Financial support: U.S. Army Medical Research and Material Command under contract DAMD17-00139, grants RR03060, RR08168 from the National Institutes of Health, and PSC-CUNY award from the State of New York.

Keywords: chemical agent, human keratinocytes,interlukin-8, simian virus 40, sulfur mustard.

Present address: # MCHK-CI, Bldg 40 Dept of Clinical Investigation, 1 Jarrett White Road, Tripler Army Medical Center, Hawaii 96859-5000.

Abbreviations:
HD: 2,2'-dichlorodiethyl sulfide, HD
HEK: Human epidermal keratinocyte
IL-8: Interleukin-8
SV40: Simian Virus 40
PI: Propidium Iodide
IB: Ibuprofen

Cytokines have been established as biomarkers to detect exposure of cells to chemical warfare agents such as sulfur mustard (2,2'-dichlorodiethyl sulfide, HD). In this study cultured normal and SV40 immortalized human epidermal keratinocyte (NHEK/IHEK) cells were compared as potential model systems to measure the efficacy of therapeutic drugs against HD. Immortalized human epidermal keratinocytes resemble their primary cell counterparts but have the advantage of being carried through long-term culture. Immortalized cells also provide consistency and durability and are less costly than primary keratinocytes. Immunoassay studies were performed to examine the response of these two cell lines to HD. We found that both normal and immortalized NHEKs secreted the pro-inflammatory mediator interleukin-8 (IL-8) when exposed to HD. However, a major difference was observed between the NHEK cell line 6207 and IHEK cell line 425. IHEK cell line 425 produced higher levels of Interleuken-8 then those of its normal counterpart cell line 6207. This observation is significant since therapeutic drugs such as ibuprofen, which depress cytokine production, may not allow these biomarkers to be detected efficiently in experimental analysis of certain NHEK cell lines. The fact that Il-8 production higher in cell line 425 cell makes this in vitro model a potential screening tool to study the efficacy of drugs that suppress production of cytokine markers.