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Kretschmer K, Jungebloud A, Stopkowicz J, Kleinke T, Hoffmann R, Weiss S. The selection of marginal zone B cells differs from that of B-1a cells. THE JOURNAL OF IMMUNOLOGY 2004; 171:6495-501. [PMID: 14662849 DOI: 10.4049/jimmunol.171.12.6495] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Transgenic (Tg) L2 mice expressing high levels of the lambda2 (315) L chain contain only B cell populations involved in the first line of defense, i.e., B-1 and marginal zone (MZ) B cells. The strongly oligoclonal IgH chain repertoire of Tg B-1a cells in such mice was attributed to strong positive selection by autoantigens. In this study, we show that the MZ B cells of L2 mice correspond very closely to MZ B cells of normal mice, as revealed by surface marker expression and gene expression profiling. We demonstrate that the IgH chain repertoire of these Tg MZ B cells is extremely heterogeneous. This is in sharp contrast to the oligoclonality found in B-1a cells of the same mice, which was attributed to strong positive selection mediated by autoantigens. Therefore, the strong positive selection of the IgH chain repertoire in L2 mice is B-1a specific. Thus, our data demonstrate that despite common functional properties, MZ B and B-1a cells exhibit striking differences in their selection and/or maintenance requirements.
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Affiliation(s)
- Karsten Kretschmer
- Molecular Immunology, Gesellschaft für Biotechnologishe Forschung, German Research Centre for Biotechnology, Braunschweig, Germany.
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2
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Brown VI, Fang J, Alcorn K, Barr R, Kim JM, Wasserman R, Grupp SA. Rapamycin is active against B-precursor leukemia in vitro and in vivo, an effect that is modulated by IL-7-mediated signaling. Proc Natl Acad Sci U S A 2003; 100:15113-8. [PMID: 14657335 PMCID: PMC299917 DOI: 10.1073/pnas.2436348100] [Citation(s) in RCA: 140] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
A balance between survival and apoptotic signals regulates B cell development. These signals are tightly regulated by a host of molecules, including IL-7. Abnormal signaling events may lead to neoplastic transformation of progenitor B cells. Signal transduction inhibitors potentially may modulate these abnormal signals. Inhibitors of the mammalian target of rapamycin (mTOR) such as rapamycin have been used as immunosuppressive agents. We hypothesized that rapamycin might demonstrate activity against B-precursor acute lymphoblastic leukemia. We have found that rapamycin inhibited growth of B-precursor acute lymphoblastic leukemia lines in vitro, with evidence of apoptotic cell death. This growth inhibition was reversible by IL-7. One candidate as a signaling intermediate cross-regulated by rapamycin and IL-7 was p70 S6 kinase. Rapamycin also demonstrated in vivo activity in E mu-ret transgenic mice, which develop pre-B leukemia/lymphoma: E mu-ret transgenic mice with advanced disease treated daily with rapamycin as a single agent showed a >2-fold increase in length of survival as compared with symptomatic littermates who received vehicle alone. These results suggest that mammalian target of rapamycin inhibitors may be effective agents against leukemia and that one of the growth signals inhibited by this class of drugs in precursor B leukemic cells may be IL-7-mediated.
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Affiliation(s)
- Valerie I Brown
- Division of Oncology, Children's Hospital of Philadelphia, and University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
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3
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Felix K, Rolink A, Melchers F, Janz S. Bcl-2 reduces mutant rates in a transgenic lacZ reporter gene in mouse pre-B lymphocytes. Mutat Res 2003; 522:135-44. [PMID: 12517419 DOI: 10.1016/s0027-5107(02)00309-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
To assess mutagenesis during early B-lymphocyte development in vitro, progenitor B cells (pre-B cells) were obtained from fetal livers of BALB/c mice and DBA/2N mice that harbored the transgenic shuttle vector, pUR288, with a lacZ reporter gene for the determination of mutant frequencies (MFs). Differentiation-arrested pre-B cells demonstrated a marked dose-dependent increase in lacZ mutant levels after exposure to gamma-irradiation with a peak MF of 250 x 10(-5) at 2.5 Gy. Without genotoxic treatment, pre-B cells undergoing spontaneous differentiation into surface IgM expressing immature B cells exhibited lacZ mutant levels of up to 95 x 10(-5). The mutational pattern was dominated in both experiments by illegitimate recombination mutations of lacZ, not point mutations. Likewise, in both experiments, the enforced expression of Bcl-2 resulted in a striking reduction of lacZ mutations. These findings indicated that mouse pre-B cells are prone to accumulate induced and self-inflicted mutations, particularly recombinations. Additionally, our studies revealed a heretofore unknown role of Bcl-2 in inhibiting mutagenesis during early B-cell development in mice.
