Identification in the chicken of GRL1 and GRL2: two granule proteins expressed on the surface of activated leukocytes.
We report the production of two monoclonal antibodies reacting, respectively, with a 92-kDa protein (GRL1) and a 40- to 65-kDa membrane glycoprotein (GRL2), both present in chicken thrombocyte and myelocyte granules. We examined the expression of GRL1 and GRL2 during the development of the hematopoietic system: GRL1 is restricted to thrombocytes and myelocytes, whereas GRL2 is present in thrombocytes, myelocytes, myeloid progenitors, and a subpopulation of erythroid progenitors. In the lymphoid lineages, neither GRL1 nor GRL2 is expressed during thymus and bursa ontogeny or on resting peripheral blood lymphocytes. However, CD3+ T lymphoblasts obtained by mitogenic stimulation of GRL2-negative quiescent T lymphocytes are stained on their surface by anti-GRL2 Mab. In vitro stimulation of thrombocytes and granulocytes with their specific secretagogues results in the expression of GRL1 and in the overexpression of GRL2 on the cell surface. These observations are consistent with the following two conclusions: the presence on the cell surface of GRL1 epitope is a marker of thrombocyte and myelocyte activation; GRL2 epitope is present on the granule membrane of leukocytes, including T cells. In that respect, GRL2 appears to share certain features with leukocyte activation antigens recently described in human.
Thomas
J L
JL
Institut d'Embryologie cellulaire et moléculaire du CNRS, Nogent-sur-Marne, France.
Pourquie
O
O
Coltey
M
M
Vaigot
P
P
Le Douarin
N M
NM
D000818:Animals; D000911:Antibodies, Monoclonal; D001792:Blood Platelets / Q000378:metabolism; D001853:Bone Marrow / Q000378:metabolism; D001854:Bone Marrow Cells; D002472:Cell Transformation, Viral; D002478:Cells, Cultured; D002645:Chickens; D003594:Cytoplasmic Granules / Q000378:metabolism; D006412:Hematopoietic Stem Cells / Q000378:metabolism; D007962:Leukocytes / Q000378:metabolism*; D008214:Lymphocytes / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000276:immunology / Q000378:metabolism*; D013154:Spleen / Q000166:cytology
D000911:Antibodies, Monoclonal; D008562:Membrane Glycoproteins