1
|
Rosado M, Diamanti AP, Cascioli S, Ceccarelli S, Caporuscio S, D'Amelio R, Carsetti R, Lagana B. Hyper-IgM, Neutropenia, Mild Infections and Low Response to Polyclonal Stimulation: Hyper-IgM Syndrome or Common Variable Immunodeficiency? Int J Immunopathol Pharmacol 2011; 24:983-91. [DOI: 10.1177/039463201102400416] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
A young woman presenting respiratory infections, polyarthritis, severe neutropenia, and increased serum IgM was treated with Intravenous Immunoglobulin (IVIG) with good clinical and laboratory outcome followed by a loss of efficacy. The increased serum IgM associated to recurrent infections and autoimmune manifestations suggested the diagnosis of a hyper–IgM syndrome (HIGMs). The frequency of peripheral T cells, the expression of CD40 on the patients' B cells and CD40L on T cells and the Activation-Induced cytidine Deaminase (AID) and Uracyl-DNA glycosylase (UNG) at mRNA level was comparable to controls. In contrast, the frequency of B cells was one half of the healthy control and all cells showed an atypical phenotype. Although AID and UNG were normal, class-switch recombination was not very efficient because circulating switched memory were reduced and, once stimulated with CpG, generated less antibody-secreting cells than controls. An increase in serum B Lymphocytes stimulator (BLyS) was also found. The patient presented a peculiar clinical and immunological phenotype fitting for many aspects of both HIGM4 and Common Variable Immunodeficiency (CVID). These findings underline the need to better explore the complex link between these two diseases.
Collapse
Affiliation(s)
- M.M. Rosado
- Research Center, Ospedale Pediatrico Bambino Gesù, Laboratory of Flow-cytometry and B cell development, IRCSS, Rome
| | - A. Picchianti Diamanti
- “Sapienza” University of Rome, II School of Medicine, S. Andrea University Hospital, Rome, Italy
| | - S. Cascioli
- Research Center, Ospedale Pediatrico Bambino Gesù, Laboratory of Flow-cytometry and B cell development, IRCSS, Rome
| | - S. Ceccarelli
- Research Center, Ospedale Pediatrico Bambino Gesù, Laboratory of Flow-cytometry and B cell development, IRCSS, Rome
| | - S. Caporuscio
- “Sapienza” University of Rome, II School of Medicine, S. Andrea University Hospital, Rome, Italy
| | - R. D'Amelio
- “Sapienza” University of Rome, II School of Medicine, S. Andrea University Hospital, Rome, Italy
| | - R. Carsetti
- Research Center, Ospedale Pediatrico Bambino Gesù, Laboratory of Flow-cytometry and B cell development, IRCSS, Rome
| | - B. Lagana
- “Sapienza” University of Rome, II School of Medicine, S. Andrea University Hospital, Rome, Italy
| |
Collapse
|
2
|
Chalubinski M, Grzegorczyk J, Kowalski ML. Glucocorticoid-induced immunoglobulin E synthesis by peripheral blood mononuclear cells from allergic and nonallergic subjects. Ann Allergy Asthma Immunol 2011; 107:251-7. [PMID: 21875545 DOI: 10.1016/j.anai.2011.05.028] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2011] [Revised: 05/24/2011] [Accepted: 05/31/2011] [Indexed: 11/28/2022]
Abstract
BACKGROUND Glucocorticoids (GCS) have been shown to induce IgE synthesis in human peripheral blood mononuclear cells (PBMCs) and purified B cells in vitro. However, the differences in immunoglobulin E (IgE) response to GCS between allergic and non-allergic individuals and the mechanism this interaction have not been elucidated. OBJECTIVE We aimed to compare the effect of GCS (budesonide) on interleukin (IL)-4-driven IgE production in vitro in allergic and non allergic subjects and assess the engagement of intracellular mechanisms. METHODS The study included 22 patients with allergic asthma and/or allergic rhinitis and 24 healthy volunteers. PBMCs were cultured for 11 days with IL-4 and budesonide and IgE concentrations in supernatants were assessed by immunoassays. T and B cell markers were assessed by flow cytometry. RESULTS Budesonide enhanced IgE synthesis to higher extent in healthy donors than in allergic patients (mean increase of 16.5 vs 6.3 kU/L, P< .05 respectively) acting through glucocorticoid receptor. Budesonide significantly increased lymhoplasmocytoid cells percentage in both media-controlled (2.5-fold increase) and IL-4-stimulated PBMCs (2-fold increase). Added to IL-4 budesonide decreased the percentage of both T cells and CD40L(+) T cells, but strongly increased the percentage of B cells. Protein tyrosine kinase (PTK) inhibitor decreased, but NF-κB and protein kinase A (PKA) inhibitors expressed modulatory effects on budesonide-induced IgE synthesis. CONCLUSIONS Budesonide-induced IgE generation in PBMCs differs in magnitude and seems to involve different mechanisms in atopic and non-atopic subjects.
