title: Differences in Fc receptor expression between small and large guinea pig monocytes.
abstract: Guinea pig monocytes have been separated into subpopulations differing in size, morphology, and cytochemistry. We report now that these peripheral blood monocyte subpopulations differ also in native Fc receptor expression. All freshly isolated small monocytes formed Fc rosettes with sensitized sheep erythrocytes, whereas Fc receptor expression was not detectable on large monocytes. However, Fc receptor expression developed rapidly in culture such that by 48 hours all monocytes were positive. This phenomenon was inhibited by 2-deoxy-D-glucose and cycloheximide, suggesting that Fc receptor expression depended upon glycolysis and protein synthesis. Large monocytes participated in antibody-dependent lysis of sheep erythrocyte targets. That large monocytes lacking Fc receptors were cytolytic in this assay was concordant with expression of Fc receptors during the 16-hour test period. We believe that the large number of lymphocytes present in the Fc receptor-positive small monocyte fraction interfered with their measurement of antibody-dependent cytotoxicity. We conclude that Fc receptor expression on guinea pig monocytes is heterogeneous within the peripheral circulation. These differences quickly diminish in vitro with the expression of Fc receptors by all monocytes. Additionally, antibody-dependent lysis of sensitized erythrocytes by guinea pig mononuclear cells is due to monocytes and not lymphocytes or Kurloff cells.
authors.forename: S J
authors.initials: SJ
authors.lastname: Noga
authors.forename: S J
authors.initials: SJ
authors.lastname: Normann
authors.forename: R S
authors.initials: RS
authors.lastname: Weiner
mesh_terms: D000818:Animals; D000920:Antibody-Dependent Cell Cytotoxicity; D002469:Cell Separation; D002478:Cells, Cultured; D006168:Guinea Pigs; D008214:Lymphocytes / Q000276:immunology; D009000:Monocytes / Q000166:cytology* / Q000276:immunology; D011961:Receptors, Fc / Q000502:physiology*; D013997:Time Factors
chemical_list: D011961:Receptors, Fc