Assessment of antibody-independent cellular cytotoxicity (AICC) of porcine neutrophilic granulocytes by quantitative flow cytometry. Lack of modulation by larval products of Oesophagostomum dentatum.
After infection of pigs by the larvae of Oesophagostomum dentatum, granulomas are formed around the third-stage larvae in the submucosa of the gut which contain a considerable number of neutrophils. This has no obvious impact on the larvae, which develop to fourth-stage larvae within these granulomas. We therefore asked, whether the products of O. dentatum larvae modulate the functional capacity of porcine neutrophils. The antibody-independent cellular cytotoxicity (AICC) was chosen as a model system. This assay was developed for the pig and quantified using flow cytometry. Bovine lymphoblastoid cells (cell line Anna TA1) served as targets. The measurement of cytotoxicity was based on the determination of absolute numbers of vital target cells. This procedure proved to be reliable and required no additional labelling of target and/or effector cells. Porcine neutrophils, when stimulated with phorbol 12-myristate 13-acetate (PMA; > or = 10 nmol/l), killed target cells at effector: target ratios between 1:1 and 9:1. AICC was not demonstrable after 4 h but could be observed between 16 h and 20 h after in vitro co-culture. Killing of targets required close physical contact between effector and targets, since supernatants of PMA-stimulated polymorphonuclear cells were not able to lyse the target cells. Homogenates of third- and fourth-stage larvae of O. dentatum did not affect the vitality of porcine granulocytes or target cells in vitro, nor did they modulate the AICC capacity of porcine granulocytes.
Schuberth
H J
HJ
Immunology Unit, School of Veterinary Medicine, Hannover, Germany. jschub@immunologie.tiho-hannover.de
Freigofas
R
R
Daugschies
A
A
Leibold
W
W
D000818:Animals; D003602:Cytotoxicity, Immunologic; D005260:Female; D005434:Flow Cytometry / Q000662:veterinary; D006099:Granuloma / Q000276:immunology / Q000469:parasitology / Q000662:veterinary*; D007411:Intestinal Diseases, Parasitic / Q000276:immunology / Q000469:parasitology / Q000662:veterinary*; D007814:Larva / Q000472:pathogenicity; D008297:Male; D009504:Neutrophils / Q000276:immunology*; D009814:Oesophagostomiasis / Q000276:immunology / Q000469:parasitology / Q000662:veterinary*; D009815:Oesophagostomum / Q000472:pathogenicity*; D011247:Pregnancy; D013552:Swine; D013553:Swine Diseases / Q000276:immunology* / Q000469:parasitology