Down-regulatory effect of alpha 1-acid glycoprotein on bovine neutrophil degranulation

Pre- and Post-partum Concentrations of Interleukin 1α, Interleukin 8, and α1-Acid Glycoprotein in Vaginal Fornix and Endometrium of Dairy Cows With Clinical Cervicitis

Innate immunity is the principal sensor responsible of the local immune response to control mucosal bacterial contamination of the reproductive tract after parturition, triggering a pro-inflammatory process in the mucosa of the uterus, the vaginal and the cervix. However, knowledge about the inflammation process and outcome of the cervix in dairy cows is scarce even though it plays an important anatomic and functional role between the vagina and the uterus. The objective of the present study was to describe the cellular and humoral local innate immune response during clinical cervicitis (CC) in the uterus and vaginal fornix in pre- and post-partum periods of dairy cows. A retrospective descriptive study was performed involving 26 animals, characterized as clinical cervicitis cows (n = 19) and healthy cows (n = 7). Blood and mucus of the different compartments of the genital tract were sampled and records of the cows' genital exam were performed four times: −1 w (day −7 ± 2, prepartum), +1 w (day +7 ± 4), +3 w (day +21 ± 4) and +5 w (day +35 ± 4) postpartum. Clinical cervicitis was defined as cows exhibiting a cervix grade−2 and healthy cows were defined as a cow clinically normal with a grade-0 cervix at time +5 w. Blood white cell count, vaginal fornix and endometrial neutrophils percentage, and the concentrations of interleukin 1α (IL1), interleukin 8 (IL8), and α1-acid glycoprotein (AGP) in mucus were determined. The results showed that 23% of the cows were categorized as CC at time +5 w. Cases of CC with purulent vaginal discharge or subclinical endometritis shown the highest cytokine production. At +3 w, IL1, IL8, and AGP concentrations in the uterus and the fornix were significantly higher in CC than healthy cows (CH). In conclusion, the 3-week postpartum is a critical point to evaluate cytokines and acute phase proteins; where IL1 and IL8 variation kept a direct relation with neutrophils numbers and function. The presence of AGP in the endometrium infer a homeostatic proinflammatory protective balance effect, modulating the local uterine innate immune response during peripartum.

Understanding the role of neutrophils in acute respiratory distress syndrome

Acute respiratory distress syndrome (ARDS) is difficult to treat and is associated with a high mortality rate. The most severe form of coronavirus disease 2019 (COVID-19) also leads to life-threatening ARDS. Neutrophil counts are positively correlated with disease severity in ARDS. Neutrophil activation not only plays a significant role in immune defense against infections, but also causes tissue damage and leads to inflammatory diseases. Activated neutrophils rapidly migrate to inflamed lung tissue, releasing toxic granular contents and generating neutrophil extracellular traps. In the last few decades, it has become apparent that neutrophils occupy a central role in ARDS pathology. In this review, we summarize the neutrophil inflammatory responses and their relationships to ARDS. According to the current literature, understanding the function of neutrophils may be helpful in the treatment of ARDS.

Acute phase proteins and markers of oxidative status in water buffalos during the transition from late pregnancy to early lactation

The transition period, from pregnancy to lactation, implies comprehensive metabolic and endocrine changes including a systemic inflammatory reaction and oxidative stress around calving in dairy cows. The aim of the present study was a longitudinal characterization of the serum concentration of acute phase proteins (APP), i.e., haptoglobin (Hp), serum amyloid A (SAA) and acidic glycoprotein (AGP), as well as of markers for oxidative stress in another large dairy animal, i.e. water buffalo, during the transition from late pregnancy to early lactation. As indicators of oxidative status, derivatives of reactive oxygen metabolites (dROM), ferric reducing ability (FRAP), thiobarbituric acid reactive substances (TBARS), and advanced oxidation protein products (AOPP) were determined in serum. Indicators for metabolic stress included nonesterified fatty acids (NEFA), ß-hydroxybutyrate (BHB) and adiponectin. Bovine specific ELISA methods for Hp and adiponectin were adapted and validated for their application to water buffalo samples. Blood samples were collected weekly from 11 pluriparous water buffalo cows (lactation number 4.6 ± 1.6; daily milk yield 9.0 ± 1.9 kg; means ± SD) from 6 weeks (wk) ante partum (ap) until 8 wk post partum (pp). The maximum concentrations of Hp were observed in wk 1 pp, followed by a decrease towards values lower than before calving starting from wk 3 pp. The concentrations of SAA also peaked in wk 1 pp and then returned to basal values. The AGP serum concentrations increased suddenly from the first to the second wk pp and remained elevated for all the observation period. Indicators of oxidative status which changed in concentration during the transition period were dROM, AOPP and the oxidative stress index (OSi) (dROM/FRAP ratio). Briefly, dROM and AOPP values were lower pp as compared to ap, and OSi was largely following the pattern of dROM due to the constant FRAP values. The TBARS values did not change during the observation period. From the metabolic indicators, adiponectin was not changing with time, whereas greater NEFA and BHB values were observed ap than pp. The time course of NEFA and of some indicators for oxidative status (dROM, OSi and AOPP) point to greater metabolic load in late pregnancy as compared with the first wk of lactation - contrary to the common situation in dairy cows. Both BHB and NEFA values remained below the thresholds applied for dairy cows to define subclinical or clinical ketosis, thus indicating that the buffaloes included in this study were not under metabolic stress. The increase in concentration of the APP around calving supports the concept that an inflammatory reaction is a physiological epiphenomenon of the onset of lactation in water buffalos that is independent of metabolic stress.

