Daniel S. Green

Current prospects of type II interferon γ signaling and autoimmunity

Interferon γ (IFNγ) is a pleiotropic protein secreted by immune cells. IFNγ signals through the IFNγ receptor, a protein complex that mediates downstream signaling events. Studies into IFNγ signaling have provided insight into the general concepts of receptor signaling, receptor internalization, regulation of distinct signaling pathways, and transcriptional regulation. Although IFNγ is the central mediator of the adaptive immune response to pathogens, it has been shown to be involved in several non-infectious physiological processes. This review will provide an introduction into IFNγ signaling biology and the functional roles of IFNγ in the autoimmune response.

Human Monocytes in the Presence of Interferons Alpha2a and Gamma Are Potent Killers of Serous Ovarian Cancer Cell Lines in Combination with Paclitaxel and Carboplatin

Interferons (IFNs) play an important role in immune surveillance of tumors; however, their efficacy in the treatment of malignancies has been limited. Monocytes are mononuclear phagocytes that are critical to the generation of an innate immune response to tumors. The authors and others have shown that treatment of tumor cell lines in vitro and in vivo with human monocytes primed with type I and type II IFNs results in killing. We now expand on this work, in an extended panel of ovarian cancer cell lines. In this study, we hypothesized that there would be variable sensitivity amongst cell lines to the killing properties of monocytes and IFNs. To this end, we explored the interactions of IFN primed monocytes in conjunction with the standard of therapy for ovarian cancer, taxane, and platinum-based chemotherapeutics. Using 6 ovarian cancer cell lines, we demonstrated that there is variation from cell line to cell line in the ability of IFN-α2a and IFN-γ primed monocytes to synergistically kill target tumor cells, and further, there is an additive killing effect when target cells are treated with both IFN primed monocytes and chemotherapy.

Monocyte and interferon based therapy for the treatment of ovarian cancer.

Cytokines and cells of the innate immune system have been shown to be critical regulators in the elimination, equilibrium and escape of malignant cells. Despite in vitro and in vivo evidence, components of the innate immune system have shown limited efficacy in the treatment of ovarian cancer. Intraperitoneal immunotherapies are a promising field that has not yet been fully explored in ovarian cancer. Cytokine immunotherapy using interferon alpha (IFN-α) and interferon gamma (IFN-γ) has predominantly been used intraperitoneally in ovarian cancer, with promising results. Early studies also showed that autologous monocytes infused into the peritoneum have anti-tumor properties. Combination therapies have been shown to be more effective in treating cancer than mono-therapies. Based on these observations the combination of cell therapy with cytokine therapy may provide a unique strategy for the treatment of chemotherapy resistant solid cancers.

A Phase 1 trial of autologous monocytes stimulated ex vivo with Sylatron ® (Peginterferon alfa-2b) and Actimmune ® (Interferon gamma-1b) for intra-peritoneal administration in recurrent ovarian cancer

BackgroundOvarian cancer has no definitive second line therapeutic options, and largely recurs in the peritoneal cavity. Locoregional immune therapy using both interferons and monocytes can be used as a novel approach. Interferons have both cytostatic and cytotoxic properties, while monocytes stimulated with interferons have potent cytotoxic properties. Due to the highly immune suppressive properties of ovarian cancer, ex vivo stimulation of autologous patient monocytes with interferons and infusion of all three agents intraperitoneally (IP) can provide a strong pro-inflammatory environment at the site of disease to kill malignant cells.MethodsPatient monocytes are isolated through counterflow elutriation and stimulated ex vivo with interferons and infused IP through a semi-permanent catheter. We have designed a standard 3 + 3 dose escalation study to explore the highest tolerated dose of interferons and monocytes infused IP in patients with chemotherapy resistant ovarian cancer. Secondary outcome measurements of changes in the peripheral blood immune compartment and plasma cytokines will be studied for correlations of response.DiscussionWe have developed a novel immunotherapy focused on the innate immune system for the treatment of ovarian cancer. We have combined the use of autologous monocytes and interferons alpha and gamma for local–regional administration directly into the peritoneal cavity. This therapy is highly unique in that it is the first study of its type using only components of the innate immune system for the locoregional delivery consisting of autologous monocytes and dual interferons alpha and gamma.Trial Registration ClinicalTrials.gov Identifier: NCT02948426, registered on October 28, 2016. https://clinicaltrials.gov/ct2/show/NCT02948426

Human macrophages survive and adopt activated genotypes in living zebrafish

The inflammatory response, modulated both by tissue resident macrophages and recruited monocytes from peripheral blood, plays a critical role in human diseases such as cancer and neurodegenerative disorders. Here, we sought a model to interrogate human immune behavior in vivo. We determined that primary human monocytes and macrophages survive in zebrafish for up to two weeks. Flow cytometry revealed that human monocytes cultured at the physiological temperature of the zebrafish survive and differentiate comparable to cohorts cultured at human physiological temperature. Moreover, key genes that encode for proteins that play a role in tissue remodeling were also expressed. Human cells migrated within multiple tissues at speeds comparable to zebrafish macrophages. Analysis of gene expression of in vivo educated human macrophages confirmed expression of activated macrophage phenotypes. Here, human cells adopted phenotypes relevant to cancer progression, suggesting that we can define the real time immune modulation of human tumor cells during the establishment of a metastatic lesion in zebrafish.

A monocyte and interferon based cell therapy for the treatment of ovarian cancer

Ovarian cancer is the number one cause of death due to gynecological malignancies, and the fifth leading cause of death in cancer in women. While surgical debulking and chemotherapy cause an initial remission in disease, approximately 75% of patients will relapse. The relapse is characterized by chemotherapy refractory disease. Currently there are no definitive second line treatments for patients who fail standard of care. Patients with ovarian cancer have a 5-year survival rate of 25-30%, making it one of the most aggressive malignancies. We have designed a new cell therapy by using the patients innate immune system (monocytes primed with Interferon Alpha and Gamma) to kill metastatic lesions of the peritoneal cavity. Monocytes isolated from patients with therapy resistant ovarian cancer and stimulated with interferons alpha and gamma are potent killers of tumor cell lines in vitro. We have also found that patient monocytes are more cytotoxic than age match healthy controls. We have shown that the major mechanism of monocyte-mediated killing is the up regulation of TRAIL on monocytes. Ovarian cancer cell death is mediated in a Caspase-8 dependent manner. Furthermore, we have shown that the non-classical (CD14loCD16+) subset of monocytes is more cytotoxic than the classical (CD14+CD16-) subset. Finally, we have shown that this therapy is effective in a mouse model of ovarian cancer. Based upon these results we are preparing an investigational new drug (IND) with the FDA to test this therapy in human subjects.