Whole-body autoradiography reveals that the Peptostreptococcus magnus immunoglobulin-binding domains of protein L preferentially target B lymphocytes in the spleen and lymph nodes in vivo
| Autor: | Lars Björck, Ulf Yrlid, James de Jersey, David Smith, Roland D'Argy, Mats Nilsson, Mary Jo Wick |
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| Rok vydání: | 2004 |
| Předmět: | |
| Zdroj: | Cellular Microbiology. 6:609-623 |
| ISSN: | 1462-5822 1462-5814 |
| Popis: | Protein L is an immunoglobulin (Ig)-binding protein produced by the Gram-positive bacterium Peptostreptococcus magnus that interacts with the variable region of Ig kappa light chains. The Ig light chain-binding capacity of protein L gives it the potential to interact with cells expressing surface Ig such as B cells. The present study was performed to address the in vivo trafficking of protein L at both the organ and the cellular level. Using the powerful technique of whole-body autoradiography in a murine model system, we demonstrate specific targeting of protein L to secondary lymphoid tissues in whole-animal analysis. The observed targeting depends on the capacity to interact with murine Ig, as tissue targeting was not apparent in mice given protein H, an Ig-binding protein produced by Streptococcus pyogenes with affinity for human but not murine Ig. Tissue targeting data were combined with flow cytometry analysis, which demonstrated the capacity of protein L to target and activate B lymphocytes in vivo. B cells targeted by protein L had increased surface expression of CD86 and MHC-II, and protein L was present in vacuolar compartments of B cells. Protein L did not bind T cells or natural killer cells but had some capacity to target dendritic cells and macrophages. The data show that protein L preferentially targets secondary lymphoid organs, and activates and is internalized by B cells in vivo. Furthermore, the observed tissue and cell targeting properties require an affinity for murine Ig. These data support the potential use of this Ig-binding protein as a targeting approach to deliver agents to defined cell populations in vivo. |
| Databáze: | OpenAIRE |
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