The purified protein derivative of turberculin, a B-cell mitogen that distinguishes in its action resting, small B cells from activated B-cell blasts.

Abstract

The purified protein derivative of tuberculin (PPD tuberculin) stimulates approximately one of two lipopolysaccharide (LPS)-activated B-cell blasts of C57BL/6J nu/nu spleen cells to continued clonal growth and maturation to IgM and IgG secretion. It alwo stimulates background, in vivo-activated large cells of normal C57BL/6J nu/nu spleen to growth and Ig secretion, at a frequency of approximately 1 of 100 large spleen cells. PPD tuberculin, therefore, is a polyclonal B-cell activator for B-cell blasts. Many single murine splenic B cells (approximately 50%) appear to have reactivities, and therefore probably receptors, for LPS and PPD tuberculin. PPD tuberculin does not stimulate small, resting B cells to growth as measured by the number of cells in culture and by thymidine uptake. However, it stimulates approximately one-fourth of all spleen cells to blast transformation. The large-size blast cells secrete IgM and, therefore, form plaques in the protein A plaque assay. IgG-secreting, plaque-forming cells develop at later stages of stimulation, indicating that the switch from IgM to IgG may occur without division in single, stimulated B cells. Stimulation of resting B cells to maturation by PPD tuberculin is polyclonal. Thus, approximately 1 in 10(2) IgM-secreting plaque-forming cells form plaques with trinitrophenyl-substituted sheep erythrocytes, 1 in 450 do so with horse erythrocytes, and 1 in 10(3) with sheep erythrocytes. Furthermore, the number of Ig-secreting cells developing from small, resting cells without growth in cultures with or without filler thymus cells suggests polyclonal activation by PPD tuberculin to maturation only of at least one out of four small, splenic B cells.

Three classes of signalling molecules on B‐cell membranes

“…BSF is likely to be required under these conditions, at least in responses of normal B cells. The ability of LPS to stimulate resting B cells [2,27] is evidence that both sIg and Ia can be bypassed. As is the case with other modes of B-cell activation, certain BSFs are still required for the differentiation of LPSstimulated B cells 1281.…”

Polyclonal Antibody Production in Murine Spleen Cells Induced by Staphylococcus

“…A variety of bacterial substances such as cell wall lipopolysaccharide (LPS) (2,16) and lipoprotein (19,32) of gram-negative organisms, polymerized flagellin from Salmonella (9), pneumococcal capsular polysaccharide (9), capsular polysac-charide of Klebsiella pneumoniae (21), polysaccharides from Corynebacterium (Levan) (9), purified protein derivative (PPD) from Mycobacterium (1,22), and components of Nocardia (5-7) and Actinomyces (8) are known to be polyclonal B cell activators. In a previous paper (30), we reported that preparations of cell walls and their peptidoglycan subunits obtained from various kinds of gram-positive bacteria such as Staphylococcus epidermidis, Micrococcus lysodeikticus , Lactobacillus plantarum, Mycobacterium rhodochrous , Streptomyces gardneri, and Nocardia corynebacteriodes have the ability to initiate the production of polyclonal antibody to murine spleen cells.…”

T cell-dependent activation of resting B cells: requirement for both nonspecific unrestricted and antigen-specific Ia-restricted soluble factors.

“…Resting anti-thy 1.2-treated B cells were used at 3 x 105 cells per ml in all restimulation assays. Incorporation of [3H]thymidine [1 ,uCi per 0.2 ml of culture (2 Ci/mmol; 1 Ci = 3.7 x 1010 becquerels; Radiochemical Centre, Amersham, England)] for 2 hr at 37°C was carried out as described (3,8). The number of cells in the culture secreting IgM was determined by the protein A-sheep erythrocyte (SRBC)-plaque assay (14).…”

“…In this paper, we describe the separation and identification of proteins found in T-cell help-conditioned media that affect the interactions between T (4,5), were cultured in Iscove's medium (6) containing transferrin, albumin, and soybean lipid as serum replacements, 2-mercaptoethanol (50 uM), and kanamycin (Bio-Cult, Irvine, Scotland). Spleen cell suspensions were enriched for small resting cells by velocity sedimentation (7,8). Treatment of lymphocytes with the rat-mouse hybridoma J-1-j that produces monoclonal anti-thy 1.2 antibody (kindly given to us by J. Sprent, University of Pennsylvania, Philadelphia, PA) was carried out as described (2 (7,9).…”