Bacterial lipopolysaccharide stimulates bovine neutrophil production of TNF-α, IL-1β, IL-12 and IFN-γ

Acute phase reaction to lipopolysaccharide-induced mastitis in early lactation dairy cows fed nitrogenic, glucogenic, or lipogenic diets

The availability of certain macronutrients is likely to influence the capacity of the immune system. Therefore, we investigated the acute phase response to intramammary (i.mam.) lipopolysaccharide (LPS) in dairy cows fed a nitrogenic diet (n = 10) high in crude protein, a glucogenic diet (n = 11) high in carbohydrates and glucogenic precursors, or a lipogenic diet (n = 11) high in lipids. Thirty-two dairy cows were fed one of the dietary concentrates directly after calving until the end of trial at 27 ± 3 days in milk (mean ± standard deviation). In wk 3 of lactation, 20 µg of LPS was i.mam. injected in one quarter, and sterile NaCl (0.9%) in the contralateral quarter. Milk samples of the LPS-challenged and control quarter were taken hourly from before (0 h) until 9 h after LPS challenge and analyzed for milk amyloid A (MAA), haptoglobin (HP), and IL-8. In addition, blood samples were taken in the morning, and composite milk samples at morning and evening milkings, from 1 d before until 3 d after LPS challenge, and again on d 9, to determine serum amyloid A (SAA) and HP in blood, and MAA and HP in milk. The mRNA abundance of various immunological and metabolic factors in blood leukocytes was quantified by quantitative reverse-transcription PCR from samples taken at -18, -1, 6, 9, and 23 h relative to LPS application. The dietary concentrates did not affect any of the parameters in blood, milk, and leukocytes. The IL-8 was increased from 2 h, HP from 2 to 3 h, and MAA from 6 h relative to the LPS administration in the milk of the challenged quarter and remained elevated until 9 h. The MAA and HP were also increased at 9 h after LPS challenge in whole-udder composite milk, whereas HP and SAA in blood were increased only after 23 h. All 4 parameters were decreased again on d 9. Similar for all groups, the mRNA abundance of HP and the heat shock protein family A increased after the LPS challenge, whereas the mRNA expression of the tumor necrosis factor α and the leukocyte integrin β 2 subunit (CD18) were decreased at 6 h after LPS challenge. The glucose transporter (GLUT)1 mRNA abundance decreased after LPS, whereas that of the GLUT3 increased, and that of the GLUT4 was not detectable. The mRNA abundance of GAPDH was increased at 9 h after LPS and remained elevated. The acute phase protein response was detected earlier in milk compared with blood indicating mammary production. However, immunological responses to LPS were not affected by the availability of specific macronutrients provided by the different diets.

Investigation of haematological, inflammatory and immunological response in naturally infected cattle with Theileria annulata

In this study, we aimed to investigate haematological, pro-inflammatory, inflammatory, anti-inflammatory and immunological responses in naturally Theileria annulata-infected cattle. The study material consisted of 25 Simmental cattle, 2-4 years of age, one of which was a control group consisting of healthy animals (Control group, n = 10), and the other was a Theileria group that include animals positive for Theileria annulata (Theileria group, n = 15). Haematological analysis (red blood cell [RBC], haemoglobin [HGB], haematocrit [HCT]), pro-inflammatory (tumour necrosis factor-α [TNF-α], nuclear factor kappa B [NF-ĸB] and interleukin-1 beta, [IL-1β]), inflammatory (neutrophil-lymphocyte ratio [NLR]), anti-inflammatory (interleukin-10 [IL-10]) and antimicrobial peptide (CAMP) analyses were performed by using ELISA kit from blood samples. It was found that the rectal temperature of the Theileria group was found to be significantly higher (p < .001) than that of the control group. Haematological and biochemical analysis revealed that the RBC and HGB count and HCT percentage decreased (p < .001), while NF-ĸB (p < .001), TNF-α (p = .002), IL-1β (p < .001), IL-10 (p = .012), NLR (p < .001) and CAMP (p = .037) levels increased in Theileria group compared to the control group. There was a strong correlation between NF-ĸB and TNF-α, NF-ĸB and IL-10, NLR and IL-1β, NF-ĸB and CAMP, TNF-α and CAMP and IL-10 and CAMP. As a result of this study, it was revealed that a pro-inflammatory and immunological response also occurs along with the anti-inflammatory response in the inflammatory process.

The effects of nutritional level and body condition score on cytokines in seminal plasma of beef bulls

Introduction

High quality semen is essential for reproductive efficiency. Nutrition and environmental factors impact the ejaculate components, like cytokines, that are essential for pregnancy establishment. We hypothesized that differing nutritional periods and body condition scores would affect seminal plasma cytokine concentrations of bulls.

Methods

Mature Angus bulls (n=11) were individually housed and randomly assigned to either over-fed (n=5) or restricted (n=6) treatment pathways. Bulls were fed different volumes of a single ration creating 8 individual treatment periods. Body weight and body condition scores were taken every 14 d to manage intake volumes. Ejaculates were collected every 84 d to determine seminal plasma cytokine profiles. A complete randomized design was used to evaluate seminal plasma cytokines after each nutritional treatment. Initial cytokine concentrations and volume of the ejaculate were included as covariates.

Results

All cytokines returned to initial concentrations following maintenance treatments at an ideal body condition score of 6. Nutritional treatments affected (P ≤ 0.05) IFN-γ, IL-8, MIP-1α, MIP-1β, TNF-α, IL-1β, and VEGF-A. However, TNF-α, IFN-γ, and MIP-1α had the greatest impact on cytokine profile.

Discussion

Nutritional levels and adiposity altered seminal plasma cytokine concentrations which could potentially impact the inflammatory balance of the uterus and the immune responses necessary for pregnancy establishment.

