RESUMO
The increasing significance of the aquaculture sector and commercially valuable species underscores the need to develop alternatives for controlling diseases such as Ichthyophthirius multifiliis-induced ichthyophthiriasis. This ciliated protozoan parasite threatens nearly all freshwater fish species, causing substantial losses in the fishery industry. Despite this, effective large-scale treatments are lacking, emphasizing the necessity of adopting preventive strategies. While the pathogenesis of ichthyophthiriasis and its immune stimulation allows for vaccination strategies, precise adjustments are crucial to ensure the production of an effective vaccine compound. Therefore, this study aimed to evaluate the impact of immunizing Astyanax lacustris with a genetic vaccine containing IAG52A from I. multifiliis and the molecular adjuvant IL-8 from A. lacustris. Transcript analysis in immunized A. lacustris indicated mRNA production in fish muscles, demonstrating an expression of this mRNA. Fish were divided into five groups, receiving different vaccine formulations, and all groups received a booster dose 14 days after the initial immunization. Samples from vaccinated fish showed increased IL-1ß mRNA expression in the spleen within 6 h post the second dose and after 14 days. In the head kidney, IL-1ß mRNA expression showed no significant difference at 6 and 24 h but an increase was noted in fish injected with IAG and IAG + IL-8 after 14 days. IL-8 mRNA expression in the spleen and kidney did not significantly differ from the control group. Histological analysis revealed no variation in leukocyte concentration at 6 and 24 h post-vaccination; however, after 14 days, the groups injected with IAG and IAG + IL-8 exhibited a higher leukocyte density at the application sites than the control. The obtained data suggest that the used vaccine is transcribed, indicating its potential to stimulate innate immune response parameters through mRNA cytokine expression and leukocyte migration.
Assuntos
Adjuvantes Imunológicos , Infecções por Cilióforos , Doenças dos Peixes , Hymenostomatida , Vacinas de DNA , Animais , Doenças dos Peixes/prevenção & controle , Doenças dos Peixes/imunologia , Doenças dos Peixes/parasitologia , Infecções por Cilióforos/veterinária , Infecções por Cilióforos/prevenção & controle , Infecções por Cilióforos/imunologia , Hymenostomatida/imunologia , Vacinas de DNA/imunologia , Vacinas de DNA/administração & dosagem , Adjuvantes Imunológicos/administração & dosagem , Vacinação/veterinária , Vacinas Protozoárias/imunologia , Vacinas Protozoárias/administração & dosagem , Characidae/imunologia , Interleucinas/imunologiaRESUMO
The spleen is an immune lymphatic organ linked with control of the immune response, which is important to fish health. Recent evidence has suggested the involvement of purinergic signaling in the modulation of immune and inflammatory responses through the nucleotide adenosine triphosphate (ATP) and the nucleoside adenosine (Ado), which are regulated by the enzymes nucleoside triphosphate diphosphohydrolase (NTPDase), 5'-nucleotidase, and adenosine deaminase (ADA). Thus, the aim of this study was to evaluate whether purinergic signaling can modulate the immune and inflammatory responses in the spleen of silver catfish (Rhamdia quelen) naturally infected with Ichthyophthirius multifiliis. Splenic NTPDase and 5'-nucleotidase activities increased in infected animals compared with uninfected animals, while the splenic ADA activity decreased. These data indicate that purinergic signaling can modulate the splenic immune and inflammatory responses through the regulation of ATP and Ado levels, which are known to participate in the physiological and pathological responses as pro-inflammatory and anti-inflammatory molecules, respectively. In summary, modulation of the splenic purinergic cascade has an anti-inflammatory role in reducing or preventing inflammatory damage.
Assuntos
Trifosfato de Adenosina/metabolismo , Adenosina/metabolismo , Peixes-Gato/parasitologia , Infecções por Cilióforos/imunologia , Hymenostomatida/imunologia , Inflamação/parasitologia , 5'-Nucleotidase/metabolismo , Adenosina Desaminase/metabolismo , Animais , Peixes-Gato/imunologia , Infecções por Cilióforos/parasitologia , Inflamação/imunologia , Pirofosfatases/metabolismo , Transdução de Sinais/fisiologia , Baço/imunologia , Baço/parasitologiaRESUMO
This study evaluated the activity of leaf essential oil (EO) from Hyptis mutabilis as well as its major constituent, (-)-globulol, in infections by the parasite Ichthyophthirius multifiliis (ich). Effects on hematological, biochemical, and immunological parameters of silver catfish, Rhamdia quelen, exposed to the same samples also were evaluated. In the first experiment, naturally infected fish were treated with EO (0, 10, and 20 mg · L-1) and ethanol, using several methods of exposure. Fish mortality and the number of trophonts per fish were assessed after 48 and 96 hr. Hour-long daily baths resulted in optimal survival, so this methodology was used for the second experiment, in which infected animals were exposed to (-)-globulol at 2.5 and 5 mg · L-1. The most effective concentrations in Experiments 1 and 2 were chosen for Experiment 3, in which healthy animals were subjected to hour-long daily baths with EO (20 mg · L-1) or (-)-globulol (2.5 mg · L-1). Additionally, an in vitro experiment was performed with EO and globulol at the same concentrations of the in vivo test. EO and (-)-globulol increased the survival of fish infected with ich and altered certain hematological and biochemical parameters. After 4 days, levels of hematocrit, erythrocytes, and leukocytes increased significantly in healthy animals exposed to EO. Exposure to (-)-globulol increased leukocyte number alone. No significant differences in nonspecific immunological parameters were detected when treated groups were compared to controls, but the leukocytosis observed in EO- and globulol-treated healthy animals indicates that EO and (-)-globulol increased innate immunity in these fish. An in vitro antiparasitic effect was observed in both samples.
