Effect of proteinases on EA (IgG)-binding receptors of rat macrophages

Fc receptor--more answers, more questions

Fc receptors, belonging to the most important surface structures of a number of cells participating in the immune processes, have been intensely studied during the past decade. The present review summarizes the contemporary knowledge of the specificity and heterogeneity of Fc receptors and of factors influencing their expression, and includes some views on their function. In addition, it mentions their relationship to other cell surface structures, expression of Fc receptors during ontogeny of the organism and in certain diseases. Finally, data concerning the isolation and biochemical characterization of the Fc receptor molecule are presented.

Influence of various detachment procedures on the functional state of cultured murine macrophages

Macrophages were obtained from seven-day-old bone marrow liquid cultures to which a colony-stimulating factor from L-cell-conditioned medium had been added. It was found that the yield of macrophages from the bone marrow liquid culture was dependent on the type and brand of culture dishes. Highest yields were obtained in teflon membrane bag cultures. The cumulative yield after serial passage of macrophages was 700-fold of the cell input after two months. After mechanical detachment from plastic culture dishes, the survival rate of cells was related to the brand of the plastic dish. Viability also varied greatly after pretreatment of cells with scandicain (28%), proteinase K (78%), or pronase (99%). After mechanical detachment of macrophages or pretreatment with scandicain, adherence to plastic, latex phagocytosis and chemotaxis was not or only slightly impaired, whereas the same functions after protease treatment were greatly reduced or even abolished and were only recovered after another culture period. Scandicain, proteinase K, and pronase treatment was mitogenic to macrophages in contrast to mechanical detachment. Pronase treatment also induced release of plasminogen activator activity. The results demonstrate that macrophages respond extremely sensitive to environmental conditions and to various insults by changing their functional state.