In vitro effects of LPS, IL-2, PDGF and CRF on haemocytes of Mytilus galloprovincialis Lmk.

The cells in charge of the innate immune response in the marine mussel Mytilus galloprovincialis Lmk. are the haemocytes. These cells respond in different ways to agents such as lipopolysaccharide (LPS), interleukin-2 (IL-2), platelet-derived growth factor (PDGF) and corticotropin releasing factor (CRF). After stimulation of the haemocytes, the expression of molecules reactive with monoclonal antibodies raised to the α chain of the IL-2 receptor, present in their membrane, differed depending on the agent used. The same happened with regard to the levels of dopamine, adrenaline and noradrenaline released to the medium by the haemocytes. It should also be noted that no catecholamine release was detected and the level of expression of IL-2Rα showed no significant variation in cultured cells that had not been treated with inducers. These facts would indicate that most haemocytes were in the same starting condition at the moment that the stimulation was performed. Therefore, cultured haemocytes can be a highly reliable model in the study of the innate immune system.