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Multiple Ligand Interactions for Bacterial Immunoglobulin‐Binding Proteins on Human and Murine Cells of the Hematopoetic Lineage
Author(s) -
AXCRONA K.,
BJÖRCK L.,
LEANDERSON T.
Publication year - 1995
Publication title -
scandinavian journal of immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.934
H-Index - 88
eISSN - 1365-3083
pISSN - 0300-9475
DOI - 10.1111/j.1365-3083.1995.tb03668.x
Subject(s) - microbiology and biotechnology , biology , population , cd19 , cd3 , streptococcus pyogenes , splenocyte , antibody , antigen , flow cytometry , immunology , cd8 , demography , sociology , genetics , bacteria , staphylococcus aureus
A group of bacterial Ig‐binding surface proteins were studied: protein H and Ml are from Streptococcus pyogenes and interact with IgG, protein L is expressed by Peptostreptococcus magnus and shows affinity for Ig light chains, whereas protein LG is a chimeric construction combining the binding properties of protein L with the IgG‐binding activity of protein G from group C and G streptococci. Proteins L and H coupled to Sepharose were mitogenic for human peripheral blood lymphocytes (PBL) and mouse splenic B cells, but not when added in soluble form. Differentiation to Ig secretion was induced by protein H‐Sepharose in mouse splenic B cells but not in human PBLs. In FACS analysis FITC‐labelled protein H stained virtually all CD19 + cells in human peripheral blood as well as a majority of the CD3 + population. Protein L bound the majority of the CD19 + population, but also a fraction of the CD19 − /CD 3 population. Protein Ml was not mitogenic but stained the entire CD19 + population and 70% of the CD3 + population. Identical staining patterns were observed with mouse splenocytes using B220 and T‐cell receptor as lineage markers. The chimeric protein LG was a potent mitogen for mouse splenic B cells when added either coupled to Sepharose or in soluble form. In addition, protein LG induced differentiation to Ig secretion of the responding mouse splenic B cells. In FACS analysis, protein LG stained the entire CD19 + and the majority of the CD19 − /CD 3 lymphocyte population as well as all B220 + mouse splenocytes and a fraction of the splenic T cells. These data indicate that the bacterial proteins studied interact with surface structures of several leucocyte populations and can hence interfere with the immune system at multiple levels.