Corynoline protects against zearalenone-induced liver injury by activating the SIRT1/Nrf2 signaling pathway

Corynoline has been reported to have anti-inflammatory and antioxidative effects. In the present study, the potential protective effects of corynoline against zearalenone (ZEA)-induced liver injury were investigated. ZEA was administered daily for 5 days. Then, liver tissues were used for subsequent experiments. Corynoline attenuated liver histopathological changes induced by ZEA. The production of tumor necrosis factor-α and interleukin-1β in liver tissues, as well as aspartate aminotransferase and alanine aminotransferase in serum, was also inhibited by corynoline. Meanwhile, ZEA-induced MPO activity and MDA content were both attenuated by corynoline. ZEA-induced NF-κB p65 and IκBα phosphorylation were inhibited by corynoline. Furthermore, SIRT1, Nrf2, and HO-1 expression were increased by corynoline. In addition, the protective effects of corynoline against liver injury were reversed by the SIRT1 inhibitor EX-527. Taken together, corynoline protected against ZEA-induced liver injury by activating the SIRT1/Nrf2 signaling pathway.

An overview on mastitis-associated Escherichia coli: Pathogenicity, host immunity and the use of alternative therapies

Escherichia coli is one of the leading causes of bovine mastitis; it can cause sub-clinical, and clinical mastitis characterized by systemic changes, abnormal appearance of milk, and udder inflammation. E. coli pathogenicity in the bovine udder is due to the interaction between its virulence factors and the host factors; it was also linked to the presence of a new pathotype termed mammary pathogenic E. coli (MPEC). However, the presence of this pathotype is commonly debated. Its main virulence factor is the lipopolysaccharide (LPS) that is responsible for causing an endotoxic shock, and inducing a strong immune response by binding to the toll-like receptor 4 (TLR4), and stimulating the expression of chemokines (such as IL-8, and RANTES) and pro-inflammatory cytokines (such as IL-6, and IL-1β). This strong immune response could be used to develop alternative and safe approaches to control E. coli causing bovine mastitis by targeting pro-inflammatory cytokines that can damage the host tissue. The need for alternative treatments against E. coli is due to its ability to resist many conventional antibiotics, which is a huge challenge for curing ill animals. Therefore, the aim of this review was to highlight the pathogenicity of E. coli in the mammary gland, discuss the presence of the new putative pathotype, the mammary pathogenic E. coli (MPEC) pathotype, study the host's immune response, and the alternative treatments that are used against mastitis-associated E. coli.

Bovine innate immune phenotyping via a standardized whole blood stimulation assay

Cattle vary in their susceptibility to infection and immunopathology, but our ability to measure and longitudinally profile immune response variation is limited by the lack of standardized immune phenotyping assays for high-throughput analysis. Here we report longitudinal innate immune response profiles in cattle using a low-blood volume, whole blood stimulation system—the ImmunoChek (IChek) assay. By minimizing cell manipulation, our standardized system minimizes the potential for artefactual results and enables repeatable temporal comparative analysis in cattle. IChek successfully captured biological variation in innate cytokine (IL-1β and IL-6) and chemokine (IL-8) responses to 24-hr stimulation with either Gram-negative (LPS), Gram-positive (PamCSK4) bacterial or viral (R848) pathogen-associated molecular patterns (PAMPs) across a 4-month time window. Significant and repeatable patterns of inter-individual variation in cytokine and chemokine responses, as well as consistent high innate immune responder individuals were identified at both baseline and induced levels. Correlation coefficients between immune response read-outs (IL-1β, IL-6 and IL-8) varied according to PAMP. Strong significant positive correlations were observed between circulating monocytes and IL-6 levels for null and induced responses (0.49–0.61) and between neutrophils and cytokine responses to R848 (0.38–0.47). The standardized assay facilitates high-throughput bovine innate immune response profiling to identify phenotypes associated with disease susceptibility and responses to vaccination.

NETosis of Peripheral Neutrophils Isolated From Dairy Cows Fed Olive Pomace

Neutrophils represent primary mobile phagocytes recruited to the site of infection, and their functions are essential to enhance animals' health performance. Neutrophils have an essential role in innate immunity and are able to kill the pathogens via the synthesis of neutrophil extracellular traps (NETs). The objective of the present work was the study of the in vitro NETosis of peripheral neutrophils isolated from dairy cows supplemented with olive pomace. Dairy cows (n = 16) balanced for parity (3.67 ± 1.5 for CON, 3.67 ± 1.9 for OP), milk yield (24.3 ± 4.5 kg d⁻¹for CON and 24.9 ± 1.7 kg d⁻¹ for OP), the number of days in milk (109 ± 83.5 for CON and 196 ± 51 for OP), and body weight (647 ± 44.3 kg for CON and 675 ± 70.7 kg for OP) were divided into two experimental groups fed with a control diet (CON) and supplemented with 6% of olive pomace (OP). Peripheral blood neutrophils were isolated and stimulated in vitro with phorbol-myristate-acetate (PMA) as a marker for activation and reactivity of the neutrophils. After isolation, both the viability and CD11b expression were analyzed by flow cytometry. Both NETosis by neutrophil elastase-DNA complex system and myeloperoxidase (MPO) activity were evaluated by ELISA. The specific antibodies against MPO and citrullination of Histone-H1 were used for investigating NETosis by immunofluorescence microscopy. The neutrophil elastase-DNA complexes produced during NETosis and MPO activity of neutrophil extracts were affected by OP supplementation. Furthermore, results from immunofluorescence analysis of NETosis depicted a similar result found by ELISA showing a higher expression of MPO and citrullination of Histone-H1 in OP than the CON neutrophils. In addition, all data showed that the OP diet resulted in a better response of neutrophils to PMA stimulation than the CON diet, which did not support the neutrophils' responses to PMA stimulation. Our results demonstrated that OP supplementation can enhance the neutrophil function in dairy cows leading to udder defense and inflammation response especially when an immunosuppression state can occur.

