INTERLEUKIN-1-ALPHA IS RELEASED DURING TRANSFECTION OF KERATINOCYTES

Keratinocytes are known to produce, store, and release IL-1 alpha and therefore we suspected that the DNA-mediated cell transfection procedu re may release the stored IL-1 alpha from keratinocytes into the mediu m. Using enzyme-linked immunosorbent assay, we determined the IL-1 alp ha concentration in culture supernatants during keratinocyte transfect ion. The following transfection methods were compared: lipofection wit h lipofectACE and lipofectAMINE (GIBCO), Ca-3(PO4)(2) co-precipitation , and polybrene-dimethylsulfoxide (DMSO). The supernatants were collec ted immediately prior to transfection, after 5-h incubation with lipof ectin or Ca-3(PO4)(2), and 24 and 48 h after transfection. In the poly brene-DMSO method, the supernatant was also collected immediately befo re and after DMSO shock. LipofectAMINE caused the highest release of I L-1 alpha, whereas the lipofectACE and polybrene-DMSO mediated transfe ction with confluent cells released the least. The other two methods r eleased intermediate levels of IL-1 alpha. Our data indicate that a su bstantial amount of IL-1 alpha is released during the keratinocyte tra nsfection procedure, which can affect the results of transfection in s tudies of gene expression.