Cytokine mRNA expression in human epidermis after patch treatment with rhus and sodium lauryl sulfate

image: Cytokines have been shown to play a pivotal role in the development and elicitation of contact hypersensitivity reactions. The sources of these cytokines in the skin include T cells, keratinocytes, and Langerhans cells. image: In an effort to characterize the cytokines involved in the elicitation phase of a contact allergic response, we examined mRNA expression in human epidermis following patch testing with a known allergen and vehicle. image: Allergic subjects were patch tested with poison ivy allergen (rhus), irritant (sodium lauryl sulfate [SLS]) and vehicle controls for 24 hours. Epidermal samples were obtained from the patch sites by a suction blister technique. Total RNA was isolated from the epidermis and the level of cytokine gene expression was determined using reverse transcriptase polymerase chain reaction (RT-PCR). PCR products for the various cytokines were confirmed and semiquantitated by liquid hybridization with 32P-labeled product-specific probes. image: Results of liquid hybridization confirmed the presence of message for interleukin (IL)-2, IL-4 and IL-10 in rhus, SLS, and vehicle treated sites. Generally, in rhus treated sites, the steady state level of message for IL-2 was highest, followed by IL-4 and IL-10, in decreasing levels. In contrast, only minimal expression of mRNA for these cytokines was observed in irritant and vehicle treated sites. Interestingly, interferon (IFN)-γ mRNA was not detected at 24 hours in rhus, SLS, or vehicle treated sites. image: These preliminary results indicate differences in the steady state levels of cytokine mRNA in allergen versus vehicle and irritant treated sites at 24 hours after treatment.