Characterization of murine polyreactive antigen‐binding B cells: presentation of antigens to T cells

• Published in: European journal of immunology Vol. 31; no. 4; pp. 1106 - 1114
• Main Authors: Wang, Zhigang, Jian Chen, Zhi, Wheeler, Jim, Shen, Shanxiang, Notkins, Abner Louis
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY‐VCH Verlag GmbH 01.04.2001
• Subjects: Animals; Antibody Specificity - immunology; Antigen Presentation - immunology; Antigens - immunology; Antigens, CD - analysis; B-Lymphocytes - immunology; B7-1 Antigen - analysis; B7-2 Antigen; B‐1 cell; CD5; Enzyme-Linked Immunosorbent Assay; Flow Cytometry; Hybridomas - immunology; Innate immunity; Interleukin-2 - immunology; Interleukin-2 - metabolism; Lymphocyte Activation; Major Histocompatibility Complex - immunology; Male; Membrane Glycoproteins - analysis; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Natural antibodies; Ovalbumin - immunology; Spleen - cytology; Spleen - immunology; T-Lymphocytes - immunology; T-Lymphocytes - metabolism; Tolerance
• ISSN: 0014-2980; 1521-4141
• DOI: 10.1002/1521-4141(200104)31:4<1106::AID-IMMU1106>3.0.CO;2-5

Monoclonal polyreactive antibodies (Ab) can bind, at low affinity, a variety of different self and non‐self antigens (Ag). Recent studies in humans showed that polyreactive Ab are expressed onthe surface of a subset of peripheral B lymphocytes and clonal analysis revealed that a variety of different Ag can bind to single cells expressing these Ab. To see if these polyreactive Ag‐bindingB (PAB) cells also are present in mice, fluorescein‐conjugated Ag and FACS sorting were used to identify and separate PAB cells from non‐polyreactive Ag‐binding B cells. Depending on the Ag used for screening, up to one‐third of mouse splenic B cells displayed polyreactive Ag‐binding properties. Confirmation that the Ag actually bound to surface Ig came from treating PAB cells with anti‐Ig which inhibited Ag binding by up to 80 %. Further studies showed that PAB cells could present Ag to Ag‐specific T cells, but despite their Ag‐presenting ability, PAB cells from normal mice failed totrigger Ag‐specific T cells to proliferate. Analysis of the co‐stimulatory molecules B7‐1 and B7‐2 showed that these molecules were not expressed on PAB cells from normal mice. These findings argue that thelack of co‐stimulatory molecules on PAB cells is the most likely explanation for their failure to stimulate Ag‐specific T cells. The ability of PAB cells from normal mice to bind and present Ag to Ag‐specific T cells, without causing them to proliferate, suggests that PAB cells may contribute to the induction and / or maintenance of immunological tolerance.