Factors that are potentially important in the pulmonary pathogenesis of asbestos and other mineral particles are: 1) morphology, 2) Fe-content, 3) solubility under intraphagosomal conditions, 4) value and sign of the surface potential of the particle, 5) hydrophobicity or hydrophilicity, 6) capacity to activate phagocytic leukocytes, and 7) duration of exposure to the particles. The order of importance of these factors in causing severe or fatal pulmonary pathogenicity is estimated to be: 1 > 3 > 7 > 6 ≫ 5 > 4 > 2. The order of pathogenicity of the minerals is estimated as: amphibole asbestos: crocidolite, tremolite, amosite > erionite > serpentine asbestos: chrysotile > talc > silica > simple metal oxides. Particle length, duration of exposure to the particles, and pre-treatment of the particles may however enhance the pathogenic potential of any of the lower-ranked particles.

This Research Communication describes the relation between somatic cells and microbial content in milk from Jersey cattle. Milk samples were classified in groups: healthy, dirty and mastitic (from Staphylococcus spp., Escherichia coli, Coliforms). The somatic cells in each of those groups were analysed by two methods – flow cytometric and automatic fluorescent cell counting. Those methods were compared. Total somatic cell count (SCC), neutrophil count, and lymphocytes with cluster of differentiation 4 (CD4+cells) were determined. There was a positive relationship between microbes and somatic cells. It was noticed that the neutrophil count was generally increased together with SCC, whilst the CD4+ cell count was higher in healthy milk samples (about 8%) compared to mastitic ones (about 3%). Lower number of CD4+ cells (from 1 to 4%) was determined in samples positive for Staphylococcus spp. but with lower SCC (from 2.7 to 4.0 × 105 cells/ml). Also, the number of CD4+ cells in Staphylococcus spp.-positive samples increased (to 4.8%) together with higher SCC, something that was not observed in the other mastitic samples. Knowledge of those relations could be useful for veterinary medical tests in the initial phase of inflammation.

This research communication describes the application of a fluorescent automatic cell counter Lactoscan SCC for simultaneous determination of somatic cell count and neutrophils in bovine milk. The obtained results were compared with results obtained by a flow cytometer and a light microscope. The Pearson correlations between the methods were calculated. A comparison between the main characteristics of the three kinds of analysis was made – the assay duration and the intra-assay precision. A relation between the SCC and neutrophil cells was observed in 55 milk samples. The obtained results confirm that the simultaneous determination of SCC and neutrophil analysis are necessary and support the early diagnosis of mastitis, the timely treatment of the animal and the avoidance of major economic losses.

This study applied causal criteria in directed acyclic graphs for handling covariates in associations for prognosis of severe coronavirus disease 2019 (COVID-19) cases. To identify non-specific blood tests and risk factors as predictors of hospitalisation due to COVID-19, one has to exclude noisy predictors by comparing the concordance statistics (area under the curve − AUC) for positive and negative cases of severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2). Predictors with significant AUC at negative stratum should be either controlled for their confounders or eliminated (when confounders are unavailable). Models were classified according to the difference of AUC between strata. The framework was applied to an open database with 5644 patients from Hospital Israelita Albert Einstein in Brazil with SARS-CoV-2 reverse transcription – polymerase chain reaction (RT-PCR) exam. C-reactive protein (CRP) was a noisy predictor: hospitalisation could have happened due to causes other than COVID-19 even when SARS-CoV-2 RT-PCR is positive and CRP is reactive, as most cases are asymptomatic to mild. Candidates of characteristic response from moderate-to-severe inflammation of COVID-19 were: combinations of eosinophils, monocytes and neutrophils, with age as risk factor; and creatinine, as risk factor, sharpens the odds ratio of the model with monocytes, neutrophils and age.

The present study describes in detail the morphological characteristics of the process of ovarian follicular atresia in Redbelly tilapia (Coptodon zillii) during the nonbreeding season using light and electron microscopy and immunohistochemistry. The follicular regression process was initiated with shrinkage and disintegration of the nuclear membrane of oocytes resulting in dispersing of chromatin within the ooplasm, followed by marked hyperplasia and hypertrophy of follicular and granulosa cells, which exhibited a strong phagocytic activity to engulf the liquefied yolk particles. Rodlet cells and granulocytes were recorded on the follicular wall and invaded the regressed follicles. Rodlet cells expressed a strong immunoreactivity to matrix metalloperoxidase (MMP-9) and α-smooth muscle actin, while neutrophils expressed a strong reactivity to Myeloperoxidase-3 (MPO). In the advanced stage of follicular atresia, the yolk was almost phagocytized and resorbed and the regressed follicle lost its integrity and appeared to be formed of a cellular mass of phagocytic cells. Transmission electron microscopy revealed the presence of neutrophils, eosinophils, and dendritic cells within the atretic follicle in between these phagocytic cells. Moreover, numerous lysosomes, granules, and phagosomes were observed within the cytoplasm of both phagocytic cells and granulocytes. Telocytes were also demonstrated within the highly thickened richly vascularized theca layer during the late stages of follicular atresia. Immunohistochemical staining for caspase-3 established the participation of apoptosis in the advanced stages of follicular regression. Immune cells, rodlet cells, and telocytes in combination with follicular cells play an essential role in follicular atresia. In conclusion, the present study provides a new evidence on the role of both somatic and immune cells in the phenomenon of ovarian follicular atresia in Redbelly tilapia (Coptodon zillii) during the nonbreeding season.

