scholarly journals Antibody selection against CD52 produces a paroxysmal nocturnal haemoglobinuria phenotype in human lymphocytes by a novel mechanism

1997 ◽  
Vol 322 (3) ◽  
pp. 919-925 ◽  
Author(s):  
Vanessa C. TAYLOR ◽  
Martin SIMS ◽  
Sara BRETT ◽  
Mark C. FIELD
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
B Cell ◽  
Cell Lines ◽  
Structural Gene ◽  
Biosynthetic Pathway ◽  
Human Lymphocytes ◽  
Paroxysmal Nocturnal Haemoglobinuria ◽  
T Cell Lines

The CD52 antigen is a lymphocyte glycoprotein with an extremely short polypeptide backbone and a single N-linked glycan, and it is attached to the cell membrane by a glycosylphosphatidylinositol (GPI) anchor. Treatment of rheumatoid arthritis patients with CAMPATH-1H, a humanized monoclonal antibody against CD52, resulted, in a small number of cases, in the appearance and persistence of CD52-negative T cells. Similarly, CD52-negative B cells emerged following in vitro treatment of a CD52-positive human B cell line with CAMPATH-1H. Both the B and T CD52-negative cells were also found to be defective in surface expression of other GPI-anchored proteins. Biochemical analysis revealed a severe defect in the synthesis of a mature GPI precursor in both the B and T cell lines. Therefore the phenotype of these CD52-negative B and T cells closely resembles that of lymphocytes from patients with paroxysmal nocturnal haemoglobinuria (PNH), in which the first step of the GPI-biosynthetic pathway, i.e. synthesis of GlcNAc-phosphatidylinositol, is blocked. In all cases studied to date, this defect maps to a mutation of the phosphatidylinositolglycan class A (PIG-A) structural gene. We therefore amplified the PIG-A gene from both the GPI-negative B and T cells by PCR and determined the nucleotide sequence. No differences from the wild-type sequence were detected; therefore a classical PNH mutation cannot be responsible for the GPI-biosynthesis defect in these cell lines. Significantly, the GPI-negative phenotype of the B cells was reversible upon separation of the positive and negative cells, resulting in a redistribution to a mixed population with either CD52-positive or -negative cells, whereas populations of 100% CD52-negative T cells were stably maintained during culture. Therefore, whereas the GPI-biosynthesis deficiency in the T cell lines may be due to a mutation in another gene required by the GPI-biosynthetic pathway, the reversible nature of this block in the B cell lines suggests a less direct cause, possibly an alteration in a regulatory factor. Overall, these data demonstrate that the PNH phenotype can be generated without a mutation in the PIG-A structural gene, and thereby identify a novel mechanism for the development of GPI deficiency.

scholarly journals Interleukin 2 induces antigen-reactive T cell lines to secrete BCGF-I.

1983 ◽  
Vol 158 (6) ◽  
pp. 2024-2039 ◽  
Author(s):  
M Howard ◽  
L Matis ◽  
T R Malek ◽  
E Shevach ◽  
W Kell ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
B Cell ◽  
Cell Line ◽  
Cell Lines ◽  
Interleukin 2 ◽  
Activated T Lymphocytes ◽  
T Cell Lines ◽  
Activated B Cells

Antigen-activated T lymphocytes produce within 24 h of stimulation a factor that is indistinguishable biochemically and functionally from the B cell co-stimulating growth factor, BCGF-I, originally identified in induced EL4 supernatants: Supernatants from antigen-stimulated T cell lines are not directly mitogenic for resting B cells, but synergize in an H-2-unrestricted manner with anti-Ig activated B cells to produce polyclonal proliferation but not antibody-forming-cell development; biochemical studies reveal the B cell co-stimulating factor present in antigen-stimulated T cell line supernatants is identical by phenyl Sepharose chromatography and isoelectric focusing (IEF) to EL4 supernatant BCGF-I. We thus conclude that normal T cells produce BCGF-I in response to antigenic stimulation. Analysis of the mechanism of BCGF-I production by antigen-stimulated T cells showed that optimum amounts of BCGF-I were obtained as quickly as 24 h post-stimulation, and that the factor producing cells in the T cell line investigated bore the Lyt-1+2- phenotype. As few as 10(4) T cells produced sufficient BCGF-I to support the proliferation of 5 X 10(4) purified anti-Ig activated B cells. Finally, the activation of normal T cell lines to produce BCGF-I required either antigen presented in the context of syngeneic antigen-presenting cells (APC) or interleukin 2 (IL-2).

scholarly journals B cell-stimulatory factor 1 (BSF-1) promotes growth of helper T cell lines.

