The Early Immune Response of Lymphoid and Myeloid Head-Kidney Cells of Rainbow Trout (Oncorhynchus mykiss) Stimulated with Aeromonas salmonicida

The teleost head kidney is a highly relevant immune organ, and myeloid cells play a major role in this organ’s innate and adaptive immune responses. Because of their complexity, the early phases of the innate immune reaction of fish against bacteria are still poorly understood. In this study, naïve rainbow trout were stimulated with inactivated A. salmonicida and sampled at 12 h, 24 h and 7 d poststimulation. Cells from the head kidney were magnetically sorted with a monoclonal antibody mAB21 to obtain one (MAb21-positive) fraction enriched with myeloid cells and one (MAb21-negative) fraction enriched with lymphocytes and thrombocytes. The gene expression pattern of the resulting cell subpopulations was analysed using a panel of 43 immune-related genes. The results show an overall downregulation of the complement pathway and cytokine production at the considered time points. Some of the selected genes may be considered as parameters for diagnosing bacterial furunculosis of rainbow trout.

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Draft Genome Sequence of Epilithonimonas sp. FP211-J200, Isolated from an Outbreak Episode on a Rainbow Trout (Oncorhynchus mykiss) Farm

Genome Announcements ◽

10.1128/genomea.00819-17 ◽

2017 ◽

Vol 5 (37) ◽

Cited By ~ 1

Author(s):

Manuel Ayala ◽

Cristopher Segovia ◽

Rodrigo Rojas ◽

Claudio Miranda ◽

Javier Santander

Keyword(s):

Rainbow Trout ◽

Oncorhynchus Mykiss ◽

Genome Sequence ◽

Draft Genome ◽

Head Kidney ◽

Fish Host ◽

Draft Genome Sequence ◽

Kidney Cells ◽

Rainbow Trout Oncorhynchus Mykiss ◽

Head Kidney Cells

ABSTRACT Here, we report the draft genome sequence of Epilithonimonas sp. FP211-J200, isolated from rainbow trout head kidney cells. The size of the genome is 4,110,772 bp, with a G+C content of 37.1%. The Epilithonimonas sp. FP211-J200 genome has genes related to tetracycline and β-lactam resistance. This is the first reported Epilithonimonas species genome isolated from a fish host.

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Cyclopamine Induced Expression of Immune-related Genes in Rainbow trout (Oncorhynchus mykiss) Head Kidney Leukocytes

Israeli Journal of Aquaculture - Bamidgeh ◽

10.46989/001c.20897 ◽

2018 ◽

Author(s):

Y.K. zdemit ◽

S. Bilen ◽

R.C. Özdemir ◽

A.Y. Sõnmev

Keyword(s):

Rainbow Trout ◽

Oncorhynchus Mykiss ◽

Head Kidney ◽

Induced Expression ◽

Rainbow Trout Oncorhynchus Mykiss ◽

Immune Related Genes

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Dawn to Dusk: Diurnal Rhythm of the Immune Response in Rainbow Trout (Oncorhynchus Mykiss)

Biology ◽

10.3390/biology9010008 ◽

2019 ◽

Vol 9 (1) ◽

pp. 8 ◽

Cited By ~ 1

Author(s):

Ruth Montero ◽

Joanna Ewa Strzelczyk ◽

Justin Tze Ho Chan ◽

Marieke Verleih ◽

Alexander Rebl ◽

...

Keyword(s):

Immune Response ◽

Rainbow Trout ◽

Phagocytic Activity ◽

Myeloid Cells ◽

Head Kidney ◽

Time Of Day ◽

Aeromonas Salmonicida ◽

Diurnal Rhythms ◽

Dark Phase ◽

Immune Competence

The daily change of light and dark periods influences different physiological processes including feeding, resting and locomotor activity. Previously, several studies on mammalian models revealed a strong link between day-night rhythms and key immunological parameters. Since teleost fishes possess innate and adaptive immune responses like those observed in higher vertebrates, we aimed to elucidate how changes in light-dark cycles shape the immune system of fish. Using the rainbow trout laboratory model, we investigated the link between diurnal rhythms and immune competence of fish. Initially, the cell composition and phagocytic activity of leukocytes was analyzed in the circulation as well as in the head kidney, the functional ortholog of mammalian bone marrow. Once the baseline was established, we evaluated the ability of fish to respond to a bacterial stimulus, as well as the changes in antimicrobial activity of the serum. Our results suggest increased immune competence during the day, manifested by the higher presence of myeloid cells in the circulation; increased overall phagocytic activity; and higher capacity of the sera to inhibit the growth of Aeromonas salmonicida. Notably, our flow cytometric analysis identified the myeloid cells as the major population influenced by the time of day, whereas IgM+ B cells and thrombocytes did not vary in a significant manner. Interestingly, the presence of myeloid cells in blood and head kidney followed complementary trends. Thus, while we observed the highest number of myeloid cells in the blood during early morning, we witnessed a reverse trend in the head kidney, suggesting a homing of myeloid cells to reservoir niches with the onset of the dark phase. Further, the presence of myeloid cells was mirrored in the expression of the proinflammatory marker tnfa as well as in the number of leukocytes recruited to the peritoneal cavity in the peritonitis model of inflammation. Overall, the data suggest a connection between diurnal rhythms and the immune response of rainbow trout and highlight the relevance of rhythmicity and its influence on experimental work in the field of fish chronoimmunology.

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