The work described in this research communication aimed to investigate whether rumen-protected methionine (Met) supplementation during the periparturient period would affect the expression of galectins in blood-derived neutrophils, and secretion of galectins, IL (interleukin)-1β, IL-6, myeloperoxidase (MPO), and glucose in plasma. Because supplementation of rumen-protected Met would alleviate inflammation and oxidative stress during the peripartal period, we hypothesized that enhancing Met supply would benefit the innate immune response at least in part by altering the expression of galectin genes associated with neutrophil activity and inflammation. Galectins (Gal) have an immuno-modulating effect acting like cell-surface receptors whose activation often results in signaling cascades stimulating cells such as neutrophils. This study revealed an association between Met supplementation and galectin expression and secretion. This implies that galectin expression and secretion can be modulated by Met supplementation. Further studies are needed to evaluate the regulation of galectin gene expression for therapeutic and dietary intervention in the peripartal cow.

Concentrate inclusion levels in dairy cow diets are often adjusted so that the milk yield responses remain economic. While changes in concentrate level on performance is well known, their impact on other biological parameters, including immune function, is less well understood. The objective of this study was to evaluate the effect of concentrate inclusion level in a grass silage-based mixed ration on immune function. Following calving 63 (45 multiparous and 18 primiparous) Holstein Friesian dairy cows were allocated to one of three isonitrogenous diets for the first 70 days of lactation. Diets comprised of a mixture of concentrates and grass silage, with concentrates comprising either a low (30%, LC), medium (50%, MC) or high (70%, HC) proportion of the diet on a dry matter (DM) basis. Daily DM intakes, milk yields and BW were recorded, along with weekly body condition score, milk composition and vaginal mucus scores. Blood biochemistry was measured using a chemistry analyzer, neutrophil phagocytic and oxidative burst assessed using commercial kits and flow cytometry, and interferon-γ production evaluated by ELISA after whole blood stimulation. Over the study period cows on HC had a higher total DM intake, milk yield, fat yield, protein yield, fat+protein yield, protein content, mean BW and mean daily energy balance, and a lower BW loss than cows on MC, whose respective values were higher than cows on LC. Cows on HC and MC had a lower serum non-esterified fatty acid concentration than cows on LC (0.37, 0.37 and 0.50 mmol/l, respectively, P=0.005, SED=0.032), while cows on HC had a lower serum β-hydroxybutyrate concentration than cows on MC and LC (0.42, 0.55 and 0.55 mmol/l, respectively, P=0.002, SED=0.03). Concentrate inclusion level had no effect on vaginal mucus scores. At week 3 postpartum, cows on HC tended to have a higher percentage of oxidative burst positive neutrophils than cows on LC (43.2% and 35.3%, respectively, P=0.078, SED=3.11), although at all other times concentrate inclusion level in the total mixed ration had no effect on neutrophil phagocytic or oxidative burst characteristics, or on interferon-γ production by pokeweed mitogen stimulated whole blood culture. This study demonstrates that for high yielding Holstein Friesian cows managed on a grass silage-based diet, concentrate inclusion levels in early lactation affects performance but has no effect on neutrophil or lymphocyte immune parameters.

Neutrophilic bronchiolitis is the primary lesion in asthma-affected horses. Neutrophils are key actors in host defense, migrating toward sites of inflammation and infection, where they act as early responder cells toward external insults. However, neutrophils can also mediate tissue damage in various non-infectious inflammatory processes. Within the airways, these cells likely contribute to bronchoconstriction, mucus hypersecretion, and pulmonary remodeling by releasing pro-inflammatory mediators, including the cytokines interleukin (IL)-8 and IL-17, neutrophil elastase, reactive oxygen species (ROS), and neutrophil extracellular traps (NETs). The mechanisms that regulate neutrophil functions in the tissues are complex and incompletely understood. Therefore, the inflammatory activity of neutrophils must be regulated with exquisite precision and timing, a task achieved through a complex network of mechanisms that regulates neutrophil survival. The discovery and development of compounds that can help regulate ROS, NET formation, cytokine release, and clearance would be highly beneficial in the design of therapies for this disease in horses. In this review, neutrophil functions during inflammation will be discussed followed by a discussion of their contribution to airway tissue injury in equine asthma.

