CD200 Checkpoint Reversal: A Novel Approach to Immunotherapy.

Purpose: Advances in immunotherapy have revolutionized care for some patients with cancer. However, current checkpoint inhibitors are associated with significant toxicity and yield poor responses for patients with central nervous system tumors, calling into question whether cancer immunotherapy can be applied to glioblastoma multiforme. We determined that targeting the CD200 activation receptors (CD200AR) of the CD200 checkpoint with a peptide inhibitor (CD200AR-L) overcomes tumor-induced immunosuppression.

Human CD19-Targeted Mouse T Cells Induce B Cell Aplasia and Toxicity in Human CD19 Transgenic Mice.

The clinical success of chimeric antigen receptor (CAR) T cell therapy for CD19 B cell malignancies can be limited by acute toxicities and immunoglobulin replacement needs due to B cell aplasia from persistent CAR T cells. Life-threatening complications include cytokine release syndrome and neurologic adverse events, the exact etiologies of which are unclear. To elucidate the underlying toxicity mechanisms and test potentially safer CAR T cells, we developed a mouse model in which human CD19 (hCD19)-specific mouse CAR T cells were adoptively transferred into mice whose normal B cells express a hCD19 transgene at hemizygous levels.

Design and Synthesis of N1-Modified Imidazoquinoline Agonists for Selective Activation of Toll-like Receptors 7 and 8.

A series of N1-modified imidazoquinolines were synthesized and screened for Toll-like receptors (TLR) 7 and 8 activities to identify recognition elements that confer high affinity binding and selectivity. These receptors are key targets in the development of immunomodulatory agents that signal the NF-κB mediated transcription of pro-inflammatory chemokines and cytokines. Results are presented showing both TLR7/8 activations are highly correlated to N1-substitution, with TLR8 selectivity achieved through inclusion of an ethyl-, propyl-, or butylamino group at this position.

Tumor-derived vaccines containing CD200 inhibit immune activation: implications for immunotherapy.

There are over 400 ongoing clinical trials using tumor-derived vaccines. This approach is especially attractive for many types of brain tumors, including glioblastoma, yet so far the clinical response is highly variable. One contributor to poor response is CD200, which acts as a checkpoint blockade, inducing immune tolerance.

Complex Partial Epilepsy Associated with Temporal Lobe Developmental Venous Anomaly.

Background: Developmental venous anomalies (DVA) are found incidentally but sometimes patients with these anomalies present with varying degrees of neurologic manifestations.

Objective: We report a patient with early onset complex partial epilepsy and associated DVA and discuss the natural history, neuroimaging and clinical characteristics, and management.

Case Description: A 21-year-old man presented with a history of complex partial epilepsy with secondary generalization which started at the age of 4 years.

Structure-activity relationship analysis of imidazoquinolines with Toll-like receptors 7 and 8 selectivity and enhanced cytokine induction.

Toll-like receptors 7 and 8 (TLRs) have emerged as key targets in the design of small molecule adjuvants and stimulants for use in immunotherapies. This study examines the structure-activity relationship of a series of C2- and N1-substituted C7-methoxycarbonylimidazoquinolines to gain insight to the structural basis to TLR-7 and -8 selective activity. The analysis is further applied to evaluate the induction of multiple cytokines, including IL-10, IL-12, IL-1β, TNF-α, IFN-α, and IFN-γ, using murine BMDCs and human PBMCs.

Discovery of Imidazoquinolines with Toll-Like Receptor 7/8 Independent Cytokine Induction.

Toll-like receptors (TLRs) are key targets in the design of immunomodulating agents for use as vaccine adjuvants and anticancer treatments. The imidazoquinolines, imiquimod and resiquimod, have been shown to activate TLR-7 and -8 which in turn induce cytokine production as part of the innate immune response. Herein, we report the synthesis and discovery of a C7-methoxycarbonyl derivative of imiquimod that stimulates cytokine production but is devoid of TLR-7/8 activity.

