Local hyperthermia decreases the expression of CCL-20 in condyloma acuminatum

Local hyperthermia has been successfully used in the treatment of viral warts. However, the mechanism of action has largely remained unclear. CCL-20 (also known as MIP-3α) is the most potent chemokine for recruitment of Langerhans cell (LC) precursors into the skin. CCL-20 expression can be increased by TNF-α and IL-1α. The effects of local hyperthermia on the mRNA expressions of CCL-20, TNF-α, IL-1α have been investigated in both condyloma acuminata (CA) and normal skin. Under an organotypic culture condition, fresh CA and normal skin were subjected to surface heating at 37°C, 42°C and 45°C for 30 mins, respectively.

The mRNA expressions of CCL-20 and IL-1α in CA specimen were significantly higher than those in normal skin. Local hyperthermia at 42°C and 45°C significantly decreased the mRNA levels of CCL-20 and IL-1α, as compared with the control groups (p < 0.01). The decrease of CCL-20 was well correlated with that of IL-1α. The expression of TNF-α in CA remained unchanged in spite of the temperature variation. Local hyperthermia at 45°C concomitantly increased the mRNA expression of CCL-20 and IL-1α in normal skin.

Our study suggests that hyperthermia decreases the expression of CCL-20 with concomitant decrease in IL-1α, and reduce the number of Langerhans cells in HPV infected skin.