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Potent immunosuppression by secretory/excretory products of larvae from the sheep blowfly Lucilia cuprina
Author(s) -
KERLIN ROY L.,
EAST IAIN J.
Publication year - 1992
Publication title -
parasite immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.795
H-Index - 75
eISSN - 1365-3024
pISSN - 0141-9838
DOI - 10.1111/j.1365-3024.1992.tb00032.x
Subject(s) - lucilia cuprina , ex vivo , biology , immune system , concanavalin a , trypan blue , immunology , in vitro , andrology , biochemistry , larva , botany , medicine , calliphoridae
Summary Secretory/excretory products (sec/ex) of parasitic larvae of the sheep blowfly Lucilia cuprina potently inhibited proliferation of peripheral blood leucocytes stimulated by mitogens in vitro . Suppression of proliferation was not due to irreversible damage because cells cultured for 24 h in high concentrations of sec/ex appeared viable (assessed by Trypan blue exclusion) and did not show impaired proliferation after washing. Furthermore, suppression induced by sec/ex could be overcome by increasing concentrations of mitogen. The inhibitory activity could be demonstrated in cultures where sec/ex was added at different times during the culture period. Inhibitory activities in sec/ex were heat‐labile and sensitive to treatment with trypsin. In addition to effects in vitro , sec/ex was strongly immunosuppressive in vivo . Sheep given combined injections of myoglo‐bin and sec/ex had markedly lower anti‐myoglobin antibody levels in sera than sheep that received injections of myoglobin alone. There was no significant antibody response to sec/ex itself. Immunosuppressive moieties in sec/ex produced by blowfly larvae may promote parasite survival by inhibiting the immune response of host sheep.