Triple negative breast cancer cells acquire lymphocyte proteins and genomic DNA during trogocytosis with T cells

Trogocytosis is the process by which a recipient cell siphons small membrane fragments and proteins from a donor cell and can be utilized by cancer cells to avoid immune detection. We observed lymphocyte specific protein expressed by triple negative breast cancer (TNBC) cells <i>via</i> immunofluorescence imaging of patient samples. Image analysis of Cluster of Differentiation 45RA (CD45RA) expression, a naïve T cell specific protein, revealed that all stages of TNBCs express CD45RA. Flow cytometry revealed TNBC cells trogocytose CD45 protein from T cells. We also showed that the acquisition of these lymphoid markers is contact dependent. Confocal and super-resolution imaging further revealed CD45+ spherical structures containing T cell genomic DNA inside TNBC cells after co-culture. Trogocytosis between T cells and TNBC cells altered tumor cell expression of <i>PTPRC</i>, the gene that encodes for CD45. Our results revealed that CD45 is obtained by TNBC cells from T cells <i>via</i> trogocytosis and that TNBC cells express CD45 intracellularly and on the membrane.