Title: Lymphocyte (peripheral blood, human)
Description: Electron microscopy.
(Cytotoxic) lymphocyte (A) with a juxtanuclear Golgi area (3) and centrioles (2), few mitochondria (4) and sparsely profiles of rough endoplasmic reticulum (RER). Dense-stained granules (1) are present. The surface exhibits short blunt microvilli.
The right lymphocyte in (B) has similar characteristics but cytotoxic granules are not visible.
Background: Cytolytic lymphocytes, i.e. NK-cells and cytotoxic T cells, recognize by different receptors (MHC-I, CD’s) antigens on infected cells and kill these cells with the content of the granules. The membrane-bound cytoplasmic granules contain proteins, including perforin and granzymes. In addition, differentiated CTL’s (cytotoxic lymphocytes), like Th1 cells are capable of secreting cytokines, mostle IFN-γ, lymphotoxin, and TNF which function to activate phagocytes and induce inflammation.
Keywords/Mesh: blood, bone marrow, lymphocyte, T cell, histology, electron microscopy, POJA collection