| First Author | Nunomura S | Year | 2015 |
| Journal | Biochem Biophys Res Commun | Volume | 456 |
| Issue | 2 | Pages | 700-5 |
| PubMed ID | 25522877 | Mgi Jnum | J:220360 |
| Mgi Id | MGI:5634257 | Doi | 10.1016/j.bbrc.2014.12.045 |
| Citation | Nunomura S, et al. (2015) Treatment of murine mast cells with IgEkappa and protein L enhances apoptotic cell death induced by IL-3 withdrawal. Biochem Biophys Res Commun 456(2):700-5 |
| abstractText | Engagement of the high-affinity IgE receptor (FcepsilonRI) can be either protective or non-protective against apoptotic cell death (ACD) in bone marrow-derived murine mast cells (BMMCs) after IL-3 withdrawal, depending on the avidity between IgE and its antigen. We recently reported that protein L (PpL), a bacterial Igkappa-binding soluble protein, is able to stimulate intracellular signaling to induce activation of BMMCs by interacting with the IgEkappa-FcepsilonRI complex. However, it is unclear if cross-linking of FcepsilonRI with IgEkappa and PpL prevents or enhances IL-3-dependent ACD in BMMCs. In the present study, we found that IL-3-dependent ACD of BMMCs is accelerated by loading soluble PpL in the presence of IgEkappa-occupied FcepsilonRIalpha. For this purpose, soluble PpL was incorporated into the BMMCs. Unlike soluble PpL, immobilized PpL failed to enhance ACD, although both forms of PpL induced IL-6 production equally in BMMCs. In addition, we observed that DNS5-BSA protected anti-DNS IgE-sensitized BMMCs from IL-3 depletion-mediated ACD by inducing the production of autocrine IL-3. In contrast, DNS5-PpL enhanced IL-3 withdrawal-induced ACD of anti-DNS IgE-sensitized BMMCs and reduced the production of autocrine IL-3. These findings suggest that PpL increases IL-3 withdrawal-induced ACD of IgEkappa-sensitized BMMCs by incorporating PpL into the BMMCs and that this internalized PpL may interfere with survival signals via FcepsilonRI. |
