Author: V. Dimov, M.D., Allergist/Immunologist and Assistant Professor at University of Chicago
Reviewer: S. Randhawa, M.D., Allergist/Immunologist and Assistant Professor at NSU
Neutrophils, also called polymorphonuclear leukocytes (PMNs), are the most abundant circulating WBCs. PMNs mediate the earliest phase of inflammatory response.
Granulocytes are CD45+ CD15+ cells.
PMNs migration to tissues
CXCL8 (IL-8) forms a chemotactic gradient that directs leukocytes towards site of tissue injury/infection. Neutrophils are activated by cytokines secreted by Th17 cells.
Neutrophils migrate into tissues via:
- f-met-leu-phe (fMLP)
- interactions between Sialyl-Lewis X, P-selectins and LFA-1/ICAM-1
Neutrophils extravasate from blood vessels to the site of tissue injury or infection during the innate immune response. Image source: Wikipedia, GNU Free Documentation License.
What is the PMN half-life?
6 hours. 100 trillion cells are produced every day by the BM.
What is the most important PMN enzyme?
PMNs do not stain either red (eosinophils) or blue (basophils).
Video: A neutrophil chasing bacteria, set to music.
Phagocyte immunodeficiencies (click to enlarge the image):