Immune Evasion of Mycoplasma bovis

Mycoplasma bovis (M. bovis) causes various chronic inflammatory diseases, including mastitis and bronchopneumonia, in dairy and feed cattle. It has been found to suppress the host immune response during infection, leading to the development of chronic conditions. Both in vitro and in vivo studies have confirmed that M. bovis can induce proinflammatory cytokines and chemokines in the host. This consists of an inflammatory response in the host that causes pathological immune damage, which is essential for the pathogenic mechanism of M. bovis. Additionally, M. bovis can escape host immune system elimination and, thus, cause chronic infection. This is accomplished by preventing phagocytosis and inhibiting key responses, including the neutrophil respiratory burst and the development of nitric oxide (NO) and inducible nitric oxide synthase (iNOS) that lead to the creation of an extracellular bactericidal network, in addition to inhibiting monocyte and alveolar macrophage apoptosis and inducing monocytes to produce anti-inflammatory factors, thus inducing the apoptosis of peripheral blood mononuclear cells (PBMCs), inhibiting their proliferative response and resulting in their invasion. Together, these conditions lead to long-term M. bovis infection. In terms of the pathogenic mechanism, M. bovis may invade specific T-cell subsets and induce host generation of exhausted T-cells, which helps it to escape immune clearance. Moreover, the M. bovis antigen exhibits high-frequency variation in size and expression period, which allows it to avoid activation of the host humoral immune response. This review includes some recent advances in studying the immune response to M. bovis. These may help to further understand the host immune response against M. bovis and to develop potential therapeutic approaches to control M. bovis infection.

Effect of Lipopolysaccharide and Muramyl Dipeptide on Apoptosis of Bovine Mammary Gland Lymphocytes

Simple Summary

Inflammation of the mammary gland in dairy cattle is a global problem and causes huge financial loss to dairy farmers. Inflammation is caused by many species of bacteria penetrating through the teat canals into the udder. Those bacteria are usually eliminated by treatment with intramammary injection of antibiotics, while they are also eliminated by the immune cells of the cow. One of the immune cells are lymphocytes which are responsible for specific immunity. When viable, they are able to carry out their normal functions. The present study focused on the investigation of cell death of lymphocytes during bovine mammary gland inflammation. We analyzed apoptosis in mammary gland lymphocytes under the stimulation of lipopolysaccharides and muramyl dipeptide as the endotoxin of Gram-negative bacteria and the natural content of the cell wall of Gram-positive bacteria. We found that they induce lymphocyte apoptosis in the early phase of inflammation, which can be associated with the expression of CD44 receptors on lymphocytes. This receptor is important in many physiological processes, including apoptosis of cells. For a better understanding of immune responses in mammary glands and for developing of immunotherapy without antibiotics, the process of inflammation, including cell death of immune cells necessitates further holistic studies.

Abstract

The aim of this study was to evaluate whether apoptosis of lymphocytes is modulated by stimulation by lipopolysaccharide (LPS) of Escherichia coli or muramyl dipeptide (MDP). Cell populations were obtained by lavaging of the mammary glands 24, 48, 72, and 168 h following intramammary induced inflammation. The portion of apoptotic lymphocytes peaked at 48 h after treatment with LPS or MDP. The analysis of CD44 expression of the same cell populations showed a higher percentage of CD44-positive lymphocytes 24- and 48-h following induction of inflammation by LPS or MDP. The results demonstrate that during both experimental infection of bovine mammary glands with LPS or MDP, apoptosis of lymphocytes was induced in the initial phase of the inflammatory response and CD44 was also overexpressed at the beginning of inflammation. These data suggest a connection of lymphocyte apoptosis with the expression of CD44 receptors.

Evaluation of Interleukin-10 and Pro-inflammatory Cytokine Profile in Calves Naturally Infected with Neonatal Calf Diarrhea Syndrome

Multifactorial neonatal calf diarrhea (NCD) is one of the main causes of mortality in calves under 1 month of age. Studies have shown that pro-inflammatory cytokines (i.e., interleukin (IL)-1&amp;beta;, IL-6, and tumor necrosis factor-alpha [TNF-&amp;alpha;]) can increase in many pathophysiological conditions. In addition, IL-10 as one of the most important anti-inflammatory cytokines contributes to the inhibition of pro-inflammatory cytokines. Few studies have addressed cytokine levels in calves with NCD. Therefore, the goal of this study was to evaluate the plasma concentrations of pro-inflammatory cytokines, as well as IL-10, in the calves naturally infected with NCD syndrome. For this purpose, 87 neonatal calves were monitored for 1 month. Out of this population, 10 cases were diagnosed with NCD and studied as the case group. In addition, a control group was considered that consisted of 10 age- and gender-matched neonatal calves without any diseases. From each calf, 5 ml blood sample was collected into EDTA tubes by jugular venipuncture. The samples were then centrifuged, and the extracted plasmas were aliquoted and stored at -20 &amp;deg;C. Finally, the plasma concentrations of pro-inflammatory cytokines (i.e., IL-1&amp;beta;, IL-6, and TNF-&amp;alpha;) and anti-inflammatory cytokine IL-10 were measured using the ELISA kits based on the manufacturer&amp;#39;s protocols. The results showed that the plasma concentrations of pro-inflammatory cytokines were significantly higher in the case group than in the control group. However, no significant difference was found between the two groups in terms of the plasma concentrations of IL-10. This study indicates that pro-inflammatory cytokines could be used to recognize the immune system response to NCD.

Potential roles of neutrophils in maintaining the health and productivity of dairy cows during various physiological and physiopathological conditions: a review

Neutrophils represent the first line of innate immunity and are the most prominent line of cellular defence against invading microorganisms. On stimulation, they can quickly move through the walls of veins and into the tissues of the body to immediately attack or monitor the foreign antigens. Neutrophils are highly versatile and sophisticated cells which are endowed with highly sensitive receptor-based perception systems. They were traditionally classified as short-lived phagocytes actively involved during infection and inflammation, but recently, it has been seen that neutrophils are capable of detecting the presence of sperms during insemination as well as an implanting embryo in the female reproductive tract. These specialised phagocytes play a major role in tissue remodelling and wound healing, and maintain homeostasis during parturition, expulsion of placenta, folliculogenesis, corpus luteum formation and luteolysis. Here, we review the role played by neutrophils in maintaining homeostasis during normal and inflammatory conditions of dairy cattle. We have summarised the alteration in the expression of some cell adhesion molecules and cytokines on bovine neutrophils during different physiological and physiopathological conditions. Some emerging issues in the field of neutrophil biology and the possible strategies to strengthen their activity during the period of immunosuppression have also been discussed.