The present study tested a hypothesis that dietary fish oil (eicosapentaenoic acid+docosahexaenoic acid) in a commonly achievable dose ameliorates a systemic inflammation in pigs. Two groups of pigs of 16 animals each were fed a diet with either 2.5% of fish oil (F) or a control diet with 2.5% of palm oil (P). After 70 days of fattening, eight F and eight P pigs were challenged (F+; P+) i.v. by lipopolysaccharide. After 3 h, all pigs were sacrificed and blood, liver and visceral adipose tissue (VAT) samples were taken. No significant effect (P>0.05) of dietary oil on the feed intake and daily weight gain was found out. Less neutrophils (16.8% v. 28.8%; P<0.05) were found in the F+-leukocytes of the peripheral blood; F+ pigs had lower (P<0.05) percentage of the swine leukocyte antigen-D-related CD163+ (SLA-DR+ CD163+) macrophages in the VAT (15.4% v. 21.8%) and lower expression of the SLA-DR-CD163+ surface molecules of the VAT macrophages. No difference (P>0.05) between F+ and P+ pigs in the peroxisome proliferator-activated receptor γ, GPR120, Adipor1 and Adipor2 (adiponectin receptor) gene expression, respectively, was established; plasma adiponectin was the same (21.1 ng/ml) in F+ and P+ pigs. In comparison with the P+ pigs, increased expression of the lipopolysaccharide-binding protein (LBP) gene and intercellular adhesion molecule 1 (ICAM1) gene was found out in the liver of the F+ pigs; expression of the tumor necrosis factor α (TNFα) gene was higher in the liver but lower in the VAT of the F+ pigs (P<0.05). The F+ pigs had higher (P<0.05) plasma concentration of both anti-inflammatory cytokine interleukin-4 (0.46 v. 0.04 ng/ml) and pro-inflammatory TNF-α (13.41 v. 7.72 ng/ml). It was concluded that dietary fish oil at the tested amount had a negligible effect on expression of the evaluated receptor genes and plasma adiponectin, and had an ambiguous effect on expression of cytokine genes and plasma cytokine levels.

The urokinase-plasminogen activator (u-PA), its receptor (u-PAR) and the inhibitors of u-PA (PAI-1 and PAI-2) provide a multi-molecular system in leucocytes that exerts pleiotropic functions influencing the development of inflammatory and immune responses. The objective of the present study was to examine the ability of water soluble extracts (WSE) obtained from traditional Greek yoghurt made from bovine or ovine milk to modulate the expression of u-PA, u-PAR, PAI-1 and PAI-2 in ovine monocytes and neutrophils. WSE were obtained from 8 commercial traditional type Greek yoghurts made from ovine or bovine milk. WSE upregulated the expression of all 4 u-PA related genes in monocytes but the upregulation was much higher in the PAI-1 (10-fold) than in u-PA and u-PAR (3–4 fold) thus, shifting the system towards inhibition. In line with this observation, WSE reduced total and membrane-bound u-PA activity in monocytes. In neutrophils, WSE caused small (50–60%) but significant (P < 0·05) reductions in expression of u-PAR and PAI-2 but had no effect on expression of u-PA, PAI-1 and on total cell-associated and membrane-bound u-PA activity. WSE from yoghurts made from bovine or ovine milk were essentially equally effective in affecting the u-PA system except for the u-PAR gene in ovine neutrophils that was affected (reduced) by the ovine and not the bovine WSE. In conclusion, peptides present in WSE modulated the expression of u-PA related genes but the effect was much more prominent in monocytes than in neutrophils.

Bovine viral diarrhea virus (BVDV) has long been associated with a wide variety of clinical syndromes and immune dysregulation, many which result in secondary bacterial infections. Current understanding of immune cell interactions that result in activation and tolerance are explored in light of BVDV infection including: depletion of lymphocytes, effects on neutrophils, natural killer cells, and the role of receptors and cytokines. In addition, we review some new information on the effect of BVDV on immune development in the fetal liver, the role of resident macrophages, and greater implications for persistent infection.

