Harnessing immune reactivity against the bacteria present in breast cancers

Project Description: Current immunotherapies are largely focused on boosting ‘killer’ T cells to destroy cancer cells. While this type of immunotherapy has shown extraordinary success in some tumours including melanoma, lung and kidney cancer, it has only been effective in a small subset of breast cancers. An increased understanding of the complexity of tumour immune responses in breast cancers is critical to increase immunotherapy effectiveness. Breast cancers have been shown to contain bacteria within tumour tissue, but its role in tumour development and metastasis is unknown. A/Prof Andreas Behren (Olivia Newton-John Cancer Research Institute) has recently uncovered new secrets on how a special type of immune cell called gamma delta T cells respond to bacteria and believe that these cells can be harnessed to produce a new type of immunotherapy. In this NBCF funded project, A/Prof Behren and colleagues will investigate the presence of tumour bacteria and gamma delta T cells in human samples of breast cancer and investigate ways in which their interactions can be harnessed to redirect anti-bacterial immune responses to destroy the cancer.

Why the Work is Needed: Immunotherapies, drugs that help the human immune system destroy cancer cells, have revolutionised the treatment of many cancers including melanoma, lung and kidney cancer, but remain largely ineffective in breast cancers. A greater understanding of the details of tumour immune responses in breast cancers will be key to improving response rates to this class of therapy.

Expected Outcomes: Outcomes from this study will reveal a better understanding of the types of bacteria that are found in breast cancers and how these bacteria interact with immune cells present in the tumour. Findings from this study will provide important new knowledge on how to increase immune reactivity against the bacteria present in breast cancers, potentially providing the foundations for a new type of immunotherapy.

Project Details

Current immunotherapies are largely focused on boosting ‘killer’ T cells to destroy cancer cells. While this type of immunotherapy has shown extraordinary success in some tumours including melanoma, lung and kidney cancer, it has only been effective in a small subset of breast cancers. An increased understanding of the complexity of tumour immune responses in breast cancers is critical to increase immunotherapy effectiveness.

In this study, A/Prof Andreas Behren (Olivia Newton John Cancer Research Institute) will focus on a different population of immune cells, gamma delta T cells, which are the first responders to bacterial or viral infections. Breast cancers have been shown to contain various bacterial species within the tumours, but the significance and function of these remain unknown.

This study will investigate the types of bacteria residing within human breast cancers and correlate it with the presence of gamma delta T cells and other immune cells. Using breast cancer cells derived from patients, the ability of gamma delta T cells to kill cancer cells will be tested in the presence or absence of bacteria. Since bacteria have been found in all subtypes of breast cancer, this approach will be tested across breast cancer subtypes with the potential to produce a new type of immunotherapy capable of treating a wide variety of breast cancer subtypes.