Functional assessment of human dendritic cells labeled for in vivo (19)F magnetic resonance imaging cell tracking.

Item does not contain fulltextBACKGROUND AIMS: Dendritic cells (DC) are increasingly being used as cellular vaccines to treat cancer and infectious diseases. While there have been some promising results in early clinical trials using DC-based vaccines, the inability to visualize non-invasively the location, migration and fate of cells once adoptively transferred into patients is often cited as a limiting factor in the advancement of these therapies. A novel perflouropolyether (PFPE) tracer agent was used to label human DC ex vivo for the purpose of tracking the cells in vivo by (19)F magnetic resonance imaging (MRI). We provide an assessment of this technology and examine its impact on the health and function of the DC. METHODS: Monocyte-derived DC were labeled with PFPE and then assessed. Cell viability was determined by examining cell membrane integrity and mitochondrial lipid content. Immunostaining and flow cytometry were used to measure surface antigen expression of DC maturation markers. Functional tests included bioassays for interleukin (IL)-12p70 production, T-cell stimulatory function and chemotaxis. MRI efficacy was demonstrated by inoculation of PFPE-labeled human DC into NOD-SCID mice. RESULTS: DC were effectively labeled with PFPE without significant impact on cell viability, phenotype or function. The PFPE-labeled DC were clearly detected in vivo by (19)F MRI, with mature DC being shown to migrate selectively towards draining lymph node regions within 18 h. CONCLUSIONS: This study is the first application of PFPE cell labeling and MRI cell tracking using human immunotherapeutic cells. These techniques may have significant potential for tracking therapeutic cells in future clinical trials.1 april 201

Efficacy and Immune Mechanisms of Cetuximab for the Treatment of Metastatic Colorectal Cancer

Cetuximab is a chimeric immunoglobulin G1 mono-clonal antibody that targets the ligand-binding domain of the epidermal growth factor receptor and inhibits downstream intra- cellular signals. Research has shown that etuximab can stimulate the autoimmune system and produce antibody-dependent cellular cytotoxicity and complement-dependent cytotoxicity reactions, which can recruit cytotoxic lymphocytes to attack and kill cancer cells. Cetuximab is mainly indicated for patients with epidermal growth factor receptor-positive metastatic colorectal cancer who fail to respond to both irinotecan- and oxaliplatin-based regimens. The efficacy and safety of cetuximab as monotherapy or in combination with other treatment options were evaluated in a series of phase II and phase III trials. Identifying the clinical and molecular markers that can predict which patient groups may best benefit from cetuximab treatment is key to improving patient outcomes and avoiding unnecessary toxicities and costs. Herein, we discuss the mechanisms of action by which cetuximab exerts its antitumor effects, as well as the possible clinical and molecular markers that may help predict therapeutic benefits for patients with metastatic colorectal cancer