Bovine peripheral blood monocyte cultures: growth characteristics and cellular receptors for immunoglobulin G and complement.

Bovine peripheral blood monocytes were cultured in vitro for as long as 60 days. Although mitotic figures were not observed, the amount of cytoplasm was observed to increase; most cultures developed multinucleated cells, some containing as many as 200 nuclei. In multinucleated cells, the nuclei were peripherally distributed around a cytoplasmic matrix and surrounded by an undulating membrane. Receptors on macrophages were identified with erythrocytes sensitized with various immunoglobulins and complement (C'). A receptor for immunoglobulin G, but not immunoglobulin M, was detected. By the use of freshly prepared equine serum, a C' receptor was detected; however, by the use of freshly prepared bovine serum, C' receptor was not detected.