Long-term bone marrow IgM-producing plasmablasts are derived during acute infection and are maintained by active proliferation (LYM6P.767)
| Autor: | Amber Papillion, Gary Winslow |
|---|---|
| Rok vydání: | 2014 |
| Předmět: | |
| Zdroj: | The Journal of Immunology. 192:131.4-131.4 |
| ISSN: | 1550-6606 0022-1767 |
| DOI: | 10.4049/jimmunol.192.supp.131.4 |
| Popis: | We have previously characterized a population of IgM-secreting B cells in the bone marrow (BM) of mice infected with the intracellular bacterium Ehrlichia muris (J. Immunol. 186:1011). The BM cells are responsible for IgM production, which is sufficient to maintain long-term immunity to fatal infection. In the present study, we have investigated the ontogeny and maintenance of the B cell population. We utilized AID-Cre-ERT2 X Rosa26loxP-EYFP mice (Nat. Immunol. 10:1292) to irreversibly mark activation-induced cytidine deaminase (AID)-expressing B cells. Following tamoxifen administration on day 10 post-infection, the time of peak spleen CD11c-positive plasmablast response, we detected EYFP+ CD138+ IgM+ BM cells for at least as long as 100 days post-infection; the EYFP+ cells were maintained at frequencies as high as 25% of the BM IgM+ B cells. These data indicated that the BM B cells were likely derived from T cell-independent spleen plasmablasts, and constituted a long-lived population. BrdU incorporation studies also demonstrated that the majority of the IgM+ cells were actively proliferating, indicating that B cells were plasmablasts. Finally, antibody-mediated blocking of CD40:CD40L signaling during acute infection did not impact the generation of the BM plasmablasts, indicating that the plasmablasts were likely generated in the absence of T cell help. These findings underscore the importance of BM IgM plasmablasts in long-term humoral immunity and host defense. |
| Databáze: | OpenAIRE |
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