The IMBG Test for Evaluating the Pharmacodynamic Response to Immunosuppressive Therapy in Kidney Transplant Patients: Current Evidence and Future Applications.

Immunosuppressive drugs are widely used to prevent rejection after kidney transplantation. However, the pharmacological response to a given immunosuppressant can vary markedly between individuals, with some showing poor treatment responses and/or experiencing serious side effects. There is an unmet need for diagnostic tools that allow clinicians to individually tailor immunosuppressive therapy to a patient's immunological profile. The Immunobiogram (IMBG) is a novel blood-based in vitro diagnostic test that provides a pharmacodynamic readout of the immune response of individual patients to a range of immunosuppressants commonly used in kidney transplant recipients. Here, we discuss the current approaches used to measure the pharmacodynamic responses of individual patients to specific immunosuppressive drugs in vitro, which can then be correlated with patient's clinical outcomes. We also describe the procedure of the IMBG assay, and summarize the results obtained using the IMBG in different kidney transplant populations. Finally, we outline future directions and other novel applications of the IMBG, both in kidney transplant patients and other autoimmune diseases.

The Immunobiogram, a Novel In Vitro Assay to Evaluate Treatment Resistance in Patients Receiving Immunosuppressive Therapy.

Immunosuppressive drugs are widely used to treat several autoimmune disorders and prevent rejection after organ transplantation. However, intra-individual variations in the pharmacological response to immunosuppressive therapy critically influence its efficacy, often resulting in poor treatment responses and serious side effects. Effective diagnostic tools that help clinicians to tailor immunosuppressive therapy to the needs and immunological profile of the individual patient thus constitute a major unmet clinical need. In vitro assays that measure immune cell responses to immunosuppressive drugs constitute a promising approach to individualized immunosuppressive therapy. Here, we present the Immunobiogram, a functional pharmacodynamic immune cell-based assay for simultaneous quantitative measurement of a patient's immune response to a battery of immunosuppressive drugs. Peripheral blood mononuclear cells collected from patients are immunologically stimulated to induce activation and proliferation and embedded in a hydrogel mixture in which they are exposed to a concentration gradient of the immunosuppressants of interest. Analysis of samples from kidney transplant patients using this procedure revealed an association between the sensitivity of individual patients to the immunosuppressive regimen and their immunological risk of transplant rejection. Incorporation of the Immunobiogram assay into clinical settings could greatly facilitate personalized optimization and monitoring of immunosuppressive therapy, and study of the mechanisms underlying resistance to immunosuppressants.

Dasatinib Reversibly Disrupts Endothelial Vascular Integrity by Increasing Non-Muscle Myosin II Contractility in a ROCK-Dependent Manner.

Purpose: Dasatinib is a short-acting dual ABL/SRC family tyrosine kinase inhibitor (TKI), which is frequently used to treat chronic myeloid leukemia. Although very effective, patients taking dasatinib often display severe adverse effects, including pleural effusions and increased risk of bleeding primarily in the gastrointestinal tract. The actual causes of these side effects are currently undetermined. We hypothesize that endothelial cells (ECs) that line the inner walls of blood vessels and control the traffic to the underlying tissues might be involved.Experimental Design: The effects of TKIs on ECs were studied by various assays, such as real-time cell impedance measurements, live-cell microscopy, wound healing, Western blot, and an in vivo model.Results: Dasatinib uniquely causes a profound, dose-dependent disorganization of the EC monolayers. Dasatinib promoted the disassembly of cell-cell contacts, altered cell-matrix contacts, and further altered the wound healing. A key observation is that this effect is fully reversible after drug washout. In line with these in vitro observations, intraperitoneal administration of dasatinib to mice caused significant vascular leakage in the intestine. The underlying molecular mechanism of dasatinib-induced reorganization of the actin involves ROCK activation, which increases the amount of the phosphorylation of myosin light chain and consequently activates the non-muscle myosin II.Conclusions: Our data are consistent with a scenario in which dasatinib triggers a transient increase in vascular leakage that probably contributes to adverse effects such as bleeding diathesis and pleural effusions. Clin Cancer Res; 23(21); 6697-707. ©2017 AACR.

Concerning immune synapses: a spatiotemporal timeline.

The term "immune synapse" was originally coined to highlight the similarities between the synaptic contacts between neurons in the central nervous system and the cognate, antigen-dependent interactions between T cells and antigen-presenting cells. Here, instead of offering a comprehensive molecular catalogue of molecules involved in the establishment, stabilization, function, and resolution of the immune synapse, we follow a spatiotemporal timeline that begins at the initiation of exploratory contacts between the T cell and the antigen-presenting cell and ends with the termination of the contact. We focus on specific aspects that distinguish synapses established by cytotoxic and T helper cells as well as unresolved issues and controversies regarding the formation of this intercellular structure.