Aneuploidy—the presence of an incorrect number of chromosomes—is common during the normal development of human embryos and is the main cause of spontaneous miscarriage.

A team of researchers at IRB Barcelona has developed a genetic tool to create customized aneuploidies and analyse their impact during development.

Published in Cell Genomics, the study demonstrates that aneuploid cells are actively eliminated by neighbouring cells through cell competition.

These mechanisms may be involved in the removal of aneuploid cells during early human development.

The study – conducted using a combination of machine learning and metagenomics, and published in Nature Medicine – could make non-invasive screening methods more accurate in the future

B lymphocytes exhibit dual roles in tumorigenesis, acting as both allies and adversaries in the tumor microenvironment (TME). Their anti-tumor functions include recognizing tumor-associated antigens, producing antibodies, activating cytotoxic immune responses, and forming tertiary lymphoid structures (TLS) that enhance immune cell coordination. Tumor-infiltrating B cells (TIL-Bs) within TLS contribute to improved patient survival and immunotherapy responses by facilitating antibody class switching, somatic hypermutation, and cytokine secretion that recruit and activate T cells, natural killer (NK) cells, and dendritic cells (DCs). Antibodies from B cells mediate complement-dependent cytotoxicity (CDC), antibody-dependent cellular phagocytosis (ADCP), and antibody-dependent cell-mediated cytotoxicity (ADCC), directly eliminating tumor cells. Additionally, B cells present antigens to T cells and secrete cytokines like IFN-γ and CXCL13, amplifying anti-tumor immunity. However, regulatory B cells (Bregs) and other subsets suppress immune responses by secreting IL-10, TGF-β, and VEGF, promoting angiogenesis, recruiting immunosuppressive cells like myeloid-derived suppressor cells (MDSCs) and regulatory T cells (Tregs), and expressing immune checkpoints like PD-L1. This duality underscores the complexity of targeting B cells in cancer therapy.