Expression of Epstein-Barr virus latent membrane proteins leads to changesin keratinocyte cell adhesion

Epstein-Barr virus (EBV) has 3 latent membrane proteins (LMPs)- LMP1, LMP2a , and LMP2b - which are expressed in nasopharyngeal carcinoma. Using kerati nocyte cell lines expressing LMP2a and LMP2b and coexpressing LMP1/LMP2a, w e grew organotypic raft cultures to analyze changes in morphology and expre ssion of the cell adhesion molecule ICAM-1; alpha 2, alpha 3, alpha 5, beta 1, and alpha 6 beta 4 integrins; laminin 5; E-cadherin; and desmoplakin. C ells expressing LMP2a or LMP2b were defective in their ability to mature an d progress through normal squamous stratification when compared to the pare ntal cell lines. Cells coexpressing LMP1/LMP2a additionally demonstrated "p seudoinvasion" into the raft dermal equivalent. There was a consistent and dramatic up-regulation in the suprabasal expression of laminin 5 and alpha 6 beta 4 and beta 1 integrins in the LMP-expressing cell lines. ICAM-1, not expressed in the control cell lines, was up-regulated in the LMP-expressin g cell lines. Expression of alpha 3 and alpha 5 integrins was also up-regul ated in the LMP-expressing cell lines, while alpha 2 demonstrated a loss of the normal basal layer expression. E-cadherin and desmoplakin expression p atterns were essentially unchanged. We conclude that LMP2a and LMP2b singly , and LMP1/LMP2a coexpressed, are capable of altering keratinocyte cell adh esion molecule expression consistent with nasopharyngeal carcinoma.