| First Author | Nording H | Year | 2022 |
| Journal | J Immunol | Volume | 208 |
| Issue | 7 | Pages | 1729-1741 |
| PubMed ID | 35277420 | Mgi Jnum | J:339790 |
| Mgi Id | MGI:7281026 | Doi | 10.4049/jimmunol.2100557 |
| Citation | Nording H, et al. (2022) Activated Platelets Upregulate beta2 Integrin Mac-1 (CD11b/CD18) on Dendritic Cells, Which Mediates Heterotypic Cell-Cell Interaction. J Immunol 208(7):1729-1741 |
| abstractText | Recent evidence suggests interaction of platelets with dendritic cells (DCs), while the molecular mechanisms mediating this heterotypic cell cross-talk are largely unknown. We evaluated the role of integrin Mac-1 (alphaMbeta2, CD11b/CD18) on DCs as a counterreceptor for platelet glycoprotein (GP) Ibalpha. In a dynamic coincubation model, we observed interaction of human platelets with monocyte-derived DCs, but also that platelet activation induced a sharp increase in heterotypic cell binding. Inhibition of CD11b or GPIbalpha led to significant reduction of DC adhesion to platelets in vitro independent of GPIIbIIIa, which we confirmed using platelets from Glanzmann thrombasthenia patients and transgenic mouse lines on C57BL/6 background (GPIbalpha(-/-), IL4R-GPIbalpha-tg, and muMac1 mice). In vivo, inhibition or genetic deletion of CD11b and GPIbalpha induced a significant reduction of platelet-mediated DC adhesion to the injured arterial wall. Interestingly, only intravascular antiCD11b inhibited DC recruitment, suggesting a dynamic DC-platelet interaction. Indeed, we could show that activated platelets induced CD11b upregulation on Mg(2+)-preactivated DCs, which was related to protein kinase B (Akt) and dependent on P-selectin and P-selectin glycoprotein ligand 1. Importantly, specific pharmacological targeting of the GPIbalpha-Mac-1 interaction site blocked DC-platelet interaction in vitro and in vivo. These results demonstrate that cross-talk of platelets with DCs is mediated by GPIbalpha and Mac-1, which is upregulated on DCs by activated platelets in a P-selectin glycoprotein ligand 1-dependent manner. |
