Amplification of extracellular matrix and oncogenes in tat-transfected human salivary gland cell lines with expression of laminin, fibronectin, collagens I, III, IV, c-myc and p53

Considerable progress has been made in the transfer of foreign genes into s alivary glands in vivo using adenovirus vectors in rats. In an attempt to a void the transient expression inherent, when using these vectors, retrovira l vectors and human cell lines where used here in attempt to develop an in vitro model of HIV-associated salivary gland disease. The HIV-1-tat protein is increasingly implicated in the pathogenesis of the AIDS through alterin g the expression of strategic cellular genes. The purpose of this study was to transfect human salivary gland (HSG) cell lines in vitro, with the pHIV -1/LTR-tat plasmid, and examine the effect of tar on expression of matrix a nd basement membrane genes known to be important in the pathogenesis of sal ivary gland disease. HSG cells were transfected with HIV-1-tat plasmid by t he lipofection method. Transfection was confirmed by polymerase chain react ion (PCR) and Southern blot, which verified that tat-specific DNA was prese nt. Tat-mRNA was analysed by Northern blotting and quantified by reverse tr anscriptase polymerase chain reaction (RT-PCR) to demonstrate its expressio n. Numerous clones were found to contain integrated tat DNA sequences and a nalysis of mRNA showed stable expression of tat-specific RNA. Further analy sis of mRNA expression for various marker proteins important in HIV pathoge nesis showed that the HSG cell line transfected with HIV-1-tat, was associa ted with significant induction of mRNA expression for extracellular matrix protein. rat-amplified transcription of the major basement membrane protein laminin, as well as of fibronectin, collagen I and III, and c-myc oncogene was demonstrated. Conversely, expression of p53 suppressor gene mRNA was r educed. Post-transfection expression of collagen IV was erratic and inconcl usive. It was concluded that the presence of HIV-tat in this in vitro model of salivary ductal epithelial cell model alters the mRNA expression of sev eral matrix, basement membrane and oncoproteins known to be involved in HIV pathogenesis. These cell lines provide a useful system for studying the ro le of tat in the immunopathogenesis of HIV-associated salivary gland diseas e. (C) 2001 Elsevier Science Ltd. All rights reserved.