Bovine oviduct epithelial cells suppress the phagocytic activity of neutrophils towards sperm but not for bacteria in vitro: Immunofluorescence and electron microscopic observations

Previously, we reported that polymorphonuclear neutrophils (PMNs) are constantly existent in the bovine oviduct fluid during the pre-ovulatory stage under physiological conditions. Moreover, incubation of PMNs with bovine oviduct epithelial cells-conditioned medium (BOEC-CM) resulted in suppression of their phagocytic activity for sperm. During pathophysiological conditions, cows may be inseminated by infected semen which exposes oviductal PMNs to allogenic sperm simultaneously with pathogens. This study aimed to visually investigate the role of oviduct epithelium in regulating the phagocytic behavior of PMNs toward sperm as a physiological stimulus, with Escherichia coli (E. coli) as a pathological stimulus. In our experiment, PMNs were incubated for 2 h in BOEC-CM. Phagocytosis was then assayed by co-incubation of these PMNs either with sperm, E. coli, or latex beads. BOEC-CM significantly suppressed the direct phagocytosis of PMNs for sperm, but did not affect their phagocytic activity for E. coli or latex beads. Additionally, an investigation with scanning electron microscopy revealed that BOEC-CM suppressed the formation of DNA-based neutrophil extracellular traps (NETs) for sperm entanglement. BOEC-CM did not alter NETs formation towards E. coli. A quantification of NETs formation using an immunofluorescence microscopy showed that the areas of NETs formation for E. coli were significantly larger than those formed for sperm. Our data clearly show that the bovine oviduct, through secretions, protects sperm from phagocytosis by PMNs and eliminates bacterial dissemination through maintaining the phagocytic activity of PMNs towards bacteria.

Effects of dietary zinc source on the metabolic and immunological response to lipopolysaccharide in lactating Holstein dairy cows

The objectives of this study were to evaluate the effects of replacing 40 mg/kg of Zn from Zn sulfate (control; CON) with Zn AA complex (AvZn) on metabolism and immunological responses following an intravenous lipopolysaccharide (LPS) challenge in lactating cows. Cows were randomly assigned to 1 of 4 treatments: (1) pair-fed (PF) control (PF-CON; 5 mL of saline; n = 5), (2) PF AvZn (PF-AvZn; 5 mL of saline; n = 5), (3) LPS euglycemic clamp control (LPS-CON; 0.375 μg of LPS/kg of BW; n = 5), and (4) LPS euglycemic clamp AvZn (LPS-AvZn; 0.375 μg of LPS/kg of BW; n = 5). Cows were enrolled in 3 experimental periods (P). During period 1 (3 d), cows received their respective dietary treatments and baseline data were obtained. During period 2 (P2; 2 d), a 12-h LPS euglycemic clamp was conducted or cows were PF to their respective dietary counterparts. During period 3 (P3; 3 d), cows received their dietary treatment and consumed feed ad libitum. Mild hyperthermia (1°C) was observed in LPS cows at 3 h postbolus. Throughout P2, the rectal temperature of LPS-AvZn cows was decreased (0.3°C) relative to LPS-CON cows. Administrating LPS decreased dry matter intake (47%) during P2, and by experimental design the pattern was similar in PF cohorts. During P3, dry matter intake from LPS cows remained decreased (15%) relative to PF cows. Milk yield from LPS cows decreased (54%) during P2 relative to PF cows, but it was similar during P3. During P2, somatic cell count increased 3-fold in LPS cows relative to PF controls. Dietary AvZn tended to decrease somatic cell count (70%) during P3 relative to LPS-CON cows. Insulin increased 7-fold in LPS cows at 12 h postbolus and remained increased (4-fold) for the duration of P2. Circulating glucagon from LPS cows increased (65%) during P2, and supplementing AvZn blunted the increase (30% relative to LPS-CON). During P2, circulating cortisol increased 7-fold post-LPS infusion relative to PF cows, and supplementing AvZn decreased cortisol (58%) from 6 to 48 h postbolus relative to LPS-CON cows. Administrating LPS increased circulating LPS-binding protein and serum amyloid A (3- and 9-fold, respectively) relative to PF cows. Compared with LPS-CON, LPS-AvZn cows had increased circulating serum amyloid A (38%) 24 h postbolus. The 12-h total glucose deficit was 36 and 1,606 g for the PF and LPS treatments, respectively, but was not influenced by Zn source. In summary, replacing a portion of the Zn sulfate with Zn AA complex appeared to reduce the inflammatory response but had no effect on the glucose deficit.

Association between Mannheimia haemolytica infection with reproductive physiology and performance in small ruminants: A review

Mannheimiosis or pneumonic pasteurellosis commonly occurs in small ruminants. Mannheimiosis is caused by Mannheimia haemolytica (M. haemolytica) a Gram-negative coccobacillus producing acute febrile and infectious condition resulting in death of animal if not diagnosed and treated promptly. M. haemolytica serotype A2 is a commensal of the nasopharynx, gaining access to the lungs when host defenses are compromised by stress or infection in small ruminants. Till date, there is a vast literature and research that has been conducted on the pathogenesis of M. haemolytica invariably on respiratory system and its related immune system and mechanisms. From the clinical point of view, infection or diseases involving vital organs will systemically affect the production and performance of the infected animal. Therefore, there is a huge gap of knowledge and research to answer the question whether there is any association between M. haemolytica infection with reproductive physiology and performance in small ruminants and how it affects the productivity level. This review will explore the possibilities of involvement and new potential research to be carried out to determine the involvement of male and female reproductive system with M. haemolytica infection among small ruminants.