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Affiliation(s)
- Klaus Felix
- Laboratory of Genetics, Center for Cancer Research, National Cancer Institute, Room 2B10, Building 37, NIH, Bethesda, MD 20892-4255, USA
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4
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Hayakawa K, Asano M, Shinton SA, Gui M, Wen LJ, Dashoff J, Hardy RR. Positive selection of anti-thy-1 autoreactive B-1 cells and natural serum autoantibody production independent from bone marrow B cell development. J Exp Med 2003; 197:87-99. [PMID: 12515816 PMCID: PMC2193793 DOI: 10.1084/jem.20021459] [Citation(s) in RCA: 106] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
A natural serum autoantibody specific for the Thy-1 glycoprotein (anti-Thy-1 autoantibody [ATA]) is produced by B-1 cells that are positively selected by self-antigen. Here, using ATA micro kappa transgenic mice we show that cells with this B cell receptor are negatively selected during bone marrow (BM) development. In a Thy-1 null environment, BM ATA B cells progress to a normal follicular stage in spleen. However, in a self-antigen-positive environment, development is arrested at an immature stage in the spleen, concomitant with induction of CD5. Such cells are tolerant and short-lived, different from B-1. Nonetheless, ATA-positive selection was evident by self-antigen-dependent high serum ATA production, comprising approximately 90% of serum immunoglobulin M in ATA micro kappa mice. Splenectomy did not eliminate ATA production and transfer of tolerant splenic B cells did not induce it. These findings demonstrate that B-1 positive selection, resulting in the production of natural serum ATA, arises independently from the major pathway of BM B cell development and selection.
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5
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Merchant M, Longnecker R. LMP2A survival and developmental signals are transmitted through Btk-dependent and Btk-independent pathways. Virology 2001; 291:46-54. [PMID: 11878875 DOI: 10.1006/viro.2001.1187] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The latent membrane protein 2A (LMP2A) of Epstein--Barr virus (EBV) has been implicated in controlling viral latency due to the ability of LMP2A to block B cell antigen receptor (BCR) signaling in vitro and to alter B cell development and enhance B cell survival in vivo. These LMP2A functions require interactions with the protein tyrosine kinases Syk and Lyn. However, a role for the Bruton's tyrosine kinase (Btk) has not been investigated for these LMP2A functions. To investigate whether Btk is important for LMP2A developmental and survival signals in vivo, LMP2A transgenic animals were mated to Btk deficient (Btk(-/-)) mice. Unlike LMP2A(+), Btk(+/+) transgenic littermate controls, LMP2A(+), Btk(-/-) animals do not generate immunoglobulin (Ig) receptorless B cells in the periphery and instead produce Ig(+) B cells similar to those in the Btk(-/-) mice. Interestingly, however, LMP2A(+), Btk(-/-) animals produce B cells at a vastly reduced level compared to Btk(-/-) littermates, indicating that LMP2A affects B cell development in the absence of Btk. In the RAG-1(-/-), Btk(-/-) double knockout background, LMP2A is still capable of enhancing the survival of Ig-receptorless B cells. Use of Btk phosphopeptide-specific antibodies reveals that Btk is constitutively phosphorylated in LMP2A-expressing cell lines. These data indicate that LMP2A initiates both Btk-dependent and Btk-independent pathways, resulting in altered B cell development and enhanced B cell survival.
