Interventional pulmonology: an update for internal medicine physicians.

Interventional pulmonology is a subspecialty that uses advanced diagnostic and therapeutic procedures to care for patients with benign and malignant diseases of the lung, airways and pleura. There has been a rapid proliferation of new pulmonary procedural technologies over the last decade. Common diagnostic applications include endobronchial ultrasound, guided bronchoscopy and a number of pleural disease interventions. Endobronchial ultrasound is performed with a specially design flexible bronchoscope and allows safe and accurate sampling of intrathoracic structures through the airway wall under direct visualization. Guided bronchoscopy methods are granting significant improvement in the diagnostic yield of flexible bronchoscopy. Virtual bronchoscopy, radial probe endobronchial ultrasound and electromagnetic navigational bronchoscopy are examples of these methods. Interventional pulmonologists can also be trained to perform ultrasound guided thoracentesis, closed-needle pleural biopsy and medical thoracoscopy to help in the diagnosis of different pleural pathologies. Therapeutic applications can be used to efficiently bring symptomatic relief of benign and malignant central airway obstruction by using a myriad of flexible and rigid bronchoscopy techniques. Airway stenting and ablative techniques such as laser, electrocautery, cryosurgery and microdebrider techniques are example of resources that can be used by interventional pulmonologists for therapeutic purposes. A number of effective therapies for the management of malignant pleural disease have been studied in recent years, including chemical pleurodesis and tunnelled pleural catheters, greatly adding to our understanding of which therapy to use in which patient. In addition, flexible bronchoscopy approaches to more common disease, such as asthma and chronic obstructive pulmonary disease are currently available or are being developed. This update aims to provide the internal medicine physician with a brief overview of some of the common clinical procedures performed by interventional pulmonary specialists and the current indications and evidence for their use.

Sorting vector producer cells for high transgene expression increases retroviral titer.

Vector producer cells are derived from helper cell lines expressing viral proteins that have been transduced to express a transgene-carrying retroviral genome. Vector producing cells express two relevant forms of RNA in their cytoplasm: vector RNA (vRNA) that is packaged as the actual gene transfer agent, and messenger RNA (mRNA) from which transgene is translated. Two premises underlie this study: (1) vRNA is limiting for virus production and (2) mRNA is proportional to vRNA. Together, these premises predict that transgene expression in the vector producing cells will be predictive of the viral titer from those cells. In this case, sorting the vector producing cells for high transgene expression should select for more virus production in vector producing cell supernatants. This prediction was supported, with a greater than fivefold benefit in viral titer. This demonstrates a rapid and simple method by which to obtain significantly increased viral titers from the same vector producing cell preparation.

Chimeric immune receptors (CIRs) specific to JC virus for immunotherapy in progressive multifocal leukoencephalopathy (PML).

Progressive multifocal leukoencephalopathy (PML) is a deadly brain disease caused by the polyomavirus JC (JCV). The aim of this study is to develop 'designer T cells' armed with anti-JCV TCR-based chimeric immune receptors (CIRs) by gene modification for PML immunotherapy. Two T cell lines specific to two dominant CTL epitopes derived from JCV VP1 protein (termed p36 and p100) from an HLA-A0201+ PML survivor were generated for TCR cloning. Two distinct dominant TCR alpha chains (Valpha6 and Valpha12) and a unique TCR beta chain (Vbeta5.1) were cloned from the p36-specific cell line, while only one alpha (Valpha8.6) and one beta (Vbeta2) chains were dominant in the p100-specific line. Retroviral constructs encoding CIRs were created with the extracellular domains of TCR alpha and beta chains fused to the transmembrane and cytoplasmic portions of CD3zeta (ValphaCalphaCD3zeta or VbetaCbetaCD3zeta). Cellular expression and screening for binding specific peptide-HLA-A0201 tetramer confirmed the reactivity of the p100 TCRalphabeta and of one of the two pairs of p36 TCRalphabeta (Valpha12 and Vbeta5.1). Functional tests confirmed CIR-expressing T cells secreted cytokines and expressed potent cytotoxicity on contact with A0201+ B-lymphoblastoid line loaded with peptides and/or with HLA-A0201+ cells expressing native JCV VP1 protein. In conclusion, anti-JCV designer T cells were generated.