scholarly journals Absolute frequencies of lipopolysaccharide-reactive B cells producing A5A idiotype in unprimed, streptococcal A carbohydrate-primed, anti-A5A idiotype-sensitized and anti-A5A idiotype-suppressed A/J mice.

1977 ◽  
Vol 146 (5) ◽  
pp. 1436-1449 ◽  
Author(s):  
K Eichmann ◽  
A Coutinho ◽  
F Melchers
Keyword(s):  
B Cells ◽  
B Cell ◽  
Qualitative Difference ◽  
Fold Increase ◽  
Precursor Cells ◽  
Antigen Specificity ◽  
Spleen Cells ◽  
Cell Precursor

The absolute frequencies of B cells-producing A5A idiotype have been determined in vitro by limiting dilution analysis in a culture system in which every LPS-reactive B cell grows into a clone of IgM-secreting cells. Spleen cells from normal A/J mice contain 1 A5A-idiotype-producing B-cell precursor in 2.5 X 10(3) LPS-reactive B cells. Approximately a 10-20-fold increase in frequencies of precursor cells from antigen priming with Strep A-CHO (1 in 2.8 X 10(2)) or from sensitization with IgG1 anti-A5A idiotype (1 in 1.3 X 10(2)). Injection of IgG2 anti-A5A idiotype which has been shown to suppress A5A idiotype in vivo results in only a marginal and maybe insignificant decrease in precursor frequencies (1 in 6.7 X 10(3)). On the other hand, priming does not result in a detectable qualitative difference in the specific precursor cells, since each clone of B cells secretes 30 ng of A5A-bearing Ig within 8 days of culture, regardless of being unprimed or primed. Nearly half of all A5A idiotype-producing clones, both from unprimed as well as from primed mice, show antigen specificity in binding A-CHO. Priming by antigen, therefore, also results in a 10-fold increase in the frequency of idiotype positive B cells without antigen specificity. This result is a prediction of the network hypothesis.

scholarly journals INDUCTION OF A HEMOLYSIN RESPONSE IN VITRO

1971 ◽  
Vol 133 (6) ◽  
pp. 1325-1333 ◽  
Author(s):  
Klaus-Ulrich Hartmann
Keyword(s):  
Bone Marrow ◽  
T Cells ◽  
B Cells ◽  
Close Contact ◽  
Precursor Cells ◽  
Spleen Cells ◽  
High Concentrations ◽  
Thymus Cells ◽  
Bone Marrow Chimeras

Spleen cells of bone marrow chimeras (B cells) and of irradiated mice injected with thymus cells and heterologous erythrocytes (educated T cells) were mixed and cultured together (17). The number of PFC developing in these cultures was dependent both on the concentration of the B cells and of the educated T cells. In excess of T cells the number of developing PFC is linearly dependent on the number of B cells. At high concentrations of T cells more PFC developed; the increase in the number of PFC was greatest between the 3rd and 4th day of culture. Increased numbers of educated T cells also assisted the development of PFC directed against the erythrocytes. It is concluded that the T cells not only play a role during the triggering of the precursor cells but also during the time of proliferation of the B cells; close contact between B and T cells seems to be needed to allow the positive activity of the T cells.

scholarly journals Differential Regulation of Mouse B Cell Development by Transforming Growth Factor β1

2002 ◽  
Vol 9 (2) ◽  
pp. 86-95 ◽  
Author(s):  
Denise A. Kaminski ◽  
John J. Letterio ◽  
Peter D. Burrows
Keyword(s):  
B Cells ◽  
Growth Factor ◽  
B Cell ◽  
Transforming Growth Factor ◽  
Plasma Cells ◽  
Population Analysis ◽  
Cell Development ◽  
B Cell Development

Transforming growth factor β (TGFβ) can inhibit thein vitroproliferation, survival and differentiation of B cell progenitors, mature B lymphocytes and plasma cells. Here we demonstrate unexpected, age-dependent reductions in the bone marrow (BM) B cell progenitors and immature B cells in TGFβ1-/-mice. To evaluate TGFβ responsiveness during normal B lineage development, cells were cultured in interleukin 7 (IL7)±TGFβ. Picomolar doses of TGFβ1 reduced pro-B cell recoveries at every timepoint. By contrast, the pre-B cells were initially reduced in number, but subsequently increased compared to IL7 alone, resulting in a 4-fold increase in the growth rate for the pre-B cell population. Analysis of purified BM sub-populations indicated that pro-B cells and the earliest BP1-pre-B cells were sensitive to the inhibitory effects of TGFβ1. However, the large BP1+pre-B cells, although initially reduced, were increased in number at days 5 and 7 of culture. These results indicate that TGFβ1 is important for normal B cell developmentin vivo, and that B cell progenitors are differentially affected by the cytokine according to their stage of differentiation.