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Affiliation(s)
- M Merchant
- Department of Microbiology-Immunology, Northwestern University Medical School, Chicago, Illinois 60611, USA
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6
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Bousquet J, Van Cauwenberge P, Khaltaev N. Allergic rhinitis and its impact on asthma. J Allergy Clin Immunol 2001; 108:S147-334. [PMID: 11707753 DOI: 10.1067/mai.2001.118891] [Citation(s) in RCA: 2090] [Impact Index Per Article: 90.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- J Bousquet
- Department of Allergy and Respiratory Diseases, University Hospital and INSERM, Montpellier, France
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7
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Gross JA, Dillon SR, Mudri S, Johnston J, Littau A, Roque R, Rixon M, Schou O, Foley KP, Haugen H, McMillen S, Waggie K, Schreckhise RW, Shoemaker K, Vu T, Moore M, Grossman A, Clegg CH. TACI-Ig neutralizes molecules critical for B cell development and autoimmune disease. impaired B cell maturation in mice lacking BLyS. Immunity 2001; 15:289-302. [PMID: 11520463 DOI: 10.1016/s1074-7613(01)00183-2] [Citation(s) in RCA: 463] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BLyS and APRIL have similar but distinct biological roles, mediated through two known TNF receptor family members, TACI and BCMA. We show that mice treated with TACI-Ig and TACI-Ig transgenic mice have fewer transitional T2 and mature B cells and reduced levels of circulating immunoglobulin. TACI-Ig treatment inhibits both the production of collagen-specific Abs and the progression of disease in a mouse model of rheumatoid arthritis. In BLyS-deficient mice, B cell development is blocked at the transitional T1 stage such that virtually no mature B cells are present, while B-1 cell numbers are relatively normal. These findings further elucidate the roles of BLyS and APRIL in modulating B cell development and suggest that BLyS is required for the development of most but not all mature B cell populations found in the periphery.
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Affiliation(s)
- J A Gross
- Department of Immunology, 1201 Eastlake Avenue East, Seattle, WA 98102, USA.
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8
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Martin F, Oliver AM, Kearney JF. Marginal zone and B1 B cells unite in the early response against T-independent blood-borne particulate antigens. Immunity 2001; 14:617-29. [PMID: 11371363 DOI: 10.1016/s1074-7613(01)00129-7] [Citation(s) in RCA: 723] [Impact Index Per Article: 31.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The rate of pathogen elimination determines the extent and consequences of an infection. In this context, the spleen with its highly specialized lymphoid compartments plays a central role in clearing blood-borne pathogens. Splenic marginal zone B cells (MZ), by virtue of their preactivated state and topographical location, join B1 B cells to generate a massive wave of IgM producing plasmablasts in the initial 3 days of a primary response to particulate bacterial antigens. Because of the intensity and rapidity of this response, combined with the types of antibodies produced, splenic MZ and B1 B cells endowed with a "natural memory" provide a bridge between the very early innate and the later appearing adaptive immune response.
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Affiliation(s)
- F Martin
- Division of Developmental and Clinical Immunology, Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
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9
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Affiliation(s)
- K Hayakawa
- Institute for Cancer Research, Fox Chase Cancer Center, Philadelphia, PA 19111, USA
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10
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Mojica MP, Perry SS, Searles AE, Elenitoba-Johnson KS, Pierce LJ, Wiesmann A, Slayton WB, Spangrude GJ. Phenotypic distinction and functional characterization of pro-B cells in adult mouse bone marrow. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2001; 166:3042-51. [PMID: 11207254 DOI: 10.4049/jimmunol.166.5.3042] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
A lymphoid-committed progenitor population was isolated from mouse bone marrow based on the cell surface phenotype Thy-1.1(neg)Sca-1(pos)c-Kit(low)Lin(neg). These cells were CD43(pos)CD24(pos) on isolation and proliferated in response to the cytokine combination of steel factor, IL-7, and Flt3 ligand. Lymphoid-committed progenitors could be segregated into more primitive and more differentiated subsets based on expression of AA4.1. The more differentiated subset generated only B lymphoid cells in 92% of total colonies assayed, lacked T lineage potential, and expressed Pax5. These studies have therefore defined and isolated a B lymphoid-committed progenitor population at a developmental stage corresponding to the initial expression of CD45R.
