Human Monocytes - CD14, CD16 - Ziegler-Heitbrock

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An Fc gamma receptor I (CD64) negative subpopulation of human peripheral blood monocytes is resistant to killing by antigen activated CD4-positive cytotoxic T cells

Abstract

It has been demonstrated that in monocyte/T cell co cultures activated with recall antigens, cytotoxic T cells were generated which are able to reduce the number of antigen presenting monocytes. In previous studies we could show that a minor subset of monocytes, the Fc gamma receptor I negative (CD64(-)) monocytes, exhibits significantly higher antigen presenting capacity than the main population of monocytes (> 90%) which are Fc gamma receptor I positive (CD64(+)). Therefore, we addressed the question whether they are also differentially susceptible to T cell mediated killing. In the present study we demonstrate that the CD64(-) monocyte subset is more resistant to killing by antigen activated T cells than CD64(+) monocytes, as indicated by a higher viability and recovery of CD64(-) monocytes. This mechanism involves CD95 (Fas) antigen, since monocyte death in co cultures with antigen activated T cells could be partially reduced by blocking anti Fas monoclonal antibodies (mAb). In agreement with this finding, although CD95 antigen was expressed on CD64(+) and CD64(-) monocytes at comparable levels, killing of CD64(-) monocytes by activating anti Fas mAb was lower than of CD64(+) monocytes.

Authors: Grage-Griebenow E, Baran J, Loppnow H, Los M, Ernst M, Flad H-D, Pryjma J
Journal: Eur. J. Immunol. 27: 2358-2365
Year: 1997
PubMed: Find in PubMed