title: Greatly increased autoantibody production in myasthenia gravis by thymocyte suspensions prepared with proteolytic enzymes.
abstract: We have previously reported that cell suspensions prepared by mechanical dispersion of thymic tissue from myasthenia gravis (MG) patients spontaneously synthesise anti-acetyl-choline receptor autoantibodies (anti-AChR) in culture in many cases. We now find a 2-200-fold greater anti-AChR production if the cell suspensions are prepared with the proteolytic enzymes collagenase and dispase (THYC + D). This difference has been seen in seven of the first 10 cases tested. Using these enzymes, we now also find comparable anti-AChR synthesis by MG lymph node cells, confirming the presumed extra-thymic production of much of this autoantibody. The increased anti-AChR synthesis by THYC + D is not simply a mitogenic effect of the enzymes, but apparently depends on several distinct factors: (1) plasma cells are often isolated much more efficiently--particularly by dispase--than by mechanical dispersion of these tissues (or of 'normal' tonsil), and the same may also be true of specific B cells. (2) The greatly increased numbers of fibroblasts, macrophages and other adherent cell types exert 'feeder' effects which enhance anti-AChR and total IgG production non-specifically. (3) Specific antigen presenting cells (APC) may also be recovered more efficiently and selectively stimulate anti-AChR production by B memory cells. These results imply that APC, plasma cells, and perhaps also B memory cells are recovered from germinal centres much more efficiently by enzymic than by conventional dispersion, a conclusion that may be relevant to workers studying antibody forming and memory B cells in other systems or species.
mesh_terms: D000293:Adolescent; D000328:Adult; D001323:Autoantibodies / Q000096:biosynthesis*; D001402:B-Lymphocytes / Q000276:immunology; D002452:Cell Count; D002478:Cells, Cultured; D002675:Child, Preschool; D010450:Endopeptidases; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000096:biosynthesis; D008198:Lymph Nodes / Q000276:immunology; D008297:Male; D003012:Microbial Collagenase; D009157:Myasthenia Gravis / Q000276:immunology*; D011950:Receptors, Cholinergic / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*; D013950:Thymus Gland / Q000276:immunology / Q000528:radiation effects
chemical_list: D001323:Autoantibodies; D007074:Immunoglobulin G; D011950:Receptors, Cholinergic; D010450:Endopeptidases; D003012:Microbial Collagenase; C023139:dispase