Alveolar macrophages and T cells from sarcoid, but not normal lung, are permissive to adenovirus infection and allow analysis of NF-kappa B-dependentsignaling pathways

Adenovirus (Adv)-mediated gene transfer requires efficient infection of tar get cells. The objective of this study was to establish whether alveolar ma crophages (AM) and T cells (AT) from sarcoid patients were permissive to in fection with Adv vectors and if this property could be used to investigate cytokine gene regulation. Sarcoid and normal bronchoalveolar lavage (BAL) s pecimens infected with Adv vectors expressing either P-galactosidase or a g reen fluorescent protein were analyzed for transgene expression by fluoresc ence-activated cell sorter (FACS) and direct immunofluorescence, respective ly. Expression of surface antigens previously associated with Adv infection , the coxsackie/adenovirus receptor (CAR), alphav beta3, and alphav beta5 i ntegrins, was also assessed using FACS analysis. Sarcoid AM and AT were fou nd to efficiently express Adv transgenes, unlike AM from normal volunteers, peripheral blood monocytes, and peripheral blood T cells. Cells permissive to Adv infection expressed the CAR and alphav beta5 integrin (also alphav beta3 integrin for AM). The data indicate that the upregulation of Adv rece ptors and the ability to infect sarcoid AM and AT are related to the inflam matory environment within the lung. Having demonstrated efficient Adv-media ted transgene delivery to sarcoid AM and AT, a construct encoding porcine I kappaB alpha. was then used to investigate the requirement for nuclear fac tor (NF)-kappaB in the regulation of cytokine gene expression in pulmonary sarcoidosis. Overexpression of I kappaB alpha in sarcoid BAL specimens indi cated that tumor necrosis factor-a and interleukin (IL)-6 production by AM and interferon (IFN)-gamma production by AT is NF-kappaB dependent, whereas IL-4 production by AT is NF-kappaB independent. This is the first occasion that the requirement for NF-kappaB in IFN-gamma gene expression within pri mary human T cells has been demonstrated. The results of this study have im plications for the future investigation of molecular pathways in inflammato ry lung disease.