Drug toxicity and viral resistance limit the long-term efficacy of antiviral drug treatment for human immunodeficiency virus (HIV) infection. Thus, alternative therapies need to be explored. We tested the infusion of T lymphocytes transduced with a retroviral vector (M87o) that expresses an HIV entry-inhibitory peptide (maC46). Gene-modified autologous T cells were infused into ten HIV-infected patients with advanced disease and multidrug-resistant virus during anti-retroviral combination therapy. T-cell infusions were tolerated well, with no severe side effects. A significant increase of CD4 counts was observed after infusion. At the end of the 1-year follow-up, the CD4 counts of all patients were still around or above baseline. Gene-modified cells could be detected in peripheral blood, lymph nodes, and bone marrow throughout the 1-year follow-up, and marking levels correlated with the cell dose. No significant changes of viral load were observed during the first 4 months. Four of the seven patients who changed their antiviral drug regimen thereafter responded with a significant decline in plasma viral load. In conclusion, the transfer of gene-modified cells was safe, led to sustained levels of gene marking, and may improve immune competence in HIV-infected patients with advanced disease and multidrug-resistant virus.

Introduction of the post-transcriptional regulatory element (PRE) of woodchuck hepatitis virus (WHV) into the 3 0 untranslated region of retroviral and lentiviral gene transfer vectors enhances both titer and transgene expression. Optimal use of the PRE is often necessary to obtain vectors with sufficient performance for therapeutic applications. The enhancing activity of the PRE depends on the precise configuration of its sequence and the context of the vector and cell into which it is introduced. However, data obtained in the context of WHVassociated hepatocellular carcinomas suggests that the PRE might potentially contribute to tumorigenesis, especially if encoding a truncated version of the WHV X protein.

Besides cancer and cardiovascular diseases, lung disorders are a leading cause of morbidity and death worldwide. For many disease conditions no effective and curative treatment options are available. Cell therapies offer a novel therapeutic approach due to their inherent anti-inflammatory and anti-fibrotic properties. Mesenchymal stem/stromal cells (MSC) are the most studied cell product. Numerous preclinical studies demonstrate an improvement of disease-associated parameters after MSC administration in several lung disorders, including chronic obstructive pulmonary disease, acute respiratory distress syndrome and idiopathic pulmonary fibrosis. Furthermore, results from clinical studies using MSCs for the treatment of various lung diseases indicate that MSC treatment in these patients is safe. In this review we summarise the results of preclinical and clinical studies that indicate that MSCs are a promising therapeutic approach for the treatment of lung diseases. Nevertheless, further investigations are required.

A variety of measurement techniques including photothermal deflection spectroscopy (PDS), auger electron spectroscopy (AES), (sub–bandgap) external quantum efficiency (EQE), and impedance spectroscopy are applied to poly[N‐900‐hepta‐decanyl‐2,7‐carbazole‐alt‐5,5‐(40,70‐di‐2‐thienyl‐20,10,30‐benzothiadiazole (PCDTBT)/[6,6]‐phenyl C71 butyric acid methyl ester (PC71BM) films and devices to probe the stability under thermal annealing. Upon annealing, solar cell performance is drastically decreased for temperatures higher than 140 °C. Detailed investigation indicate changes in polymer:fullerene interactions resulting in the formation of a polymer wetting layer upon annealing at temperatures higher than 140 °C. Upon device completion this wetting layer is located close to the metal electrode and therefore leads to an increase in recombination and a decrease in charge carrier extraction, providing an explanation for the reduced fill factor (FF) and power conversion efficiency (PCE).

Chimeric antigen receptor (CAR) redirected T cells are efficacious in the treatment of leukemia/lymphoma, however, showed less capacities in eliminating solid tumors which is thought to be partly due to the lack of cytokine support in the tumor lesion. In order to deliver supportive cytokines, we took advantage of the inherent ability of mesenchymal stem cells (MSCs) to actively migrate to tumor sites and engineered MSCs to release both IL7 and IL12 to promote homeostatic expansion and Th1 polarization. There is a mutual interaction between engineered MSCs and CAR T cells; in presence of CAR T cell released IFN-γ and TNF-α, chronic inflammatory Th2 MSCs shifted towards a Th17/Th1 pattern with IL2 and IL15 release that mutually activated CAR T cells with extended persistence, amplification, killing and protection from activation induced cell death. MSCs releasing IL7 and IL12 were superior over non-modified MSCs in supporting the CAR T cell response and improved the anti-tumor attack in a transplant tumor model. Data demonstrate the first use of genetically modified MSCs as vehicles to deliver immuno-modulatory proteins to the tumor tissue in order to improve the efficacy of CAR T cells in the treatment of solid malignancies.

Binding of the human immunodeficiency virus (HIV) envelope glycoprotein (Env) to the cellular CD4 receptor and a chemokine coreceptor initiates a series of conformational changes in the Env subunits gp120 and gp41. Eventually, the trimeric gp41 folds into a six-helix bundle, thereby inducing fusion of the viral and cellular membranes. C peptides derived from the C-terminal heptad repeat (CHR) of gp41 are efficient entry inhibitors as they block the six-helix bundle formation. Previously, we developed a membrane-anchored C peptide (maC46) expressed from a retroviral vector that also shows high activity against virus strains resistant to enfuvirtide (T-20), an antiviral C peptide approved for clinical use. Here, we present a systematic analysis of mutations in Env that confer resistance of HIV type 1 (HIV-1) to maC46. We selected an HIV-1 BaL strain with 10-fold reduced sensitivity to maC46 (BaL_C46) by passaging virus for nearly 200 days in the presence of gradually increasing concentrations of maC46. In comparison to wild-type BaL, BaL_C46 had five mutations at highly conserved positions in Env, three in gp120, one in the N-terminal heptad-repeat (NHR), and one in the CHR of gp41. No mutations were found in the NHR domain around the GIV motif that are known to cause resistance to enfuvirtide. Instead, maC46 resistance was found to depend on complementary mutations in the NHR and CHR that considerably favor binding of the mutated NHR to the mutated CHR over binding to maC46. In addition, resistance was highly dependent on mutations in gp120 that accelerated entry. Taken together, resistance to maC46 did not develop readily and required multiple cooperating mutations at conserved positions of the viral envelope glycoproteins gp120 and gp41.

No abstract

Membrane-anchored C-peptides (for example, maC46) derived from human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein gp41 effectively inhibit HIV-1 entry in cell lines and primary human CD4+ cells in vitro. Here we evaluated this gene therapy approach in animal models of AIDS. We adapted the HIV gp41-derived maC46 vector construct for use in rhesus monkeys. Simian immunodeficiency virus (SIV and SHIV) sequence-adapted maC46 peptides, and the original HIV-1-derived maC46 expressed on the surface of established cell lines blocked entry of HIV-1, SIVmac251 and SHIV89.6P. Furthermore, primary rhesus monkey CD4+ T cells expressing HIV sequence-based maC46 peptides were also protected from SIV entry. Depletion of CD8+ T cells from PBMCs enhanced the yield of maC46-transduced CD4+ T cells. Supplementation with interleukin-2 (IL-2) increased transduction efficiency, whereas IL-7 and/or IL-15 provided no additional benefit. Phenotypic analysis showed that maC46-transduced and expanded cells were predominantly central memory CD4+ T cells that expressed low levels of CCR5 and slightly elevated levels of CD62L, b7-integrin and CXCR4. These findings show that maC46-based cell surface-expressed peptides can efficiently inhibit primate immunodeficiency virus infection, and therefore serve as the basis for evaluation of this gene therapy approach in an animal model for AIDS.