emergent host defense mechanism triggered by targets larger than a single neutrophil’s capacity to phagocytose. Swarming synergizes neutrophil functions, including chemotaxis, phagocytosis, and reactive oxygen species (ROS) production, and coordinates their deployment by many interacting neutrophils. The potent inflammatory lipid mediator leukotriene B4 (LTB4) has been established as central to orchestrating neutrophil activities during swarming. However, the details regarding how this eicosanoid choreographs the neutrophils involved in swarming are not well explained. Here we leverage microfluidics, genetically deficient mouse cells, and targeted metabolipidomic analysis to demonstrate that transcellular biosynthesis occurs among neutrophils to generate LTB4. Furthermore, transcellular biosynthesis is an entirely sufficient means of generating LTB4 for the purposes of orchestrating neutrophil swarming. These results further our understanding of how neutrophils coordinate their activities during swarming, which will be critical in the design of eventual therapies that can harness the power of swarming behavior.

Longitudinal characterization of circulating neutrophils uncovers phenotypes associated with severity in hospitalized COVID-19 patients

Mechanisms of neutrophil involvement in severe COVID-19 remain incompletely understood. Here we collect longitudinal blood samples from 306 hospitalized COVID-19+ patients and 86 controls, and perform bulk RNA-sequencing of enriched neutrophils, plasma proteomics, and high-throughput antibody profiling to investigate relationships between neutrophil states and disease severity. We identify dynamic switches between 6 distinct neutrophil subtypes. At days 3 and 7 post-hospitalization, patients with severe disease display a granulocytic myeloid-derived suppressor cell-like gene expression signature, while patients with resolving disease show a neutrophil progenitor-like signature. Humoral responses are identified as potential drivers of neutrophil effector functions, with elevated SARS-CoV-2-specific IgG1-to-IgA1 ratios in plasma of severe patients who survived. In vitro experiments confirm that while patient-derived IgG antibodies induce phagocytosis in healthy donor neutrophils, IgA antibodies predominantly induce neutrophil cell death. Overall, our study demonstrates a dysregulated myelopoietic response in severe COVID-19 and a potential role for IgA-dominant responses contributing to mortality.

Evolution of functional antibodies following acute Epstein-Barr virus infection

While Epstein-Barr virus causes mostly asymptomatic infection, associated malignancies, and autoimmune and lymphoproliferative diseases occur. To dissect the evolution of humoral immune responses over the course of EBV infection and to gain a better understanding of the potential contribution of antibody (Ab) function to viral control, we comprehensively profiled Ab specificities and Fc-functionalities using systems serology and VirScan. Ab functions against latent (EBNA1), early (p47/54) and two late (gp350/220 and VCA-p18) EBV proteins were overall modest and/or short-lived, differing from humoral responses induced during acute infection by other viruses such as HIV. In the first year post infection, only p18 elicited robust IgM-driven complement deposition and IgG-driven neutrophil phagocytosis while responses against EBNA-1 were largely Fc-functionally silent and only matured during chronic infection to drive phagocytosis. In contrast, Abs against Influenza virus readily mediated broad Fc-activity in all participants. These data suggest that EBV evades the induction of robust Fc-functional Abs, potentially due to the virus’ life cycle, switching from lytic to latent stages during infection.

Induction, decay, and determinants of functional antibodies following vaccination with the RTS,S malaria vaccine in young children