Montmorillonite improved the intestinal mucosal barrier functions of laying hens in late production

This study was conducted to investigate the effects of dietary supplementation with montmorillonite (MMT) on performance, intestinal endotoxin concentration, gut mucosal oxidation status, intestinal morphology and permeability, and immunological barrier function of laying hens during late production. Four hundred and eighty 75-week-old laying hens (Lohmann Brown) were randomly assigned to five treatments with eight replicates per treatment and 12 hens in each replicate. The hens were fed the basal diet supplemented with 0 (control), 0.3, 0.6, 0.9, or 1.2 g MMT/kg for 70 days. Compared with the control, supplemented with 0.9 g MMT/kg increased egg mass significantly (p < 0.05) during weeks 1-5 of the experiment. Supplemented with 0.6 and 0.9 g MMT/kg also increased the endotoxin concentration in the ileal digesta (p < 0.05), but decreased the MDA concentration in the ileum significantly (p < 0.05). The T-AOC in the jejunum of the group fed 0.3 g MMT/kg was significantly increased (p < 0.05). Compared with the control, the villus height:crypt depth of ileum from the groups fed 0.6, 0.9, and 1.2 g MMT/kg increased significantly (p < 0.05). The sIgA concentration of jejunum in the groups fed 0.6 and 0.9 g MMT/kg was higher (p < 0.05) than the control. The MMT supplementation linearly increased (p < 0.05) the mRNA expression of claudin-1 and claudin-5 in the jejunum. Dietary MMT supplementation down-regulated the mRNA expression of NF-κB P65 and TNF-α in the jejunum in a linear and quadratic manner (p < 0.05). The IL-1β mRNA expression of jejunum in the group fed 0.6 g MMT/kg was lower (p < 0.05) than the control. In conclusion, dietary supplementation with MMT may improve the gut barrier functions and suggests that 0.9 g/kg of MMT in diets may be the optimal supplemental level for laying hens in late production.

Cucumarioside A2-2 causes changes in the morphology and proliferative activity in mouse spleen

The immunomodulatory effect of triterpene glycoside cucumarioside A2-2 (CA2-2), isolated from the Far Eastern sea cucumber Cucumaria japonica, on the mouse spleen was investigated in comparison with lipopolysaccharide (LPS). It has been shown that the intraperitoneal (i.p.) glycoside administration did not influence on splenic weights, while the statistically significant increase in splenic weight was observed after LPS administration. Changes in the ratio of red to white pulp after CA2-2 or LPS administration were observed. The proportion of splenic white pulp after glycoside or LPS administration increased by up to 34% and 36%, respectively. A detailed study of the distribution of the РСNA (Proliferating Cell Nuclear Antigen) marker showed that the proliferative activity in the white pulp under CA2-2 and LPS influence increased 2.07 and 2.24 times, respectively. The localization of PCNA-positive nuclei in the white pulp region, as well as their dimensional characteristics, suggests that a large proportion of the proliferating cell population consisted of B cells. The mass spectrometry profiles of spleen peptide/protein homogenate were obtained using the MALDI-TOF-MS (Matrix -Assisted Laser Desorption/Ionization Time-Of-Flight Mass Spectrometry) approach. It was found that i.p. stimulation of animals with CA2-2 or LPS leads to marked changes in the intensity of revealed characteristic peaks of peptides/proteins after exposure to immunostimulants.

Neonatal lipopolysaccharide exposure does not diminish the innate immune response to a subsequent lipopolysaccharide challenge in Holstein bull calves

The innate immune response following experimental mastitis is quite variable between individual dairy cattle. An inflammatory response that minimizes collateral damage to the mammary gland while still effectively resolving the infection following pathogen exposure is beneficial to dairy producers. The ability of a lipopolysaccharide (LPS) exposure in early life to generate a low-responding phenotype and thus reduce the inflammatory response to a later-life LPS challenge was investigated in neonatal bull calves. Ten Holstein bull calves were randomly assigned to either an early life LPS (ELL) group (n=5) or an early life saline (ELS) group (n=5). At 7d of age, calves received either LPS or saline, and at 32d of age, all calves were challenged with an intravenous dose of LPS to determine the effect of the early life treatment (LPS or saline) on the immune response generated toward a subsequent LPS challenge. Dermal fibroblast and monocyte-derived macrophage cultures from each calf were established at age 20 and 27d, respectively, to model sustained effects from the early life LPS exposure on gene expression and protein production of components within the LPS response pathway. The ELL calves had greater levels of plasma IL-6 and tumor necrosis factor-α than the ELS calves following the early life LPS or saline treatments. However, levels of these 2 immune markers were similar between ELL and ELS calves when both groups were subsequently challenged with LPS. A comparison of the in vitro LPS responses of the ELL and ELS calves revealed similar patterns of protein production and gene expression following an LPS challenge of both dermal fibroblast and monocyte-derived macrophage cultures established from the treatment groups. Whereas an early life exposure to LPS did not result in a dampened inflammatory response toward a later LPS challenge in these neonatal bull calves, the potential that exposure to inflammation or stress in early life or in utero can create an offspring with a low-responding phenotype as an adult is intriguing and has been documented in rodents. Further work is needed to determine if an inflammatory exposure in utero in a dairy animal would result in a low-responding innate immune phenotype.

Role of the NOD1/NF-κB pathway on bovine neutrophil responses to crude lipopolysaccharide

Cytosolic nucleotide oligomerisation domain (NOD)-like receptors play an important role in host defence against infection. Reduced NOD1 expression has been observed in dysfunctional neutrophils derived from periparturient cattle known to be most susceptible to coliform mastitis. However, whether impairment of NOD1 suppresses the immune responses of bovine neutrophils during bacterial infections remains unknown. Crude (phenol extracted) lipopolysaccharide (cLPS), which often contains other immunostimulatory molecules, including NOD1 agonist, is known to induce almost the whole bacterial response. This study was conducted to explore the role of NOD1/nuclear factor (NF)-κB pathway in the cytokine and functional responses of bovine neutrophils challenged with Escherichia coli-derived cLPS. Freshly isolated blood neutrophils from healthy heifers were pre-incubated for 2 h with ML130, a selective inhibitor of NOD1/NF-κB pathway. Cells were then exposed to cLPS for additional 4 h. Inhibition of the NOD1/NF-κB pathway resulted in a decrease in cLPS-induced phosphorylation of the inhibitor of NF-κBα (IκBα) in neutrophils. Impairment of the NOD1/NF-κB pathway tended to down-regulate mRNA levels of pro-inflammatory cytokines interleukin (IL)-1β and tumour necrosis factor (TNF)-α, chemokines IL-8 and C-X-C motif ligand 2 (CXCL2), and adhesion molecules CD11b and CD62L, in cLPS-challenged cells. Functional analyses showed that blocking the NOD1/NF-κB pathway inhibited neutrophil migration and phagocytic killing capacity, and promoted neutrophil death upon cLPS stimulation. The data presented here demonstrate that activation of NOD1/NF-κB pathway contributes to the functional responses of neutrophils to cLPS.

