False-colour transmission electron micrograph (TEM) of a single,activated cytotoxic ("killer") T-lymphocyte (left,a class of white blood cell) delivering the "kiss of death" to its target cell. T-lymphocytes are involved in cell-mediated response to invasion of body by foreign microorganisms,notably viruses and some bacteria,which are protected from antibodies (secreted by B-lymphocytes) by their host cells. "Killer" T- cells recognize antigens on their target cell & bind to the surface membrane. Dark vesicles at edge of T-cell contain enzymes that penetrate the target cell membrane & destroy the cell | |
Lizenzart: | Lizenzpflichtig |
Credit: | Science Photo Library / Edelmann |
Bildgröße: | 4878 px × 3595 px |
Modell-Rechte: | nicht erforderlich |
Eigentums-Rechte: | nicht erforderlich |
Restrictions: |
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