Assuntos
Peixes-Gato/parasitologia , Infecções por Cilióforos/veterinária , Doenças dos Peixes/tratamento farmacológico , Hymenostomatida , Hyptis/química , Óleos Voláteis/uso terapêutico , Testes de Aglutinação/veterinária , Animais , Atividade Bactericida do Sangue , Contagem de Células Sanguíneas/veterinária , Análise Química do Sangue/veterinária , Brasil , Infecções por Cilióforos/sangue , Infecções por Cilióforos/tratamento farmacológico , Infecções por Cilióforos/imunologia , Doenças dos Peixes/sangue , Doenças dos Peixes/imunologia , Pesqueiros , Hymenostomatida/efeitos dos fármacos , Hymenostomatida/imunologia , Óleos Voláteis/administração & dosagem , Óleos Voláteis/farmacologia , Extratos Vegetais/administração & dosagem , Extratos Vegetais/farmacologia , Extratos Vegetais/uso terapêutico , Folhas de Planta/química , Sesquiterpenos/farmacologia , Sesquiterpenos/uso terapêutico , Qualidade da Água/normasRESUMO
The objective of this study was to evaluate differential expression of innate and adaptive immune genes, including immunoglobulin, immune cell receptor, cytokine, inflammatory protein, toll-like receptors (TLR) and recombination-activating gene (RAG) in skin from channel catfish, Ictalurus punctatus after immunization with live theronts of Ichthyophthirius multifiliis (Ich) by intraperitoneal injection. The immunized catfish showed significantly higher survival rate (95%) than those of mock-immunized control fish (0% survival) after the theront challenge. The gene expression of innate immune system, such as cytokines (IL-1ß type a, IL-1ß type b, IFN-γ, TGF1-ß and TNF-α) and inflammatory proteins (NF-kB and iNOS 2), showed significant upregulation at day 1 (D1) post-immunization. Expression of TLR genes exhibited a rapid increase from hour 4 (h4) to D10 post-immunization. Genes of the adaptive response, such as the cell receptor MHC I, CD8+ , CD4+ and TCR-α, showed upregulation at D1, D6 and D10. The TCR-ß expression increased rapidly at h4 and remained upregulated until D10. Immunoglobulin IgM upregulation was detected from h4 until D2 while IgD expression was increased from D1 until D10. Rapid upregulation of innate and adaptive immune genes in skin of catfish following live theront vaccination was demonstrated in this study ultimately resulting in significant protection against Ich infection.
Assuntos
Infecções por Cilióforos/veterinária , Doenças dos Peixes/imunologia , Hymenostomatida/imunologia , Ictaluridae/imunologia , Ictaluridae/parasitologia , Pele/imunologia , Animais , Anticorpos Antiprotozoários/imunologia , Infecções por Cilióforos/imunologia , Doenças dos Peixes/parasitologia , Imunização/veterinária , Imunoglobulina M , NF-kappa B , Fator de Necrose Tumoral alfaRESUMO
This study evaluated the influence of temperature on the immune responses and hematological parameters in channel catfish Ictalurus punctatus immunized via intraperitoneal injection with live theronts of Ichthyophthirius multifiliis. Fish were distributed in 18 aquaria and received 9 treatments: 4 groups of fish were vaccinated with live theronts and maintained at constant temperature 15 °C, 20 °C, 25 °C and 30 °C; 3 groups of fish vaccinated and subjected to cycling temperature regime from 15-25 °C, 20-25 °C and 20-30 °C, changed 5 °C each day; 2 groups of fish were not vaccinated and served as controls at 25 °C, one with Ich challenge and the other without challenge. Non vaccinated fish and those vaccinated at 15 °C or 15-25 °C did not show anti-Ich antibodies in the serum 14 and 21 days post-immunization. The antibody levels were significantly higher from fish vaccinated at 25 °C, 30 °C, 20-25 °C and 20-30 °C compared to fish at 15 °C, 20 °C and 15-25 °C both 14 and 21 days post-immunization. At constant water temperature, fish vaccinated at 15 °C showed significantly higher mortality rate (67.8%, P < 0.05) than those vaccinated at 20 °C, 25 °C, and 30 °C (0-10.7% mortalities). At cycling water temperature, fish vaccinated at 15-25 °C showed significantly higher mortality rate (67.8%) than those vaccinated at 20-25 °C and 20-30 °C (P < 0.05). Twenty days after immunization fish vaccinated at 30 °C and 20-30 °C showed significant increase in the red blood cells, white blood cells, thrombocytes and monocytes. Six days after challenge with I. multifiliis theronts the fish showed decreased white blood cells, thrombocytes and monocytes. This study suggests that vaccinated catfish were severely impacted by low temperature, either at 15 °C constant temperature or at 15-25 °C cycling temperature. The fish showed no anti-Ich antibodies and suffered high mortality similar to non vaccinated control fish.