VEGFR2-specific FnCAR effectively redirects the cytotoxic activity of T cells and YT NK cells.

T and NK cells armed with chimeric antigen receptors (CAR) are promising tools for the specific elimination of cancer cells. In most CAR designs implemented to date, the recognition of target cells is mediated by single-chain variable fragments (scFvs) derived from murine monoclonal antibodies. This format, however, has a number of limitations, including its relatively large size and potential immunogenicity in humans. In this study, we explored the feasibility of using human fibronectin type III domains (Fn3) as the antigen recognition domain in CARs. Human Fn3 domains have lower predicted immunogenicity compared to mouse-derived sequences, and a reduced molecular weight compared to scFvs. We created a functional CAR using a VEGFR2-specific Fn3 module replacing the conventional scFv. The resulting FnCAR specifically potentiates the cytotoxic activity of human T cells and YT NK cells in the presence of VEGFR2-positive targets. These findings demonstrate that Fn3 domains can be used in CARs for antigen recognition.

Bone marrow- and subcutaneous adipose tissue-derived mesenchymal stem cells: differences and similarities.

Bone marrow (BM) and subcutaneous adipose tissue (Ad) are both considered being prospective sources of MSC for therapeutic applications. However, functional properties and therapeutic efficacy of MSC derived from different tissues of the same patient are still poorly investigated. In our study, BM-MSC and F-MSC cultures from 43 adult donors were evaluated in successive passages for immunophenotype, secretion of VEGF, SDF1, MCP1, IL6 and TGFß1, frequency of colony-forming units (CFU-F), frequency of adipo- and osteo-progenitors (CFU-Ad, CFU-Ost), and for onset of in vitro replicative senescence. We have demonstrated that at early passages (P2-P4 or up to 14-15 in vitro population doublings) BM- and Ad- derived MSC cultures are comparable in such important characteristics as proliferation rate (population doubling time: 3.4±0.2% in BM-MSC, 3±0.3% in F-MSC), clonogenity (CFU-F frequency: 32±5% in BM-MSC, 31±5% in F-MSC), differentiation potential (CFU-Ad frequency: 10.4±2% in BM-MSC, 13±3% in F-MSC; CFU-Ost frequency: 18.5±5.5% in BM-MSC, 18±5% in F-MSC), but differ significantly in abundance of CD146⁺ fraction within the sample (25±5% in BM-MSC, 7±3% in F-MSC) and in a level of VEGF, SDF-1, MCP1 and TGFß1 secretion. We have also demonstrated that BM-MSC enter senescence after P3-4 while most of F-MSC did not show senescence features up to P6-8. Together, these data demonstrate that specific properties of MSC from different sources should be always taken into account, when developing and optimizing the specific protocols for MSC expansion and evaluation for each particular clinical application.

Diabetes mellitus, cachexia and obesity in heart failure: rationale and design of the Studies Investigating Co-morbidities Aggravating Heart Failure (SICA-HF).

BACKGROUND: Chronic heart failure (CHF) is increasing in prevalence. Patients with CHF usually have co-morbid conditions, but these have been subjected to little research and consequently there is a paucity of guidance on how to manage them. Obesity and diabetes mellitus are common antecedents of CHF and often complicate management and influence outcome. Cachexia is an ominous and often missed sign in patients with CHF. METHODS: This manuscript describes the rationale and the design of Studies Investigating Co-morbidities Aggravating Heart Failure (SICA-HF), a prospective, multicentre, multinational, longitudinal, pathophysiological evaluation study, which is being conducted in 11 centres across six countries in the European Union and in Russia. We aim to recruit >1,600 patients with CHF due to various common aetiologies, irrespective of left ventricular ejection fraction, and with or without co-morbidities at study entry. In addition, >300 patients with type 2 diabetes mellitus without CHF and >150 healthy subjects will serve as control groups. Participants will be systematically investigated at annual intervals for up to 48 months. Additional investigations focusing on cellular and subcellular mechanisms, adipose and skeletal muscle tissue, and in endothelial progenitor cells will be performed in selected subgroups. CONCLUSIONS: SICA-HF will provide insights into common co-morbidities in CHF with a specific emphasis on diabetes mellitus and body mass. This will provide a more thorough pathophysiological understanding of the complexity of CHF that will help develop therapies tailored to manage specific co-morbidities.

T lymphocyte chemotactic chemokines in acute myelogenous leukemia (AML): local release by native human AML blasts and systemic levels of CXCL10 (IP-10), CCL5 (RANTES) and CCL17 (TARC).

T cell targeting immunotherapy is now considered in acute myelogenous leukemia (AML), and local recruitment of antileukemic T cells to the AML microcompartment will then be essential. This process is probably influenced by both intravascular as well as extravascular levels of T cell chemotactic chemokines. We observed that native human AML cells usually showed constitutive secretion of the chemotactic chemokines CXCL10 and CCL5, whereas CCL17 was only released for a subset of patients and at relatively low levels. Coculture of AML cells with nonleukemic stromal cells (i.e., fibroblasts, osteoblasts) increased CXCL10 and CCL17 levels whereas CCL5 levels were not altered. However, a wide variation between patients in both CXCL10 and CCL5 levels persisted even in the presence of the stromal cells. Neutralization of CXCL10 and CCL5 inhibited T cell migration in the presence of native human AML cells. Furthermore, serum CCL17 and CXCL10 levels varied between AML patients and were determined by disease status (both chemokines) as well as patient age, chemotherapy and complicating infections (only CCL17). Thus, extravascular as well as intravascular levels of T cell chemotactic chemokines show a considerable variation between patients that may be important for T cell recruitment and the effects of antileukemic T cell reactivity in local AML compartments.

Successful non-myeloablative allogeneic transplantation for treatment of idiopathic hypereosinophilic syndrome.

In this report, we describe two patients with idiopathic hypereosinophilic syndrome (HES) who received a non-myeloablative allogeneic transplantation following a reduced-intensity preparative regimen of melphalan and fludarabine. In both cases, complete donor chimaerism and remission were achieved, and have lasted for more than 10 months. This report provides proof of principle for the feasibility of non-myeloablative transplantation for patients with idiopathic HES, who can show co-morbidity due to eosinophilic infiltration of their organs.