scholarly journals IMMUNOLOGIC REACTIONS TO HAPTENS ON AUTOLOGOUS CARRIERS

1973 ◽  
Vol 137 (2) ◽  
pp. 411-423 ◽  
Author(s):  
John W. Moorhead ◽  
Curla S. Walters ◽  
Henry N. Claman
Keyword(s):  
T Cells ◽  
B Cells ◽  
Aminocaproic Acid ◽  
Single Amino Acid ◽  
Secondary Response ◽  
Spleen Cells ◽  
Activated T Cells ◽  
Thymus Cells

Both thymus-derived (T) and bone marrow-derived (B) lymphocytes participate in the response to a hapten 4-hydroxy-3-iodo-5-nitrophenylacetic acid (NIP), coupled to a nonimmunogenic isologous carrier, mouse gamma globulin (MGG). Spleen cells from mice immunized with NIP-MGG show increased DNA synthesis in vitro when cultured with NIP-MGG. The participation of and requirement for T cells in the response was demonstrated by treating the spleen cells with anti-θ serum. This treatment resulted in a 77% inhibition of the antigen response. Furthermore, adoptively transferred normal thymus cells could be specifically "activated" by NIP-MGG in vivo and they responded secondarily to the antigen in vitro. The active participation of B cells in the secondary response was demonstrated by passing the immune spleen cells through a column coated with polyvalent anti-MGG serum. Column filtration reduced the number of NIP-specific plaque-forming cells and NIP-specific rosette-forming cells (both functions of B cells) and produced a 47% inhibition of the NIP-MGG response. The ability of the cells to respond to phytohemagglutinin (PHA) was not affected by column filtration showing that T cells were not being selectively removed. The participation of B cells in the in vitro NIP-MGG response was also shown by treatment of the spleen cells with antiserum specific for MGG and MGG determinants. B cells were removed by treatment with anti-IgM or polyvalent anti-MGG serum plus complement, resulting in a respective 46 and 49% inhibition of the response to NIP-MGG. (Treatment with anti-IgM serum had no effect on T cells.) The contribution of the hapten NIP to stimulation of T cells was investigated using NIP-MGG-activated thymus cells. These activated T cells responded in vitro very well to the NIP-MGG complex but not to the MGG carrier alone demonstrating the requirement of the hapten for T cell stimulation. The response was also partially inhibited (41%) by incubating the activated cells with NIP coupled to a single amino acid (epsilon-aminocaproic acid) before addition of NIP-MGG. These results demonstrated that T cells recognize the hapten NIP when it is coupled to the isologous carrier MGG.

CD40 inhibits B cell apoptosis by upregulating bcl-xL expression and blocking oxidant accumulation

1997 ◽  
Vol 272 (3) ◽  
pp. C950-C956 ◽  
Author(s):  
W. Fang ◽  
K. A. Nath ◽  
M. F. Mackey ◽  
R. J. Noelle ◽  
D. L. Mueller ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Cd40 Ligand ◽  
Antioxidant Response ◽  
Immunoglobulin M ◽  
Inhibitory Protein ◽  
Wehi 231 ◽  
Immature Mouse

Signaling through the CD40 receptor on human and murine B lymphocytes is necessary for germinal center formation and immunoglobulin class switching in vivo and rescues B cells from apoptosis triggered by cross-linking of surface immunoglobulin M in vitro. Ligation of CD40 on the immature mouse B cell line WEHI-231 with recombinant CD40 ligand (CD40L) was found to protect cells from apoptosis after gamma irradiation, as well as that following treatment with the sphingomyelin ceramide or compounds that deplete intracellular glutathione. CD40 signaling led to a rapid increase in the expression of the apoptosis inhibitory protein Bcl-xL. In addition, the apoptosis-induced accumulation of intracellular oxidants in WEHI-231 B cells was rapidly diminished by CD40 crosslinking. This antioxidant response was observed within 1 h and coincided with a preservation of intracellular thiols. These findings indicate that CD40 signaling induces a generalized cellular resistance to apoptosis characterized by an upregulation of Bcl-xL and changes in the intracellular redox potential.

scholarly journals Lack of mature B cells in nude mice with X-linked immune deficiency.

