Uptake of HLA Alloantigens via CD89 and CD206 Does Not Enhance Antigen Presentation by Indirect Allorecognition

Figure 3

HLA-DR mediated antigen presentation by monocytes is not enhanced through CD89-targeted endocytosis. (a) HLA-DR1+/HLA-A2− monocytes were either pulsed (dark bar) or not (light bar) with HLA-A2 peptides and cocultured with T-cell clone. After 24 h incubation supernatants were harvested and IFN-γ was measured. (b) CD89-A was incubated at a ratio of 1 : 1 with biotinylated HLA-A2 monomer for 2 hours (CD89-A2), before they were added to the monocytes for 4 hours and then washed. T-cells were then added and IFN-γ measured. In comparison monocytes were also incubated with HLA-A2 alone (A2). ((c) and (d)) Different ratios of CD89 and A2 were used as explained in (b) and titrated. All experiments were performed at least 3 times; shown is the mean with SD of one experiment in triplicate except for (a) and (b) where the mean of 3 experiments in triplicate is shown with SD. ND: nondetectable.

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