BackgroundRTS,S is the first malaria vaccine recommended for implementation among young children at risk. However, vaccine efficacy is modest and short-lived. Antibodies play the major role in vaccine-induced immunity, but knowledge on the induction, decay, and determinants of antibody function is limited, especially among children. Antibodies that promote opsonic phagocytosis and other cellular functions appear to be important contributors to RTS,S immunity.MethodsWe studied a phase IIb trial of RTS,S/AS02 conducted in young children in malaria-endemic regions of Mozambique. We evaluated the induction of antibodies targeting the circumsporozoite protein (CSP, vaccine antigen) that interact with Fcγ-receptors (FcRγs) and promote phagocytosis (neutrophils, monocytes, THP-1 cells), antibody-dependent respiratory burst (ADRB) by neutrophils, and natural killer (NK) cell activity, as well as the temporal kinetics of responses over 5 years of follow-up (ClinicalTrials.gov registry number NCT00197041).ResultsRTS,S vaccination induced CSP-specific IgG with FcγRIIa and FcγRIII binding activity and promoted phagocytosis by neutrophils, THP-1 monocytes, and primary human monocytes, neutrophil ADRB activity, and NK cell activation. Responses were highly heterogenous among children, and the magnitude of neutrophil phagocytosis by antibodies was relatively modest, which may reflect modest vaccine efficacy. Induction of functional antibodies was lower among children with higher malaria exposure. Functional antibody magnitude and the functional activity of antibodies largely declined within a year post-vaccination, and decay were highest in the first 6 months, consistent with the decline in vaccine efficacy over that time. Decay rates varied for different antibody parameters and decay was slower for neutrophil phagocytosis. Biostatistical modelling suggested IgG1 and IgG3 contribute in promoting FcγR binding and phagocytosis, and IgG targeting the NANP-repeat and C-terminal regions CSP were similarly important for functional activities.ConclusionsResults provide new insights to understand the modest and time-limited efficacy of RTS,S in children and the induction of antibody functional activities. Improving the induction and maintenance of antibodies that promote phagocytosis and cellular functions, and combating the negative effect of malaria exposure on vaccine responses are potential strategies for improving RTS,S efficacy and longevity.

Junctional adhesion molecule-A deletion increases phagocytosis and improves survival in a murine model of sepsis

Expression of the tight junction–associated protein junctional adhesion molecule-A (JAM-A) is increased in sepsis, although the significance of this is unknown. Here, we show that septic JAM-A –/– mice have increased gut permeability, yet paradoxically have decreased bacteremia and systemic TNF and IL-1β expression. Survival is improved in JAM-A–/– mice. However, intestine-specific JAM-A–/– deletion does not alter mortality, suggesting that the mortality benefit conferred in mice lacking JAM-A is independent of the intestine. Septic JAM-A–/– mice have increased numbers of splenic CD44hiCD4+ T cells, decreased frequency of TNF+CD4+ cells, and elevated frequency of IL-2+CD4+ cells. Septic JAM-A–/– mice have increased numbers of B cells in mesenteric lymph nodes with elevated serum IgA and intraepithelial lymphocyte IgA production. JAM-A–/– × RAG–/– mice have improved survival compared with RAG–/– mice and identical mortality as WT mice. Gut neutrophil infiltration and neutrophil phagocytosis are increased in JAM-A–/– mice, while septic JAM-A–/– mice depleted of neutrophils lose their survival advantage. Therefore, increased bacterial clearance via neutrophils and an altered systemic inflammatory response with increased opsonizing IgA produced through the adaptive immune system results in improved survival in septic JAM-A–/– mice. JAM-A may be a therapeutic target in sepsis via immune mechanisms not related to its role in permeability.

Morphological and biochemical changes in blood parameters in cats with infectious peritonitis

