Leukemia vaccine overcomes limitations of checkpoint blockade by evoking clonal T cell responses in a murine acute myeloid leukemia model.

We have developed a personalized vaccine whereby patient derived leukemia cells are fused to autologous dendritic cells, evoking a polyclonal T cell response against shared and neo-antigens. We postulated that the dendritic cell (DC)/AML fusion vaccine would demonstrate synergy with checkpoint blockade by expanding tumor antigen specific lymphocytes that would provide a critical substrate for checkpoint blockade mediated activation. Using an immunocompetent murine leukemia model, we examined the immunologic response and therapeutic efficacy of vaccination in conjunction with checkpoint blockade with respect to leukemia engraftment, disease burden, survival and the induction of tumor specific immunity. Mice treated with checkpoint blockade alone had rapid leukemia progression and demonstrated only a modest extension of survival. Vaccination with DC/AML fusions resulted in the expansion of tumor specific lymphocytes and disease eradication in a subset of animals, while the combination of vaccination and checkpoint blockade induced a fully protective tumor specific immune response in all treated animals. Vaccination followed by checkpoint blockade resulted in upregulation of genes regulating activation and proliferation in memory and effector T cells. Long term survivors exhibited increased T cell clonal diversity and were resistant to subsequent tumor challenge. The combined DC/AML fusion vaccine and checkpoint blockade treatment offers unique synergy inducing the durable activation of leukemia specific immunity, protection from lethal tumor challenge and the selective expansion of tumor reactive clones.

Infratemporal Fossa Abscess Drainage via a Trans-Oral Image Guided Approach.

Deep neck space infections can cause antibiotic-resistant abscesses that can impinge on vital anatomical structures. Image-guided surgery systems using preoperative computed tomography (CT) imaging can be utilized to characterize pathology and assist surgeons in avoiding iatrogenic injury. This manuscript explores the presentation and unique CT-guided surgical management of an infratemporal fossa abscess in a 48-year-old male who presented with left-sided dental pain and facial swelling that had progressed despite antibiotics and dental extraction. CT-guided imaging can assist in localizing and protecting vital anatomical structures during deep neck abscess drainage and can prevent the potential risks and complications of classic surgical approaches.

A Case of Hepatopulmonary Syndrome as a Complication of Metastatic Breast Cancer to the Liver.

Many patients with metastatic breast cancer develop liver metastases. A rare complication of this is hepatopulmonary syndrome (HPS), which is associated with exertional dyspnea and intrapulmonary shunting. We present a patient who presented with HPS as a consequence of liver metastases and subsequently treated with chemotherapy leading to resolution of her symptoms.

DCOne as an Allogeneic Cell-based Vaccine for Multiple Myeloma.

Multiple myeloma (MM) is characterized by progressive immune dysregulation, loss of myeloma-specific immunity, and an immunosuppressive milieu that fosters disease growth and immune escape. Accordingly, cancer vaccines that reverse tumor-associated immune suppression represent a promising therapeutic avenue of investigation. We examined the potential of an allogeneic cellular vaccine to generate immune responses against MM tumor cells. The DCOne vaccine is comprised of a human myeloid leukemia cell line differentiated into a fully functional dendritic cell, expressing a range of tumor-associated antigens that are also known targets in MM. We found that the myeloma-specific antigens expressed by the DCOne vaccine can traffic via extracellular vesicles to surrounding antigen-presenting cells, thus stimulating autologous T-cell responses. Indeed, coculture of peripheral blood mononuclear cells from patients with MM with the DCOne vaccine resulted in the expansion of activated CD8 T cells expressing interferon-γ and perforin, with no significant change in the percentage of CD4 T cells producing interleukin-10. Further, coculture of patient's tumor cells with peripheral blood mononuclear cells and DCOne induced cytotoxic T-lymphocyte-mediated killing of autologous MM cells. These findings demonstrate that the allogeneic DCOne vaccine can induce T-cell activation and myeloma-specific immunity via cross presentation of antigens by native antigen-presenting cells.

Endothelial cell tube formation assay for the in vitro study of angiogenesis.

Angiogenesis is a vital process for normal tissue development and wound healing, but is also associated with a variety of pathological conditions. Using this protocol, angiogenesis may be measured in vitro in a fast, quantifiable manner. Primary or immortalized endothelial cells are mixed with conditioned media and plated on basement membrane matrix. The endothelial cells form capillary like structures in response to angiogenic signals found in conditioned media. The tube formation occurs quickly with endothelial cells beginning to align themselves within 1 hr and lumen-containing tubules beginning to appear within 2 hr. Tubes can be visualized using a phase contrast inverted microscope, or the cells can be treated with calcein AM prior to the assay and tubes visualized through fluorescence or confocal microscopy. The number of branch sites/nodes, loops/meshes, or number or length of tubes formed can be easily quantified as a measure of in vitro angiogenesis. In summary, this assay can be used to identify genes and pathways that are involved in the promotion or inhibition of angiogenesis in a rapid, reproducible, and quantitative manner.