1986 ◽  
Vol 164 (2) ◽  
pp. 580-593 ◽  
Author(s):  
R Fernandez-Botran ◽  
P H Krammer ◽  
T Diamantstein ◽  
J W Uhr ◽  
E S Vitetta
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
B Cell ◽  
Cell Lines ◽  
Activated T Cells ◽  
Growth Promoting ◽  
T Cell Lines ◽  
Stimulatory Factor

T cell-derived supernatants (SN) that contain B cell-stimulatory factor 1 (BSF-1) and lack IL-2 promote the growth of the IL-2-dependent T cell line, HT-2, as well as three other clones or lines of T cells that can provide help to B cells. The BSF-1 purified from these SNs promotes growth of HT-2 cells approximately 50% as effectively as purified IL-2. A potential involvement for contaminating IL-2 in the BSF-1 preparations was excluded by the demonstration that anti-BSF-1 mAbs blocked the BSF-1-induced growth of HT-2 cells; in contrast, these antibodies did not block the IL-2-induced proliferation of the HT-2 cells. In addition, anti-IL-2 mAbs or anti-IL-2-R antibodies blocked the HT-2 growth-promoting activity of purified IL-2, but not BSF-1. Finally, BSF-1 promoted only a very modest growth of Con A-induced T cell blasts, and failed to induce significant growth in seven other cytotoxic, alloreactive, and long-term T cell lines. Taken together, these results indicate that in addition to its known effects on resting and LPS-stimulated B cells, BSF-1 can promote growth of certain subsets of activated T cells, in particular, those that provide help to B cells.

Adoptive T-Cell Therapy for B-Cell Acute Lymphoblastic Leukemia: Preclinical Studies

Blood ◽  
1999 ◽  
Vol 94 (10) ◽  
pp. 3531-3540 ◽  
Author(s):  
Angelo A. Cardoso ◽  
J. Pedro Veiga ◽  
Paolo Ghia ◽  
Hernani M. Afonso ◽  
W. Nicholas Haining ◽  
...  
Keyword(s):  
Bone Marrow ◽  
T Cells ◽  
T Cell ◽  
B Cell ◽  
Cell Lines ◽  
Lymphoblastic Leukemia ◽  
Adoptive T Cell Therapy ◽  
Leukemic Cells ◽  
Acute Leukemias ◽  
T Cell Lines

We have previously shown that leukemia-specific cytotoxic T cells (CTL) can be generated from the bone marrow of most patients with B-cell precursor acute leukemias. If these antileukemia CTL are to be used for adoptive immunotherapy, they must have the capability to circulate, migrate through endothelium, home to the bone marrow, and, most importantly, lyse the leukemic cells in a leukemia-permissive bone marrow microenvironment. We demonstrate here that such antileukemia T-cell lines are overwhelmingly CD8+ and exhibit an activated phenotype. Using a transendothelial chemotaxis assay with human endothelial cells, we observed that these T cells can be recruited and transmigrate through vascular and bone marrow endothelium and that these transmigrated cells preserve their capacity to lyse leukemic cells. Additionally, these antileukemia T-cell lines are capable of adhering to autologous stromal cell layers. Finally, autologous antileukemia CTL specifically lyse leukemic cells even in the presence of autologous marrow stroma. Importantly, these antileukemia T-cell lines do not lyse autologous stromal cells. Thus, the capacity to generate anti–leukemia-specific T-cell lines coupled with the present findings that such cells can migrate, adhere, and function in the presence of the marrow microenvironment enable the development of clinical studies of adoptive transfer of antileukemia CTL for the treatment of ALL.

scholarly journals T and B cells that recognize the same antigen do not transcribe similar heavy chain variable region gene segments.

