CD16. Developmentally regulated IgG Fc receptors on cultured human monocytes.

Abstract

We have demonstrated that one Fc receptor for IgG (FcR) (CD16) on cultured human monocytes appears to be a developmentally regulated membrane protein. This receptor appears to contain less carbohydrate (if any) than does its counterpart on human neutrophils. Expression of CD16 on cultured monocytes increases with respect to both percentage of positive cells and numbers of sites per cell with length of time in culture. This was in contrast to expression of other types of FcRs that either decreased (CDw32) or did not change (FcRp72). Unlike an FcR that binds monomeric IgG (FcRp72), expression of CD16 on monocytes from most normal individuals was not influenced by IFN-gamma. After 14 d in culture, CD16 appeared to be the predominant FcR on cultured monocytes, and was capable of mediating both ligand attachment and phagocytosis. These findings support the hypothesis that CD16 plays an important role in mediating immunophagocytosis.

Induced Expression of FcγRIIIa (CD16a) on CD4+ T Cells Triggers Generation of IFN-γhigh Subset

“…In direct staining, these proteins did not react to anti-mouse-HRP conjugate. Previously, a 29 and 31 kDa protein along with a broad band at 50 -75 kDa that is recognized by anti-CD16 (3G8) antibody has been reported from monocytes (30). Similar size proteins were observed in Jurkat and P116 cells IPs, using anti-CD16 polyclonal antibody (Fig.…”

Platelets induce monocyte differentiation in serum-free coculture

“…Using a pure platelet fraction we tested the ability of intact platelets to induce MO maturation. Under serum-free conditions, platelet-induced MO differentiation was comparable to serum-induced differentiation in terms of the expression of differentiation-associated antigens, e.g., CD16 (Fc␥-receptor type III; Fc␥RIII) [8]. The up-regulation of CD16 on MO by platelet cocultures has been reported by Phillips et al [30] as a consequence of TGF-␤ release by platelets.…”

“…Until now regulatory signals responsible for this terminal differentiation step have not been well characterized. In vitro culture of peripheral blood MO with human serum [3][4][5] is a useful model to study signals modulating this maturation step, which can be analyzed by the expression of typical differentiation-associated antigens like carboxypeptidase M (MAX.1/CPM) [6,7], MAX.3 [6,7], CD16 [8,9], CD 51 (vitronectin-receptor, ␣-chain) [9,10], CD71 (transferrin-receptor) [9], or CD105 (Endoglin) [11]. In addition to serum proteins like immunoglobulins, fibronectin and albumin [12,13], 1,25-dihydroxyvitamin D 3 [14,15] has also been discussed as a possible maturation-inducing factor.…”

Squamous cell carcinoma: infiltrating monocyte/macrophage subpopulations express functional mature phenotype

“…Characterisation of cultured blood Mo showed that at the beginning of culture about 60% express the 27E10-antigen (Zwadlo et al, 1986) and will loose it in favour of the antigens Rm3/1 and later 25F9 (Zwadlo et al, 1985;. Other studies pointed out that cultured blood Mo gained or showed enhanced expression of Fcy-receptors (Baumgartner et al, 1988;Clarkson & Ory, 1988), HLA-DR (Peters et al, 1987) or the CD4 antigen (Crowe et al, 1987). The results of our study indicate that most MS found in tumour tissues are of a functionally 'mature' phenotype.…”