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Korkut, Gül Gizem
Publications (3 of 3) Show all publications
Korkut, G. G., Söderhäll, I., Söderhäll, K. & Noonin, C. (2018). The effect of temperature on bacteria-host interactions in the freshwater crayfish, Pacifastacus leniusculus. Journal of Invertebrate Pathology, 157, 67-73
Open this publication in new window or tab >>The effect of temperature on bacteria-host interactions in the freshwater crayfish, Pacifastacus leniusculus
2018 (English)In: Journal of Invertebrate Pathology, ISSN 0022-2011, E-ISSN 1096-0805, Vol. 157, p. 67-73Article in journal (Refereed) Published
Abstract [en]

Water temperature is known to affect many aspects of aquatic life including immune responses and susceptibility to diseases. In this context, we studied the effect of temperature on the defense system of the freshwater crayfish Pacifastacus leniusculus. Animals were challenged with two pathogenic Gram-negative bacteria, Aeromonas hydrophila and Pseudomonas gessardii, as well as the bacterial cell wall component lipopolysaccharide (LPS) at two different temperatures, cold (6 °C) and room temperature (22 °C). The immune responses were compared by means of differences in mortality, phagocytosis, bacterial clearance, and the melanization reaction of the hemolymph at these two temperatures. We observed that crayfish survival was higher at cold temperature. The mortality rate was zero at 6 °C following A. hydrophila or LPS injections. Furthermore, the bacteria were completely cleared from crayfish after they had been held at 6 °C for more than 9 days. We also observed a strong melanization reaction of hemolymph at 22 °C when stimulated with LPS, as well as with bacteria. Taken together, our results suggest that the cellular immunity is more effective at low temperature in this cold-adapted animal and pathogens are efficiently removed from the body by mean of phagocytosis.

Keywords
Aeromonas hydrophila, Pseudomonas gessardii, Temperature, Innate immunity, Melanization, Invertebrate
National Category
Immunology
Identifiers
urn:nbn:se:uu:diva-366280 (URN)10.1016/j.jip.2018.08.001 (DOI)000444783000009 ()30077692 (PubMedID)
Funder
Swedish Research Council Formas, 2011-606Swedish Research Council, 621-2012-2418
Available from: 2018-11-26 Created: 2018-11-26 Last updated: 2018-11-26Bibliographically approved
Korkut, G. G., Noonin, C. & Söderhäll, K. (2018). The effect of temperature on White Spot Disease progression in a crustacean, Pacifastacus leniusculus. Developmental and Comparative Immunology, 89, 7-13
Open this publication in new window or tab >>The effect of temperature on White Spot Disease progression in a crustacean, Pacifastacus leniusculus
2018 (English)In: Developmental and Comparative Immunology, ISSN 0145-305X, E-ISSN 1879-0089, Vol. 89, p. 7-13Article in journal (Refereed) Published
Abstract [en]

The effects of temperature on the progression of White Spot Disease (WSD) have been studied in the freshwater crayfish Pacifastacus leniusculus. In this study, we aimed to understand the reason for previously observed low mortalities with white spot syndrome virus (WSSV) infected crayfish at low temperatures. The susceptibility of freshwater crayfish to WSSV was studied at different temperatures. The mortality rate at 6°C was zero, meanwhile the animals kept at 22°C developed WSD symptoms and died in a few days after WSSV injections, however upon transfer of animals from 6°C to 22°C the mortality reached 100% indicating that the virus is not cleared. Moreover, the VP28 expression at 6°C was significantly lower compared to animals kept at 22°C. We injected animals with demecolcine, an inhibitor that arrests the cell cycle in metaphase, and observed a delayed mortality. Furthermore, the VP28 expression was found to be lower in these animals receiving both injections with WSSV and demecolcine since cell proliferation was inhibited by demecolcine. We quantified WSSV copy numbers and found that virus entry was blocked at 6°C, but not in demecolcine treatments. We supported this result by quantifying the expression of a clip domain serine protease (PlcSP) which plays an important role for WSSV binding, and we found that the PlcSP expression was inhibited at 6°C. Therefore, our hypothesis is that the WSSV needs proliferating cells to replicate, and an optimum temperature to enter the host hematopoietic stem cells successfully. 

Keywords
White spot syndrome virus, temperature, innate immunity, crustacean, serine protease
National Category
Immunology
Identifiers
urn:nbn:se:uu:diva-356485 (URN)10.1016/j.dci.2018.07.026 (DOI)000444932200002 ()30071208 (PubMedID)
Funder
Swedish Research Council, 621-2012-2418Swedish Research Council Formas, 2011-606
Available from: 2018-07-31 Created: 2018-07-31 Last updated: 2019-06-26Bibliographically approved
Guo, E., Korkut, G. G., Jaree, P., Söderhäll, I. & Söderhäll, K. (2017). A Pacifastacus leniusculus serine protease interacts with WSSV. Fish and Shellfish Immunology, 68, 211-219
Open this publication in new window or tab >>A Pacifastacus leniusculus serine protease interacts with WSSV
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2017 (English)In: Fish and Shellfish Immunology, ISSN 1050-4648, E-ISSN 1095-9947, Vol. 68, p. 211-219Article in journal (Refereed) Published
Abstract [en]

Serine proteases are involved in many critical physiological processes including virus spread and replication. In the present study, we identified a new clip-domain serine protease (PIcSP) in the crayfish Pacifastacus leniusculus hemocytes, which can interact with the White Spot Syndrome Virus (WSSV) envelope protein VP28. It was characterized by a classic clip domain with six strictly conserved Cys residues, and contained the conserved His-Asp-Ser (H-D-S)motif in the catalytic domain. Furthermore, signal peptide prediction revealed that it has a 16-residue secretion signal peptide. Tissue distribution showed that it was mainly located in P. leniusculus hemocytes, and its expression was increased in hemocytes upon WSSV challenge. In vitro knock down of PIcSP decreased both the expression of VP28 and the WSSV copy number in hematopoietic stem (HPT) cells. Accordingly, these data suggest that the new serine protease may be of importance for WSSV infection into hematopoietic cells.

Keywords
Hematopoietic tissue, Invertebrate, Serine protease, Virus, WSSV
National Category
Immunology
Identifiers
urn:nbn:se:uu:diva-335858 (URN)10.1016/j.fsi.2017.07.026 (DOI)000411299500022 ()28705723 (PubMedID)
Funder
Swedish Research Council, 621-2012-2418
Available from: 2018-01-24 Created: 2018-01-24 Last updated: 2018-06-26Bibliographically approved
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