Characterization and functional classification of American lobster (Homarus americanus) immune factor transcripts.

The American lobster (Homarus americanus) is the most important commercially exploited marine species in Canada. Very little is known about the H. americanus molecular humoral immune response or how to determine if a seemingly healthy lobster is infected with a pathogen. The goal of this work is to characterize several important H. americanus immune genes as well as highlight and classify hundreds of others into functional immune groups. The protein sequence of H. americanus acute phase serum amyloid protein A (SAA) was found to be similar to that of vertebrate SAA, and is likely a good clinical marker for immune activation in lobsters and some crustaceans. Additionally, only one gene, Trypsin 1b, was found to be differentially regulated during bacterial, microparasitic and viral challenges in lobster and is likely critical for the activation of the H. americanus immune response. Bioinformatic analysis was used to functionally annotate, 263 H. americanus immune genes and identify the few shared patterns of differential gene expression in lobsters in response to bacterial, parasitic and viral challenge. Many of the described immune genes are biomarker candidates which could be used as clinical indicators for lobster health and disease. Biomarkers can facilitate early detection of pathogens, or anthropomorphic stressors, so that mitigation strategies can be developed in order to prevent the devastating economic losses that have occurred in Southern New England, USA. This work is contributes to further our understanding of how the lobster immune system works and how it can be used to maintain the health and sustainability of the overall American lobster fishery.

Effects of dietary ß-1,3-glucan, chitosan or raffinose on the growth, innate immunity and resistance of koi (Cyprinus carpio koi).

This study was performed to determine the efficacy of three immunomodulators viz., ß-1,3 glucan, chitosan and raffinose on the innate immune response of koi, Cyprinus carpio koi. Kois were divided into 4 groups and each group was fed with diets supplemented with or without immunostimulant for 56 days. Total leukocyte counts (WBC), the non-specific humoral (lysozyme, alternative complement pathway and superoxide dismutase) and cellular (phagocytic capacity and respiratory burst activity) responses were determined and compared with controls (no supplement) after 7, 14, 21 and 56 days of feeding. The results of 8 weeks feeding trial showed that ß-1,3 glucan supplementation significantly enhanced koi growth, whereas other immunostimulants did not. Variation in the levels of responses was evident among different supplements. Compared with chitosan or raffinose, ß-1,3 glucan could maintain the immunity of kois at a higher level during the experimental period. However, continuously applying ß-1,3 glucan, chitosan or raffinose into the diet caused immunity fatigue in koi. No significant change in alternative complement pathway (ACP) activity was observed for any of the three supplements over the four different periods. After feeding for 14 days, the total leukocyte count (WBC), respiratory burst activity and superoxide dismutase (SOD) activity of the kois fed with chitosan or raffinose continuously remained relatively unchanged, subsequently decreased on the 56th day, but SOD did not. Meanwhile, lysozyme activity was no longer significantly higher on the 7th day, and for phagocytic capacity on the 14th day. After 56 days, these three immunostimulants groups also exhibited a decrease in the cumulative symptom rates compared to the controls when challenged with Aeromonas veronii. These results indicated that dietary intake containing immunostimulants could enhance the immune responses of koi and improve its resistance to infection by A.veronii. Especially supplementation with ß-1,3 glucan to the kois for 56 days showed considerable improvement in the growth, survival and immune response of the kois.

Microbial challenge promotes the regenerative process of the injured central nervous system of the medicinal leech by inducing the synthesis of antimicrobial peptides in neurons and microglia.

Following trauma, the CNS of the medicinal leech, unlike the mammalian CNS, has a strong capacity to regenerate neurites and synaptic connections that restore normal function. In this study, we show that this regenerative process is enhanced by a controlled bacterial infection, suggesting that induction of regeneration of normal CNS function may depend critically upon the coinitiation of an immune response. We explore the interaction between the activation of a neuroimmune response and the process of regeneration by assaying the potential roles of two newly characterized antimicrobial peptides. Our data provide evidence that microbial components differentially induce the transcription, by microglial cells, of both antimicrobial peptide genes, the products of which accumulate rapidly at sites in the CNS undergoing regeneration following axotomy. Using a preparation of leech CNS depleted of microglial cells, we also demonstrate the production of antimicrobial peptides by neurons. Interestingly, in addition to exerting antibacterial properties, both peptides act as promoters of the regenerative process of axotomized leech CNS. These data are the first to report the neuronal synthesis of antimicrobial peptides and their participation in the immune response and the regeneration of the CNS. Thus, the leech CNS appears as an excellent model for studying the implication of immune molecules in neural repair.

The effect of intraperitoneally administered recombinant IL-1beta on immune parameters and resistance to Aeromonas salmonicida in the rainbow trout (Oncorhynchus mykiss).

