▪ Abstract Infection in insects stimulates a complex defensive response. Recognition of pathogens may be accomplished by plasma or hemocyte proteins that bind specifically to bacterial or fungal polysaccharides. Several morphologically distinct hemocyte cell types cooperate in the immune response. Hemocytes attach to invading organisms and then isolate them by phagocytosis, by trapping them in hemocyte aggregates called nodules, or by forming an organized multicellular capsule around large parasites. These responses are often accompanied by proteolytic activation of the phenoloxidase zymogen that is present in the hemolymph. A component of insect immune responses to bacteria is the synthesis by fat body and hemocytes of a variety of antibacterial proteins and peptides, which are secreted into the hemolymph. These molecules attack bacteria by several mechanisms. Inducible antifungal proteins have also been recently discovered in insect hemolymph. The promoters for several antibacterial protein genes in ins...

Biological mediators of insect immunity

Parasites do not always harm their hosts because the immune system keeps an infection at bay. Ironically, the cost of using immune defenses could itself reduce host fitness. This indirect cost of parasitism is often not visible because of compensatory resource intake. Here, workers of the bumblebee, Bombus terrestris, were challenged with lipopolysaccharides and micro-latex beads to induce their immune system under starvation (i.e., not allowing compensatory intake). Compared with controls, survival of induced workers was significantly reduced (by 50 to 70%).

https://science.sciencemag.org/content/sci/290/5494/1166.full.pdf

Survival for immunity: the price of immune system activation for bumblebee workers.

The acute phase proteins (APP) are a group of blood proteins that contribute to restoring homeostasis and limiting microbial growth in an antibody-independent manner in animals subjected to infection, inflammation, surgical trauma or stress. In the last two decades, many advances have been made in monitoring APP in both farm and companion animals for clinical and experimental purposes. Also, the mechanism of the APP response is receiving attention in veterinary science in connection with the innate immune systems of animals. This review describes the results of recent research on animal APP, with special reference to their induction and regulatory mechanisms, their biological functions, and their current and future applications to veterinary diagnosis and animal production.

Current research on acute phase proteins in veterinary diagnosis: an overview.

On the relationship between lactational performance and health: is it yield or metabolic imbalance that cause production diseases in dairy cattle? A position paper

Mastitis affects the quality of milk and is a potential health risk for the other cows. In a well managed dairy herd, in addition to clinical mastitis, subclinical mastitis should be efficiently detected. Bacteriological sampling is not feasible as a routine test to identify subclinical mastitis, and indirect tests of mastitis are more suitable for selecting cows with intramammary infections for subsequent bacteriological sampling. Mastitis affects the composition of milk, and the degree of changes depends on the infecting agent and the inflammatory response. Indicators of inflammation in the milk which can be determined using rapid, reliable and easy routine techniques, can be used for the early detection of mastitis. The measuring of the somatic cell count in milk is the standard method, but the analysis technique is problematic for routine use in herds. The most promising parameters for monitoring subclinical mastitis are milk N-acetyl-beta-D-glucosaminidase activity, lactose, and electrical conductivity along with some other indicators such as optical and milk flow measurements, preferably with an inter-quarter evaluation included in the test. Acute phase proteins, haptoglobin and serum amyloid A, are also potential candidates for mastitis monitoring. New mastitis detection systems which can be adapted into on-line use are urgently needed, since dairy units are growing bigger and automatic milking systems are being taken into use.

Indicators of inflammation in the diagnosis of mastitis

Bovine alpha 1-acid glycoprotein (alpha 1AG) was purified from pooled normal bovine sera by successive ammonium sulfate precipitation, ion-exchange chromatographies and gel filtration. Bovine alpha 1AG had a molecular weight of 42,000 +/- 2,000 and a sedimentation coefficient of 3.4S. It contained 26.6% carbohydrate. Gel isoelectric focusing revealed a microheterogeneity with 7 to 8 bands in a pI range of 3.2 to 3.7. It migrated to the alpha 1-globulin region upon immunoelectrophoresis. Single radial immunodiffusion was developed for the quantitative measurement of bovine alpha 1AG in serum. The mean serum value of alpha 1AG in 152 healthy Holstein cattle (1-12 years old) was 283.2 +/- 82.3 micrograms/ml. Elevated values (cut-off value = 450 micrograms/ml) were observed in cattle with traumatic pericarditis (100%), arthritis (100%), mastitis (91%), pneumonia (70%), and mesenteric liponecrosis (43%).

https://agriknowledge.affrc.go.jp/RN/2010442351.pdf

Isolation, characterization, and quantitative measurement of serum alpha 1-acid glycoprotein in cattle.

