coli to CD89 on monocytes has led to efficient bacterial uptake into these cells and a rapid breakdown of the bacteria .
In the current study we have investigated the possibility of CD89 and CD206 targeting on monocytes and moDCs to enhance processing of HLA class I alloantigen and antigen presentation to CD4 T-cells, as a tool to facilitate the detection and monitoring of indirect T-cell alloreactivity.
3, IgG1 ), CD209/DC-SIGN (R&D, IgG2a), and CD89 (clone 2D11, IgG1 ).
Alternatively antibody HLA-monomer complexes were made by incubating biotinylated CD89 or MR with biotinylated HLA-A2 monomer and APC-labeled streptavidine (at a ratio of 2 : 2 : 1, resp.
Monocytes expressed high levels of CD14 and CD89 but no detectable levels of "mannose receptor" (MR/CD206) or DC-SIGN (CD209).
In view of the high expression of CD89 on monocytes, we aimed to target the HLA monomer towards CD89 for more efficient presentation of this alloantigen.
Next, we investigated if "receptor mediated endocytosis" (RME) was affected when CD89-A rather than CD89 was used.
CD89 Mediated Uptake of Antigen by Monocytes Does Not Enhance T-Cell Activation When Compared to Antigen Alone.
Targeting of HLA-A2 to CD89 on monocytes and CD206 on moDCs led to efficient antigen delivery into the cell and presentation of the relevant allopeptide to a CD4 T-cell clone.
Cross-linking of CD89 on B-cells transfected with Fc[alpha]RI activates PI3-kinase/phosphatidyl inositol-dependent kinase 1/PKB[alpha] signaling pathway and inhibition of PI3-kinase blocks MHC class II presentation of CD89-targeted antigen .