Details

Autor(en) / Beteiligte

• Katzenback, Barbara A.
• Plouffe, Debbie A.
• Belosevic, Miodrag

Titel

Goldfish (Carassius auratus L.) possess natural antibodies with trypanocidal activity towards Trypanosoma carassii in vitro

Ist Teil von

• Fish & shellfish immunology, 2013-05, Vol.34 (5), p.1025-1032

Ort / Verlag

England: Elsevier Ltd

Erscheinungsjahr

2013

Link zum Volltext

Quelle

MEDLINE

Beschreibungen/Notizen

• Natural infection of cyprinids, such as carp, with the extracellular protozoan parasite Trypanosoma carassii can attain up to 100% prevalence and cause significant host morbidity and mortality, particularly in aquaculture settings. Host recovery from T. carassii infection has been shown to be antibody (Immunoglobulin M; IgM)-mediated, conferring long-term immunity in recovered animals upon challenge. To assess the role of IgM in parasite clearance in the goldfish, IgM was purified by PEG-6000 precipitation from goldfish serum collected at 0 (naïve), 21 (peak parasitaemia) and 42 (recovery phase; immune) days post infection (dpi) and used for in vitro assays. Purified IgM from 0, 21, and 42 dpi serum showed dose- and time-dependent trypanocidal activity in vitro. Incubation of T. carassii with 0 dpi IgM showed the greatest reduction in trypanosome numbers after 24 h, followed by 42 dpi IgM, and finally by 21 dpi IgM. The trypanocidal activity of the PEG-purified IgM was abrogated by pre-absorption with parasites in vitro and was affected by temperature. Furthermore, studies using 0 dpi IgM purified using gel permeation chromatography showed increased trypanocidal activity, with complete elimination of parasites after 12 h when incubated with 200 μg of 0 dpi IgM, or by 24 h when incubated with 80 μg or 100 μg of 0 dpi IgM. Lastly, in vivo passive transfer experiments demonstrated that while immune serum or purified IgM from 42 dpi serum conferred protection against a challenge, neither 0 dpi serum or 0 dpi purified IgM conferred protection against challenge with T. carassii. ► Purified IgM from naïve and Trypanosoma carassii-infected goldfish had dose- and time-dependent trypanocidal activity in vitro. ► Purified IgM from naïve goldfish serum shows the highest trypanocidal activity against T. carassii in vitro. ► Trypanocidal activity of IgM from naïve goldfish serum against T. carassii, in vitro, is temperature dependent. ► Passive transfer of IgM from immune, but not naïve goldfish, conferred protection against challenge with T. carassii.