Immune profiling of rainbow trout (Oncorhynchus mykiss) exposed to Lactococcus garvieae: Evidence in asymptomatic versus symptomatic or vaccinated fish

Lactococcosis, caused by the Gram-positive bacterium Lactococcus garvieae, is a major concern in rainbow trout (Oncorhynchus mykiss) farms, which are regularly affected by outbreaks especially during the summer/fall months. In these farms, unvaccinated healthy and symptomatic fish can coexist with vaccinated fish. In the present study, innate (leukogram, serum lysozyme activity, peroxidase activity, antiprotease activity, bactericidal activity, total IgM and total proteins), and specific immune parameters (serum antibodies to L. garvieae) were assessed in unvaccinated adult rainbow trout naturally exposed to the pathogen, with or without evidence of clinical signs, or subjected to vaccination. Blood was drawn from all three groups, and blood smears were prepared. Bacteria were found in the blood smears of 70% of the symptomatic fish but not in any of the asymptomatic fish. Symptomatic fish showed lower blood lymphocytes and higher thrombocytes than asymptomatic fish (p ≤.05). Serum lysozyme and bactericidal activity did not vary substantially among groups; however, serum antiprotease and peroxidase activity were significantly lower in the unvaccinated symptomatic group than in the unvaccinated and vaccinated asymptomatic groups (p ≤.05). Serum total proteins and total immunoglobulin (IgM) levels in vaccinated asymptomatic rainbow trout were significantly higher than in unvaccinated asymptomatic and symptomatic groups (p ≤.05). Similarly, vaccinated asymptomatic fish produced more specific IgM against L. garvieae than unvaccinated asymptomatic and symptomatic fish (p ≤.05). This preliminary study provides basic knowledge on the immunological relationship occurring between the rainbow trout and L. garvieae, potentially predicting health outcomes. The approach we proposed could facilitate infield diagnostics, and several non-specific immunological markers could serve as reliable indicators of the trout's innate ability to fight infection

The Consensus from the Mycobacterium avium ssp. paratuberculosis (MAP) Conference 2017.

On March 24 and 25, 2017 researchers and clinicians from around the world met at Temple University in Philadelphia to discuss the current knowledge of Mycobacterium avium ssp. paratuberculosis (MAP) and its relationship to human disease. The conference was held because of shared concern that MAP is a zoonotic bacterium that poses a threat not only to animal health but also human health. In order to further study this problem, the conferees discussed ways to improve MAP diagnostic tests and discussed potential future anti-MAP clinical trials. The conference proceedings may be viewed on the www.Humanpara.org website. A summary of the salient work in this field is followed by recommendations from a majority of the conferees

CUORE-0 detector: design, construction and operation

The CUORE experiment will search for neutrinoless double-beta decay of$^{130}$Te with an array of 988 TeO$_2$ bolometers arranged in 19 towers.CUORE-0, the first tower assembled according to the CUORE procedures, was builtand commissioned at Laboratori Nazionali del Gran Sasso, and took data fromMarch 2013 to March 2015. In this paper we describe the design, constructionand operation of the CUORE-0 experiment, with an emphasis on the improvementsmade over a predecessor experiment, Cuoricino. In particular, we demonstratewith CUORE-0 data that the design goals of CUORE are within reach