Topical imiquimod has therapeutic and immunomodulatory effects against intracranial tumors.

Topical imiquimod cream (trade name: Aldara) is a Toll-like receptor (TLR) 7 agonist that is approved for the treatment of cutaneous tumors. Aldara is also used as a vaccine adjuvant in clinical trials in patients with glioma and other tumors. The main mechanism of action ascribed to Aldara has been the local activation of TLR7(+) cells near the application site.

Superior efficacy of tumor cell vaccines grown in physiologic oxygen.

Purpose: Atmospheric oxygen (∼20% O(2)) has been the universal condition employed to culture tumor cells used as vaccine antigen. We tested the hypothesis that reducing oxygen tension would increase the efficacy of tumor cell lysate vaccines.

Experimental Design: GL261 glioma cells and EMT6 breast carcinoma cells were grown in 5% or 20% O(2).

Effective CpG immunotherapy of breast carcinoma prevents but fails to eradicate established brain metastasis.

Purpose: Breast cancer patients with brain metastasis have a dismal prognosis. We determined the ability of immunostimulatory CpG oligodeoxynucleotides (ODN) to treat or prevent brain metastasis in a mouse model.

Experimental Design: Mice bearing orthotopic breast carcinoma with or without concurrent i.

Small-animal PET of melanocortin 1 receptor expression using a 18F-labeled alpha-melanocyte-stimulating hormone analog.

Unlabelled: (18)F-Labeled small synthetic peptides have emerged as attractive probes for imaging various molecular targets with PET. The alpha-melanocyte-stimulating hormone (alpha-MSH) receptor (melanocortin type 1 receptor [MC1R]) is overexpressed in most murine and human melanomas. It is a promising molecular target for diagnosis and therapy of melanomas.

64Cu-labeled alpha-melanocyte-stimulating hormone analog for microPET imaging of melanocortin 1 receptor expression.

The alpha-melanocyte-stimulating hormone (alpha-MSH) receptor (melanocortin type 1 receptor, or MC1R) plays an important role in the development and growth of melanoma cells. It was found that MC1R was overexpressed on most murine and human melanoma, making it a promising molecular target for melanoma imaging and therapy. Radiolabeled alpha-MSH peptide and its analogs that can specifically bind with MC1R have been extensively explored for developing novel agents for melanoma detection and radionuclide therapy.

In vivo bioluminescence tumor imaging of RGD peptide-modified adenoviral vector encoding firefly luciferase reporter gene.

Purpose: The goal of this study is to demonstrate the feasibility of chemically modified human adenovirus (Ad) vectors for tumor retargeting.

Procedures: E1- and E3-deleted Ad vectors carrying firefly luciferase reporter gene under cytomegalovirus promoter (AdLuc) was surface-modified with cyclic arginine-glycine-aspartic acid (RGD) peptides through a bifunctional poly(ethyleneglycol) linker (RGD-PEG-AdLuc) for integrin alpha(v)beta(3) specific delivery. The Coxsackie and adenovirus viral receptor (CAR) and integrin alpha(v)beta(3) expression in various tumor cell lines was determined by reverse transcriptase PCR and fluorescence-activated cell sorting.

Near-infrared fluorescent deoxyglucose analogue for tumor optical imaging in cell culture and living mice.

2-deoxy-2-[18F]fluoro-D-glucose ([18F]FDG) has extensively been used for clinical diagnosis, staging, and therapy monitoring of cancer and other diseases. Nonradioactive glucose analogues enabling the screening of the glucose metabolic rate of tumors are of particular interest for anticancer drug development. A nonradioactive fluorescent deoxyglucose analogue may have many applications for both imaging of tumors and monitoring therapeutic efficacy of drugs in living animals and may eventually translate to clinical applications.

Comparative in vitro and in vivo evaluation of two 64Cu-labeled bombesin analogs in a mouse model of human prostate adenocarcinoma.

