ISSN:
1432-0878
Keywords:
Key words: Macrophages – Monoclonal antibody – Antigen – Purification – Differentiation – Activation – Mouse [(CBA/Rij
;
C57BL/Rij) F1 (BCBA)]
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Abstract. We describe the purification and intracellular distribution of an antigen present on a subpopulation of murine macrophages and recognized by monoclonal antibody ER-HR3 against bone marrow-derived haemo- poietic reticulum cells. Using the ER-HR3 antibody as an immobilizing ligand, two proteins were isolated as determined by SDS polyacrylamide gel electrophoresis. Under non-reducing conditions, there was a major band with an apparent molecular mass of 69 kDa and a minor band of 55 kDa. Under reducing conditions, the apparent molecular mass of each band was estimated as 76 kDa and 67 kDa, respectively. Intracellularly, these proteins occurred in close association with membranous structures, as demonstrated with gold-labelled protein A in an electron-microscopic study of the ER-HR3-positive cell line AP284. Some of the antigen was present in vesicles. To gain further insight into the possible function of the ER-HR3 antigen, its tissue distribution was investigated under distinct experimental conditions. In mice infected with Bacillus Calmette Gurèrin, ER-HR3-positive cells were observed in many, but not all, granulomata of the spleen, the lung and the liver. The ER-HR3 reactivity in these mice clearly differed from that of other anti-macrophage monoclonal antibodies, such as F4/80, M5/114 and M1/70. Furthermore, phenylhydrazine-induced extramedullary erythropoiesis in the liver was accompanied by ER-HR3 expression on a subpopulation of macrophages. Finally, the addition of ER-HR3 to an antigen-specific T cell proliferation assay did not inhibit T cell proliferation.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00318826
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