Science Immunology

The ABCs of ovarian cancer immunology: IgA, B cells, and CTLs

Intratumoral B cells in ovarian cancers produce IgA, which binds tumor antigens and inhibit tumor growth through myeloid cell–dependent mechanisms or by neutralization of secreted factors, and by antigen-nonspecific binding to poly-Ig receptor on cancer cells leading to transcytosis, which sensitizes the cells for CTL killing.

Uptake of lipids from ascites drives NK cell metabolic dysfunction in ovarian cancer

High-grade serous ovarian cancer (HGSOC) remains an urgent unmet clinical need, with more than 70% of patients presenting with metastatic disease. Many patients develop large volumes of ascites, which promotes metastasis and is associated with poor therapeutic response and survival. Immunotherapy trials have shown limited success, highlighting the need to better understand HGSOC immunology. Here, we analyzed cytotoxic lymphocytes [natural killer (NK), T, and innate T cells] from patients with HGSOC and observed widespread dysfunction across primary and metastatic sites. Although nutrient rich, ascites was immunosuppressive for all lymphocyte subsets. NK cell dysfunction was driven by uptake of polar lipids, with associated dysregulation in lipid storage. Phosphatidylcholine was a key immunosuppressive metabolite, disrupting NK cell membrane order and cytotoxicity. Blocking lipid uptake through SR-B1 protected NK cell antitumor functions in ascites. These findings offer insights into immune suppression in HGSOC and have important implications for the design of future immunotherapies.

Selfish antibodies target auto-antigens in cancer

Auto-antibodies against MMP14 define tumor-reactive humoral responses in ovarian cancer.