Bombesin (BBN), an analog of human gastrin-releasing peptide (GRP), binds to the GRP receptor (GRPR) with high affinity and specificity. Overexpression of GRPR has been discovered in mostly androgen-independent human prostate tissues and, thus, provides a potential target for prostate cancer diagnosis and therapy. We have previously demonstrated the feasibility of the positron emission tomography (PET) imaging using 64Cu-1,4,7,10-tetraazadodecane-N,N',N'',N'''-tetraacetic acid (DOTA)-[Lys3]BBN to detect GRPR-positive prostate cancer.

Imaging chemically modified adenovirus for targeting tumors expressing integrin alphavbeta3 in living mice with mutant herpes simplex virus type 1 thymidine kinase PET reporter gene.

Unlabelled: The aim of this study was to change adenovirus tropism by chemical modification of the fiber knobs with PEGylated RGD peptide for targeting integrin alpha(v)beta(3) that is uniquely or highly expressed in tumor cells and neovasculature of tumors of various origins.

Methods: The first generation Ad (Ad) vector, which expresses the herpes simplex virus type 1 mutant thymidine kinase (HSV1-sr39tk) gene under the control of cytomegalovirus (CMV) promoter was conjugated with poly(ethylene glycol) (PEG) or RGD-PEG. The transduction efficiency of Ads (Adtk, PEG-Adtk, and RGD-PEG-Adtk) into different types of cells (293T, MCF7, MDA-MB-435, and U87MG) was analyzed and quantified by thymidine kinase (TK) assay using 8-(3)H-penciclovir (8-(3)H-PCV) as substrate.

Quantitative PET imaging of tumor integrin alphavbeta3 expression with 18F-FRGD2.

Unlabelled: The development of noninvasive methods to visualize and quantify integrin alpha(v)beta(3) expression in vivo appears to be crucial for the success of antiangiogenic therapy based on integrin antagonism. Precise documentation of integrin receptor levels will allow appropriate selection of patients who will most likely benefit from an antiintegrin treatment regimen. Imaging can also be used to provide an optimal dosage and time course for treatment based on receptor occupancy studies.

Near-infrared fluorescent RGD peptides for optical imaging of integrin alphavbeta3 expression in living mice.

Near-infrared fluorescence optical imaging is a powerful technique for studying diseases at the molecular level in preclinical models. We recently reported that monomeric RGD peptide c(RGDyK) conjugated to the NIR fluorescent dye specifically targets integrin receptor both in cell culture and in living subjects. In this report, Cy5.

microPET imaging of glioma integrin {alpha}v{beta}3 expression using (64)Cu-labeled tetrameric RGD peptide.

Unlabelled: Integrin alpha(v)beta(3) plays a critical role in tumor-induced angiogenesis and metastasis and has become a promising diagnostic indicator and therapeutic target for various solid tumors. Radiolabeled RGD peptides that are integrin specific can be used for noninvasive imaging of integrin expression level as well as for integrin-targeted radionuclide therapy.

Methods: In this study we developed a tetrameric RGD peptide tracer (64)Cu-DOTA-E{E[c(RGDfK)](2)}(2) (DOTA is 1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetic acid) for PET imaging of integrin alpha(v)beta(3) expression in female athymic nude mice bearing the subcutaneous UG87MG glioma xenografts.

[Effect of astragalus injection on immune function in patients with congestive heart failure].

Objective: To study the effect of Astragalus Injection (AI) on the humoral immunity (IgG, IgA and IgM), cellular immunity (T-lymphocyte subsets) and soluble interleukin-2 receptor (sIL-2R) in patients with congestive heart failure (CHF).

Methods: Sixty-two in-patients with CHF, whose heart function belonged to NYHA grade II-IV, were randomly divided into two groups. The treated group was treated with AI 30 ml (equivalent to 60 g crude drug), and the control group was treated by nitroglycerine injection 10 mg, the drugs were administered respectively by adding in 5% glucose solution 500 ml for intravenous dripping, once a day, 20 days as one therapeutic course.