ZIA BC 009369 (ZIA) | |||
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Title | Studies of Receptor Interactions and Effects of Alarmins | ||
Institution | NCI, Bethesda, MD | ||
Principal Investigator | Oppenheim, Joost | NCI Program Director | N/A |
Cancer Activity | N/A | Division | CCR |
Funded Amount | $905,756 | Project Dates | null - null |
Fiscal Year | 2018 | Project Type | Intramural |
Research Topics w/ Percent Relevance | Cancer Types w/ Percent Relevance | ||
Autoimmune Diseases (10.0%) Cancer (100.0%) Digestive Diseases (20.0%) |
Breast (20.0%) Melanoma (20.0%) |
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Research Type | |||
Vaccines Systemic Therapies - Discovery and Development |
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Abstract | |||
Alarmins are characterized by having in vitro chemotactic or in vivo recruitment activity for cells expressing GiPCR, together with the capacity to interact with other receptors resulting in the activation of immature dendritic cells (iDC) into mature antigen-presenting capable of interacting with T lymphocytes. These alarmins, if administered together with an antigen result in considerable augmentation of both in vivo cellular and humoral immune responses. We previously identified both alpha and beta types of defensins as alarmins with chemotactic and activating effects on immature dendritic cells (iDCs) as having in vivo immunoadjuvant effects. Some of the beta defensins interact with the CCR6 chemokine receptor, others with CCR2. Defensins by binding to DNA also can activate DC's by triggering TLR-9. The resultant cytokine production has considerable proinflammatory effects. We recently prepared genetically engineered mice deficient in Beta-Defensins 4 and 14 in collaboration with Drs. Teizo Yoshimura and Lino Tessarollo. These mice remained phenotypically normal for 1-2 years. However, when sensitized and challenged with the contact sensitizer, Dinitrochlorobenzene (DNCB), they were markedly deficient in developing cutaneous delayed hypersensitivity responses and antibodies to DNCB. This reinforced our hypothesis that defensins promote immune responses. We previously showed that HMGN-1 knockout mice exhibit reduced resistance to tumor (EG-7 or EL-4) challenge. Conversely, tumor cells (EG-7 or EL-4) when transfected to overexpress HMGN1 showed a marked reduction in the rate of growth in normal mice. These observations indicated that HMGN1 is capable of augmenting tumor immunity. To maximize the adjuvant effects of HMGN1, we covalently linked it to a gp100 melanoma tumor antigen. We have immunized mice with gp100 linked to HMGN1 in the form of plasmid DNA using gene gun technology. This succeeded in inducing about 70% of the immunized mice to be resistant to a challenge with B16 melanoma tumor cells. However, therapy of mice with this plasmid DNA, which had been injected with B16 melanoma tumor cells four days previously, failed to inhibit tumor growth. We therefore injected a recombinant HMGN1 protein directly intratumorally into CT26 colon tumors in mice to proximate the adjuvant and antigen. This therapeutic vaccine trial did slow the tumor growth and prolonged the survival of mice, but did not cure any of the mice. We therefore improved the potency of the tumor vaccine by employing it in conjunction with other antitumor therapies to cure mice with larger tumors. We used R848, a TLR7/8 ligand, together with HMGN1, a TLR4 ligand, because they synergistically stimulated the maturation of dendritic cells and markedly increased their production of IL-12 and TNF. We have been able to show that intratumoral injections of several TLR ligands together with checkpoint inhibitors cures mice with five types of tumors and results in their subsequent resistance to re-challenge with these tumors. The combination of immunotherapeutic agents consisting of HMGN1, R848 (Resiquimod), a checkpoint inhibitor such as anti PDL-1 or anti CTLA4 antibody or a low dose of cytoxan successfully cured large (1cm diam.) tumors of the colon (CT26), kidney (RENCA), thymoma (EG7) lung (Lewis Lung) and liver (Hepa1-6) in mice. We have termed this combination of antitumor therapeutics, ""TheraVac"". We have also developed a means of delivering the HMGN1 and R848 on gold nanoparticles intravenously with success in curing large colon and liver tumors. In addition, we have even been able to cure 80% of mice bearing B16/F10 melanoma tumors by adding cGAMP, a a ligand of the STING pathway to our TheraVac antitumor protocol. In collaboration with Dr. Mihai Netea's laboratory at Radboud University at the Nijmegen Medical Center in the Netherlands, we investigated the possibility that HMGN1 induces epigenetic effects. Pre-exposure of TLR4 expressing cells to HMGN1 or |