Membrane surface properties of lymphocytes of normal (DBA/2) and autoimmune (NZB/NZW)F1 mice: effects of L-canavanine and a proposed mechanism for diet-induced autoimmune disease.
Partitioning cells in a dextran polyethylene glycol aqueous two-phase system (countercurrent distribution, CCD) is a sensitive method for learning about cell surface membrane properties and for subfractionating cell populations. In this study, we subjected lymphocytes from normal DBA/2 mice and autoimmune F1 New Zealand black/New Zealand white [NZB/NZW)F1) mice to countercurrent distribution and found that T cells partition to the right and B cells partition to the left of the CCD curve. We found no difference between the CCD patterns of normal and autoimmune mice. When the murine lymphocytes were exposed to a cationic dietary amino acid (L-canavanine) in vitro, L-canavanine selectively affected the CCD pattern of autoimmune B cells, reflecting an alteration in surface membrane properties. We separated these lymphocytes with altered surface membrane properties by CCD. Impaired B-cell immune responses associated with L-canavanine were isolated to this lymphocyte fraction. This study provides the first evidence that alterations in the charged surface membrane properties are associated with abnormal (auto) immune response.
D000818:Animals; D001327:Autoimmune Diseases / Q000097:blood* / Q000209:etiology; D001402:B-Lymphocytes / Q000166:cytology / Q000187:drug effects / Q000276:immunology; D002172:Canavanine / Q000494:pharmacology*; D002469:Cell Separation / Q000379:methods; D003377:Countercurrent Distribution; D004032:Diet / Q000009:adverse effects; D007518:Isoantibodies / Q000276:immunology; D008214:Lymphocytes / Q000166:cytology*; D051379:Mice; D008811:Mice, Inbred DBA / Q000097:blood*; D013499:Surface Properties; D013601:T-Lymphocytes / Q000166:cytology / Q000187:drug effects / Q000276:immunology
D007518:Isoantibodies; C035678:anti-Thy antibody; D002172:Canavanine