Clearance of lipopolysaccharide in hemolymph of the silkworm Bombyx mori: Its role in the termination of cecropin mRNA induction

A new, automated turbidimetric-kinetic (ATK) assay was used to quantitate bacterial endotoxin in rumen fluid or in serum of Holstein steers. The ATK method used Limulus amebocyte lysate (LAL) reagent with added beta-glucan (LAL-ES) which improved specific sensitivity to endotoxin. Design of the feeding trial permitted comparison of endotoxin levels found during consumption of a basal ration with those higher levels detected at various times following the introduction of increasing percentages of rolled barley to that basal ration. Both serum and ruminal endotoxin levels were significantly higher in steers on the higher concentrate rations. Peak endotoxin levels were detected 20 days following the change to the highest concentrate ration which contained 60% barley. Endotoxin levels from both sources subsequently decreased. Ruminal endotoxin stabilized at about 10 times the level, and serum endotoxin stabilized at 2 to 4 times the level, of that previously found during feeding of the basal ration. Test protocol included sample dilution and heating in order to avoid the effects of endotoxin inhibitors. Recovery rates for added endotoxin to either serum or rumen fluid supernates ranged from 120 to 136%. Coefficient of variation for endotoxin concentration in serum was lower than 10%, and in rumen fluid only slightly higher. There was significant correlation between ruminal concentration as measured by the ATK method and an alternative chromogenic substrate assay procedure. Changes in endotoxin level in experimental steers were those predictable from experience with naturally occurring incidents of grain engorgement. The ATK assay appears to be an accurate and rather simple technique which will prove useful for experimental and clinical studies in the future.

Turbidimetric-Kinetic Assay of Endotoxin in Rumen Fluid or Serum of Cattle Fed Rations Containing Various Levels of Rolled Barley

Changes in serum alpha 1-acid glycoprotein (alpha 1AG) concentration in cattle with hepatic abscesses were observed, and function of alpha 1AG was evaluated, particularly its influence on cellular immune response. Test cattle (n = 4) were inoculated with Fusobacterium necrophorum, control cattle (n = 2) were inoculated with inactivated bacteria, and naturally affected cattle (n = 11) were found in a slaughterhouse. Determination of alpha 1AG was made by use of a single radial immunodiffusion method. The action on lymphocyte blastogenesis was determined by [3H]thymidine incorporation. Cultured lymphocytes from healthy cattle were treated with variable concentrations of alpha 1AG purified from serum obtained from cattle with hepatic abscesses and suppression of blastogenesis stimulated by each of 3 mitogens was measured. In cattle with experimentally induced abscesses, serum alpha 1AG concentration increased for 7 to 10 days after F necrophorum inoculation, its change being parallel to that of sialic acid. High concentration of alpha 1AG was found in naturally affected cattle and was highly correlated to sialic acid concentration. Suppression of lymphocyte blastogenesis in cattle with experimentally induced hepatic abscesses was highly correlated to serum alpha 1-AG concentration.

Correlation of serum concentration of alpha 1-acid glycoprotein with lymphocyte blastogenesis and development of experimentally induced or naturally acquired hepatic abscesses in cattle.

Yoshiko Motoi

Papers

Isolation, characterization, and quantitative measurement of serum alpha 1-acid glycoprotein in cattle.

Clearance of lipopolysaccharide in hemolymph of the silkworm Bombyx mori: Its role in the termination of cecropin mRNA induction

Turbidimetric-Kinetic Assay of Endotoxin in Rumen Fluid or Serum of Cattle Fed Rations Containing Various Levels of Rolled Barley

Correlation of serum concentration of alpha 1-acid glycoprotein with lymphocyte blastogenesis and development of experimentally induced or naturally acquired hepatic abscesses in cattle.

Serum alpha 1-acid glycoprotein in cattle with inflammatory disease and that after operation.