Targeted Immuno-Oncology

Exploring the fine architecture of the tumor microenvironment

Not only the frequency and composition of tumor-infiltrating leukocytes but also their spatial organization is a major determinant of tumor progression and response to therapy. However, most studies focused only on how the fine tumor architecture can discriminate tumor subtypes rather than evaluate its prognostic potential. We employ co-detection by indexing (CODEX) multiparametric imaging and flow cytometry to measure the major leukocyte subsets and an ad-hoc computational framework to identify and analyze discrete cellular neighborhoods. We are discovering an extraordinary structural architecture of the tumor microenvironment in which leukocytes are not randomly distributed but rather organized into tissue infiltrating “mini-organs” that play an essential role in their function and in tumor progression.

Detecting Head and Neck squamous cell carcinoma early

The development of sensitive and specific diagnostic assays for the early detection of Head and Neck Cancer is a still unmet medical need. Most assays that are being developed rely on a neoplastic cell biomarker often present in only a proportion of neoplastic cells and/or subset of patients with Head and Neck squamous Cell carcinoma (HNSCC). As such, the intrinsic heterogeneity of the neoplastic cell within a single patient and across patients limits the sensitivity of these assays. To overcome this problem, we monitor HNSCC presence in the oral rinse by using RNA aptamers that recognize tumor infiltrating myeloid cells. These cells infiltrate the lesion in high number and early during tumorigenesis, participate in tumor initiation and progression, and predict tumor recurrence in HNSCC.

Repolarizing tumor infiltrating Myeloid cells for an effective therapy of cancer

Tumor-infiltrating myeloid cells (TIMC) promote tumor growth and metastases and inhibit immune surveillance and the efficacy of most therapeutic approaches. Many molecular pathways that regulate TIMC polarization and function have been identified. However, their involvement in many biological processes in other cells and healthy tissues prevent the use of small molecules and other untargeted drugs. Targeted delivery of therapeutics to TIMC is thus necessary to inhibit or repolarize myeloid cells in the tumor. Toward this goal, we identified RNA aptamers able to recognize specifically mouse and human myeloid cells in the tumor microenvironment but not their counterparts in other organs or in circulation. Using these aptamers, functionalized dendrimers, and RNA therapeutics, we identified that the integration of two signaling pathways regulates the commitment of myeloid precursors to differentiate in either tumor-favoring or tumoricidal myeloid cells. We are further dissecting these pathways and developing new smart drugs for the immunological treatment of cancer.

Increasing breast cancer immunogenicity

Even with the FDA approval of checkpoint inhibitors for PDL1 positive triple negative breast cancer, metastatic breast cancer is still a deadly disease. The modest impact of checkpoint inhibitor therapy can be explained by the relatively low tumor mutation burden, by the low expression of neoantigens, and by the overall low immunogenicity of metastatic breast cancer.

We are using RNA aptamer to silence the spliceosome machinery, specifically in breast cancer, to increase the number of intron-derived neoantigens and cancer immunogenicity and to restore the efficacy of checkpoint inhibition therapy. Since our aptamers recognize both mouse and human metastatic cancers, the translation of positive findings in the clinic should be facilitated, and we might provide effective immunotherapy with limited side effects.

Type 1 Diabetes

Increasing beta cell mass

This project aims to develop and validate new “intelligent” drugs able to induce the expansion of insulin producing beta cells without undesirable side effect on other tissues or organs. Important progresses have been made in understanding the mechanisms that limit beta cell proliferation and protect these cells from autoimmunity. Unfortunately, these mechanisms are present also in other cells and tissues and thus preclude the use of conventional “non-intelligent” drugs. To overcome this problem, we developed a new class of bifunctional drugs called aptamer chimera. These bifunctional drugs are generated by the conjugation of RNA aptamers specific for beta cells and siRNAs. As such, these aptamer can recognize insulin producing cells in the body and instruct them to release the anti-proliferative brakes. We are testing these smart-bifunctional drugs in immunocompromised mice transplanted with human islets. This new class of safe therapeutics that, by controlling beta cell proliferation in vivo, may lead to a tight control of blood glucose concentration without the need for exogenous insulin or off-target effects on other tissues.

Inducing exhaustion in diabetogenic T cells to reverse autoimmune diabetes

Compelling evidences point to T cell exhaustion as an important mechanism that controls the clinical manifestation of Type 1 (T1) diabetes in mice and human. In human T cell exhaustion correlates with the length of the honeymoon phase; PDL1 is found on residual islets of patients with long history of diabetes; and autoantibodies positive, non-diabetic patients undergoing anti-cancer treatment with checkpoint inhibitors develop fulminant diabetes. In NOD mice, PDL1 is expressed on the islets of those that do not develop diabetes, anti-PD1 treatment induces diabetes in male NOD, and transgenic expression of PDL1 on β cells prevent diabetes. These data suggest that modulation of PDL1 on β cells is an important therapeutic opportunity to prevent diabetes clinical manifestations.

We use bifunctional RNA therapeutics to modulate PDL1 expression on β cells to test the hypothesis that this will halt the autoimmunity and prevent or reverse T1 diabetes. Our bifunctional RNA therapeutic comprises aptamers specific for β cells and small activated (sa) RNA able to bind to the PDL1 promoter. We are evaluating how this therapeutic modulates the pancreatic microenvironment, exhaustion in T cells, and the progression of this autoimmune disease.

Deleting diabetogenic T cells with smart lipid nanoparticles

Substantial progress has been made in understanding the mechanisms that regulate the interaction of beta cells with the immune system. In particular, the Fas/FasL pathway is emerging as crucial for maintaining peripheral immune tolerance, but it is also involved in β cell death. We have recently identified two RNA aptamers specific for β cells that can deliver imaging reagents or small therapeutic RNA to mouse and human β cells in vivo. Building on the clinical success of lipid nanoparticles (LNPs) and mRNA delivery, we generated aptamer decorated LNPs. These smart LNPs have favorable pharmacokinetic and biodistribution and, when given systemically, allow the in vivo preferential transfection of islet cells. We use these aptamer-LNPs to interfere with the Fas/FasL pathways by delivering FasL mRNA and Fas shRNA to β cells. We anticipate that these treatments will be safe, targeted to β cells, and effective in inhibiting Fas-mediated β cell apoptosis and in triggering Fas ligand-mediated death of diabetogenic T cells. In summary, this project is functionally testing two smart drugs with the potential to protect beta cells and restrain autoimmunity in vivo.