1983 ◽  
Vol 158 (1) ◽  
pp. 192-209 ◽  
Author(s):  
E Kraig ◽  
M Kronenberg ◽  
J A Kapp ◽  
C W Pierce ◽  
A F Abruzzini ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
Cell Lines ◽  
Variable Region ◽  
Antigenic Specificity ◽  
Helper T Cell ◽  
Region Gene ◽  
Vh Gene ◽  
T Cell Lines

We have attempted to determine whether T cells and B cells that have the same antigenic specificity and whose receptors share idiotypic determinants in fact express similar VH gene segments. To do this, we have obtained and characterized a cDNA clone containing the entire coding sequence for the VH gene from a glutamic acid60/alanine30/tyrosine10 (GAT)-binding immunoglobulin that carries the CGAT idiotype. The GAT-VH clone was hybridized to Northern blots of GAT-specific T cell RNAs; there was no evidence of a T cell transcript that hybridized to the GAT-VH probe. The T cells analyzed included: (a) 10 GAT-binding suppressor T cell hybridomas, 6 of which secreted factors with CGAT idiotypic determinants, (b) one GAT-specific helper T cell hybridoma, and (c) two GAT-specific helper T cell lines grown in the absence of feeder cells. The detection limit of the Northern blot analysis was 1-2 copies of a particular mRNA species per cell for the hybridomas and 5-10 copies per cell for the T cell lines. Therefore, we conclude that T and B lymphocytes responding to GAT do not utilize similar VH gene segments. Furthermore, the presence of idiotypic determinants on T lymphocytes does not necessarily imply close structural similarity between T and B cell antigen receptors.

scholarly journals Expression of T cell receptor genes in human B cells.

1986 ◽  
Vol 164 (6) ◽  
pp. 1940-1957 ◽  
Author(s):  
A F Calman ◽  
B M Peterlin
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
B Cell ◽  
Cell Lines ◽  
Transcriptional Activity ◽  
Myeloid Cell ◽  
Cdna Clones ◽  
Gene Rearrangements ◽  
Beta Gene

We analyzed the transcription and rearrangement of the T cell antigen receptor (Ti) genes Ti alpha and Ti beta in human B cell, T cell, and myeloid cell lines, as well as in purified tonsillar B and T cells. All four B cell lines examined, as well as one of two myeloid cell lines, expressed low levels of truncated Ti beta transcripts, as did freshly purified tonsillar B cells. Two of the B cell lines and one of the myeloid lines also expressed truncated Ti alpha transcripts, while tonsillar B cells did not. Sequence analysis of cDNA clones from a B cell line demonstrated that these truncated Ti alpha and Ti beta transcripts were composed of unrearranged J and C gene segments. Comparison of cDNA clones from T and B cells suggests that D alpha genes or N regions contribute to the formation of Ti alpha transcripts in T cells but not in B cells. None of the B cell or myeloid cell lines in this study showed evidence of Ti beta gene rearrangements by Southern blotting. Our data, and other studies of gene rearrangements in human tumors, demonstrate that the level of Ti beta transcriptional activity and the frequency of Ti beta gene rearrangements are correlated in all cell types examined. Thus, our data support the accessibility model of antigen receptor gene rearrangement, whereby the susceptibility of gene segments to recombination enzymes is correlated with their transcriptional activity.

scholarly journals Major histocompatibility complex-restricted, polyclonal B cell responses resulting from helper T cell recognition of antiimmunoglobulin presented by small B lymphocytes.

