Histopathology of the thymus in Saprolegnia-infected wild brown trout, Salmo trutta L.

Álvarez, Francisco; Villena, A.; Zapata, A.; Razquin, B.

doi:10.1016/0165-2427(94)05384-5

Cited by 21 publications

(20 citation statements)

References 15 publications

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“…However, the same distribution and mean log titres were observed in positive samples from fish with or without saprolegniosis. Other authors have tried to characterize the immune response, both cellular and humoral, against Saprolegnia infection and have shown evidence of a lack of an effective response, which might favour the course of the disease (Sohnle & Chusid 1983, El-Feki 1987, Álvarez et al 1988, 1995, Bly et al 1994. Results from the present study are along the same lines.…”

Section: Discussionsupporting

confidence: 80%

Prevalence of serum antibodies against Saprolegnia parasitica in wild and farmed brown trout Salmo trutta

2009

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The prevalence of serum antibodies against Saprolegnia parasitica in wild and farmed brown trout Salmo trutta from the province of León (NW Spain) was studied by enzyme-linked immunosorbent assay (ELISA). Blood samples from healthy and Saprolegnia-infected brown trout were collected over 2 yr with a seasonal periodicity (January, April, July and October) from a hatchery and river with frequent presence of saprolegniosis (River Porma) and from a river in which the disease was rarely observed (River Omaña). The individual prevalence was 30.1%, but statistically significant differences were observed between the prevalence in trout from the hatchery (43.0%), from River Porma (31.8%) and from River Omaña (6.4%) and also between the prevalence observed in October (42.9%) and the values obtained in January (24.8%), April (22.7%) and July (27.5%). There was no difference between the seroprevalence in females (34.8%) and males (38.2%), but a positive correlation between raised serum antibody levels and larger (older) fish was found. The low prevalence of antibodies observed in Saprolegnia-infected trout (18.0%) suggests possible immune suppression and the lack of an effective specific immune response in fish with saprolegniosis.

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Section: Discussionsupporting

confidence: 80%

Prevalence of serum antibodies against Saprolegnia parasitica in wild and farmed brown trout Salmo trutta

2009

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“…The suppression of the immune response of vertebrate hosts during oomycete infection, although suggested in the literature (8,13,26,27), has never been clearly demonstrated in vivo. Our results reveal the immune response of salmonids to oomycete infection after exposure to S. parasitica.…”

Section: Discussionmentioning

confidence: 99%

Role of Pathogen-Derived Cell Wall Carbohydrates and Prostaglandin E ₂ in Immune Response and Suppression of Fish Immunity by the Oomycete Saprolegnia parasitica

et al. 2014

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e Saprolegnia parasitica is a freshwater oomycete that is capable of infecting several species of fin fish. Saprolegniosis, the disease caused by this microbe, has a substantial impact on Atlantic salmon aquaculture. No sustainable treatment against saprolegniosis is available, and little is known regarding the host response. In this study, we examined the immune response of Atlantic salmon to S. parasitica infection and to its cell wall carbohydrates. Saprolegnia triggers a strong inflammatory response in its host (i.e., induction of interleukin-1␤ 1 [IL-1␤ 1 ], IL-6, and tumor necrosis factor alpha), while severely suppressing the expression of genes associated with adaptive immunity in fish, through downregulation of T-helper cell cytokines, antigen presentation machinery, and immunoglobulins. Oomycete cell wall carbohydrates were recognized by fish leukocytes, triggering upregulation of genes involved in the inflammatory response, similar to what is observed during infection. Our data suggest that S. parasitica is capable of producing prostaglanding E 2 (PGE 2 ) in vitro, a metabolite not previously shown to be produced by oomycetes, and two proteins with homology to vertebrate enzymes known to play a role in prostaglandin biosynthesis have been identified in the oomycete genome. Exogenous PGE 2 was shown to increase the inflammatory response in fish leukocytes incubated with cell wall carbohydrates while suppressing genes involved in cellular immunity (gamma interferon [IFN-␥] and the IFN-␥-inducible protein [␥-IP]). Inhibition of S. parasitica zoospore germination and mycelial growth by two cyclooxygenase inhibitors (aspirin and indomethacin) also suggests that prostaglandins may be involved in oomycete development.

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“…Early studies have already disclosed that viruses, fungi, parasites, and bacteria can affect the thymus direct or indirectly, harm the host immune response and contribute to the pathogenicity of these microorganisms (Price et al 1993;Sutton et al 1994;Alvarez et al 1995;Ozeki et al 1997;Islam et al 1998). Acute thymic atrophy observed during infections is accompanied by the loss of the maintenance of thymic microenvironment and abnormal development of thymocytes (Savino et al 1986;Sodora et al 2002;Brito et al 2003;Souto et al 2003;Savino 2006;Seixas and Ostler 2005;Cotta-de-Almeida et al 2003;Andrade et al 2008).…”

Section: Discussionmentioning

confidence: 95%

Effects of Plasmodium berghei on thymus: High levels of apoptosis and premature egress of CD4+CD8+ thymocytes in experimentally infected mice

et al. 2011

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Histopathology of the thymus in Saprolegnia-infected wild brown trout, Salmo trutta L.

Cited by 21 publications

References 15 publications

Prevalence of serum antibodies against Saprolegnia parasitica in wild and farmed brown trout Salmo trutta

Prevalence of serum antibodies against Saprolegnia parasitica in wild and farmed brown trout Salmo trutta

Role of Pathogen-Derived Cell Wall Carbohydrates and Prostaglandin E ₂ in Immune Response and Suppression of Fish Immunity by the Oomycete Saprolegnia parasitica

Effects of Plasmodium berghei on thymus: High levels of apoptosis and premature egress of CD4+CD8+ thymocytes in experimentally infected mice

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Histopathology of the thymus in Saprolegnia-infected wild brown trout, Salmo trutta L.

Cited by 21 publications

References 15 publications

Prevalence of serum antibodies against Saprolegnia parasitica in wild and farmed brown trout Salmo trutta

Prevalence of serum antibodies against Saprolegnia parasitica in wild and farmed brown trout Salmo trutta

Role of Pathogen-Derived Cell Wall Carbohydrates and Prostaglandin E 2 in Immune Response and Suppression of Fish Immunity by the Oomycete Saprolegnia parasitica

Effects of Plasmodium berghei on thymus: High levels of apoptosis and premature egress of CD4+CD8+ thymocytes in experimentally infected mice

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Role of Pathogen-Derived Cell Wall Carbohydrates and Prostaglandin E ₂ in Immune Response and Suppression of Fish Immunity by the Oomycete Saprolegnia parasitica