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Affiliation(s)
- M P Mojica
- Department of Human Genetics, University of Utah, Salt Lake City, UT 84132, USA
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11
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Illges H, Braun M, Peter HH, Melchers I. Reduced expression of the complement receptor type 2 (CR2, CD21) by synovial fluid B and T lymphocytes. Clin Exp Immunol 2000; 122:270-6. [PMID: 11091285 PMCID: PMC1905766 DOI: 10.1046/j.1365-2249.2000.01379.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The expression of CR2 (CD21) by synovial B and T lymphocytes of patients suffering from various forms of arthritis was analysed with cytofluorometry and with reverse transcriptase-polymerase chain reaction. CR2 (CD21) cell surface protein was detected in normal quantities on peripheral B cells, but was almost absent on synovial B lymphocytes of the same patients. This reduction was most severe in patients with rheumatoid arthritis, but also observed in all other cases. CR2 (CD21) did not reappear after in vitro culture. CR2 (CD21) mRNA was also strongly reduced in synovial B and T lymphocytes. Synovial fluid B lymphocytes were larger than peripheral blood B lymphocytes, while T cells from the same patients showed no size differences. We conclude that synovial fluid B lymphocytes have undergone an irreversible step towards terminal differentiation. The presence or absence of CR2 (CD21) mRNA in peripheral versus synovial T cells indicates that CR2 (CD21) is also differentially expressed by T lymphocytes.
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MESH Headings
- Adult
- Arthritis/genetics
- Arthritis/immunology
- Arthritis, Psoriatic/genetics
- Arthritis, Psoriatic/immunology
- Arthritis, Reactive/genetics
- Arthritis, Reactive/immunology
- Arthritis, Rheumatoid/genetics
- Arthritis, Rheumatoid/immunology
- B-Lymphocytes/immunology
- Base Sequence
- Case-Control Studies
- DNA Primers/genetics
- Gene Expression
- Humans
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Receptors, Complement 3d/genetics
- Receptors, Complement 3d/metabolism
- Spondylitis, Ankylosing/genetics
- Spondylitis, Ankylosing/immunology
- Still's Disease, Adult-Onset/genetics
- Still's Disease, Adult-Onset/immunology
- Synovial Fluid/cytology
- Synovial Fluid/immunology
- T-Lymphocytes/immunology
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Affiliation(s)
- H Illges
- Clinical Research Unit for Rheumatology, Albert-Ludwigs-University Medical Centre, Freiburg, Germany
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12
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Searles AE, Pohlmann SJ, Pierce LJ, Perry SS, Slayton WB, Mojica MP, Spangrude GJ. Rapid, B lymphoid-restricted engraftment mediated by a primitive bone marrow subpopulation. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2000; 165:67-74. [PMID: 10861036 DOI: 10.4049/jimmunol.165.1.67] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Utilizing multiparameter flow cytometry, we have defined a subset of bone marrow cells containing lymphoid-restricted differentiation potential after i.v. transplantation. Bone marrow cells characterized by expression of the Sca-1 and c-kit Ags and lacking Ags of differentiating lineages were segregated into subsets based on allele-specific Thy-1.1 Ag expression. Although hematopoietic stem cells were recovered in the Thy-1.1low subset as previously described, the Thy-1.1neg subset consisted of progenitor cells that preferentially reconstituted the B lymphocyte lineage after i.v. transplantation. Recipients of Thy-1.1neg cells did not survive beyond 30 days, presumably due to the failure of erythroid and platelet lineages to recover after transplants. Thy-1.1neg cells predominantly reconstituted the bone marrow and peripheral blood of lethally irradiated recipients with B lineage cells within 2 weeks, although a low frequency of myeloid lineage cells was also detected. In contrast, myeloid progenitors outnumbered lymphoid progenitors when the Thy-1.1neg population was assayed in culture. When Thy-1. 1low stem cells were rigorously excluded from the Thy-1.1neg subset, reconstitution of T lymphocytes was rarely observed in peripheral blood after i.v. transplantation. Competitive repopulation studies showed that the B lymphoid reconstitution derived from Thy-1.1neg cells was not sustained over a 20-wk period. Therefore, the Thy-1. 1neg population defined in these studies includes transplantable, non-self-renewing B lymphocyte progenitor cells.
