Immune response of teleost fish to helminth parasite infection / Resposta imune de peixes teleósteos às infecções por parasitos helmintos

Abstract Fish immune systems have become the subject of several studies due to the growing development of aquaculture and fisheries, and the demand for healthy produce for human consumption. Among the parasites responsible for diseases in fish farming, helminths stand out because they cause infections in farmed fish and decrease food conversion, zootechnical performance and meat quality. In the present review, the components that participate in the innate and adaptive immune responses of teleost fish that have so far been described are presented in order to summarize the defenses that these hosts have recourse to, in combating different groups of helminth parasites.

Resumo O sistema imune dos peixes tem se tornado alvo de muitas pesquisas devido ao crescente desenvolvimento da aquicultura e da pesca, assim como a exigência de obtenção de animais saudáveis para o consumo humano. Dentre os parasitos responsáveis pelas enfermidades na piscicultura, os helmintos destacam-se por causarem infecções nos peixes cultivados e por ocasionarem diminuição da conversão alimentar, do desempenho zootécnico e da qualidade da carne. Nesta revisão, apresentaremos os componentes que participam das respostas imunes inata e adaptativa dos peixes teleósteos já descritos, a fim de sintetizar à quais defesas o hospedeiro recorre frente aos diferentes grupos de parasitos.

Immunomodulatory effects of dietary ß-glucan in silver catfish (Rhamdia quelen) / Efeito imunomodulador da ß-glucana usada como aditivo alimentar em jundiás (Rhamdia quelen)

The immunomodulatory effects of dietary ß-glucan were evaluated in silver catfish. ß-glucan was added to the diet (0.01%, and 0.1%) and fed to the fish for 21 days, to evaluate effects on blood and some innate immune parameter, or fed for 42 days, to evaluate growth rate and resistance to challenge with pathogenic Aeromonas hydrophila. We found that adding ß-glucan to the diet had no effect on fish growth and no effect on blood cells, or serum bacterial agglutination and serum myeloperoxidase activity. However, fish that received ß-glucan in the diet had the natural hemolytic activity of complement significantly higher compared to control fish. Furthermore, fish fed with ß-glucan and challenged with A. hydrophila had fewer bacteria in blood and presented a significantly higher survival rate compared to control fish. Thus, we concluded that ß-glucan might be explored as feed additive aiming to improve silver catfish innate immunity and resistance to specific pathogen.(AU)

O uso da ß-glucana como suplemento alimentar foi avaliado em jundiás. A ß-glucana foi adicionada à ração na proporção de 0.01%, e 0.1% e fornecida aos peixes por 21, para avaliar dados hematológicos e parâmetros do sistema imune natural, ou 42 dias, para avaliar ganho de peso e resistência ao desafio com Aeromonas hydrophila. A adição da ß-glucana na dieta não afetou o ganho de peso e não induziu alterações hematológicas nem alterações nos níveis de aglutininas e mieloperoxidase sanguínea. No entanto, a atividade hemolítica natural do sistema do complemento foi significativamente maior nos peixes alimentados com ß-glucana. Além disso, nos peixes alimentados com ß-glucana e desafiados com A. hydrophila, o número de bactérias isoladas do sangue foi significativamente menor, e a sobrevivência ao desafio foi significativamente maior do que nos peixes que não receberam ß-glucana. Consequentemente, concluímos que a ß-glucana tem potencial imunomodulador quando adicionada à dieta, nas condições experimentais aqui indicadas, e contribui para aumentar imunidade natural e a resistência dos jundiás ao desafio com patógenos específicos.(AU)

A small new species of Crenicichla Heckel, 1840 from middle rio Xingu, Brazil (Teleostei: Cichlidae)

A new species of Crenicichla is described from the middle rio Xingu and tributaries, upstream from Volta Grande do Xingu. The largest specimen measured 47.8 mm SL. The new speciescan be distinguished from all other Crenicichlaspecies by the combination of the following character states: presence of serrae on supracleithrum (diagnostic of Crenicichla wallaciispecies group), large caudal blotch centrally located on caudal lateral line (shared with C. urosemaand C. virgatula), vertical dark stripes on the caudal fin and up to three series of teeth on premaxilla and maxilla (vs.more than four series of teeth). The new species described hereinis the eleventh species of Crenicichlalisted from the rio Xingu basin. Similarities of color pattern among small species of Crenicichla is discussed.

