| First Author | Liu X | Year | 2011 |
| Journal | J Immunol | Volume | 186 |
| Issue | 8 | Pages | 4674-86 |
| PubMed ID | 21402891 | Mgi Jnum | J:172524 |
| Mgi Id | MGI:5008213 | Doi | 10.4049/jimmunol.1003584 |
| Citation | Liu X, et al. (2011) The neonatal FcR-mediated presentation of immune-complexed antigen is associated with endosomal and phagosomal pH and antigen stability in macrophages and dendritic cells. J Immunol 186(8):4674-86 |
| abstractText | The FcgammaRs found on macrophages (Ms) and dendritic cells (DCs) efficiently facilitate the presentation or cross-presentation of immune-complexed Ags to T cells. We found that the MHC class I-related neonatal FcR for IgG (FcRn) in both Ms and DCs failed to have a strong effect on the cross-presentation of immune complex (IC) OVA Ag to CD8(+) T cells. Interestingly, endosomal FcRn enhanced the presentation of the monomeric OVA-IC to CD4(+) T cells robustly, whereas FcRn in phagosomes exerted distinctive effects on Ag presentation between Ms and DCs. The presentation of phagocytosed OVA-ICs to CD4(+) T cells was considerably enhanced on wild-type versus FcRn-deficient Ms, but was not affected in FcRn-deficient DCs. This functional discrepancy was associated with the dependence of IgG-FcRn binding in an acidic pH. Following phagocytosis, the phagosomal pH dropped rapidly to <6.5 in Ms but remained in the neutral range in DCs. This disparity in pH determined the rate of degradation of phagocytosed ICs. Thus, our findings reveal that FcRn expression has a different effect on Ag processing and presentation of ICs to CD4(+) T cells in the endosomal versus phagosomal compartments of Ms versus DCs. |