Feline infectious peritonitis is a feline disease, the causative agent of which is a mutant coronavirus, which leads to the death of young animals. Presently, this pathology is considered incurable, and therefore it requires a detailed study. The purpose of this study was to establish the features of clinical manifestation and haematological parameters in cats with infectious peritonitis. This paper presents the results of a clinical and laboratory study of 12 cats aged from 6 months to 3 years who were diagnosed with effusive and dry infectious peritonitis. Clinical, laboratory, and visual research methods were used. Laboratory analysis included a study of morphological and biochemical parameters of blood, cytological examination of effusion from the abdominal and pleural cavities, and a Rivalta test. As a result of cytological examination of effusion from these cavities, a high concentration of cells, macrophage accumulation, neutrophil phagocytosis, and red blood cells were detected in the entire field of view. It was found that the predictive value of the Rivalta test for feline infectious peritonitis is 62.5%. According to haematological examination, all sick animals were diagnosed with anaemia, lymphopenia, hypoalbuminemia, hyperglobulinemia, hyperbilirubinemia, increased activity of relative liver- specific enzymes (aspartate aminotransferase, alkaline phosphatase). Trobmocytopenia was observed in two animals, and an increase in blood markers of the functional state of the kidneys (creatinine, urea) was found in one cat. The serum albumin/globulin ratio should also be considered an important diagnostic indicator. Thus, with feline infectious peritonitis, this indicator should be &lt; 0.4. In 11 sick cats, this ratio was characterized by values below 0.4, and in one animal this indicator was 0.46. In general, the obtained data of morphological and biochemical blood tests are not specific for feline infectious peritonitis, and therefore the authors of this paper recommend their comprehensive investigation for diagnostic purposes. An objective assessment of the available methods of laboratory diagnostics will contribute to the creation of a diagnostic protocol for feline infectious peritonitis

Modulatory Contribution of Oxygenating Hydrogels and Polyhexamethylene Biguanide on the Antimicrobial Potency of Neutrophil-like Cells.

Neutrophils are a first line of host defense against infection and utilize a series of oxygen-dependent processes to eliminate pathogens. Research suggests that oxygen availability can improve anti-infective mechanisms by promoting the formation of reactive oxygen species. Also, oxygen can synergistically upregulate the antibacterial properties of certain antibiotics against bacteria by altering their metabolism and causing an increase in the antibiotic uptake of bacteria. Therefore, understanding the effects of oxygen availability, as provided via a biomaterial treatment alone or along with potent antibacterial agents, on neutrophil functions can lead us to the development of new anti-inflammatory and anti-infective approaches. However, the study of neutrophil functions in vitro is often limited by their short life span and nonreproducibility, which suggests the need for cell line-based models as a substitute for primary neutrophils. Here, we took advantage of the differentiated human leukemia-60 cell line (HL-60), as an in vitro neutrophil model, to test the effects of local oxygen and antibacterial delivery by fluorinated methacrylamide chitosan (MACF) hydrogels incorporated with polyhexamethylene biguanide (PHMB) antibacterial agent. Considering the natural modes of neutrophil actions to combat bacteria, we studied the impact of our dual functioning oxygenating-antibacterial platforms on neutrophil phagocytosis and antibacterial properties as well as the formation of neutrophil extracellular traps (NETs) and reactive oxygen species (ROS). Our results demonstrated that supplemental oxygen and antibacterial delivery from MACF-PHMB hydrogel platforms upregulated neutrophil antibacterial properties and ROS production. NET formation by neutrophils upon treatment with MACF and PHMB varied when chemical and biological stimuli were used. Overall, this study presents a model to study immune responses in vitro and lays the foundation for future studies to investigate if similar responses also occur in vivo.

Clinical outcome and gut development after insulin-like growth factor-1 supplementation to preterm pigs.

