The Effect of High Dose UVA - 1 and UVA - 2 Irradiation on the Expression of Surface Markers of Epidermal Langerhans Cells and Induction of contact Hypersensitivity in Mice Skin

Jang, Min Soo; Chae, Young Soo; Suh, Kee Suck; Kim, Sang Tae

Abstract

BACKGROUND: It is knovn that Langerhans cells are damaged fuctionally and morphologically by UV irradiation. Recently, high-dose UVA-1 therapy (340-400nm) was introduced as an effective treatment of severe exacerbated atopic dermatitis. However, the effect of UVA-1 therapy on surface markers and function of epidermal Langerhans cells are still unclear.
OBJECTIVE
To determine whether a high dose UVA-1 irradiation affects cutaneous immune system, the effect of UVA-1 on the expression of ATPase and Ia antigen of mouse epidermal Langerhans cells and induction of contact hypersensitivity in mice skin were investigated and were compared to those of UVA-2.
METHODS
Balb/c mice were irradiated with 150J/cm and 300J/cm of UVA-1 and UVA-2 in a single dose at one time or 3 fractionated doses for 3 days. The number of Langerhans cells was evaluated using ATPase and immunoperoxidase-stained epidermal sheets. Balb/c mice were irradiated with same manner after induction of contact hypersensiyity by applying 0.5% oxazolone solution and the influence of UV irradiation was evaluated by measuring the ear swelling of mice.
RESULTS
1. The expression of surface markers of Langerhans cells was not affected by 150J/cm and fractionated 300J/cm of UVA-1. However, single irradiation of 300J/cm of UVA-1 reduced signifi-cantly the expression of surface markers. The irradiation of UVA-2 induced more prominent reduction of the expression of surface markers compared to UVA-l. 2. Although the induction of contact hypersensitity was not inhibited in groups irradiated by single or fractionated 150J/cm of UVA-1, it was inhibited in groups irradiated with 300J/cm of UVA-1. The inhibition of contact hypersensitivity induction by UVA-2 irradiation was also more prominent than that by UVA-1.
CONCLUSION
These results suggest that epidermal Langerhans cells could be damaged by high doses of UVA-1 and the damage of Langerhans cells by UVA-1 is weaker than that by UVA-2.