As one of the main populations of the immune system, B cells exert a key role in both the innate and adaptive branches of immunity. Depending on the context, different specialized B cell subsets are solicited and engage a various range of responses. Beyond their ability to mediate humoral responses, B cells are potent antigen presenting cells, and could provide co-stimulatory or co-inhibitory signals and secrete cytokines that modulate the immune responses. In cancer, B cells represent the second most abundant tumor-infiltrating lymphocyte and therefore might play an important role in modulating the immune response to cancer. However, it remains ambiguous how B cells orient anti-tumor immunity, indicated by divergent conclusions of studies addressing this question. Indeed, B cells can inhibit tumor growth through the production of tumor-reactive antibodies promoting tumor killing by NK cells or phagocytosis by macrophages. Their ability to present tumor-antigens is also important to prime T cell anti-tumor responses. On the other hand, B cells could also promote tumor development through production of autoantibodies, tumor growth factors or tolerogenic cytokines, dampening anti-tumor responses. A better understanding of the tumor-infiltrating B cell subsets remains essential to dissect how they influence cancer immunity. Interestingly, some B cell subsets express immunosuppressive enzymes that have been described to be involved in tumor progression. Previously, I found that one of these enzymes, IL4I1, impacts B-cell development and responses and promotes tumor progression in a mouse model of melanoma. Currently, we are using single-cell RNAseq (scRNAseq) technology combined with throughput flow cytometry (BD FACSymphonyTM) to investigate tumor-infiltrating B cell diversity and their potential role on tumor progression. A better identification of pro- and anti-tumor B cells may help designing therapies targeting one of these subsets and improve clinical outcome.

Linkedin link:

Invitation: LNC - Lionel Apetoh - UMR1231

Le séminaire aura lieu Salle R17 de 11h00 à 12H30

Renseignements - omicheau@u-bourgogne.fr Tel: 03 80 39 34 68