Characterisation of thrombocytes in Osteichthyes

Abstract

Thrombocytes in vertebrates other than mammals, inter alia in fish, are analogues of platelets in mammals. In Osteichthyes, these cells take part in haemostatic processes, including aggregation and release reactions in cases of blood vessel damage, and in the immune response development as well. This paper discusses the development of thrombocytes in Osteichthyes, taking into account the need to make changes to the concept of grouping progenitor cells as suggested in the literature. The following pages present the morphological and cytochemical properties of thrombocytes as well as their defence functions, and also point out differences between thrombocytes in fish and platelets in mammals. The paper further highlights the level of thrombocytes’ immune activity observed in fish and based on an increased proportion of these cells in response to antigenic stimulation, on morphological shifts towards forms characteristic of dendritic cells after antigenic stimulation and on the presence of surface structures and cytokines released through, inter alia, gene expression of TLR receptors, MHC class II protein-coding genes and pro-inflammatory cytokines. The study also points out the need to recognise thrombocytes in Osteichthyes as specialised immune cells conditioning non-specific immune mechanisms and playing an important role in affecting adaptive immune mechanisms.

Hematological and cytochemical characteristics of peripheral blood cells in the argus snakehead (Ophiocephalus argus Cantor)

“…Different thrombocyte shapes, including round, oval, oblong, and spindle-shaped, were observed in O. argus , which was consistent with the reports in other fish ( Fang et al, 2014 ; Gao et al, 2007b ; Michał, Beata & Wiesław, 2019 ; Rio-Zaragoza et al, 2011 ; Zhang et al, 2011 ; Zheng et al, 2016 ). The spindle-shaped thrombocytes often existed alone with some vacuoles in the cytoplasm and were related to cell phagocytosis ( Nagasawa, Somamoto & Nakao, 2015 ; Stosik et al, 2002 ).…”

“…These results were similar to those of the Murray cod ( Shigdar, Harford & Ward, 2009 ), tilapia ( Ueda et al, 2001 ), and piebald naked carp ( Zheng et al, 2016 ). The thrombocytes of lower vertebrates are functionally similar to platelets in mammals ( Michał, Beata & Wiesław, 2019 ), playing an important role in the process of hemostasis and coagulation ( Chen et al, 2018 ; Ferdous & Scott, 2015 ; Peng et al, 2018 ). Studies have investigated whether thrombocytes in some fish have phagocytotic abilities ( Da Silva et al., 2011 ; Michał, Beata & Wiesław, 2019 ; Shigdar et al, 2007 ; Shigdar, Harford & Ward, 2009 ; Tavares-Dias et al., 2007 ; Zhang et al, 2019 ).…”

The contribution of fish models in understanding of blood disorders

“…In literature is reported that thrombocytes in fish, amphibians, reptiles and birds are analogues of platelets in mammals and also human (Stosik et al, 2019). The difference between fish and mammalian thrombocytes, including human is that fish thrombocytes are nucleated cells ( Fig.…”

“…In fish, electron microscopy studies reveal a canalicular structure similar to human platelets and pseudopodia-like projections in aggregates (Carradice and Lieschke, 2008). Both human and fish thrombocytes have a major role in maintaining vascular integrity, hemostasis and in aggregation and release reactions in cases of blood vessel damage and in the immune response development (Thomas and Storey, 2015;Stosik et al, 2019). Moreover, it was discovered that Danio rerio thrombocytes function analogously to human platelets in adherence, secretion and aggregation (Carradice and Lieschke, 2008).…”

From Classical to Unconventional: The Immune Receptors Facilitating Platelet Responses to Infection and Inflammation

“…Higher up the evolutionary chain, small nucleated thrombocytes with features similar to that of the mammalian platelet are present in species such as birds, reptiles, fish, and amphibians [ 8 , 9 ]. Not only do these nucleated thrombocytes play a role in coagulation [ 10 , 11 ], but, similar to mammalian platelets, have been shown to play significant roles in the immune responses of these organisms [ 9 , 12 , 13 ]. For example, avian thrombocytes and fish thrombocytes have been reported to possess functional toll like receptors that initiate immune responses to various pathogens, in addition to being able to phagocytose beads, viruses, and bacteria [ 12 , 13 ].…”