title: Surface immunoglobulin on rabbit lymphoid cells. VII. Binding of exogenous Ig by neonatal lymphocytes and ability of aggregated Ig in neonatal sera to bind to adult cells.
abstract: The expression of endogenous and exogenous surface immunoglobulin (sIg) on the surface peripheral blood lymphocytes from adult and neonatal rabbits has been examined. Endogenous and exogenous sIg on rabbit lymphocytes differ in ultrastructural appearance and modulation characteristics. At 0 degree C immunoferritin-labeled endogenous sIg appears as small flat patches on the surface membrane whereas exogenous Ig appears as large ramose clumps. Immunoferritin-labeled endogenous Ig undergoes endocytosis at 37 degrees C, whereas exogenous Ig is shed or sloughed from the cell membrane within 60-90 min at 37 degrees C. Ig from serum or plasma which has been frozen and thawed shows a high degree of binding to peripheral blood lymphocytes, whereas Ig from fresh serum or plasma shows little or no binding. Aggregated Ig from both adult and newborn sera are able to bind to lymphocyte Fc receptors and both adult and neonatal PBLs are able to bind exogenous aggregated Ig.
mesh_terms: D000375:Aging; D000818:Animals; D000831:Animals, Newborn; D001666:Binding Sites, Antibody; D005293:Ferritins / Q000378:metabolism; D005615:Freezing; D006041:Goats; D007126:Immunoglobulin Allotypes / Q000032:analysis / Q000235:genetics; D008214:Lymphocytes / Q000378:metabolism* / Q000648:ultrastructure; D046911:Macromolecular Substances; D011817:Rabbits; D011947:Receptors, Antigen, B-Cell / Q000235:genetics / Q000378:metabolism*; D011961:Receptors, Fc / Q000032:analysis / Q000235:genetics
chemical_list: D007126:Immunoglobulin Allotypes; D046911:Macromolecular Substances; D011947:Receptors, Antigen, B-Cell; D011961:Receptors, Fc; D005293:Ferritins