Publications by authors named "Matthew M Seavey"

Encouraging protection results from current mRNA-based SARS-CoV-2 vaccine platforms are primarily due to the induction of SARS- CoV-2- specific B cell antibody and CD4 + T cell. Even though, current mRNA vaccine platforms are adept in inducing SARS-CoV2-specific CD8 + T cell, much less is known about CD8 T cells contribution to the overall vaccine protection. Our allogeneic cellular vaccine, based on a secreted form of the heat-shock protein gp96-Ig, achieves high frequencies of polyclonal CD8 + T cell responses to tumor and infectious antigens through antigen cross-priming .

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Given the aggressive spread of COVID-19-related deaths, there is an urgent public health need to support the development of vaccine candidates to rapidly improve the available control measures against SARS-CoV-2. To meet this need, we are leveraging our existing vaccine platform to target SARS-CoV-2. Here, we generated cellular heat shock chaperone protein, glycoprotein 96 (gp96), to deliver SARS-CoV-2 protein S (spike) to the immune system and to induce cell-mediated immune responses.

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Constitutively activated STAT3 and STAT5 are expressed in a wide variety of human malignancies including solid and hematopoietic cancers and often correlate with a poor prognosis and resistance to multiple therapies. Given the well established role of STAT3 in tumorigenesis, inhibition of Janus-activated kinase 2 (JAK2) activity might represent an attractive therapeutic approach. Using a mouse model of colitis-induced colorectal cancer, we show that a novel, orally active, selective JAK2 inhibitor, CEP-33779, induced regression of established colorectal tumors, reduced angiogenesis, and reduced proliferation of tumor cells.

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Janus kinases have proved to be essential for many immunological processes but there is growing evidence that they also play a critical role in pathogenesis of many diseases including inflammatory diseases and cancer where they promote multiple steps of tumorigenesis. Several companies are in late stage clinical programs for the development of JAK kinase inhibitors and the first small molecule JAK inhibitor, Jakafi® (ruxolitinib) has been just approved for treatment of myeloproliferative neoplasms. Several other molecules are on the rise to treat arthritis, psoriasis and multiple types of cancer.

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Current therapies for late-stage systemic lupus erythematosus (SLE) are limited to cytotoxic agents. Delanzomib (CEP-18770) is an orally active, reversible P2 threonine boronic acid inhibitor of the 26S mammalian proteasome. Delanzomib was tested in a head-to-head comparison against bortezomib to protect and treat mice with fatal lupus nephritis (LN).

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The recent announcement of the first FDA-approved therapeutic vaccine for prostate cancer, Sipuleucel-T, is a watershed moment for the field of tumor immunotherapy. However, while Sipuleucel-T provides a powerful tool to clinicians for the most prevalent form of cancer in men, there remains an unmet need for a similar therapeutic strategy against breast cancer, the most prevalent cancer in women. While current breast cancer vaccines in development target several antigens, the most prevalent is the tumor-associated antigen, HER2.

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Systemic Lupus Erythematosus (SLE) is a debilitating and often fatal autoimmune disease that involves multiple organ systems. It can develop for years before being diagnosed. Current treatments for SLE usually involve the use of cytotoxic or immunosuppressive agents that can lead to infection or cancer.

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Accumulating evidence suggests that autoreactive plasma cells play an important role in systemic lupus erythematosus (SLE). In addition, several proinflammatory cytokines promote autoreactive B cell maturation and autoantibody production. Hence, therapeutic targeting of such cytokine pathways using a selective JAK2 inhibitor, CEP-33779 (JAK2 enzyme IC(50) = 1.

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Introduction: Janus kinase 2 (JAK2) is involved in the downstream activation of signal transducer and activator of transcription 3 (STAT3) and STAT5 and is responsible for transducing signals for several proinflammatory cytokines involved in the pathogenesis of rheumatoid arthritis (RA), including interleukin (IL)-6, interferon γ (IFNγ) and IL-12. In this paper, we describe the efficacy profile of CEP-33779, a highly selective, orally active, small-molecule inhibitor of JAK2 evaluated in two mouse models of RA.