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Affiliation(s)
- A E Searles
- Department of Oncological Sciences, University of Utah, Salt Lake City 84132, USA
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13
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Martin F, Kearney JF. Positive selection from newly formed to marginal zone B cells depends on the rate of clonal production, CD19, and btk. Immunity 2000; 12:39-49. [PMID: 10661404 DOI: 10.1016/s1074-7613(00)80157-0] [Citation(s) in RCA: 284] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Using immunoglobulin heavy chain transgenic mice, we show that B cell clones reaching the long-lived pool are heterogeneous: some are enriched in the CD21(high) compartment (mostly marginal zone [MZ]), others reside primarily in the follicles (FO). Altering the composition of the B cell receptor through N region additions decreases the rate of clonal production and the MZ enrichment. This process can be recapitulated by purified CD21(low) B cells and is due to a preferential clonal survival that requires a functional btk tyrosine kinase. We also show that generation of the MZ population is dependent on CD19. These findings suggest that the MZ B cell repertoire is positively selected and have functional implications for antigenic responses effected by B cells from this microenvironment.
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MESH Headings
- Agammaglobulinaemia Tyrosine Kinase
- Animals
- Antigens, CD19/genetics
- Antigens, CD19/metabolism
- Antigens, CD19/physiology
- B-Lymphocytes/cytology
- B-Lymphocytes/immunology
- Bone Marrow Cells/cytology
- Bone Marrow Cells/immunology
- Cell Differentiation
- Cells, Cultured
- Clone Cells
- Hematopoietic Stem Cells/cytology
- Hematopoietic Stem Cells/immunology
- Immunoglobulin Idiotypes
- Immunophenotyping
- Mice
- Mice, Inbred BALB C
- Mice, Inbred C57BL
- Mice, Inbred CBA
- Mice, Transgenic
- Protein-Tyrosine Kinases/metabolism
- Protein-Tyrosine Kinases/physiology
- Receptors, Antigen, B-Cell/metabolism
- Receptors, Complement 3d/metabolism
- Receptors, IgE/metabolism
- Spleen/cytology
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Affiliation(s)
- F Martin
- Department of Microbiology, University of Alabama at Birmingham, 35294-3300, USA
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14
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Parker GA, Peng B, He M, Gould-Fogerite S, Chou CC, Raveché ES. In vivo and in vitro antiproliferative effects of antisense interleukin 10 oligonucleotides. Methods Enzymol 1999; 314:411-29. [PMID: 10565029 DOI: 10.1016/s0076-6879(99)14119-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
MESH Headings
- Animals
- B-Lymphocyte Subsets/drug effects
- B-Lymphocyte Subsets/pathology
- CD5 Antigens
- Dose-Response Relationship, Drug
- Humans
- Interleukin-10/genetics
- Leukemia, Experimental/drug therapy
- Leukemia, Experimental/mortality
- Leukemia, Lymphocytic, Chronic, B-Cell/drug therapy
- Leukemia, Lymphocytic, Chronic, B-Cell/mortality
- Liver/pathology
- Mice
- Oligonucleotides, Antisense/therapeutic use
- Spine/pathology
- Spleen/pathology
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Affiliation(s)
- G A Parker
- Department of Pathology, New Jersey Medical School, University of Medicine and Dentistry of New Jersey, Newark 07103, USA
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15