The present work provides the first information concerning the immunostimulatory activity of trout recombinant interleukin-1 beta (rIL-1beta) in vivo. The predicted rainbow trout mature IL-1beta peptide was produced as a recombinant protein in Escherichia coli. Optimal migration of peritoneal leucocytes and rIL-1beta induced phagocytosis occurred following intraperitoneal injection of 1 microg of the recombinant protein. Moreover, systemic IL-1beta, COX-2 and lysozyme II gene expression was enhanced following >or=1 microg rIL-1beta administration. Finally, resistance to Aeromonas salmonicida, the causative agent of furunculosis, was augmented at early times (2 days) post-injection of 1 microg rIL-1beta.

Effect of ascorbic acid on the immune response of the catfish, Mystus gulio (Hamilton), to different bacterins of Aeromonas hydrophila.

Ascorbic acid is one of the essential vitamins for normal physiological activities of any organism. The present study demonstrates an immunostimulatory effect of vitamin C on the humoral and cell mediated immunity of the bagrid catfish, Mystus gulio, determined using different bacterins of Aeromonas hydrophila. Humoral as well as cell mediated immune responses were elucidated in the vitamin supplemented, vaccinated and unvaccinated groups. The vitamin supplemented lipopolysaccharide (LPS) vaccinated group exhibited greater immune (both humoral and cell mediated) responses than its formalin killed (FK) and heat killed (HK) bacterin vaccinated counterparts. Nevertheless, in the challenge study, the relative percent survival (RPS) was found to be the same for both FK and LPS immunised vitamin treated groups while lower for the HK immunised vitamin treated group.

Immunization with bacterial antigens: furunculosis.

Although the nature of the antigens and the immune responses they elicit to achieve immunity to furunculosis are still not well defined, the currently available vaccines comprising A. salmonicida bacterins emulsified in oil adjuvants and delivered by intraperitoneal injection provide remarkably high levels of long-lasting protection. Despite some concern over side-effects, these vaccines have been adopted by most Atlantic salmon farmers over the last four years, transforming a situation where furunculosis outbreaks were becoming catastrophic to one where losses from the disease are negligible. Present evidence indicates that antibody responses to the polysaccharide capsule and iron regulated outer membrane proteins are associated with protection. Furthermore, cell-mediated immune responses involving antigen-induced release of cytokines from lymphocytes and the resultant activation of macrophages with the ability to kill the pathogen are also considered important protective mechanisms. Vaccines comprising whole A. salmonicida cultures grown under iron-restricted conditions and delivered by injection in an oil adjuvant are expected to induce prolonged stimulation of all the above responses. While these vaccines are suitable and effective for administration to salmon smolts there is still a need for mass vaccination by immersion or oral routes for salmonid fry. Effective means of achieving this are still required.

[Effect of gentamycin in combination with prodigiozan on the immunological reactivity of the body]. / Vliianie gentamitsina v sochetanii s prodigiozanom na immunologicheskuiu reaktivnost' organizma.

The effect of gentamicin sulphate and its combination will prodigiozan on antibody formation in experiments and the levels of the immunobiologic reactivity of patients with purulent inflammatory processes was studied with a purpose of developing rational schemes of antibiotic therapy of infectious diseases. A decrease in the titers of the antibodies to Aeromonas and the number of antibody-forming cells in the spleen was noted on repeated administration of gentamicin to albino mice in a dose of 20 mg/kg. This was prevented by the use of prodigiozan in a dose of 500 micrograms/kg once every 4 days. The use of gentamicin in patients with purulent inflammatory diseases in doses of 40 or 80 mg twice a day for 7--10 days had no significant effect on the titers of IgA, IgG, IgM, lysozyme blood serum levels, serum bactericidal activity and absorption activity of the peripheral blood neutrophils. Still, it induced a marked suppression of the neutrophil digestive capacity as compared to the initial levels, especially on administration of gentamicin in a dose of 40 mg twice a day. An increase in the level of IgM and no suppression of the neutrophil digestive capacity were noted after completion of the therapy in the patients treated with gentamicin administered in a dose of 40 mg twice a day and prodigiozan administered in a dose of 50 micrograms once every 4 days. It is recommended to use prodigiozan in combinaed therapy with gentamicin for correction of the changes in the specific and nonspecific protective forces of the host.

Interactions between aerolysin, erythrocytes, and erythrocyte membranes.

Aerolysin, a hemolytic and lethal exotoxin of Aeromonas hydrophila, was analyzed for amino acids. Assuming 8 histidine residues/mol, the purified toxic protein has, by summation, a molecular weight of 49,000, a value in agreement with earlier estimates by other methods. Erythrocytes from different animal species differ greatly in sensitivity to aerolysin's lytic action. There is some correlation between sensitivity and phosphatidyl choline content. Erythrocyte membranes of different species bind the toxin, and the efficiency of binding is a function of sensitivity to lysis. Binding is temperature independent, is not dependent upon membrane sialic acid, and is decreased by prior treatment with phospholipase C and proteases. Preparations of aerolysin convert substantial amounts of membrane phosphorus to water-soluble form; the conversion is concentration and temperature dependent. Most of the conversion is attributable to contaminating phospholipase(s) that is separable from the toxin. Aerolysin purified by electrophoresis in polyacrylamide gel retains some phospholipase activity, and this activity may or may not be a contaminant.