1985 ◽  
Vol 161 (1) ◽  
pp. 223-241 ◽  
Author(s):  
H P Tony ◽  
D C Parker
Keyword(s):  
Major Histocompatibility Complex ◽  
T Cell ◽  
B Cells ◽  
Cell Surface ◽  
B Cell ◽  
Cell Lines ◽  
Major Histocompatibility ◽  
Helper T Cell ◽  
Histocompatibility Complex ◽  
T Cell Lines

Anti-Ig has been widely used as a model for antigen receptor-mediated B cell activation. B cells activated with mitogenic concentrations of anti-Ig (approximately 10 micrograms/ml) become responsive to a set of T cell-derived, antigen-nonspecific helper factors that enable the B cells to proliferate, and, in some cases, mature to Ig secretion. In the present experiments, we show that anti-Ig can also be used as a model for major histocompatibility complex (MHC)-restricted, antigen-specific T-B cell collaboration. We used murine helper T cell lines and T cell hybridomas specific for a protein antigen, the F(ab')2 fragment of normal rabbit IgG. Small B cells are very efficient at presenting rabbit anti-IgM or rabbit anti-IgD to these rabbit Ig-specific T cell lines and hybridomas, and the responding (initially) small B cells, appear to be the only antigen-presenting cells required. Efficient presentation depends upon binding of rabbit antibody to mIg on the B cell surface. MHC-restricted recognition of rabbit Ig determinants on the B cell surface results in a polyclonal B cell response. This response is qualitatively different from the well-studied response to blastogenic concentrations of anti-Ig plus stable, T cell-derived helper factors, since it (a) requires 1,000-fold lower concentrations of anti-Ig, (b) involves helper T cell functions other than, or in addition to, the local production of the same stable helper factors, and (c) is largely MHC-restricted at the T-B cell level.

scholarly journals Isolation and immunological characterization of a major surface glycoprotein (gp54) preferentially expressed on certain human B cells.

1979 ◽  
Vol 149 (6) ◽  
pp. 1424-1437 ◽  
Author(s):  
C Y Wang ◽  
S M Fu ◽  
H G Kunkel
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
B Cell ◽  
B Lymphocytes ◽  
Cell Lines ◽  
Cytotoxicity Assay ◽  
Leukemic Cells ◽  
Immunofluorescent Staining ◽  
Single Individual

A major membrane glycoprotein with mol wt of approximately 54,000 has been isolated from membrane preparations of B-type lymphoid cell lines. Antiserum prepared against the isolated material specifically precipitated this glycoprotein from membranes labeled by surface radioiodination or by metabolic labeling. This antiserum was shown by complement-mediated cytotoxicity assay, membrane immunofluorescent staining, and by quantitative absorption analysis to react preferentially with certain B-lymphoblastoid cell lines, with a minor population of peripheral blood B lymphocytes, and a major population of tonsillar B lymphocytes. Certain B-cell leukemias also expressed the antigen, whereas others did not. Considerable variability was observed among positive B cells in the intensity of fluorescent staining even among the leukemic cells from a single individual. Although T cells, including T cells, were negative by direct immunofluorescent and cytotoxicity assay, evidence for low levels of the antigen on the cells of T cell lines was obtained. The whole specific antiserum and its F(ab')2 fragments stimulated B lymphocytes to proliferate. This proliferation did not produce differentiation to plasma cells and was T-cell independent. The monovalent Fab fragments had no effect. None of these preparations timulated T cells. The possibility that this antigen, termed gp54, may play some role in B-cell activation is discussed.

scholarly journals Antiproliferative effect of antilymphocyte globulins on B cells and B- cell lines

Blood ◽  
1992 ◽  
Vol 79 (8) ◽  
pp. 2164-2170
Author(s):  
N Bonnefoy-Berard ◽  
M Flacher ◽  
JP Revillard
Keyword(s):  
Cell Proliferation ◽  
T Cell ◽  
B Cells ◽  
B Cell ◽  
Cell Lines ◽  
Immunosuppressive Agents ◽  
Lymphoproliferative Disorders ◽  
Hla Dr ◽  
T Cell Lines ◽  
Vitro Effect