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Pedersen AE, Bregenholt S, Johansen B, Skov S, Claesson MH. MHC-I-induced apoptosis in human B-lymphoma cells is dependent on protein tyrosine and serine/threonine kinases. Exp Cell Res 1999; 251:128-34. [PMID: 10438578 DOI: 10.1006/excr.1999.4571] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In addition to providing the framework for peptide presentation, major histocompatibility complex class I (MHC-I) molecules can act as signal transducing molecules in lymphoid cells. Here we show that the mobilization of intracellular calcium, which follows crosslinking of MHC-I molecules on human B lymphoma cells, is dependent on protein tyrosine kinases and the phosphatidylinositol 3 (PI-3) kinase. Functional studies showed that MHC-I crosslinking induced almost complete inhibition of the spontaneous proliferation of the B lymphoma cells as early as 6 h post-crosslinking and apoptosis 24 h post-crosslinking. Preincubation with either protein tyrosine kinase or protein serine/threonine kinase inhibitors reduced the MHC-I-induced apoptosis to background levels, whereas inhibition of PI-3 kinase had no effect. These data demonstrate a pivotal role for protein tyrosine and serine/threonine kinases in MHC-I-mediated apoptosis in human B-cells and suggest the presence of several MHC-I signaling pathways leading to diverse effects in these cells.
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Affiliation(s)
- A E Pedersen
- Department of Medical Anatomy, The Panum Institute, University of Copenhagen, Building 18.3, Blegdamsvej 3, Copenhagen, DK-2200, Denmark
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16
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Oliver AM, Martin F, Kearney JF. IgMhighCD21high Lymphocytes Enriched in the Splenic Marginal Zone Generate Effector Cells More Rapidly Than the Bulk of Follicular B Cells. THE JOURNAL OF IMMUNOLOGY 1999. [DOI: 10.4049/jimmunol.162.12.7198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Abstract
Ag encounter will recruit Ag-specific cells from the pool of mature B lymphocytes in the spleen and activate them to perform effector functions: generation of Ab-forming cells (plasma cells) and presentation of Ag to T cells. We have compared the ability of mature follicular and marginal zone cells to develop into effector B cells. The generation of marginal zone B cells and their localization in the marginal sinus area are T cell and CD40 ligand independent, suggesting that they do not represent a postgerminal center population. Compared with mature recirculating follicular B cells, they express several characteristics of previous antigenic experience, including higher levels of B7.1 (CD80) and B7.2 (CD86) when freshly isolated and following in vitro stimulation. After a brief 6- to 8-h in vitro stimulation with LPS or anti-CD40 Abs, marginal zone B cells become potent APCs. In addition, their ability to proliferate and differentiate into plasma cells in response to low doses of T-independent polyclonal stimuli (LPS) is far greater than that of follicular B cells. These findings indicate a functional heterogeneity within splenic mature B lymphocytes, with marginal zone B cells having the capacity to generate effector cells in early stages of the immune response against particulate Ags scavenged efficiently in this special anatomical site.
