Capture of plasma membrane fragments from target cells by trogocytosis requires signaling in T cells but not in B cells.
Upon recognition of their respective cellular partners, T and B cells acquire their antigens by a process of membrane capture called trogocytosis. Here, we report that various inhibitors of actin polymerization or of kinases involved in intracellular signaling partially or fully inhibited trogocytosis by CD8(+) and CD4(+) T cells, whereas they had no effect on trogocytosis by B cells. Similarly, trogocytosis by T cells was inhibited at 4 degrees C, whereas in B cells it was independent of temperature, indicating that trogocytosis by B cells does not rely on active processes. By contrast, most inhibitors we tested impaired both T-cell and B-cell activation. The differential effect of inhibitors on T-cell and B-cell trogocytosis was not due to the higher affinity of the B-cell receptor for its cognate antigen compared with the affinity of the T-cell receptor for its own antigen, but it correlated tightly with the abilities of T cells and B cells to form conjugates with their target cells in the presence of inhibitors. Trogocytosis thus has different requirements in different cell types. Moreover, the capture of membrane antigen by B cells is identified as a novel signaling-independent event of B-cell biology.
Aucher
Anne
A
Institut de Pharmacologie et de Biologie Structurale, Centre National de Recherche Scientifique, Unité Mixte de Recherche 5089, Toulouse, France.
Magdeleine
Eddy
E
Joly
Etienne
E
Hudrisier
Denis
D
D008841:Actin Cytoskeleton / Q000276:immunology; D000818:Animals; D017951:Antigen Presentation / Q000276:immunology; D001402:B-Lymphocytes / Q000166:cytology* / Q000276:immunology / Q000378:metabolism*; D018414:CD8-Positive T-Lymphocytes / Q000166:cytology* / Q000276:immunology / Q000378:metabolism*; D002460:Cell Line; D002462:Cell Membrane / Q000276:immunology / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D008213:Lymphocyte Activation; D051379:Mice; D008822:Mice, Transgenic; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D000081082:Phosphoinositide-3 Kinase Inhibitors; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D011947:Receptors, Antigen, B-Cell / Q000378:metabolism; D011948:Receptors, Antigen, T-Cell / Q000378:metabolism; D015398:Signal Transduction / Q000276:immunology*; D000072377:Syk Kinase; D019061:src-Family Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism
D004791:Enzyme Inhibitors; D047908:Intracellular Signaling Peptides and Proteins; D019869:Phosphatidylinositol 3-Kinases; D000081082:Phosphoinositide-3 Kinase Inhibitors; D011505:Protein-Tyrosine Kinases; D011947:Receptors, Antigen, B-Cell; D011948:Receptors, Antigen, T-Cell; D000072377:Syk Kinase; D019061:src-Family Kinases; C000606896:SYK protein, human; C000606897:Syk protein, mouse