Trevin Kurtanich

Current asthma treatments manage disease symptoms but fail to address the underlying cause of allergic disease. Allergen immunotherapy holds the promise for durable disease control by establishing allergen-specific tolerance through repeated introduction of native allergens; however, its efficacy can be limited by long interventions, reactions upon administration, and poor patient compliance. Here, we developed a rapid, safe, and effective liver-targeted allergen immunotherapy (LIT) to provide long-term disease control. We developed LIT tolerogens from native respiratory allergens, which induced antigen-specific regulatory T (T _reg ) cells in vivo with only two interventions. Synthetic mannosylation of native allergens prevented antibody-mediated recognition and subsequent life-threatening anaphylaxis upon administration. Protein engineering prevented sensitization events that occurred because of the proteolytic activity of native respiratory allergens, which limit the effectiveness of allergen immunotherapy. In preclinical models of allergic asthma, LIT ameliorated clinical, pathological, and serological features, and protection was dependent on antigen-specific T _reg cells. In sensitized mice, LIT provided a year-long control of allergic asthma symptoms in the absence of additional intervention. Last, LIT induced antigen-specific T _reg cells against Der p 1, a major protein in the clinically relevant house dust mite (HDM) respiratory allergen. In mice with established HDM allergy, LIT was well tolerated and provided allergic symptom relief. Together, our data provide a proof of concept that LIT with synthetically mannosylated tolerogens provides a rapid, safe, and effective approach to allergen immunotherapy and holds promise for durable control of allergic asthma.

Background: The use of immune checkpoint inhibitors (CPIs) has become a dominant regimen in modern cancer therapy, however immune resistance induced by tumor-associated macrophages (TAMs) with immune suppressive and evasion properties limits responses. Therefore, the rational design of immune modulators that can control the immune suppressive properties of TAMs and polarize them, as well as dendritic cells (DCs), toward a more proinflammatory phenotype is a principal objective in cancer immunotherapy. Methods: Here, using a protein engineering approach to enhance cytokine residence in the tumor microenvironment, we examined combined stimulation of the myeloid compartment via tumor stroma-binding granulocyte–macrophage colony-stimulating factor (GM-CSF) to enhance responses in both DCs and T cells via stroma-binding interleukin-12 (IL-12). We evaluated tumor responses at the levels of outcome, cellular responses, and cytokine responses in both the tumors and the tumor-draining lymph nodes. We further investigated the potentiation of DC response to IL-12 by GM-CSF stimulation ex vivo. Results: Engineered GM-CSF restored an antitumorigenic tumor myeloid microenvironment otherwise suppressed by TAMs, while engineered IL-12 provided effector signals to T cells, thereby boosting both tumor-resident antitumor macrophage and CD8⁺ T cell populations. Furthermore, engineered GM-CSF potentiated DC response to IL-12, upregulating DC expression of IL-12 receptor and enhancing their expression of proinflammatory cytokines and chemokines on IL-12 exposure. This resulted in remarkable synergistic efficacy in multiple solid tumor models treated with the dual cytokine combination. The combination therapy also improved the efficacy of CPI in a CPI-resistant genetically-engineered melanoma model and exhibited synergistic antitumor efficacy in a pulmonary metastasis model. Conclusion: Our strategy provides a rational design for combination immunotherapy targeting both myeloid and lymphoid compartments through complementary mechanisms.

Cancer immunotherapy is moving toward combination regimens with agents of complementary mechanisms of action to achieve more frequent and robust efficacy. However, compared with single-agent therapies, combination immunotherapies are associated with increased overall toxicity because the very same mechanisms also work in concert to enhance systemic inflammation and promote off-tumor toxicity. Therefore, rational design of combination regimens that achieve improved antitumor control without exacerbated toxicity is a main objective in combination immunotherapy. Here, we show that the combination of engineered, tumor matrix-binding interleukin-7 (IL-7) and IL-12 achieves remarkable anticancer effects by activating complementary pathways without inducing any additive immunotoxicity. Mechanistically, engineered IL-12 provided effector properties to T cells, while IL-7 prevented their exhaustion and boosted memory formation as assessed by tumor rechallenge experiments. The dual combination also rendered checkpoint inhibitor (CPI)–resistant genetically engineered melanoma model responsive to CPI. Thus, our approach provides a framework of evaluation of rationally designed combinations in immuno-oncology and yields a promising therapy.

The inability of CD8⁺ effector T cells (Teffs) to reach tumor cells is an important aspect of tumor resistance to cancer immunotherapy. The recruitment of these cells to the tumor microenvironment (TME) is regulated by integrins, a family of adhesion molecules that are expressed on T cells. Here, we show that 7HP349, a small-molecule activator of lymphocyte function–associated antigen-1 (LFA-1) and very late activation antigen-4 (VLA-4) integrin cell-adhesion receptors, facilitated the preferential localization of tumor-specific T cells to the tumor and improved antitumor response. 7HP349 monotherapy had modest effects on anti–programmed death 1–resistant (anti–PD-1–resistant) tumors, whereas combinatorial treatment with anti–cytotoxic T lymphocyte–associated protein 4 (anti–CTLA-4) increased CD8⁺ Teff intratumoral sequestration and synergized in cooperation with neutrophils in inducing cancer regression. 7HP349 intratumoral CD8⁺ Teff enrichment activity depended on CXCL12. We analyzed gene expression profiles using RNA from baseline and on treatment tumor samples of 14 melanoma patients. We identified baseline CXCL12 gene expression as possibly improving the likelihood or response to anti–CTLA-4 therapies. Our results provide a proof-of-principle demonstration that LFA-1 activation could convert a T cell–exclusionary TME to a T cell–enriched TME through mechanisms involving cooperation with innate immune cells.