Magselectofection: an integrated method of nanomagnetic separation and genetic modification of target cells

Research applications and cell therapies involving genetically modified cells require reliable, standardized, and cost-effective methods for cell manipulation. We report a novel nanomagnetic method for integrated cell separation and gene delivery. Gene vectors associated with magnetic nanoparticles are used to transfect/transduce target cells while being passaged and separated through a high gradient magnetic field cell separation column. The integrated method yields excellent target cell purity and recovery. Nonviral and lentiviral magselectofection is efficient and highly specific for the target cell population as demonstrated with a K562/Jurkat T-cell mixture. Both mouse and human enriched hematopoietic stem cell pools were effectively transduced by lentiviral magselectofection, which did not affect the hematopoietic progenitor cell number determined by in vitro colony assays. Highly effective reconstitution of T and B lymphocytes was achieved by magselectofected murine wild-type lineage-negative Sca-1(+) cells transplanted into Il2rg(-/-) mice, stably expressing GFP in erythroid, myeloid, T-, and B-cell lineages. Furthermore, nonviral, lentiviral, and adenoviral magselectofection yielded high transfection/transduction efficiency in human umbilical cord mesenchymal stem cells and was fully compatible with their differentiation potential. Upscaling to a clinically approved automated cell separation device was feasible. Hence, once optimized, validated, and approved, the method may greatly facilitate the generation of genetically engineered cells for cell therapies. (Blood. 2011;117(16): e171-e181

Cotton Rat (Sigmodon hispidus) Signaling Lymphocyte Activation Molecule (CD150) Is an Entry Receptor for Measles Virus

Cotton rats (Sigmodon hispidus) replicate measles virus (MV) after intranasal infection in the respiratory tract and lymphoid tissue. We have cloned the cotton rat signaling lymphocytic activation molecule (CD150, SLAM) in order to investigate its role as a potential receptor for MV. Cotton rat CD150 displays 58% and 78% amino acid homology with human and mouse CD150, respectively. By staining with a newly generated cotton rat CD150 specific monoclonal antibody expression of CD150 was confirmed in cotton rat lymphoid cells and in tissues with a pattern of expression similar to mouse and humans. Previously, binding of MV hemagglutinin has been shown to be dependent on amino acids 60, 61 and 63 in the V region of CD150. The human molecule contains isoleucine, histidine and valine at these positions and binds to MV-H whereas the mouse molecule contains valine, arginine and leucine and does not function as a receptor for MV. In the cotton rat molecule, amino acids 61 and 63 are identical with the mouse molecule and amino acid 60 with the human molecule. After transfection with cotton rat CD150 HEK 293 T cells became susceptible to infection with single cycle VSV pseudotype virus expressing wild type MV glycoproteins and with a MV wildtype virus. After infection, cells expressing cotton rat CD150 replicated virus to lower levels than cells expressing the human molecule and formed smaller plaques. These data might explain why the cotton rat is a semipermissive model for measles virus infection

Socioeconomic disparities in mortality after diffuse large B-cell lymphoma in the modern treatment era

Despite advances in treatment, including the introduction of rituximab, survival after diffuse large B-cell lymphoma (DLBCL) remains heterogeneous. However, no studies have considered the association between neighborhood socioeconomic status (SES) and race/ethnicity on DLBCL mortality before (1988-2000) and after (2001-2009) the introduction of rituximab. We studied all 33 032 DLBCL patients diagnosed between 1988-2009 in California for vital status through December 31, 2010. Patients diagnosed from 2001 to 2009 vs 1988 to 2000 had significantly decreased overall and DLBCL-specific mortality. However, those living in lower SES neighborhoods had 34% (95% confidence interval [CI], 27%-40%) and 24% (95% CI, 16%-32%) higher mortality rate from all causes and lymphoma, respectively, than patients in higher SES neighborhoods. The magnitude of mortality disparities by neighborhood SES was more marked in younger (<65 years) than in older patients (≥65 years), in married than nonmarried patients, and after 2000. We concluded that patients living in low SES neighborhoods had substantially worse survival after DLBCL, and this disparity was striking in younger (ie, not eligible for Medicare-aged) patients, married patients, and after the introduction of rituximab. These disparities suggest there are barriers, including inadequate insurance coverage with additional financial burden, to effective treatment among socioeconomically disadvantaged patients