Leuzzi Laboratory
BACKGROUND
The immune system plays a pivotal role in protecting the body from cancer by identifying and eliminating tumor cells. However, as tumors evolve, they accumulate mutations and chromosomal alterations that reshape their ability to trigger immune responses—a phenomenon known as tumor immunogenicity. While some tumors exploit these genomic changes to evade immune detection, others become more immunogenic, increasing their susceptibility to immune surveillance and immunotherapy (RD Schreiber, Science, 2011).
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A central question driving our research is: How do DNA repair mechanisms and genomic instability influence the dynamic interplay between cancer cells and the immune system?
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To address this, we integrate high-throughput functional screens—both in vitro and in vivo—with advanced molecular and cellular biology approaches. Our goal is to identify DNA damage response (DDR) factors and single nucleotide variants (SNVs) that impact cancer immunity and response to immunotherapy. Ultimately, we aim to translate these discoveries into innovative immuno-oncology strategies that enhance immune recognition and overcome tumor resistance to therapy.
Tumors with DNA repair defects can trigger immune responses via cytosolic DNA, increased mutational burden, and immunogenic cell death. However, the specific DDR factors regulating these processes remain largely uncharacterized. To identify such factors, we use CRISPR-Cas9 screening platforms developed in our lab (Leuzzi et al., Cell, 2024), which systematically quantify the impact of DDR factors on immune signaling. By identifying key regulators of tumor immunogenicity, we aim to discover novel therapeutic targets to enhance immune recognition of tumors.
Figure 1. Schematic of CRISPR screens to identify regulators of nuclear IRF3 and PD-L1.
CURRENT STUDIES
Mapping the regulators of tumor immunogenicity
Investigating the impact of tumor-associated SNVs on immunotherapy
Many cancer-associated single nucleotide variants (SNVs) are poorly characterized and often classified as variants of uncertain significance (VUS). Understanding their functional impact on immunotherapy response is critical for uncovering new biomarkers and therapeutic opportunities. Leveraging CRISPR-dependent base editing, we introduce cancer-associated SNVs into DDR and immune-related genes at scale, enabling high-throughput assessment of their effects on DNA repair, immune signaling, and tumor immunogenicity. This project aims to identify specific mutations that drive immune evasion and therapy resistance, enabling more effective and personalized cancer treatments.
Figure 2. Fingerprint plot from CRISPR-dependent base editing screens showing mutation annotation for sgRNAs targeting the indicated genes.
Defining the role of DDR in primary human CD8+ T cells
Therapy-induced DNA damage can impair CD8+ T cell activity, which is crucial for anti-tumor immunity. Understanding how these cells respond to genotoxic stress during cancer treatment is crucial for developing effective combinatorial strategies that integrate DNA-damaging therapies with immunotherapy. We are particularly interested in identifying the DNA repair pathways that sustain T cell functionality under these conditions, with the goal of enhancing T cell resilience and improving immunotherapy outcomes.
Figure 3. Schematics for the study described on the left. Created with BioRender.com