Simvastatin attenuates the lipopolysaccharideinduced inflammatory response of rat pulmonary microvascular endothelial cells by downregulating toll-like receptor 4 expression

Objective

The therapeutic potential of simvastatin as an anti-inflammatory agent was explored by investigating its effect on the lipopolysaccharide (LPS)-induced inflammatory response in rat pulmonary microvascular endothelial cells (RPMVECs).

Methods

RPMVECs were isolated and the mRNA and protein levels of different toll-like receptors (TLR) were assessed by qRT-PCR and western blotting. The LPS-induced expressions of TLR4, TNF-α and iNOS were analyzed in RPMVECs treated with different concentrations of simvastatin for different times. NF-κB activation was examined by immuofluroscence, luciferase reporter assay and western blotting.

Results

TLR4 is abundantly expressed in RPMVECs, and its expression is induced by LPS stimulation. Simvastatin inhibited LPS-induced TLR4 expression at the mRNA and protein levels in a time-dependent manner (p<0.01), and alleviated inflammation in RPMVECs by inhibiting the release of inflammatory factors such as TNF-α and iNOS. Further study indicated that simvastatin significantly attenuated NF-κB activity by inhibiting the degradation of IκB-α. Pretreatment with pyrrolidine dithiocarbamate (PDTC) and knock-down of TLR4 expression by RNA interference down-regulated the LPS-induced inflammatory response in RPMVECs.

Conclusion

Simvastatin inhibits the LPS-induced inflammatory response in RPMVECs by down-regulating TLR4 expression, suggesting its role as a potential inhibitor of LPS-induced inflammation

In vitro effects of Escherichia coli lipopolysaccharide on the function and gene expression of neutrophils isolated from the blood of dairy cows

The objectives of this study were to investigate the effect of Escherichia coli lipopolysaccharide (LPS) on the function of bovine neutrophils (PMNL) collected from mid lactation cows and determine the differential effects of LPS on gene expression of PMNL purified from early and mid lactation cows. The PMNL from mid lactation cows (187±13 d postpartum) were incubated with 0, 1, 25, and 50 μg/mL of LPS for 120 min, and the generation of reactive oxygen species (ROS), PMNL extracellular traps (NET), chemotaxis, and killing of Staphylococcus aureus were determined. Incubation of PMNL with 25 μg/mL of LPS increased intracellular ROS by 79% in mitogen-stimulated PMNL. Addition of 50 μg/mL of LPS enhanced intracellular ROS by nonstimulated and stimulated PMNL by 184 and 154%, respectively. Nonstimulated PMNL incubated with 25 and 50 μg/mL of LPS had a 105% increase in NET. Addition of LPS had no effect on subsequent PMNL chemotaxis or killing of Staph. aureus. To examine the effect of LPS on the expression of genes involved in PMNL function and cytokine production, mRNA was purified from PMNL isolated from mid lactation (146±2 postpartum; n=10) and early lactation cows (7 d postpartum; n=10), after a 120-min incubation with 0 or 50 μg/mL of LPS. Amounts of interleukin-8 (IL-8), tumor necrosis factor (TNF), bactericidal/permeability-increasing protein (BPI), myeloperoxidase (MPO), superoxide dismutase 2 (SOD2), NADPH oxidase 4 (NOX4), Cytochrome b-245, α polypeptide (CYBA), histone H2A/1 (H2A/1), and histone H2B-like (H2B) mRNA were determined relative to that of β-actin by real-time quantitative PCR. Regardless of stage of lactation, PMNL incubated with 50 μg/mL of LPS had 537 and 45% higher mRNA contents of IL-8 and SOD2 compared with 0 μg/mL LPS, respectively. In addition, LPS augmented the expression of TNF, BPI, and CYBA (2,908, 59, and 158% compared with controls, respectively) only in PMNL from mid lactation cows. Addition of LPS did not affect mRNA levels of MPO, NOX4, H2A/1, or H2B. Independent of LPS treatment, PMNL from mid lactation cows had 99% higher mRNA contents of IL-8 compared with PMNL from early lactation cows. The PMNL from early lactation cows had a 634% increase in MPO mRNA expression relative to that from mid lactation cows. These results support that LPS directly stimulates PMNL to produce ROS and express NET. In addition, LPS enhances the generation of ROS by PMNL in response to other stimuli and increases the expression of genes encoding inflammatory mediators and enzymes involved in the production of ROS. Finally, reduced PMNL gene expression of IL-8 (regardless of LPS activation), TNF, CYBA, and BPI (upon stimulation with LPS) in early lactation may elucidate several mechanisms by which PMNL may become immune-incompetent during this period.

Vascular and immune regulation of corpus luteum development, maintenance, and regression in the cow

The bovine corpus luteum (CL) is a unique, transient organ with well-coordinated mechanisms by which its development, maintenance, and regression are effectively controlled. Angiogenic factors, such as vascular endothelial growth factor A and basic fibroblast growth factor, play an essential role in promoting progesterone secretion, cell proliferation, and angiogenesis. These processes are critically regulated, through both angiogenic and immune systems, by the specific immune cells, including macrophages, eosinophils, and neutrophils, that are recruited into the developing CL. The bovine luteolytic cascade appears to be similar to that of general acute inflammation in terms of time-dependent infiltration by immune cells (neutrophils, macrophages, and T lymphocytes) and drastic changes in vascular tonus and blood flow, which are regulated by luteal nitric oxide and the vasoconstrictive factors endothelin-1 and angiotensin II. Over the period of maternal recognition of pregnancy, the maternal immune system should be well controlled to accept the semiallograft fetus. The information on the presence of the developing embryo in the genital tract is suggested to be transmitted to the ovary by both the endocrine system and the circulating immune cells. In the bovine CL, the lymphatic system, but not the blood vascular system, is reconstituted during early pregnancy, and interferon tau from the embryo could trigger this novel phenomenon. Collectively, the angiogenic and vasoactive factors produced by luteal cells and the time-dependently recruited immune cells within the CL and their interactions appear to play critical roles in regulating luteal functions throughout the life span of the CL.