PARAMETRI IMMUNITARI DELLA TROTA IRIDEA (O. MYKISS) QUALI INDICATORI DI RESISTENZA GENETICA ALLA LATTOCOCCOSI

Le strategie mirate al controllo delle malattie batteriche nei pesci prevedono l\u2019utilizzo di vaccini autologhi o commerciali e l\u2019eventuale trattamento terapeutico. Tuttavia, la vaccinazione spesso non viene effettuata in quanto troppo costosa o per la ridotta efficacia che gli allevatori attribuiscono ai vaccini disponibili. Dall\u2019altro lato, l\u2019utilizzo di antibiotici \ue8 ampiamente criticato in quanto determina la dispersione di residui chimici nell\u2019ambiente, con conseguente rischio di insorgenza di ceppi antibiotico resistenti. Risulta pertanto utile ricercare forme alternative e/o complementari di controllo delle malattie, tra cui l\u2019individuazione di fattori genetici intrinseci che consentano di selezionare ceppi di pesci resistenti.Il presente studio illustra i risultati ottenuti nel corso di un'infezione sperimentale sub-clinica per immersione con Lactococcus garvieaein gruppi di trote iridee selezionate su base genetica come resistenti e suscettibili alla malattia in esame. L\u2019intento era quello di analizzare il profilo di alcuni parametri di immunit\ue0 innata e adattativa ritenuti rilevanti per definire le attitudini difensive (Magnadottir, 2010; Das & Sahoo, 2014) dei due stock ittici, sia in condizioni normali (pre-challenge) sia in seguito ad uno stimolo di tipo infettivo prodotto dall\u2019interazione con un batterio patogeno per la specie stessa.La condizione immunologica di un organismo pu\uf2 suggerire, infatti, la presenza di specifici tratti genetici che lo rendono resistente nei confronti di un agente biologico. Con questa finalit\ue0 26 soggetti resistenti e 26 suscettibili sono stati sottoposti a challenge come descritto nell\u2019abstract presentato da Colussi et al., (Convegno SIPI 2018). Nell\u2019ambito dello stesso protocollo sperimentale 10 soggetti resistenti e 10 suscettibili sono stati utilizzati come controllo negativo. I prelievi di campioni biologici (siero, sangue, muco, rene anteriore) condotti al temine del challenge nei soggetti di controllo (suscettibili e resistenti) e nei soggetti infettati (suscettibili e resistenti) sono stati analizzati avvalendosi di metodiche immunologiche classiche (attivit\ue0 del lisozima in siero e muco; leucogramma in sangue; burst ossidativo dei leucociti in rene anteriore; livello di IgM specifiche per L. garvieae in siero) e mediante uno studio di espressione genica nel rene anteriore con qPCR (IL-1\u3b2, IL-10, TNF-\u3b1, IL-8, IgT, Tlr5, \u3b2-actin, IL-6, IgM, MHC-I, MHC-II, TCR-\u3b2).Considerando i meccanismi di risposta aspecifica, l\u2019attivit\ue0 del lisozima nel siero e nel muco \ue8 risultata pi\uf9elevata nei soggetti appartenenti allo stock ittico resistente rispetto a quello suscettibile, gi\ue0 in fase di pre-infezione, e tale attivit\ue0 \ue8 incrementata in modo significativo in entrambi gli stock genetici in seguito all\u2019esposizione a L. garvieae.Per quanto riguarda la risposta cellulare, l\u2019attivit\ue0 di burst ossidativo dei leucociti \ue8 risultata maggiore nei soggetti resistenti rispetto a quelli suscettibili, soprattutto in fase di pre-infezione. Inoltre, \ue8 stata rilevata una maggiore espressione di IL-1\u3b2eIL-10 nei soggetti suscettibili sottoposti ad infezione, rispetto alle trote resistenti sottoposte allo stesso trattamento. Nella presente ricerca entrambi i gruppi sperimentali (suscettibile e resistente) hanno mostrato un livello elevato di IgM reattive nei confronti di L. garvieae,ma ulteriori indagini al riguardo sono necessarie per chiarire il possibile impiego di questo parametro per la selezione di stock di trota iridea resistenti alle malattie.Nei soggetti resistenti l\u2019infezione ha stimolato una maggiore espressione dei geni codificanti per IgM e MHC-II rispetto a quanto osservato nei soggetti suscettibili, suggerendo l\u2019attivazione di meccanismi quali la presentazione dell\u2019antigene e la sintesi di anticorpi utili alla protezione delle trota dal patogeno L. garvieae.Sulla base di queste osservazioni preliminari emergono spunti interessanti per proseguire lo studio immunologico di diverse linee genetiche di trota iridea, finalizzato allo screening di popolazioni resistenti da dedicare all\u2019allevamento intensivo in contesti ambientali suscettibili alla lattococcosi

Innovative vaccination protocol against vibriosis in Dicentrarchus labrax (L.) juveniles: Improvement of immune parameters and protection to challenge.

The effect of vaccination on immune parameters of European sea bass, Dicentrarchus labrax, is not fully established, as well as surveyed throughout rearing till the commercial size. Furthermore, available information on the possible role of booster treatments is scarce. Sea bass juveniles were vaccinated against Listonella anguillarum using a commercial bivalent formulation administered by immersion (priming: 95 dph; booster: 165 dph) or by immersion (priming: 95 dph; booster: 165 dph) and subsequent i.p. injection (booster: 233 dph). Serum specific IgM and numbers of IgM+ cells in head kidney and spleen evidenced B-cell responses mainly after the immersion booster, accompanied by increased TcR-\u2c7 transcripts and leucocyte respiratory burst. Immune enhancement was confirmed by the protection towards i.p. challenges with a virulent strain. RPS accounted for >70% in fish immersion-boosted and near 100% in fish further boosted i.p. Differently from usual farm practices, this innovative vaccination protocol proved to be highly effective. Booster treatments are therefore strongly recommende