Uma nova espécie de Crenicichla é descrita para o médio rio Xingu e seus afluentes acima de Volta Grande do Xingu. O maior espécime mede 47,8 mm CP. A nova espécie pode ser distinguida de todas as outras espécies de Crenicichla pela seguinte combinação de caracteres: presença de serrilhas no supracleitro (diagnóstico das espécies do grupo C. wallacii), ampla mancha caudal centralmente posicionada sobre a linha lateral caudal (compartilhada com C. urosema e C. virgatula), série de faixas verticais escuras entre os raios da nadadeira caudal e até três séries de dentes no premaxilar e dentário (vs.mais de quatro séries de dentes). A nova espécie aqui descrita é a décima primeira espécie de Crenicichla listada para a bacia do rio Xingu. Semelhanças no padrão de coloração entre as espécies de Crenicichlade pequeno porte são discutidas.

Fish and egg specific immunoglobin E in multiple sclerosis patients

The effect of nutrition in the course of multiple sclerosis [MS] is a topic of great interest. The present study was aimed to evaluate the immunoglobin E [IgE] against egg and fish in MS patients compared to healthy controls. Between March 2012 and July 2012, 48 MS patients were selected and compared with 48 healthy subjects to assess the frequency of IgE against egg and fish in MS patients compared to healthy control. Fish and Egg specific IgE was determined by Immuno CAP. Sex and the frequency of specific IgE were compared between study groups by Chi-square test. Total of 96 subjects was assessed [22% male and 78% female]. The mean age of the study subjects was 30.8 +/- 6.6 years. Mean age of case and control groups was 30.7 [ +/- 6.9] versus 30.9 +/- 6.3, respectively [P = 0.83]. There were no detection of egg and fish specific IgE in serum of MS patients and healthy subjects. IgE allergy against fish and egg may be very unlikely to affect MS course

Vaccines for finfish aquaculture: what do we need to know to make them work?

Aquaculture still faces serious economic impacts due to the loss of animals to disease. A conservative estimate of 5 percent losses due to disease means that the finfish aquaculture industry loses over $1 billion annually on a global scale. One proven way to prevent costly disease outbreaks is to vaccinate fish against common or known pathogens. Current vaccination schemes still result in losses, however, and this may be due in part to vaccine design. Vaccines are currently designed using state of the art knowledge of immune responses, which is based primarily on mammalian studies. Just how applicable is this information to fish immunity and vaccine design, however? This review discusses what is currently known for teleost fish about two key processes that drive immune response: antigen presentation and cytokine regulation. In both cases many of the genes known to be involved have been identified; in the case of cytokines recent genome projects have added to the total rapidly in recent years. Most functional studies to date in these areas have focused on gene expression and mRNA levels, due to a lack of available antibodies that are required for studies at the protein level. These studies are confounded by the fact that in many cases the teleost equivalents of single copy mammalian genes are duplicated and are regulated in very different ways. This suggests that vaccines designed around mammalian immunological principles will not be as efficient as they could be. Future research goals for fish immunologists should be to develop the antibodies required for protein level functional studies in order to provide the true understanding of fish immunity that is required for the design of finfish aquaculture vaccines that are truly effective.

Biología comparada del sistema de complemento en peces / Comparative biology of the complement system in fish / Biologia comparativa do sistema complemento em peixes

Dentro de la respuesta inmune humoral se encuentran componentes que mantienen la homeostasis de los organismos a través del control de agentes patógenos por medio de la opsonización, quimiotaxis de células fagocíticas facilitando el proceso de eliminación de lo extraño o sin su acompañamiento, en el caso de la formación de poros en la membrana celular. A un grupo de este conjunto de componentes de origen molecular proteico se denominósistema del complemento, el cual posee tres vías de activación (Clásica, Alternativa y Lectinas), funciona comoanafilatoxinas, reguladores y receptores. La presente revisión tiene como objetivo discutir acerca de los diferentes componentes del sistema del complemento en la escala animal enfocándose principalmente en peces teleósteos y mamíferos, como organismos modelos en busca de elucidar sus diferencias, homologías y respuestas.

