Primary cultures of human keratinocytes were challenged with increasing doses from 10 ng/mL to 2 <FONT FACE="Symbol">m</FONT>g/mL of Loxosceles gaucho venom, responsible for dermonecrotic lesion in humans. TNF-<FONT FACE="Symbol">a</FONT> was investigated by bioassay and ELISA in the supernatant of the cultures challenged with 100 ng/mL, 500 ng/mL, 1 and 2 <FONT FACE="Symbol">m</FONT>g/mL of venom. TNF-<FONT FACE="Symbol">a</FONT> was detected by bioassay in the supernatant of cultures challenged with 100 ng/mL, after 6 h. The cytokine was detected by ELISA in the supernatant of the cells challenged with doses of l <FONT FACE="Symbol">m</FONT>g/mL, after 6 and 12 h. The results point out the capacity of this venom to activate the keratinocytes in primary cultures to produce TNF-<FONT FACE="Symbol">a</FONT>. The production of cytokines could contribute to the local inflammatory process in patients bitten by Loxosceles sp.
Loxosceles; Keratinocytes; Cell culture; TNF-<FONT FACE=Symbol>a</FONT>