Antithymocyte and antilymphocyte globulins (ALG) are currently used as immunosuppressive agents in organ transplantation and for the treatment of acute graft-versus-host disease and aplastic anemia. Since any type of immunosuppressive treatment is known to carry the risk of developing B-cell lymphoproliferative disorders, we investigated the in vitro effect of ALG on human B-cell activation and proliferation. The data demonstrate that whatever the source of lymphocytes used for ALG preparation (thymocytes, thoracic duct lymphocytes, B- or T-cell lines), (1) ALG react with both B- and T-cell lines, and (2) ALG contain antibodies specific for B cells (eg, CD21) or common to T and B cells (eg anti-beta 2-microglobulin, anti-HLA-DR, CD18, CD11a) in addition to T-cell-specific antibodies. Unlike all other T-cell mitogens tested (Concanavalin A [Con A], Pokeweek mitogen [PWM], CD3 and CD2 antibodies), ALG do not trigger B-cell differentiation into immunoglobulin-secreting cells at concentrations which induce maximum T- cell proliferation. This effect could be attributed to a direct interaction of ALG with B lymphocytes as shown by the capacity of ALG to block the response of purified B cells to a variety of activators. Furthermore, all the ALG tested were shown to inhibit the proliferation of six of the seven Epstein-Barr virus (EBV)-transformed lymphoblastoid cell lines and six of the seven Burkitt's lymphoma cell lines studied. This selective B-cell antiproliferative property of ALG was not reproduced with CD11a, CD18, CD21, CD24, or anti-HLA-DR monoclonal antibodies (MoAbs). These results suggest that, although suppressing T- cell responses, ALG treatment may directly control B cell proliferation to some extent, in keeping with the relatively low risk of posttransplant lymphoproliferative disorders reported with ALG.

Splenic Macrophages Maintain the Anti-Platelet Autoimmune Response Via Uptake of Opsonized Platelets in Patients with Chronic ITP.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 221-221 ◽  
Author(s):  
Masataka Kuwana ◽  
Yutaka Kawakami ◽  
Yasuo Ikeda
Keyword(s):  
Monoclonal Antibody ◽  
T Cells ◽  
T Cell ◽  
B Cells ◽  
Cell Lines ◽  
Antibody Production ◽  
Tryptic Peptides ◽  
Splenic Macrophages ◽  
Hla Dr ◽  
T Cell Lines

Abstract ITP is an autoimmune disease mediated by autoantibodies to platelet membrane glycoproteins, such as GPIIb-IIIa. We recently identified CD4+ T cells reactive with GPIIb-IIIa in patients with chronic ITP, and these T cells are considered pathogenic because they help B cells produce antibodies that bind normal platelet surfaces in vitro. GPIIb-IIIa-reactive T cells respond to tryptic peptides of GPIIb-IIIa or recombinant GPIIb-IIIa fragments produced in bacteria, but not to native GPIIb-IIIa, indicating that the epitopes they recognized are ’cryptic’ determinants, generated at a subthreshold level by the processing of native GPIIb-IIIa under normal circumstances. We have found that activation of T cells and subsequent anti-platelet antibody production occur primarily in the spleen of ITP patients, but mechanisms that induce the processing and presentation of cryptic peptides of GPIIb-IIIa remains unknown. In this study, antigen-presenting cells (APCs) presenting the GPIIb-IIIa cryptic peptides was evaluated by their ability to induce a specific response of GPIIb-IIIa-reactive CD4+ T-cell lines generated from ITP patients undergoing splenectomy. All 6 T-cell lines used were HLA-DR-restricted Th0 cells with various antigenic specificity and 5 of them had helper activity. To identify splenic APCs responsible for presentation of the GPIIb-IIIa cryptic peptides, GPIIb-IIIa-reactive T-cell lines were cultured with freshly isolated autologous splenic APCs, including CD14+ macrophages, CD19+ B cells, or Lin−CD11c+ dendritic cells, in the presence or absence of GPIIb-IIIa tryptic peptides. All APCs induced a T-cell proliferation in response to the antigen. Interestingly, macrophages stimulated GPIIb-IIIa-reactive T-cell lines without any exogenous antigen, but B cells or dendritic cells did not. This response was blocked by anti-HLA-DR monoclonal antibody, indicating presentation of GPIIb-IIIa cryptic peptides by splenic macrophages in vivo in ITP patients. To further examine whether uptake of opsonized platelets by macrophages results in presentation of the GPIIb-IIIa cryptic peptides, GPIIb-IIIa-reactive T-cell lines were cultured with autologous macrophages, which were prepared by culturing peripheral blood monocytes with M-CSF, in the presence of platelets derived from ITP patients and healthy individuals. Cultured macrophages required preincubation of GPIIb-IIIa tryptic peptides to stimulate GPIIb-IIIa-reactive T-cell lines. As expected, cultured macrophages preincubated with autologous or allogeneic ITP platelets, but not with healthy platelets, were able to stimulate GPIIb-IIIa-reactive T-cell lines. A response of the T-cell line was also induced by macrophages carrying healthy platelets pre-treated with ITP platelet eluates. This response induced by macrophages carrying ITP platelets was completely inhibited by anti-FcγRI, but not by anti-FcγRII monoclonal antibody. Finally, GPIIb-IIIa-reactive T-cell lines failed to induce anti-GPIIb-IIIa antibody production in culture with autologous B cells and platelets, but anti-GPIIb-IIIa antibody production was observed when this culture was carried out on autologous macrophages. In summary, splenic macrophages are a source of the GPIIb-IIIa cryrptic peptides in ITP patients. It is likely that splenic macrophages that phagocytose opsonized platelets via FcγRI have the ability to efficiently concentrate small quantities of platelet antigens that were previously cryptic, and to maintain continuous production of pathogenic anti-platelet antibody.

