Why do human B cells secrete granzyme B?
In conflict with this dogma, recent studies have demonstrated that the combination of interleukin-21 (IL-21) and B-cell receptor (BCR) stimulation enables B cells to produce and secrete the active form of the cytotoxic serine protease granzyme B (GrB).
Are there cytotoxic B cells?
Our findings suggest GzmB(+) cytotoxic B cells may have a role in early cellular immune responses including tumor immunosurveillance, before fully activated, antigen-specific cytotoxic T cells are on the spot.
What is perforin and granzyme?
Perforin and Granzyme Perforin is a pore-forming protein and also known as cytoplasmic granule toxins. Granzyme is a family of structurally related serine proteases stored within the cytotoxic granules of cytotoxic lymphocytes (CLs). Perforin and granzyme induce target-cell apoptosis cooperatively (Figure 1).
What does granzyme B do?
Granzyme B is a cytotoxic serum protease protein that participates in inducing apoptosis of target cells for NK Cells and cytotoxic CD8+ lymphocytes which are part of the innate immune system.
What do regulatory B cells do?
Regulatory B cells (Bregs or Breg cell) represent a small population of B cells which participates in immunomodulations and in suppression of immune responses. These cells regulate the immune system by different mechanisms. The main mechanism is a production of anti-inflammatory cytokine interleukin 10 (IL-10).
How do B cells work in the immune system?
B-cells fight bacteria and viruses by making Y-shaped proteins called antibodies, which are specific to each pathogen and are able to lock onto the surface of an invading cell and mark it for destruction by other immune cells.
What is the function of perforin?
Perforin is a glycoprotein responsible for pore formation in cell membranes of target cells. Perforin is able to polymerize and form a channel in target cell membrane.
How do you detect perforin?
Perforin and granzymes work synergistically to induce apoptosis in target cells recognized by cytotoxic T lymphocytes. While perforin is readily detectable by flow cytometry in resting CD8 T cells, upregulation of perforin in activated cells is thought to require proliferation.