The formation of immune complexes is involved in the acute phase of periodontal destruction in rats

BACKGROUND AND OBJECTIVE

Loss of clinical attachment and alveolar bone destruction are major symptoms of periodontitis, caused by not only the destructive effect of periodontopathic bacteria but also the overactive response of the host immune system against periodontal pathogens. The details of the participation of the immune system in the onset and progression of periodontitis are unclear. In this study, we attempted to determine whether the host immune system, and in particular the formation of immune complexes, is involved in the periodontal destruction.

MATERIAL AND METHODS

We applied ovalbumin or lipopolysaccharide (LPS) as antigens and their specific immunoglobulin G (IgG) antibodies purified from rat serum to rat gingival sulcus alternately. Loss of attachment, alveolar bone destruction and the numbers of inflammatory cells infiltrating the periodontal tissue and osteoclasts on the alveolar bone surface were investigated histometrically. The formation of immune complex was confirmed by immunohistological staining of complement C1qB.

RESULTS

Loss of attachment and the presence of C1qB were observed histopathologically in both experimental groups. The group that had been treated with LPS and anti-LPS IgG showed greater loss of attachment. The number of inflammatory cells in the periodontal tissue was increased in both experimental groups, while osteoclasts at the alveolar bone crest were observed only in the group that had been treated with LPS and anti-LPS IgG.

CONCLUSION

In the present study, we showed that the formation of immune complex appears to be involved in the acute phase of periodontal destruction and that the biological activity of antigens is also important.

Rapid accumulation of polymorphonuclear neutrophils in the Corpus luteum during prostaglandin F(2α)-induced luteolysis in the cow

Prostaglandin F_2α (PGF_2α) induces luteolysis within a few days in cows, and immune cells increase in number in the regressing corpus luteum (CL), implying that luteolysis is an inflammatory-like immune response. We investigated the rapid change in polymorphonuclear neutrophil (PMN) numbers in response to PGF_2α administration as the first cells recruited to inflammatory sites, together with mRNA of interleukin-8 (IL-8: neutrophil chemoattractant) and P-selectin (leukocyte adhesion molecule) in the bovine CL. CLs were collected by ovariectomy at various times after PGF_2α injection. The number of PMNs was increased at 5 min after PGF_2α administration, whereas IL-8 and P-selectin mRNA increased at 30 min and 2 h, respectively. PGF_2α directly stimulated P-selectin protein expression at 5–30 min in luteal endothelial cells (LECs). Moreover, PGF_2α enhanced PMN adhesion to LECs, and this enhancement by PGF_2α was inhibited by anti-P-selectin antibody, suggesting that P-selectin expression by PGF_2α is crucial in PMN migration. In conclusion, PGF_2α rapidly induces the accumulation of PMNs into the bovine CL at 5 min and enhances PMN adhesion via P-selectin expression in LECs. It is suggested that luteolytic cascade by PGF_2α may involve an acute inflammatory-like response due to rapidly infiltrated PMNs.

Functional adaptations of the transcriptome to mastitis-causing pathogens: the mammary gland and beyond

Application of microarrays to the study of intramammary infections in recent years has provided a wealth of fundamental information on the transcriptomics adaptation of tissue/cells to the disease. Due to its heavy toll on productivity and health of the animal, in vivo and in vitro transcriptomics works involving different mastitis-causing pathogens have been conducted on the mammary gland, primarily on livestock species such as cow and sheep, with few studies in non-ruminants. However, the response to an infectious challenge originating in the mammary gland elicits systemic responses in the animal and encompasses tissues such as liver and immune cells in the circulation, with also potential effects on other tissues such as adipose. The susceptibility of the animal to develop mastitis likely is affected by factors beyond the mammary gland, e.g. negative energy balance as it occurs around parturition. Objectives of this review are to discuss the use of systems biology concepts for the holistic study of animal responses to intramammary infection; providing an update of recent work using transcriptomics to study mammary and peripheral tissue (i.e. liver) as well as neutrophils and macrophage responses to mastitis-causing pathogens; discuss the effect of negative energy balance on mastitis predisposition; and analyze the bovine and murine mammary innate-immune responses during lactation and involution using a novel functional analysis approach to uncover potential predisposing factors to mastitis throughout an animal's productive life.

Colonic gene expression patterns of mucin Muc2 knockout mice reveal various phases in colitis development

BACKGROUND

Mucin Muc2 knockout (Muc2(-/-)) mice spontaneously develop colitis.

METHODS

To identify genes and biological responses which play a pivotal role during colitis development in Muc2(-/-) mice, gene expression profiles of colonic tissues from 2- and 4-week-old Muc2(-/-) and wildtype mice were determined using microarrays.

RESULTS

The majority of highly upregulated genes in 2-week-old as well as 4-week-old Muc2(-/-) mice were primarily involved in immune responses related to antigen processing/presentation, B-cell and T-cell receptor signaling, leukocyte transendothelial migration, and Jak-STAT signaling. Specifically, Muc2(-/-) mice expressed high levels of immunoglobulins, murine histocompatibility-2, proinflammatory cytokines, chemokines, and antimicrobial proteins. Additionally, in 4-week-old Muc2(-/-) mice, expression of genes involved in cell structure related pathways was significantly altered. Particularly, the tight junction-associated gene claudin-10 was upregulated, whereas claudin-1 and claudin-5 were downregulated. Furthermore, 4-week-old Muc2(-/-) mice showed increased expression of genes regulating cell growth in conjunction with increased crypt length and increased epithelial proliferation.