Heat shock protein 70 kDa (HSP70) increase in sea bass (Dicentrarchus labrax, L 1758) thymus after vaccination against Listonella anguilla rum

Heat shock proteins 70 kDa (HSP70) and apoptosis were investigated in thymus of sea bass juveniles (Dicentrarchus labrax) subsequently to a vaccination against Listonella (syn. Vibrio) anguillarum. HSP70 expression was measured by immunohistochemistry and immunoenzymatic methods, resulting in increase in HSP70 after bath immunization and persistent in fish exposed to an intraperitoneal (i.p.) booster. The HSP70 increase in thymus was suggested as induction in lymphocytic cells, to be related to immune system stimulation after vaccination. However, a thymic recruitment of lymphocyte subpopulations, characterized by higher expression of HSP70, was also hypothesized after vaccination. No apparent relationships were found between HSP70 and apoptosis. In fact, the vaccination did not modulate the apoptosis response, as measured by TUNEL assay and by immunohistochemistry for active caspase-3 expression. The lack of apoptosis effects could be ascribed to the use of inactivated bacteria that appeared not able to interfere with programmed cell death mechanisms. This manuscript aims to contribute to the knowledge of some biochemical features underlying the immunization, with a particular emphasis on the modulation of HSP70. However, further parameters involved in innate/adaptative immunity and apoptosis pathways have to be taken into account to well establish the functional role of HSP70 in fish vaccination

Heat shock protein 70 kDa (HSP70) increase in sea bass (Dicentrarchus labrax, L 1758) thymus after vaccination against Listonella anguillarum

Heat shock proteins 70 kDa (HSP70) and apoptosis were investigated in thymus of sea bass juveniles (Dicentrarchus labrax) subsequently to a vaccination against Listonella (syn. Vibrio) anguillarum. HSP70 expression was measured by immunohistochemistry and immunoenzymatic methods, resulting in increase in HSP70 after bath immunization and persistent in fish exposed to an intraperitoneal (i.p.) booster. The HSP70 increase in thymus was suggested as induction in lymphocytic cells, to be related to immune system stimulation after vaccination. However, a thymic recruitment of lymphocyte subpopulations, characterized by higher expression of HSP70, was also hypothesized after vaccination. No apparent relationships were found between HSP70 and apoptosis. In fact, the vaccination did not modulate the apoptosis response, as measured by TUNEL assay and by immunohistochemistry for active caspase-3 expression. The lack of apoptosis effects could be ascribed to the use of inactivated bacteria that appeared not able to interfere with programmed cell death mechanisms. This manuscript aims to contribute to the knowledge of some biochemical features underlying the immunization, with a particular emphasis on the modulation of HSP70. However, further parameters involved in innate/adaptative immunity and apoptosis pathways have to be taken into account to well establish the functional role of HSP70 in fish vaccination.[...

Heat shock protein 70 kDa (HSP70) increase in sea bass (Dicentrarchus labrax, L 1758) thymus after vaccination against Listonella anguillarum.

Heat shock proteins 70 kDa (HSP70) and apoptosis were investigated in thymus of sea bass juveniles (Dicentrarchus labrax) subsequently to a vaccination against Listonella (syn. Vibrio) anguillarum. HSP70 expression was measured by immunohistochemistry and immunoenzymatic methods, resulting in increase in HSP70 after bath immunization and persistent in fish exposed to an intraperitoneal (i.p.) booster. The HSP70 increase in thymus was suggested as induction in lymphocytic cells, to be related to immune system stimulation after vaccination. However, a thymic recruitment of lymphocyte subpopulations, characterized by higher expression of HSP70, was also hypothesized after vaccination. No apparent relationships were found between HSP70 and apoptosis. In fact, the vaccination did not modulate the apoptosis response, as measured by TUNEL assay and by immunohistochemistry for active caspase-3 expression. The lack of apoptosis effects could be ascribed to the use of inactivated bacteria that appeared not able to interfere with programmed cell death mechanisms. This manuscript aims to contribute to the knowledge of some biochemical features underlying the immunization, with a particular emphasis on the modulation of HSP70. However, further parameters involved in innate/adaptative immunity and apoptosis pathways have to be taken into account to well establish the functional role of HSP70 in fish vaccination