Translocation of CD45RA in neutrophils

• Published in: Journal of leukocyte biology Vol. 49; no. 4; pp. 317 - 328
• Main Authors: Caldwell, Charles W., Patterson, William P., Yesus, Yohannes W.
• Format: Journal Article
• Language: English
• Published: Bethesda, MD Society for Leukocyte Biology 01.04.1991; Federation of American Societies for Experimental Biology
• Subjects: 1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; Antigens, Differentiation - biosynthesis; Biological and medical sciences; Calcimycin - pharmacology; Calcium - pharmacology; Calcium Channel Blockers - pharmacology; Calmodulin - antagonists & inhibitors; Calmodulin - physiology; Cell Membrane - metabolism; Flow Cytometry; Fundamental and applied biological sciences. Psychology; Fundamental immunology; Gene Expression Regulation; Histocompatibility Antigens - biosynthesis; Humans; Immunobiology; Isoantigens; Isoquinolines - pharmacology; Leukocyte Common Antigens; Myeloid cells: ontogeny, maturation, markers, receptors; Neutrophils - metabolism; Piperazines - pharmacology; Polynuclears; Protein Kinase Inhibitors; Protein Kinases - physiology; protein tyrosine phosphatase; Sulfonamides - pharmacology; T200 antigen; Tetradecanoylphorbol Acetate - pharmacology; Time Factors; tyrosine phosphatase; Up-Regulation - drug effects; Human; Translocation; Flow cytometry; Calcium; Induction; Neutrophile; Granulocyte; Stimulation; Ionophore; Cell surface; Cytoplasm
• ISSN: 0741-5400; 1938-3673
• DOI: 10.1002/jlb.49.4.317

The CD45 family of high‐Mr glycoprotein antigens is expressed in some molecular form on all lymphohematopoietic cells. Different cell types express various isoforms in a precisely programmed fashion. In addition to cell surface CD45 antigens, we recently demonstrated a cytoplasmic granule‐associated pool of CD45RA, the highest Mr isoform, in mature neutrophils that is generally absent from the cell surface under nonstimulatory conditions. Under such conditions, the major cell surface form is CD45RO, the low‐Mr isoform. In the present study, we demonstrate the ability of calcium ionophore A23187 to induce translocation of cytoplasmic CD45RA to the cell surface as well as to increase the cell surface expression of CD45RO and CD45. This process was calcium dependent and rapid, occurring within 5 min. A series of experiments using chemical antagonists of protein kinases suggest that this up‐regulation may be mediated via the calmodulin system rather than via protein kinase C. Although the exact function(s) of the various isoforms of CD45 is not known, this translocation suggests a role for CD45RA in neutrophil activation.