Terminally differentiated human intestinal B cells. J chain expression of IgA and IgG subclass-producing immunocytes in the distal ileum compared with mesenteric and peripheral lymph nodes.
Two-colour immunofluorescence staining for intracellular J chain and IgA (or J chain and IgG) was performed on tissue sections of normal human ileal mucosa (eight adult kidney donors), mesenteric lymph nodes (MLN), peripheral lymph nodes, and palatine tonsils. The most prominent J chain positivity was seen for IgA (97.3%) and IgG (81.7%) immunocytes in the ileal lamina propria (LP). Moreover, the proportion of J chain-expressing extrafollicular immunocytes was significantly higher (P less than 0.05) in MLN than in peripheral lymph nodes for the IgA class (58.5% versus 25.6%); the same proportion for the IgG class was 45.9% versus 30.4%. In clinically normal palatine tonsils of adults, extrafollicular J chain expression was much lower than in peripheral lymph nodes; 14.2% for IgA cells and 5.5% for IgG cells. When related to subclass production, J chain expression was found to be higher for IgA2 than for IgA1 cells in all tissues examined (palatine tonsils excluded because of a small number of IgA2 cells), the difference being significant in MLN and ileal LP (P less than 0.05). The J chain positivity tended to be higher for all IgG subclasses in MLN than in peripheral lymph nodes; this difference was significant (P less than 0.05) for IgG2-producing immunocytes. Taking J chain expression as a marker of clonal immaturity, our results may reflect to some extent distribution of newly generated memory B cell clones from gut-associated lymphoid tissue to MLN, peripheral lymph nodes, and palatine tonsils in a strikingly decreasing order.
Bjerke
K
K
Laboratory for Immunohistochemistry and Immunopathology (LIIPAT), University of Oslo, National Hospital, Norway.
Brandtzaeg
P
P
D001402:B-Lymphocytes / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D002454:Cell Differentiation; D006801:Humans; D007082:Ileum / Q000276:immunology*; D007070:Immunoglobulin A / Q000096:biosynthesis* / Q000145:classification; D007074:Immunoglobulin G / Q000096:biosynthesis* / Q000145:classification; D007144:Immunoglobulin J-Chains / Q000378:metabolism*; D008198:Lymph Nodes / Q000276:immunology*; D008643:Mesentery; D014066:Palatine Tonsil / Q000276:immunology
D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007144:Immunoglobulin J-Chains