scholarly journals Antiproliferative effect of antilymphocyte globulins on B cells and B- cell lines

Blood ◽  
1992 ◽  
Vol 79 (8) ◽  
pp. 2164-2170 ◽  
Author(s):  
N Bonnefoy-Berard ◽  
M Flacher ◽  
JP Revillard
Keyword(s):  
Cell Proliferation ◽  
T Cell ◽  
B Cells ◽  
B Cell ◽  
Cell Lines ◽  
Immunosuppressive Agents ◽  
Lymphoproliferative Disorders ◽  
Hla Dr ◽  
T Cell Lines ◽  
Vitro Effect

Abstract Antithymocyte and antilymphocyte globulins (ALG) are currently used as immunosuppressive agents in organ transplantation and for the treatment of acute graft-versus-host disease and aplastic anemia. Since any type of immunosuppressive treatment is known to carry the risk of developing B-cell lymphoproliferative disorders, we investigated the in vitro effect of ALG on human B-cell activation and proliferation. The data demonstrate that whatever the source of lymphocytes used for ALG preparation (thymocytes, thoracic duct lymphocytes, B- or T-cell lines), (1) ALG react with both B- and T-cell lines, and (2) ALG contain antibodies specific for B cells (eg, CD21) or common to T and B cells (eg anti-beta 2-microglobulin, anti-HLA-DR, CD18, CD11a) in addition to T-cell-specific antibodies. Unlike all other T-cell mitogens tested (Concanavalin A [Con A], Pokeweek mitogen [PWM], CD3 and CD2 antibodies), ALG do not trigger B-cell differentiation into immunoglobulin-secreting cells at concentrations which induce maximum T- cell proliferation. This effect could be attributed to a direct interaction of ALG with B lymphocytes as shown by the capacity of ALG to block the response of purified B cells to a variety of activators. Furthermore, all the ALG tested were shown to inhibit the proliferation of six of the seven Epstein-Barr virus (EBV)-transformed lymphoblastoid cell lines and six of the seven Burkitt's lymphoma cell lines studied. This selective B-cell antiproliferative property of ALG was not reproduced with CD11a, CD18, CD21, CD24, or anti-HLA-DR monoclonal antibodies (MoAbs). These results suggest that, although suppressing T- cell responses, ALG treatment may directly control B cell proliferation to some extent, in keeping with the relatively low risk of posttransplant lymphoproliferative disorders reported with ALG.

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