The Immune Functions of α1 Acid Glycoprotein

α1-acid glycoprotein (orosomucoid, AGP) is an Acute Phase Protein produced by liver and peripheral tissues in response to systemic reaction to inflammation. AGP functions have been studied mostly in human, cattle and fish, although the protein has been also found in many mammalian species and birds. AGP fulfils at least two set of functions, which are apparently different from each other but in fact intimately linked. On one hand, AGP is an immunomodulatory protein. On the other hand, AGP is one of the most important binding proteins in plasma and, beside modulating pharmacokinetics and pharmacodynamics of many drugs, it is also able to bind and transport several endogen ligands related to inflammation. The focus of this review is the immunomodulatory activity of AGP. This protein regulates every single event related to inflammation, including binding of pathogens and modulating white blood cells activity throughout the entire leukocyte attacking sequence. The regulation of AGP activity is complex: the inflammation induces not only an increase in AGP serum concentration, but also a qualitative change in its carbohydrate moiety, generating a multitude of glycoforms, each of them with different, and sometimes opposite and contradictory, activities. We also present the most recent findings about the relationship between AGP and adipose tissue: AGP interacts with leptin receptor and, given its immunomodulatory function, it may be included among the potential players in the field of immunometabolism.

Acute Phase Protein Levels as An Auxiliary Tool in Diagnosing Viral Diseases in Ruminants-A Review

We examined acute phase protein (APP) concentrations in viral infections of dairy ruminants and assessed the potential role of characteristic patterns of APP changes in auxiliary diagnosing viral diseases. All viruses reviewed are common causes of farm animal diseases. APPs are among the first agents of immunity, and their concentrations could be diagnostically relevant. In the most common ruminant viral diseases, elevated serum amyloid A (SAA) and haptoglobin (Hp) levels in blood serum have been observed. However, since these proteins are the main APPs in many viral infections, it is impossible to use their levels for diagnosing particular infections. Decreased Cp and albumin expression could help differentiate the bluetongue virus infection from other diseases. Lastly, analysis of SAA levels in blood serum and milk could be helpful in diagnosing small ruminant lentivirus infection. While promising, APP levels can only be considered as an auxiliary tool in diagnosing viral diseases in ruminants.

The effect of transport stress on turkey (Meleagris gallopavo) liver acute phase proteins gene expression

The aim of this study was to investigate the effects of transport-related stress on the liver gene expression of four acute phase proteins (APP), namely α1-acid glycoprotein (AGP), C-Reactive Protein (CRP), Serum Amyloid A (SAA) and PIT54, in turkeys (Meleagris gallopavo). A group of seven BUT BIG 6 commercial hens was subjected to a two-hour long road transportation and the quantitative gene expression of APP in the liver was compared to that of a non transported control group. The expression of AGP and CRP mRNA was found to be increased in animals slaughtered after road transport. The presence of AGP protein was also confirmed by immunohistochemistry and Western blotting. The results of this study showed that road-transport may induce the mRNA expression of immune related proteins. The finding that AGP and CRP can be upregulated during transport could suggest their use as for the assessment of turkey welfare during transport.

Hyposialylated α1-acid glycoprotein inhibits phagocytosis of feline neutrophils

Feline α1-acid glycoprotein (fAGP) modifies both its serum concentration and its glycan moiety during diseases. fAGP is hyposialylated in cats with feline infectious peritonitis (FIP), but not in clinically healthy cats or in cats with other diseases. This study was aimed to determine whether hyposialylated fAGP influences phagocytosis. A flow cytometric method based on ingestion of fluoresceinated bacteria and adapted to feline blood was used to assess phagocytosis of leukocytes incubated with 'non-pathological' fAGP (purified from sera with normal concentrations of AGP) and 'pathological' fAGP (purified from sera with >1.5mg/mL hyposialylated AGP). The flow cytometric method provided repeatable results for neutrophils (coefficients of variations, CVs <15%) but not for monocytes (CVs>20%) which had also a high individual variability. Compared with saline solution and with non-pathological fAGP, pathological fAGP significantly decreased phagocytosis in neutrophils and monocytes. This study demonstrated that hyposialylated fAGP down-regulates the phagocytic activity of feline neutrophils.