1982 ◽  
Vol 155 (3) ◽  
pp. 903-913 ◽  
Author(s):  
H H Wortis ◽  
L Burkly ◽  
D Hughes ◽  
S Roschelle ◽  
G Waneck
Keyword(s):  
Immune Deficiency ◽  
B Cells ◽  
B Cell ◽  
Nude Mice ◽  
Normal Serum ◽  
The Other ◽  
Spleen Cells ◽  
Virtual Absence ◽  
Immunoglobulin Levels

Mice were bred that simultaneously expressed the mutations nude and x-linked immune deficiency (xid). These doubly deficient animals had less than 10% of normal serum immunoglobulin levels. Their spleen cells did not respond to thymus-independent antigens in vitro nor did they respond to lipopolysaccharide. There was a virtual absence of cells with surface mu, kappa, or lambda 1, as detected by fluorescence. Sections of lymphoid organs revealed an absence of primary B cell follicles. Taken together, these results indicate a lack of mature B cells in nude xid mice. The possibility is considered that mature B cells belong to two subpopulations representing two lineages, one controlled by alleles at the xid locus and the other by alleles at the nude locus.

scholarly journals MATURATION OF THE HUMORAL IMMUNE RESPONSE IN MICE

1974 ◽  
Vol 139 (2) ◽  
pp. 249-263 ◽  
Author(s):  
Patricia G. Spear ◽  
Gerald M. Edelman
Keyword(s):  
T Cell ◽  
B Cells ◽  
Cell Function ◽  
Spleen Cells ◽  
Con A ◽  
Humoral Immune ◽  
Humoral Immune Responses ◽  
Humoral Antibodies

In spite of the prenatal appearance of immunoglobulin-bearing lymphocytes and θ-positive lymphocytes in the spleens of Swiss-L mice, these mice are not able to produce detectable levels of humoral antibodies in response to antigen until after 1 wk of age. Adult levels of response are not achieved until 4–8 wk of age. In the presence of bacterial lipopolysaccharides, which can substitute for or enhance T-cell function, the B cells from young Swiss-L mice were found to be indistinguishable in function from adult B cells, both with respect to the numbers of plaque-forming cells (PFC) produced in vitro in response to antigen and with respect to the kinetics of PFC induction. The spleen cells from young Swiss-L mice are significantly less sensitive than adult spleen cells, however, to stimulation by the T cell mitogens, concanavalin A (Con A) and phytohemagglutinin (PHA). Very few Con A-responsive cells could be detected at birth but the numbers increased sharply with age until 3 wk after birth. On the other hand, PHA-responsive cells could not be detected in the spleen until about 3 wk of age. The latter cells were found to respond also to Con A, but at a lower dose (1 µg/ml) than that required for the bulk of the Con A-responsive cells (3 µg/ml). The cells that respond both to PHA and to Con A appear in the spleen at about the time that Swiss-L mice acquire the ability to produce humoral antibodies, and these cells can be depleted from the spleen by the in vivo administration of antithymocyte serum. The development of humoral immune responses in these mice therefore appears to be correlated with the appearance of recirculating T lymphocytes that are responsive both to PHA and to Con A.

scholarly journals Epstein-Barr Virus LMP2A Alters In Vivo and In Vitro Models of B-Cell Anergy, but Not Deletion, in Response to Autoantigen

2005 ◽  
Vol 79 (12) ◽  
pp. 7355-7362 ◽  
Author(s):  
Michelle A. Swanson-Mungerson ◽  
Robert G. Caldwell ◽  
Rebecca Bultema ◽  
Richard Longnecker
Keyword(s):  
B Cells ◽  
B Cell ◽  
Epstein Barr Virus ◽  
Nuclear Translocation ◽  
Cell Receptor ◽  
Barr Virus ◽  
Low Levels ◽  
Epstein Barr

