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Carter D.,Pai Life Sciences, Inc. | Carter D.,Compliment Corporation | Lieber A.,University of Washington
FEBS Letters | Year: 2014

The complement system is composed of soluble factors in plasma that enhance or "complement" immune-mediated killing through innate and adaptive mechanisms. Activation of complement causes recruitment of immune cells; opsonization of coated cells; and direct killing of affected cells through a membrane attack complex (MAC). Tumor cells up-regulate complement inhibitory factors - one of several strategies to evade the immune system. In many cases as the tumor progresses, dramatic increases in complement inhibitory factors are found on these cells. This review focuses on the classic complement pathway and the role of major complement inhibitory factors in cancer immune evasion as well as on how current protein engineering efforts are being employed to increase complement fixing or to reverse complement resistance leading to better therapeutic outcomes in oncology. Strategies discussed include engineering of antibodies to enhance complement fixation, antibodies that neutralize complement inhibitory proteins as well as engineered constructs that specifically target inhibition of the complement system. © 2013 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved. Source

Beyer I.,University of Washington | Beyer I.,Heinrich Heine University Dusseldorf | Cao H.,University of Washington | Persson J.,University of Washington | And 12 more authors.
Clinical Cancer Research | Year: 2012

Purpose: Epithelial junctions between tumor cells inhibit the penetration of anticancer drugs into tumors. We previously reported on recombinant adenovirus serotype 3-derived protein (JO-1), which triggers transient opening of intercellular junctions in epithelial tumors through binding to desmoglein 2 (DSG2), and enhances the antitumor effects of several therapeutic monoclonal antibodies. The goal of this study was to evaluate whether JO-1 cotherapy can also improve the efficacy of chemotherapeutic drugs. Experimental Design: The effect of intravenous application of JO-1 in combination with several chemotherapy drugs, including paclitaxel/Taxol, nanoparticle albumin-bound paclitaxel/Abraxane, liposomal doxorubicin/Doxil, and irinotecan/Camptosar, was tested in xenograft models for breast, colon, ovarian, gastric and lung cancer. Because JO-1 does not bind to mouse cells, for safety studies with JO-1, we also used human DSG2 (hDSG2) transgenic mice with tumors that overexpressed hDSG2. Results: JO-1 increased the efficacy of chemotherapeutic drugs, and in several models overcame drug resistance. JO-1 treatment also allowed for the reduction of drug doses required to achieve antitumor effects. Importantly, JO-1 coadmininstration protected normal tissues, including bone marrow and intestinal epithelium, against toxic effects that are normally associated with chemotherapeutic agents. Using the hDSG2-transgenic mouse model, we showed that JO-1 predominantly accumulates in tumors. Except for a mild, transient diarrhea, intravenous injection of JO-1 (2 mg/kg) had no critical side effects on other tissues or hematologic parameters in hDSG2-transgenic mice. Conclusions: Our preliminary data suggest that JO-1 cotherapy has the potential to improve the therapeutic outcome of cancer chemotherapy. ©2012 AACR. Source

University of Washington and Compliment Corporation | Date: 2010-03-31

This invention relates to agents capable of reducing the activity, amount or density of complement regulatory proteins (CRPs) on target cells. The invention also provides methods of identification of such agents, methods of making, and uses thereof.

Beyer I.,University of Washington | Beyer I.,Heinrich Heine University Dusseldorf | Cao H.,University of Washington | Persson J.,University of Washington | And 14 more authors.
Molecular Therapy | Year: 2013

We have developed a technology that depletes the complement regulatory protein (CRP) CD46 from the cell surface, and thereby sensitizes tumor cells to complement-dependent cytotoxicity triggered by therapeutic monoclonal antibodies (mAbs). This technology is based on a small recombinant protein, Ad35K++, which induces the internalization and subsequent degradation of CD46. In preliminary studies, we had demonstrated the utility of the combination of Ad35K++ and several commercially available mAbs such as rituximab, alemtuzumab, and trastuzumab in enhancing cell killing in vitro as well as in vivo in murine xenograft and syngeneic tumor models. We have completed scaled manufacturing of Ad35K++ protein in Escherichia coli for studies in nonhuman primates (NHPs). In macaques, we first defined a dose of the CD20-targeting mAb rituximab that did not deplete CD20-positive peripheral blood cells. Using this dose of rituximab, we then demonstrated that pretreatment with Ad35K++ reconstituted near complete elimination of B cells. Further studies demonstrated that the treatment was well tolerated and safe. These findings in a relevant large animal model provide the rationale for moving this therapy forward into clinical trials in patients with CD20-positive B-cell malignancies. © The American Society of Gene &Cell Therapy. Source

Yumul R.,University of Washington | Richter M.,University of Washington | Lu Z.-Z.,University of Washington | Lu Z.-Z.,Chinese National Institute for Viral Disease Control and Prevention | And 7 more authors.
Human Gene Therapy | Year: 2016

A central resistance mechanism in solid tumors is the maintenance of epithelial junctions between malignant cells that prevent drug penetration into the tumor. Human adenoviruses (Ads) have evolved mechanisms to breach epithelial barriers. For example, during Ad serotype 3 (Ad3) infection of epithelial tumor cells, massive amounts of subviral penton-dodecahedral particles (PtDd) are produced and released from infected cells to trigger the transient opening of epithelial junctions, thus facilitating lateral virus spread. We show here that an Ad3 mutant that is disabled for PtDd production is significantly less effective in killing of epithelial human xenograft tumors than the wild-type Ad3 virus. Intratumoral spread and therapeutic effect of the Ad3 mutant was enhanced by co-administration of a small recombinant protein (JO; produced in Escherichia coli) that incorporated the minimal junction opening domains of PtDd. We then demonstrated that co-administration of JO with replication-competent Ads that do not produce PtDd (Ad5, Ad35) resulted in greater attenuation of tumor growth than virus injection alone. Furthermore, we genetically modified a conditionally replicating Ad5-based oncolytic Ad (Ad5Δ24) to express a secreted form of JO upon replication in tumor cells. The JO-expressing virus had a significantly greater antitumor effect than the unmodified AdΔ24 version. Our findings indicate that epithelial junctions limit the efficacy of oncolytic Ads and that this problem can be address by co-injection or expression of JO. JO has also the potential for improving cancer therapy with other types of oncolytic viruses. © 2016 Mary Ann Liebert, Inc. Source

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