Differentiation Pathway within Germinal Centers of Human Tonsils

Functional anatomy of germinal centers

“…Further experiments have demonstrated the presence of antigen-specific antibodies in cells of GC (Fitch et al, 1969;Sordat et al, 1970;Terashima et al, 1977;Steven, 1980;Rooijen et al, 1983) and have provided information regarding Ig heavy-chain isotypes of cIg+ cells in GC, showing that all isotypes may occur, however, in varying proportions which may depend on the stage of a GCR and its location (Stein et al, 1980;Sminia and Plesch, 1982;Sminia and Janse, 1982). It seems that most authors would agree with a statement by Sordat et al (1969) that "in view of the migrational pathway from the base to the cap of the (tonsillar) GC, it is attractive to postulate that differentiation towards antibody producing cells occurs in at least a fraction of cells produced by the germinoblasts." As to a role for locally produced antibody, if any, opinions vary widely.…”

“…The characteristic cell type of this stage, the germinoblast, has been shown to be "sessile." Subsequently, when there is differentiation from germinoblasts (centroblasts) to centrocytes, a "steady state" will develop including signs of cell efflux from the GC (Koburg, 1967;Sordat et al, 1969;. Recent data also indicate that centrocytes possibly are less "sessile" than germinoblasts: they have a lower PNA receptor density (Butcher et al, 1982a,b), they may become MEL-14+ (G. Kraal, personal communication), and they have less affinity for the GC microenvironment (Opstelten et al, 1983).…”

Description of Age-Depending Cellular Changes in the Human Tonsil

“…An increase in cells is possible by proliferation and/or by accumulation of recirculating T cells. Proliferation of cells in the tonsil was found by numerous authors using different methods (Bömberg et al, 1968;Donovan and Soothill, 1973;Geha andMerler, 1974;Holowiecki et al, 1975;Mayer zum Gcttesberge and Koburg, 1967;Mitrou et al, 1969;Siegel and Wilke, 1975a, Sordat et al, 1969.Sprekelsen, 1975Staub et al, 1976;Stein, 1975;Suzuki and Ino, 1973). Therefore, proliferation processes may be considered to be one of the causes of the increase in cell quantity.…”

“…Therefore, proliferation processes may be considered to be one of the causes of the increase in cell quantity. According to the papers of Mayer zum Gottesberge and Koburg (1967), Mitrou et al (1969), Sordat et al (1969), andSprekelsen (1975), cell proliferation mainly takes place in the germinal centres. Takeuchi et al (1976) succeeded in identifying germinal centre cells to be B cells and Holowiecki et al (1975) found proliferating B cells in suspensions of tonsillar cells.…”