Within the humoral immune response can be found components that maintain an organism’s homeostasis viacontrol of pathogenic agents using opsonization, chemotaxis of phagocytic cells which facilitates the processof elimination of foreign bodies, or in its absence, the formation of pores in the cellular membrane. One of these groups of components, of protein origin, is referred to as the complement system, which has 3 means of activation (Classic, Alternative, and Lectins) and functions as anaphylactic toxins, regulators and receptors. The aim of this review is to discuss the different components of the complement system in the animal kingdom, focusing principally on teleost fish and mammals, as model organisms in the search to elucidate their differences, homologies, and answers.

Dentro da resposta imune humoral encontram-se componentes que mantém a homeostase do organismo através docontrole de patógenos, por opsonização, quimiotaxia de células fagocíticas que facilita o processo de eliminaçãode corpos estranhos, ou na sua ausência, a formação de poros na membrana celular. Este conjunto de componentes moleculares de origem protéica são chamados de sistema complemento, que tem três vias de ativação (clássica, alternativa e lectinas), funciona como anafilatoxinas, reguladores e receptores. Esta revisão tem como objetivo discutir os vários componentes do sistema complemento na escala animal focando principalmente em peixes teleósteos e mamíferos como organismos modelos na busca de elucidar suas diferenças, homologias e respostas.

Characterization of the acute inflammatory response in the hybrid tambacu (Piaractus mesopotamicus male × Colossoma macropomum female) (Osteichthyes) / Caracterização da resposta inflamatória aguda no híbrido tambacu (Piaractus mesopotamicus macho × Colossoma macropomum fêmea) (Osteichthyes)

This work evaluated the acute inflammatory response induced by injections of 0.5 mL saline solution (control), 500 µg carrageenin and 0.5 mL thioglycollate 3 percent in the swim bladder of juvenile tambacu hybrid. Fish were distributed in three treatments, three replications and acclimated for a period of 10 days before assay. The cell characterization from the inflammatory exudate was performed in Giemsa and PAS stained smears. Carrageenin, injected in fish, showed an increase on the total number of cells in the inflammatory exudate when compared to saline and thioglycollate injected. Whereas, for carrageenin-injected fish, the percentage of thrombocyte was higher than thioglycollate. On the other hand, granulocyte percentage in thioglycollate-injected fish was higher than the ones injected using carrageenin. Carrageenin provoked the highest migration of macrophage to the inflammatory site. The PAS method confirmed the presence of three types of granulocytes: eosinophilic granular cell (EGC) type 1 with the characteristics of a special granulocytic cell commonly found in the circulating blood; EGC type 2 shorter than the last one and neutrophil. This study contributes to a better understanding of the inflammatory response and infectious processes in native fish.

Este estudo avaliou a resposta inflamatória aguda induzida por injeções de 0,5 mL de solução salina (controle), 500 µg de carragenina e 0,5 mL de tioglicolato a 3 por cento na bexiga natatória de juvenis do híbrido tambacu. Os peixes foram distribuídos em três tratamentos, três repetições e aclimatados durante 10 dias antes do ensaio. A caracterização das células do exsudato inflamatório foi feita após coloração com Giemsa e PAS. Peixes injetados com carragenina apresentaram maior número de células no exsudato inflamatório do que com salina e tioglicolato. A porcentagem de trombócitos no exsudato foi maior nos injetados com carragenina quando comparada com a dos injetados com tioglicolato. Por outro lado, o percentual de granulócitos foi maior em animais injetados com tioglicolato do que em animais injetados com carragenina. A carragenina provocou maior migração de macrófagos para o foco inflamatório. O método de PAS confirmou a presença de três tipos de granulócitos: célula granular eosinofílica (CGE) tipo 1 com as características da célula granulocítica especial encontrada no sangue, CGE tipo 2, menor do que esta última, e de neutrófilos. Este estudo contribui para o melhor entendimento da resposta inflamatória e dos processos infecciosos em peixes nativos.

