Cancer cell lines play a vital role in immunotherapy research by serving as valuable tools for studying the interactions between immune cells and cancer cells. Here are some key roles of cancer cell lines in immunotherapy research:

1. Antigen Presentation and Tumor Antigen Discovery: Cancer cell lines are commonly used to identify tumor antigens that can be recognized by the immune system. By studying the expression of antigens on cancer cell lines, researchers can discover potential targets for immunotherapeutic interventions, such as tumor-associated antigens or neoantigens derived from specific mutations.
2. Immunogenicity Assessment: Cancer cell lines are used to assess the immunogenicity of tumors and evaluate their ability to elicit immune responses. Researchers can investigate the expression of immune-related molecules on cancer cell lines, such as major histocompatibility complex (MHC) molecules, co-stimulatory molecules, and immune checkpoint proteins. This information helps in understanding the tumor’s interaction with the immune system and designing immunotherapeutic strategies.
3. Immune Cell Co-culture and Functional Assays: Cancer cell lines provide a controlled environment for studying the interactions between immune cells and tumor cells. They can be co-cultured with immune cells, such as T cells, natural killer (NK) cells, or dendritic cells, to assess immune cell activation, proliferation, and effector functions. Functional assays, including cytotoxicity assays and cytokine release assays, can be performed using cancer cell lines to evaluate the efficacy of immunotherapeutic agents.
4. Immune Checkpoint Inhibitor Testing: Cancer cell lines are widely used to evaluate the effectiveness of immune checkpoint inhibitors (e.g., anti-PD-1, anti-PD-L1, anti-CTLA-4 antibodies). By assessing the response of cancer cell lines to checkpoint inhibitors, researchers can gain insights into the tumor’s susceptibility to immunotherapy and identify predictive biomarkers of response.
5. Targeted Therapy and Combination Approaches: Cancer cell lines are utilized to study the combination of immunotherapies with other targeted therapies. By co-administering targeted agents, such as small molecule inhibitors or monoclonal antibodies, researchers can investigate the synergistic effects and potential mechanisms of action underlying combination therapies.
6. Resistance Mechanisms: Cancer cell lines can be used to study mechanisms of resistance to immunotherapies. By exposing cancer cell lines to immunotherapeutic agents over time, researchers can induce resistance and investigate the underlying genetic, epigenetic, or phenotypic changes that contribute to treatment failure.
7. Preclinical Models for Immunotherapy Development: Cancer cell lines are employed in preclinical studies to evaluate the efficacy and safety of novel immunotherapeutic approaches. They provide a controlled and scalable system for testing different immunotherapeutic strategies before advancing to in vivo models or clinical trials.

Cancer cell lines, while simplified models, contribute to our understanding of immune-tumor interactions and aid in the development of effective immunotherapies. It is important to validate findings obtained from cancer cell lines using more complex models and ultimately in clinical settings to ensure translation into successful immunotherapeutic interventions.