Methods: Collagen antibody-induced arthritis (CAIA) and collagen type II (CII)-induced arthritis (CIA) were established before the oral administration of a small-molecule JAK2 inhibitor, CEP-33779, twice daily at 10 mg/kg, 30 mg/kg, 55 mg/kg or 100 mg/kg over a period of 4 to 8 weeks.

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Background: The use of mouse models to study human disease provides useful data that can provide support for research projects or an existing drug discovery program. How well a model recapitulates the human condition and the ease and reproducibility of data collected will determine how much confidence a scientist can place on results obtained. Designing new treatments for rheumatic diseases, such as rheumatoid arthritis (RA), requires complex immunocompetent models that depend on intricate cytokine networks.

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Although vaginal immunization has been explored as a strategy to induce mucosal immunity in the female reproductive tract, this site displays unique immunological features that probably evolved to inhibit anti-paternal T cell responses after insemination to allow successful pregnancy. We previously demonstrated that estradiol, which induces an estrus-like state, prevented CD8(+) T cell priming during intravaginal immunization of mice. We now show that estradiol prevented antigen loading of vaginal antigen presenting cells (APCs) after intravaginal immunization.

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Thirty years after angiogenesis was shown to play an enabling role in cancer, modern medicine is still trying to develop novel compounds and therapeutics to target the tumor vasculature. However, most therapeutics require multiple rounds of administration and can have toxic side effects. In this study, we use anti-angiogenesis immunotherapy to target cells actively involved in forming new blood vessels that support the growth and spread of breast cancer.

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Purpose: The aim of this study was to efficiently design a novel vaccine for human Her-2/neu-positive (hHer-2/neu) breast cancer using the live, attenuated bacterial vector Listeria monocytogenes.

Experimental Design: Three recombinant L. monocytogenes-based vaccines were generated that could express and secrete extracellular and intracellular fragments of the hHer-2/neu protein.

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Targeting tumors using cancer vaccine therapeutics has several advantages including the induction of long-term immunity, prime boost strategies for additional treatments and reduced side effects compared to conventional chemotherapeutics. However, one problem in targeting tumor antigens directly is that this can lead to antigen loss or immunoediting. We hypothesized that directing the immune response to a normal cell type required for tumor growth and survival could provide a more stable immunotherapeutic target.

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Our laboratory is interested in how immunogenicity may be modulated in vivo in order to better design more effective immunotherapeutics against cancer. Our main approach is to use a facultative intracellular bacterium, Listeria monocytogenes, which has the unusual ability to live and grow in the cytoplasm of the cell and is thus an excellent vector for targeting passenger antigens to the major histocompatibility complex (MHC) class I pathway of antigen processing with the generation of authentic CTL epitopes. We have used this approach to target tumor antigens expressed on breast, melanoma and cervical cancer.

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The high molecular weight melanoma-associated antigen (HMW-MAA), also known as melanoma chondroitin sulfate proteoglycan, has been used as a target for the immunotherapy of melanoma. This antigen is expressed on the cell surface and has a restricted distribution in normal tissues. Besides its expression in a broad range of transformed cells, this antigen is also found in pericytes, which are important for tumor angiogenesis.

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Immunological tolerance to the fetus is essential for fetal survival during pregnancy. The semi-allogeneic fetus expresses genes foreign to the mother that can be recognized by maternal T cells. Under times of stress or infection, deleterious immune responses can result in fetal destruction and/or maternal death.

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Maternal immunological tolerance of the semiallogeneic fetus involves several overlapping mechanisms to balance maternal immunity and fetal development. Anti-paternal CD8+ T cells are suppressed during pregnancy in some but not all mouse models. Since semen has been shown to mediate immune modulation, we tested whether exposure to paternal Ag during insemination activated or tolerized anti-paternal CD8+ T cells.

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