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Affiliation(s)
- Alyce M. Oliver
- Division of Developmental and Clinical Immunology, Department of Microbiology, University of Alabama, Birmingham, AL 35294
| | - Flavius Martin
- Division of Developmental and Clinical Immunology, Department of Microbiology, University of Alabama, Birmingham, AL 35294
| | - John F. Kearney
- Division of Developmental and Clinical Immunology, Department of Microbiology, University of Alabama, Birmingham, AL 35294
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17
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T-, B-, and Natural Killer Cell Dysfunction in Murine Systemic Lupus Erythematosus Models. Lupus 1999. [DOI: 10.1007/978-1-59259-703-1_14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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18
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Giorgetti CA, Press JL. Somatic Mutation in the Neonatal Mouse. THE JOURNAL OF IMMUNOLOGY 1998. [DOI: 10.4049/jimmunol.161.11.6093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Abstract
Several mechanisms that diversify the adult immune repertoire, such as terminal deoxynucleotidyl transferase-dependent N region addition, are not available to the neonatal mouse. One important process that contributes to protective immunity in the adult is somatic mutation, which plays a major role in the generation of high affinity memory B cells. It is not clear whether B cells in the neonatal mouse can activate the somatic mutation machinery. To investigate this, we immunized neonates with poly(l-Tyr,l-Glu)-poly-d, l-Ala–poly-l-Lys complexed with methylated BSA, or (4-hydroxy-3-nitrophenyl)acetyl coupled to chicken γ-globulin. Eight to fourteen days after priming, V(D)J rearrangements of known VH genes (VHSM7 family) were screened for mutations using a temperature-melt hybridization assay and oligonucleotide probes specific for complementarity-determining regions I and II; possible mutations were confirmed by sequence analysis. More mutations per sequence were found in heavy chains from neonates immunized with (4-hydroxy-3-nitrophenyl)acetyl coupled to chicken γ-globulin than in those from neonates immunized with poly(l-Tyr, l-Glu)-poly-d,l-Ala-poly-l-Lys complexed with methylated BSA. Mutations were found in heavy chains lacking N regions, suggesting that B cells of the putative fetal lineage can somatically mutate and diversify an initially limited repertoire. Since neonates immunized as early as 1 or 2 days after birth had mutations, the somatic mutation machinery can be activated soon after birth, suggesting that early vaccination should result in affinity maturation and protective immunity in the neonate.
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Affiliation(s)
| | - Joan L. Press
- Brandeis University, Rosenstiel Research Center, Waltham, MA 02454
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19
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Ghia P, ten Boekel E, Rolink AG, Melchers F. B-cell development: a comparison between mouse and man. IMMUNOLOGY TODAY 1998; 19:480-5. [PMID: 9785673 DOI: 10.1016/s0167-5699(98)01330-9] [Citation(s) in RCA: 92] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
A common variable immunodeficiency (CVID) patient, who carries mutations on both alleles of the gene encoding the surrogate light chain component lambda 5/14.1, shows a similar phenotype of B-cell deficiency as the lambda 5-deficient mutant mouse. As discussed here by Paolo Ghia and colleagues, this points to a remarkably similar developmental pathway of B cells in humans and mice.
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Affiliation(s)
- P Ghia
- Dana Farber Cancer Institute Boston, MA, USA
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20
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Abstract
Eμ-ret mice carrying an RFP/RET fusion gene under the transcriptional control of the immunoglobulin heavy chain enhancer develop B lineage leukemias/lymphomas. We have characterized B-cell development in these mice before the onset of clinical disease to determine the steps involved in leukemogenesis. Flow cytometry reveals that the CD45R+CD43+CD24+BP-1+late pro–B-cell population is markedly expanded in the bone marrow of 3- to 5-week-old Eμ-ret mice. Compared with late pro–B cells from transgene-negative mice, Eμ-ret late pro–B cells have a limited capacity to differentiate in interleukin (IL)-7 and a higher incidence of VDJ rearrangements, but a similar cell cycle profile. In contrast, CD45R+CD43+CD24+BP-1−early pro–B cells from 3- to 5-week-old Eμ-ret mice, which also express the RFP/RET transgene, differentiate in IL-7 similarly to their normal counterparts. Furthermore, early pro–B cells from Eμ-ret and transgene-negative mice have an identical pattern of growth inhibition when exposed to interferons (IFNs)-α/β and -γ, whereas, pro–B-cell leukemia lines derived from Eμ-ret mice are markedly less sensitive to growth inhibition by these IFNs. In 13-week-old well-appearing Eμ-ret mice, late pro–B cells upregulate CYCLIN D1 expression and downregulate CASPASE-1 expression in a pattern that correlates with the emergence of B precursor cells in the peripheral blood and the loss of other B lineage subsets in the bone marrow. Taken together, these results suggest that the expression of the RFP/RET transgene initially prevents the normal elimination of late pro–B cells with nonproductive rearrangements. Secondary events that simultaneously disturb the normal transcriptional regulation of genes involved in the control of the cell cycle and apoptosis may allow for subsequent malignant transformation within the expanded late pro–B-cell population.
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