Quercetin, a flavonoid found in fruits and vegetables, is a strong antioxidant with anti-inflammatory, antimicrobial and immune-modulating properties. The purpose of the present study was to investigate the effects of long-term quercetin supplementation on innate immune function and inflammation in human subjects. Female subjects (n 120; aged 30–79 years) were recruited from the community and randomised to one of three groups, with supplements administered using double-blinded procedures: 500 mg quercetin/d (n 38), 1000 mg quercetin/d (n 40) or placebo (n 42). Subjects ingested two soft chew supplements twice daily during the 12-week study period. Fasting blood samples were obtained pre- and post-study and were analysed for plasma quercetin, IL-6, TNF-α and leucocyte subset cell counts. Natural killer cell activity (NKCA) and lymphocyte subsets were assessed in a subset of seventy-four subjects. Granulocyte oxidative burst activity (GOBA) and phagocytosis were assessed in sixty-four subjects. Eighteen subjects had overlapping data. Quercetin supplementation at two doses compared with placebo increased plasma quercetin (interaction effect; P < 0·001) but had no significant influence on blood leucocyte subsets, plasma IL-6 or TNF-α concentration, NKCA, GOBA or phagocytosis. NKCA was inversely correlated with BMI (r − 0·25; P = 0·035) and body fat percentage (r − 0·38; P = 0·001), and positively correlated with self-reported physical fitness level (r 0·24; P = 0·032). In summary, results from the present double-blinded, placebo-controlled, randomised trial indicated that quercetin supplementation at 500 and 1000 mg/d for 12 weeks significantly increased plasma quercetin levels but had no influence on measures of innate immune function or inflammation in community-dwelling adult females.

Anti-parasitic drugs may achieve their therapeutic effect either by direct activity against the pathogenic organism, or by altering host factors which lead to parasite killing. In this review, we discuss the evidence for an indirect mode of action for one major anti-filarial drug, diethylcarbamazine (DEC). The interpretation most consistent with existing data is that DEC alters arachidonic acid metabolism in microfilariae and in host endothelial cells. These changes may result in vasoconstriction and amplified endothelial adhesion leading to immobilization of microfilarial parasites, enhanced adherence and cytotoxic activity by host platelets and granulocytes. These events would represent activation of the innate, non-specific immune system, independent of the adaptive, antigen-specific, immune response. This model explains the paradox between rapid clearance in vivo and the lack of an in vitro effect, as well as the efficacy of DEC in non-immune animals.

Neutrophil chemotactic activity was detected in the fluid of Toxoplasma gondii cultures by the agarose plate and the Boyden chamber methods. Toxoplasma culture fluid was obtained by incubating the tachyzoites at 37 °C in a 5% CO2 atmosphere for 6 h in Dulbecco's modified Eagle's minimum essential medium containing 10% heat-inactivated foetal calf serum. Soluble extracts from tachyzoites had negligible activity, indicating that the chemotactic factors were metabolites secreted from tachyzoites. The chemotactic activity in Toxoplasma culture fluid depended on the number of tachyzoites and the period of incubation. The substances responsible for neutrophil chemotaxis were two heat-labile peptides with estimated Mr 4·5 and 14 kDa with N-terminal groups free.

Human neutrophils were infected with tachyzoites of Toxoplasma gondii in vitro. Infection rates after 1 h of incubation were 38·6–52·0% and 16·0–25·8% in the presence or absence of specific antibody respectively. Apparently, neutrophils killed tachyzoites 18 h after infection in the presence of antibody, whereas tachyzoites proliferated in 25·0–35·0% of infected neutrophils in the absence of antibody. Total tachyzoite counts 18 h after infection were approximately 4 times as high as those 1 h after infection in the absence of antibody and complement. Complement also enhanced phagocytosis and killing of tachyzoites by neutrophils, but the effects were less than that of antibody. Superoxide anion was produced intensively within 1 h after infection, depending on the presence of antibody or complement. Neutrophils seem to be responsible for dissemination of tachyzoites in the host during the initial phase of Toxoplasma infection until antibody is produced.

The participation of neutrophil granulocytes in the cellular reaction to skin microfilariae of Onchocerca volvulus was studied by immunohistochemistry. Skin biopsies were obtained from adult Liberian and Ugandan patients with generalized onchocerciasis after exposure to topically applied diethylcarbamazine (DEC) and from untreated patients. After DEC many damaged microfilariae were observed either in dermal infiltrates or in epidermal microabscesses consisting both of neutrophils and eosinophils. Infiltrates and microabscesses contained some intact granulocytes and many neutrophils releasing myeloperoxidase, elastase, lactoferrin, defensin, lysozyme, α1-antitrypsin and α1-antichymotrypsin. Eosinophils discharged peroxidase and cationic proteins. Released granule proteins and remnants of disrupted granulocytes were found on the surface and in close proximity of damaged microfilariae in dermal infiltrates and epidermal microabscesses. In larger microabscesses neutrophils were predominant. These observations show that neutrophils and not only eosinophils recruit, accumulate, localize around and release their helminthotoxic granule proteins such as myeloperoxidase onto or closely around skin microfilariae of O. volvulus after topical DEC administration. The association between these processes and the damage of the microfilariae indicated that neutrophils together with eosinophils attack and damage microfilariae of O. volvulus after DEC treatment in the skin.