BackgroundElevation of circulating insulin-like growth factor-1 (IGF-1) within normal physiological levels may alleviate several morbidities in preterm infants but safety and efficacy remain unclear. We hypothesized that IGF-1 supplementation during the first 1–2 weeks after preterm birth improves clinical outcomes and gut development, using preterm pigs as a model for infants.MethodsPreterm pigs were given vehicle or recombinant human IGF-1/binding protein-3 (rhIGF-1, 2.25 mg/kg/d) by subcutaneous injections for 8 days (Experiment 1, n = 34), or by systemic infusion for 4 days (Experiment 2, n = 19), before collection of blood and organs for analyses.ResultsIn both experiments, rhIGF-1 treatment increased plasma IGF-1 levels 3-4 fold, reaching the values reported for term suckling piglets. In Experiment 1, rhIGF-1 treatment increased spleen and intestinal weights without affecting clinical outcomes like growth, blood biochemistry (except increased sodium and gamma-glutamyltransferase levels), hematology (e.g., red and white blood cell populations), glucose homeostasis (e.g., basal and glucose-stimulated insulin and glucose levels) or systemic immunity variables (e.g., T cell subsets, neutrophil phagocytosis, LPS stimulation, bacterial translocation to bone marrow). The rhIGF-1 treatment increased gut protein synthesis (+11%, p < 0.05) and reduced the combined incidence of all-cause mortality and severe necrotizing enterocolitis (NEC, p < 0.05), but had limited effects on intestinal morphology, cell proliferation, cell apoptosis, brush-border enzyme activities, permeability and levels of cytokines (IL-1β, IL-6, IL-8). In Experiment 2, rhIGF-1 treated pigs had reduced blood creatine kinase, creatinine, potassium and aspartate aminotransferase levels, with no effects on organ weights (except increased spleen weight), blood chemistry values, clinical variables or NEC.ConclusionPhysiological elevation of systemic IGF-1 levels for 8 days after preterm birth increased intestinal weight and protein synthesis, spleen weight and potential overall viability of pigs, without any apparent negative effects on recorded clinical parameters. The results add further preclinical support for safety and efficacy of supplemental IGF-1 to hospitalized very preterm infants.

Integrating network pharmacology and transcriptomic validation to investigate the efficacy and mechanism of Mufangji decoction preventing lung cancer

Ethnopharmacological relevanceMufangji decoction (MFJD), a famous traditional Chinese medicine formula in Synopsis of Golden Chamber (Jingui yaolue), has been utilized to treat cough and asthma and release chest pain over 2000 years in China. Chinese old herbalist doctor use MFJD to treat lung cancer and cancerous pleural fluid, but the preventive effect of MFJD on lung cancer and the underlying mechanism are indefinite. Aim of the studyThe goal of this study is to explore the efficacy and mechanism of Mufangji decoction preventing lung cancer referring to the traditional use. Materials and methodsTumor allograft experiment and host versus tumor experiment were used to observe the direct anti-tumor effect and indirect anti-tumor immune effect, the mouse lung carcinogenic model was used to evaluate the dose-response and the preventive effect of MFJD on lung cancer. The active ingredients of MFJD were obtained by UPLC-MS/MS. The potential targets of MFJD were screened by network pharmacology and transcriptomics. The therapeutic targets and pathways of MFJD on lung cancer were obtained by protein-protein interaction, molecular docking and David database. The predicted results were verified in vitro and in vivo. ResultsMFJD could significantly prevent tumor growth in host versus tumor experiment but could not in tumor allograft experiment, indicating an anti-tumor immune effect against lung cancer. MFJD could reduce lung nodules with a dose-response in mouse lung carcinogenic model. Myeloperoxidase (MPO) was selected as the core target due to the highest degree value in Protein-Protein interaction network and had potently binding activity to sinomenine and dehydrocostus lactone in molecular docking. In vivo, MPO-expressed neutrophils are negatively correlated with lung cancer progression and MFJD could promote the neutrophil-related immune surveillance. In vitro, sinomenine and dehydrocostus lactone could promote neutrophil phagocytosis, MPO and ROS production in a dose dependent manner. The major compounds from MFJD were identified to regulate 36 targets for lung cancer prevention by UPLC-MS/MS, network pharmacology and transcriptomics. David database exhibited that MFJD plays an important role in immunoregulation by modulating 4 immune-related biological processes and 3 immune-related pathways. ConclusionsMFJD prevents lung cancer by mainly promoting MPO expression to maintain neutrophil immune surveillance, its key compounds are sinomenine and dehydrocostus lactone.