Induction of CD43 Expression during Activation and Terminal Differentiation of Human B Cells

Abstract

Only a small population (25-30%) of human peripheral blood B lymphocytes expresses large sialoglycoprotein (LSGP) (CD43). However, in the presence of autologous T cells and pokeweed mitogen (PWM) a majority (50-90%) of the immunoglobulin-producing cells (cIg+ cells) that develop from these B cells express CD43 is detected with anti-CD43 monoclonal antibodies (MoAb) B1B6, and the proportion of CD43+cIg+ cells increases with time of culture. Furthermore, a relatively larger proportion (60-80%) of the IgG-producing cIg+ cells are CD43+ compared with IgM-containing cIg+ cells (30-50%). In human tonsils, significantly more CD43+ cells (35%) are found in the in vivo-activated fraction of B cells than in the fraction of resting B cells (5%). A majority of the cIg+ cells that develop from the resting or the in vivo-activated tonsillar B cells in a PWM-induced B-cell differentiation system are CD43+ (80-100%). Furthermore, tonsillar B cells depleted of CD43+ cells give rise to cIg+ cells, of which the majority are CD43+, and the proportion of such cells increases with time of culture (60-90%). Taken together, these results indicate that LSGP belongs to a group of B-cell membrane molecules that are induced and upregulated upon activation and differentiation.

Leukosialin (CD43) defines hematopoietic progenitors in human embryonic stem cell differentiation cultures

“…In humans, both CD45 and CD43 are considered as pan-hematopoietic markers, 26,27 though CD45 is not expressed on platelets and cells of the erythroid lineage, 27 whereas CD43 is expressed on platelets and erythroid progenitors, but it is not detected on mature erythrocytes and B-cell subsets. 26,28 CD41a and CD235a are known markers of megakaryocytic and erythroid cell lineages, respectively. 29,30 Using PCR and flow cytometry, we found that undifferentiated hESCs did not express CD235a and CD45 mRNA ( Figure 1A) or protein (not shown).…”

Follicular Dendritic Cells Carry MHC Class II-Expressing Microvesicles at Their Surface

“…B cells were purified as previously described (31,32). In short, T cells were removed by two cycles of rosetting with neuraminidasetreated sheep erythrocytes.…”

Disregulation of leukosialin (CD43, Ly48, sialophorin) expression in the B-cell lineage of transgenic mice increases splenic B-cell number and survival.

“…B cells demonstrate a unique developmental program for mCD43 expression that makes them particularly amenable for the in vivo manipulation of mCD43 within a physiologically relevant context. CD43 is present on the surface of early B-cell progenitors and on terminally differentiated plasma cells but is absent on mature B cells (24)(25)(26)(27)(28)(29)(30). We took advantage of this "ON-OFF-ON" expression pattern of mCD43 in the B-cell lineage and altered its temporal expression in transgenic (TG) mice by using the immunoglobulin heavy chain enhancer to drive mCD43 expression in mature B cells (31).…”

“…1). The hybrid construct was microinjected into fertilized mouse eggs, implanted into pseudopregnant females, and allowed to develop to term (36 (24,(26)(27)(28)(29)(30). In the three TG lines examined, however, >95% of B220+ B cells expressed mCD43, as indicated by the large double-positive population (Fig.…”