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ARS Home » Midwest Area » Ames, Iowa » National Animal Disease Center » Food Safety and Enteric Pathogens Research » Research » Publications at this Location » Publication #74630
Title: COMPARISON OF THE PK(15) AND WEHI 164 (CLONE 13)-BASED BIOASSAYS FOR THE DETECTION OF PORCINE TUMOR NECROSIS FACTOR

Author
item MAROUSHEK BOURY, N - IOWA STATE UNIVERSITY
item Stabel, Thomas
item Kehrli Jr, Marcus
item TAYLOR, M - IOWA STATE UNIVERSITY

Submitted to: American Journal of Veterinary Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/15/1997
Publication Date: N/A
Citation: N/A

Interpretive Summary: Salmonella species of bacteria are a serious worldwide problem causing swine disease estimated to cost $100 million annually in the United States. Salmonella bacteria also are important human pathogens and are of great concern in food safety. In response to infection with Salmonella bacteria, and numerous other gram-negative bacteria, swine produce tumor necrosis factor (TNF). A certain amount of TNF is good for stimulation of the immune system; however, overproduction of TNF can cause a variety of diseases sometimes ending in death. Since the amount of TNF produced is important to the outcome of disease, the ability to accurately measure TNF will provide important information necessary for regulation of TNF levels and control of salmonellosis. We compared the sensitivity of a pig (PK-15) and mouse (WEHI 164-13) cell line to human, mouse, and pig TNF. We found that PK-15 cells are 50 times less sensitive to mouse TNF, and 15 times less sensitive to human TNF than are WEHI 164-13 cells. The PK-15 cells are, however, 4 times more sensitive to recombinant pig TNF and 15 times more sensitive to serum TNF. Because the PK-15-based bioassay was more sensitive for detecting pig TNF in serum, this bioassay may be particularly useful to researchers in the study of salmonellosis and other pig diseases. Once all levels of TNF activity can be accurately measured, methods to reduce the activity of excess TNF can be developed and thus reduce the economic impact of salmonellosis in swine. Ultimately, this will benefit the consumer through a continued supply of inexpensive, wholesome pork and pork products.

Technical Abstract: It has been reported that a subclone of the murine WEHI 164 cell line, clone 13, is one hundred times more sensitive to human TNF-mediated lysis than is another murine cell line, L929. Recently, a new bioassay was described using a porcine cell line, PK(15) (ATCC CCL 33) in the place of more commonly used murine cell lines. The PK(15) based bioassay was 100-1000 times more sensitive than the L929 based assay when detecting porcine TNF. We compared the sensitivity of PK(15) and WEHI 164(13) cells to human, murine and porcine TNF-mediated lysis. Our data indicates the PK(15) cells are 50 times less sensitive to murine TNF and 15-fold less sensitive to human TNF than are WEHI 164(13) cells. The PK(15) cells are, however, 4 times more sensitive to recombinant porcine TNF and 15 times more sensitive to porcine serum containing TNF. Because the PK(15)-based bioassay was more sensitive for detecting porcine TNF in serum, this bioassay may be particularly useful in the study of infectious disease processes of swine.