Detection of wild type and deleted latent membrane protein 1 (LMP1) of Epstein-Barr virus in clinical biopsy material.

The latent membrane protein 1 (LMP1) of Epstein-Barr virus (EBV) is one of two postulated viral oncogenic proteins. Sequence variations, and in particular a 30 base pair deletion variant called CAO, may define different disease populations. We developed a panel of rat monoclonal antibodies (MAb) specific for the non-wild type LMP1 and compared the presence of the antibody staining with LMP1 DNA sequence analysis on clinical samples of nasopharyngeal carcinoma, peripheral T-cell lymphoma (PTCL), Hodgkin's disease, lymphoblastoid cell lines (LCL) from normal volunteers, and patients with nasopharyngeal carcinoma. The results demonstrate specificity of the monoclonal cocktail for detecting the non-wild type LMP1 and the ability to sub-differentiate between the mediterranean type of LMP1 and the CAO-LMP1. Double immunofluorescence on paraffin material using the traditional CS1-4 monoclonal antibodies and the CAO-cocktail revealed no dual population of cells in the biopsy material from the Asian region.