ABSTRACT A significant percentage of the population latently harbors Epstein-Barr virus (EBV) in B cells. One EBV-encoded protein, latent membrane protein 2A (LMP2A), is expressed in tissue culture models of EBV latent infection, in human infections, and in many of the EBV-associated proliferative disorders. LMP2A constitutively activates proteins involved in the B-cell receptor (BCR) signal transduction cascade and inhibits the antigen-induced activation of these proteins. In the present study, we investigated whether LMP2A alters B-cell receptor signaling in primary B cells in vivo and in vitro. LMP2A does not inhibit antigen-induced tolerance in response to strong stimuli in an in vivo tolerance model in which B cells are reactive to self-antigen. In contrast, LMP2A bypasses anergy induction in response to low levels of soluble hen egg lysozyme (HEL) both in vivo and in vitro as determined by the ability of LMP2A-expressing HEL-specific B cells to proliferate and induce NF-κB nuclear translocation after exposure to low levels of antigen. Furthermore, LMP2A induces NF-κB nuclear translocation independent of BCR cross-linking. Since NF-κB is required to bypass tolerance induction, this LMP2A-dependent NF-κB activation may complete the tolerogenic signal induced by low levels of soluble HEL. Overall, the findings suggest that LMP2A may not inhibit BCR-induced signals under all conditions as previously suggested by studies with EBV immortalized B cells.

scholarly journals Identification of an Essential Cytoplasmic Region of Interleukin-7 Receptor α Subunit in B-Cell Development

2018 ◽  
Vol 19 (9) ◽  
pp. 2522 ◽  
Author(s):  
Hirotake Kasai ◽  
Taku Kuwabara ◽  
Yukihide Matsui ◽  
Koichi Nakajima ◽  
Motonari Kondo
Keyword(s):  
B Cells ◽  
B Cell ◽  
Myeloid Cell ◽  
Cell Development ◽  
B Cell Development ◽  
Α Subunit ◽  
Interleukin 7 ◽  
In Cells

Interleukin-7 (IL-7) is essential for lymphocyte development. To identify the functional subdomains in the cytoplasmic tail of the IL-7 receptor (IL-7R) α chain, here, we constructed a series of IL-7Rα deletion mutants. We found that IL-7Rα-deficient hematopoietic progenitor cells (HPCs) gave rise to B cells both in vitro and in vivo when a wild-type (WT) IL-7Rα chain was introduced; however, no B cells were observed under the same conditions from IL-7Rα-deficient HPCs with introduction of the exogenous IL-7Rα subunit, which lacked the amino acid region at positions 414–441 (d414–441 mutant). Signal transducer and activator of transcription 5 (STAT5) was phosphorylated in cells with the d414–441 mutant, similar to that in WT cells, in response to IL-7 stimulation. In contrast, more truncated STAT5 (tSTAT5) was generated in cells with the d414–441 mutant than in WT cells. Additionally, the introduction of exogenous tSTAT5 blocked B lymphopoiesis but not myeloid cell development from WT HPCs in vivo. These results suggested that amino acids 414–441 in the IL-7Rα chain formed a critical subdomain necessary for the supportive roles of IL-7 in B-cell development.

scholarly journals Normal mouse peritoneum contains a large population of Ly-1+ (CD5) B cells that recognize phosphatidyl choline. Relationship to cells that secrete hemolytic antibody specific for autologous erythrocytes.

1988 ◽  
Vol 168 (2) ◽  
pp. 687-698 ◽  
Author(s):  
T J Mercolino ◽  
L W Arnold ◽  
L A Hawkins ◽  
G Haughton
Keyword(s):  
B Cells ◽  
Cell Surface ◽  
Phosphatidyl Choline ◽  
Large Population ◽  
In Vivo Studies ◽  
Antigen Specificity ◽  
Adult Mice ◽  
Large Numbers

We have found that, in the peritoneums of normal adult mice, 5-15% of lymphocytes bind a fluorescent liposome probe. In ontogeny, cells with this specificity were shown to appear by 8 d after birth, and increase to the adult frequency by 2-3 wk. Some older mice contain an expanded population of these cells. We have shown that liposome binding occurs by cell surface IgM recognizing the common membrane phospholipid, phosphatidyl choline (PtC). Virtually all of these PtC-specific cells bear the cell surface marker Ly-1. Our results indicate that roughly 1 in 10 peritoneal Ly-1+ B cells has this single specificity. We have found that the precursors to all the cells that form plaques on protease-treated autologous erythrocytes (BrMRBC) are included in the PtC-specific population and can be isolated by FACS. We believe this is the first report of sorting large numbers of B cells with a single antigen specificity from normal, unimmunized animals. This method will allow for in vitro and in vivo studies of differentiative and proliferative properties of Ly-1+ B cells, which may help define their role in development and disease.

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