CONCLUSIONS

Muc2-deficiency leads to an active inflammatory response in 2- and 4-week-old Muc2(-/-) mice as demonstrated by the altered expression in immune response related genes. In addition, 4-week-old Muc2(-/-) mice also showed a decrease in epithelial barrier function and an increase in epithelial proliferation as indicated by, respectively, the altered expression in tight junction-related genes and upregulation of genes stimulating cell growth. Remarkably, upregulation of genes stimulating cell growth correlated with increased crypt length and increased epithelial proliferation in 4-week-old Muc2(-/-) mice. Together, these data demonstrate that there are distinct phases in colitis development in 2-4-week-old Muc2(-/-) mice.

Differential stress responses among newly received calves: variations in reductant capacity and Hsp gene expression

Bovine respiratory disease complex (BRD), a major economic concern to the beef cattle industry all over the world, is triggered by physical, biological and psychological stresses. It is becoming noticeable that the key to reducing BRD appears to be centered at reducing the response to stress. The aims of the present study were to detect individual variations in the stress response of newly received young calves through their leukocyte heat shock protein (Hsp) response, selected neutrophil-related gene expression and oxidative stress, and relate them to pulmonary adhesions at slaughter, an indicative sign of clinical and subclinical episodes of BRD at an early age. Differential expression patterns of Hsp60 and Hsp70A1A were revealed in newly received calves 1 h, 5 h and 1 day after arrival, distinguishing between stress-responsive and non-stress-responsive individuals. Plasma cortisol was also indicative of stress-responsive and non-stress-responsive individuals, 1 h and 5 h after arrival. At the longer term, β-glycan levels were highest 7 days after arrival and significantly correlated with an adhesion-free phenotype at slaughter. Oxidative stress responses, measured through the oxidation products of the exogenous linoleoyl tyrosine (LT) marker, revealed that hydroperoxidation and epoxidation of membranes may readily occur. Based on the LT oxidation products and levels of β-glycan, we present a discriminant analysis model, according to which vulnerable individuals may be predicted at near 100% probability 7 days after arrival. Since clinical signs of BRD may often go undetected in feedlot calves, such a model, after its examination in large-scale experiments, may be a reliable tool for an early prediction of subclinical signs of BRD.

A distinct subset of proinflammatory neutrophils isolated from patients with systemic lupus erythematosus induces vascular damage and synthesizes type I IFNs

Neutrophil-specific genes are abundant in PBMC microarrays from lupus patients because of the presence of low-density granulocytes (LDGs) in mononuclear cell fractions. The functionality and pathogenicity of these LDGs have not been characterized. We developed a technique to purify LDGs from lupus PBMCs and assessed their phenotype, function, and potential role in disease pathogenesis. LDGs, their autologous lupus neutrophils, and healthy control neutrophils were compared with regard to their microbicidal and phagocytic capacities, generation of reactive oxygen species, activation status, inflammatory cytokine profile, and type I IFN expression and signatures. The capacity of LDGs to kill endothelial cells and their antiangiogenic potential were also assessed. LDGs display an activated phenotype, secrete increased levels of type I IFNs, TNF-alpha, and IFN-gamma, but show impaired phagocytic potential. LDGs induce significant endothelial cell cytotoxicity and synthesize sufficient levels of type I IFNs to disrupt the capacity of endothelial progenitor cells to differentiate into mature endothelial cells. LDG depletion restores the functional capacity of endothelial progenitor cells. We conclude that lupus LDGs are proinflammatory and display pathogenic features, including the capacity to synthesize type I IFNs. They may play an important dual role in premature cardiovascular disease development in systemic lupus erythematosus by simultaneously mediating enhanced vascular damage and inhibiting vascular repair.

Binding of different forms of lipopolysaccharide and gene expression in bovine blood neutrophils

The objective of this study was to evaluate the effect of smooth (S) and rough (R) forms of lipopolysaccharide (LPS) on gene expression in bovine blood neutrophils. Isolated neutrophils (10(7) cells/mL) were treated with Escherichia coli LPS serotype O111:B4 (S+R) and R forms (Ra, Rd, or Rc). Flow cytometry was used to assess surface expression of toll-like receptor 4 (TLR-4). Specific primers for IL-8, tumor necrosis factor-alpha (TNF-alpha), IL-1beta, cluster of differentiation antigen 14 (CD14), and natural resistance associated macrophage protein 1 (Nramp1) were used to assess transcription. Secretion of IL-8, TNF-alpha, or IL-1beta was determined using ELISA kits. Both S and R forms of LPS bound to neutrophils. Exposure induced increased surface expression of TLR-4. No TLR-4 or CD14 mRNA was detected but transcripts for IL-8, TNF-alpha, IL-1beta, and Nramp1 were detected. Secretion of IL-8 and TNF-alpha but not IL-1beta was observed following treatment with R forms of LPS. The longest R form tested (Ra) increased RNA purity and IL-8 and TNF-alpha secretion in bovine neutrophils. The Rd form increased TLR-4 expression and reduced IL-8 and TNF-alpha secretion. Exposure to LPS induced increased cell surface expression of TLR-4 and enhanced expression of IL-8 genes. Enhanced TLR-4 activity by LPS was not dependent on transcriptional activation. Recruitment of TLR-4 to the cell membrane may account for increased cell surface expression. A CD14-independent, TLR-4-dependent pathway may be important in the response to different forms of LPS by bovine neutrophils.

Pathogen-dependent induction of cytokines and other soluble inflammatory mediators during intramammary infection of dairy cows

Mastitis is a highly prevalent and costly disease of dairy cows that is commonly caused by intramammary bacterial infection. The innate immune response to bacterial penetration of the mammary gland is evoked within hours of infection, and the rapidity and magnitude of this response have been demonstrated to influence the resolution of this disease. Cytokines and other mediators of inflammation are known to play critical roles in the innate immune response to intramammary infection. The objectives of this review are to summarize the current understanding of the cytokine response to intramammary infection, highlight recent findings identifying differences in the cytokine response to various bacterial pathogens, and discuss future research directions that will increase our knowledge of the role of inflammatory mediators in predicting and governing the outcome of mastitis.