Identification of allergens in Indian fishes: hilsa and pomfret exemplified by ELISA and immunoblotting.

Enzymed-linked immunosorbent assay of hilsa and pomfret muscle extracts showed specific IgE binding to ten allergic patients' sera, the results corroborated to that of skin prick test. Comparison of allergen profiles of the two fish extracts by immunoblotting revealed a common antigenic protein of 50 kDa and some high molecular weight fish allergens instead of low molecular weight parvalbumin found in several fishes. Purified and well characterized fish allergens are always considered better than crude fish extracts for diagnostic use.

Immunostimulatory effect of azadirachtin in Oreochromis mossambicus (Peters).

The effect of azadirachtin, a triterpenoid derived from Azadirachta indica on the immune response was studied in the freshwater teleost, O. mossambicus. Bovine serum albumin (BSA) and sheep erythrocytes (SRBC) were used as antigens to evoke immune response. The immune responses in fish were measured by quantifying antibodies produced and counting the peripheral blood leucocytes in control and experimental fish. In general, azadirachtin significantly enhanced the antibody response and leucocyte count in a dose dependent manner. An inverse relationship was observed between the dose of azadirachtin and the degree of immunostimulation. Timing of azadirachtin administration in relation to immunization revealed that the maximum enhancement of antibody response was observed when the stimulant was given two days prior to immunization. The observed immunostimulatory property of azadirachtin has an implication in the maintenance of finfish health in freshwater intensive aquaculture practices.

Evaluation of the addition of ascorbic acid to the ration of cultivated Piaractus mesopotamicus (Characidae) on the infrapopulation of Anacanthorus penilabiatus (Monogenea)

Sixty Piaractus mesopotamicus Holmberg, 1887 (pacu) fry fed a diet containing 0, 50, 100 and 200 mg ascorbic acid/kg dry feed were studied to evaluate the effect on parasitic infestation by the monogenean Anacanthorus penilabiatus Boeger, Husak and Martins, 1995 (Monogenea: Dactylogyridae) for a period of 24 weeks. The temperature of the aquaria was measured daily and remained between 28 and 31ºC. At the beginning of the experimental, fish showed 6.15 + 0.33 cm standard lengh and 8.64 + 1.62 g average body weight. A sample of fish was examined and showed 43 + 17 monogeneans per fish. At the end of the experiment, the gills of control and vitamin C-treated fish were collected for parasite counts. Control fish had 42.5 parasites per fish, a significantly higher number (P<0.05) when compared with fish fed vitamin C, that showed 16.5 parasites per fish. Ascorbic acid fortification in the food promoted an increase in fish resistance to parasites. It is suggested that an optimum level of 139 mg/kg vitamin C supplementation either elicited better nutritional conditions by stimulating the appetite of the fish or improved to immune response.

Molecular and immunocytogenetics of Brazilian fishes

Fish cytogenetics has incorporated during the last years new methodologies that employ molecular techniques, such as in situ hybridization with DNA probes for localization of chromosomal segments, chromosome banding using in situ digestion with restriction enzymes, in vivo incorporation of DNA base analogues, base-specific fluorochrome staining and, more recently, immunolabelling of chromosomes with antinucleoside antibodies. These techniques, associated with results obtained by using classical cytogenetic markers such as C-bands and nucleolus organizer regions, have allowed a more comprehensive understanding of the molecular structure of chromosomes and enlarged the area of cytogenetic evolutive studies. In neotropical fish the use of these modern techniques resulted in the localization of rDNA segments and the analysis of their activity; the localization of telomeric DNA segments; the identification of C-band modified patterns in species analyzed by in situ digestion of chromosomes with restriction endonucleases; the identification of R-handing patterns after incorporation of 5-bromodeoxyuridine; and, using the antibody antimethylcytosine, the identification of the methylated state of the heterochromatin in diploids and triploids.