Basic Science and Pathogenesis.

Background: Microglial processing and recycling of debris is implicated in AD. AD GWAS loci are enriched for genes in efferocytosis, phagocytosis, endosomal trafficking and cholesterol efflux. Acting as a buffer, lipid droplets increase as a consequence of an imbalance between lipid debris influx and efflux rates.

ERK Activation in CAR T Cells Is Amplified by CD28-Mediated Increase in CD3ζ Phosphorylation.

Chimeric antigen receptors (CARs) are engineered receptors that mediate T cell activation. CARs are comprised of activating and co-stimulatory intracellular signaling domains derived from endogenous T cells that initiate signaling required for T cell activation, including ERK activation through the MAPK pathway. Understanding the mechanisms by which co-stimulatory domains influence signaling can help guide the design of next-generation CARs.

Understanding the Dynamics of T-Cell Activation in Health and Disease Through the Lens of Computational Modeling.

T cells in the immune system are activated by binding to foreign peptides (from an external pathogen) or mutant peptide (derived from endogenous proteins) displayed on the surface of a diseased cell. This triggers a series of intracellular signaling pathways, which ultimately dictate the response of the T cell. The insights from computational models have greatly improved our understanding of the mechanisms that control T-cell activation.

Computational Model of Chimeric Antigen Receptors Explains Site-Specific Phosphorylation Kinetics.

Chimeric antigen receptors (CARs) have recently been approved for the treatment of hematological malignancies, but our lack of understanding of the basic mechanisms that activate these proteins has made it difficult to optimize and control CAR-based therapies. In this study, we use phosphoproteomic mass spectrometry and mechanistic computational modeling to quantify the in vitro kinetics of individual tyrosine phosphorylation on a variety of CARs. We show that each of the 10 tyrosine sites on the CD28-CD3ζ CAR is phosphorylated by lymphocyte-specific protein-tyrosine kinase (LCK) with distinct kinetics.

CAR-T Cells Surface-Engineered with Drug-Encapsulated Nanoparticles Can Ameliorate Intratumoral T-cell Hypofunction.

One limiting factor of CAR T-cell therapy for treatment of solid cancers is the suppressive tumor microenvironment (TME), which inactivates the function of tumor-infiltrating lymphocytes (TIL) through the production of immunosuppressive molecules, such as adenosine. Adenosine inhibits the function of CD4 and CD8 T cells by binding to and activating the A2a adenosine receptor (A2aR) expressed on their surface. This suppression pathway can be blocked using the A2aR-specific small molecule antagonist SCH-58261 (SCH), but its applications have been limited owing to difficulties delivering this drug to immune cells within the TME.

In Vivo Expansion and Antitumor Activity of Coinfused CD28- and 4-1BB-Engineered CAR-T Cells in Patients with B Cell Leukemia.

Several recent clinical trials have successfully incorporated a costimulatory domain derived from either CD28 or 4-1BB with the original CD3ζ T cell activating domain to form second-generation chimeric antigen receptors (CARs) that can increase the responsiveness and survival of CAR-engineered T (CAR-T) cells. However, a rigorous assessment of the individual benefits of these costimulatory components relative to the in vivo performance of infused T cells in patients is still lacking. Therefore, we have designed a study that allows us to investigate and compare the impact of different costimulatory signal domains on CAR-T cells in vivo.

Combination drug delivery via multilamellar vesicles enables targeting of tumor cells and tumor vasculature.

Blood vessel development is critical for the continued growth and progression of solid tumors and, therefore, makes an attractive target for improving cancer therapy. Indeed, vascular-targeted therapies have been extensively explored but they have shown minimal efficacy as monotherapies. Combretastatin A4 (CA-4) is a tubulin-binding vascular disrupting agent that selectively targets the established tumor endothelium, causing rapid vascular beak down.

Combination Cancer Therapy Using Chimeric Antigen Receptor-Engineered Natural Killer Cells as Drug Carriers.

The therapeutic limitations of conventional chemotherapeutic drugs include chemo-resistance, tumor recurrence, and metastasis. Numerous nanoparticle-based active targeting approaches have emerged to enhance the intracellular concentration of drugs in tumor cells; however, efficient delivery of these systems to the tumor site while sparing healthy tissue remains elusive. Recently, much attention has been given to human immune-cell-directed nanoparticle drug delivery, because immune cells can traffic to the tumor and inflammatory sites.

Predictive Model of Lymphocyte-Specific Protein Tyrosine Kinase (LCK) Autoregulation.

Lymphocyte-specific protein tyrosine kinase (LCK) is a key activator of T cells; however, little is known about the specific autoregulatory mechanisms that control its activity. We have constructed a model of LCK autophosphorylation and phosphorylation by the regulating kinase CSK. The model was fit to existing experimental data in the literature that presents an reconstituted membrane system, which provides more physiologically relevant kinetic measurements than traditional solution-based systems.

Predictive model of thrombospondin-1 and vascular endothelial growth factor in breast tumor tissue.

Angiogenesis, the formation of new blood capillaries from pre-existing vessels, is a hallmark of cancer. Thus far, strategies for reducing tumor angiogenesis have focused on inhibiting pro-angiogenic factors, while less is known about the therapeutic effects of mimicking the actions of angiogenesis inhibitors. Thrombospondin-1 (TSP1) is an important endogenous inhibitor of angiogenesis that has been investigated as an anti-angiogenic agent.

Co-Eradication of Breast Cancer Cells and Cancer Stem Cells by Cross-Linked Multilamellar Liposomes Enhances Tumor Treatment.

The therapeutic limitations of conventional chemotherapeutic drugs have emerged as a challenge for breast cancer therapy; these shortcomings are likely due, at least in part, to the presence of the cancer stem cells (CSCs). Salinomycin, a polyether antibiotic isolated from Streptomyces albus, has been shown to selectively inhibit cancer stem cells; however, its clinical application has been hindered by the drug's hydrophobility, which limits the available administration routes. In this paper, a novel drug delivery system, cross-linked multilamellar liposomal vesicles (cMLVs), was optimized to allow for the codelivery of salinomycin (Sal) and doxorubicin (Dox), targeting both CSCs and breast cancer cells.

Generation of Targeted Adeno-Associated Virus (AAV) Vectors for Human Gene Therapy.

Adeno-associated virus (AAV) vectors are promising human gene delivery vehicles due to their ability to establish long-term gene expression in a wide variety of target tissues; however, the broad native viral tropism raises concerns over the feasibility and safety of their systemic administration. To overcome this issue, much effort has been made to redirect AAVs toward specific tissues. This review presents several design strategies that have been applied to generate AAVs that target specific tissues and cells while inhibiting the transduction of non-target tissues.

Advances and challenges in the use of nanoparticles to optimize PK/PD interactions of combined anti-cancer therapies.

Combination chemotherapy has become the primary strategy for treating cancer; however, the clinical success of combination treatments is limited by the distinct pharmacokinetics (PK) of different drugs, which lead to nonuniform distribution and an inability to coordinate dosing regimes at the site of the tumor. In the first half of this review, we will discuss the recent development of nanoparticlebased combination strategies to overcome these limitations. Nanoparticles are able to co-encapsulate and carry multiple drugs with different hydrophobicities while maintaining precise ratiometric loading and delivery.