Collapse
Affiliation(s)
- Maciej Chalubinski
- Department of Immunology, Rheumatology and Allergy, Faculty of Medicine, Medical University of Lodz, Lodz, Poland
| | | | | |
Collapse
|
3
|
Jabara HH, Angelini F, Brodeur SR, Geha RS. Ligation of CD46 to CD40 inhibits CD40 signaling in B cells. Int Immunol 2011; 23:215-21. [PMID: 21393637 DOI: 10.1093/intimm/dxq474] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
CD40 induces B cells to switch to IgE in the presence of IL-4 and up-regulates their expression of the low-affinity receptor for IgE, CD23, which promotes the immune response to allergen complexed with IgE antibody. CD40 binds to CD40L and to the C4b-binding protein (C4BP) using distinct sites. CD46 is a receptor for the product of activated complement C4b. Some microbial antigens bind both C4BP and CD46, potentially bridging CD40 to CD46. In addition, immune complexes containing both C4b and C4BP may cross-link CD40 to CD46. We demonstrate that cross-linking CD46 to CD40 on B cells inhibits CD40-mediated up-regulation of surface CD23 expression and induction of IL-4-dependent IgE isotype switching. This was associated with inhibition of induction of Cε germ line transcripts and of activation-induced cytidine deaminase mRNA expression. Furthermore, co-ligation of CD46 to CD40 blocked CD40-mediated NF-κB activation. These observations suggest that complement components may play an important role in regulating CD40 activation of B cells and the allergic response.
Collapse
Affiliation(s)
- Haifa H Jabara
- Division of Immunology, Children's Hospital, Boston, MA 02115, USA
| | | | | | | |
Collapse
|
4
|
Abstract
Asthma is a chronic inflammatory disease of the bronchial airways. Current research in humans and animals suggests that T-helper type 2 (Th2) cells and the cytokines they elaborate cause many of the pathophysiologic abnormalities characteristic of the disease. We review the evidence implicating Th2 cells in asthma and discuss the cellular and molecular mechanisms that control Th2 cell differentiation in the respiratory tract. Based on the steps in Th cell development, we discuss how traditional therapies can modulate Th2 cell function. Furthermore, we explore newer immunomodulatory strategies to inhibit Th2 cell effects, including therapies that may block Th2 cell differentiation, neutralize cytokines, and redirect immune responses towards Th1 and away from Th2.
Collapse
Affiliation(s)
- L Cohn
- Section of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Yale University School of Medicine, 333 Cedar Street, PO Box 208057, 06520-8057, New Haven, CT, USA.
| | | |
Collapse
|
5
|
Sakata N, Hamelmann E, Siadak AW, Terada N, Gerwins P, Aruffo A, Johnson GL, Gelfand EW. Differential regulation of CD40-mediated human B cell responses by antibodies directed against different CD40 epitopes. Cell Immunol 2000; 201:109-23. [PMID: 10831320 DOI: 10.1006/cimm.2000.1645] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Ligation of CD40 using anti-CD40 or soluble CD40-ligand activates numerous intracellular kinases which transduce signals to the nucleus. The nature whereby these signaling events are coupled to distal functional events in B cells is poorly understood. In this study, using anti-CD40 monoclonal antibodies which recognize different epitopes on CD40, we compare the ability to activate the stress-activated protein kinases (SAPK) such as c-Jun NH(2) terminal kinase and p38 in human B cells with CD40 function. Activation of the SAPK pathway correlated with levels of activation of Rel/NF-kappaB transcription factors, but did not appear to be associated with rescue from anti-IgM induced apoptosis by suppressing caspase (CPP32) activity. Somewhat surprisingly, in the presence of IL-4, those antibodies to CD40 which failed to activate SAPK were most active in IgE production. IgE production was augmented in the presence of wortmannin. These studies suggest that rescue from apoptosis and IgE production mediated via CD40 may be independent of SAPK activation, induction of Rel/NF-kappaB, or suppression of CPP32 and that IgE production is, at least in part, regulated by signaling pathways that are dependent on phosphatidylinositol 3-kinase.
Collapse
Affiliation(s)
- N Sakata
- Division of Basic Sciences, National Jewish Medical and Research Center, Denver, CO 80206, USA
| | | | | | | | | | | | | | | |
Collapse
|
6
|
Abstract
IgE antibody plays an important role in allergic diseases. IgE synthesis by B cells requires two signals. The first signal is delivered by the cytokines IL-4 or IL-13, which target the Cepsilon gene for switch recombination. The second signal is delivered by interaction of the B cell surface antigen CD40 with its ligand (CD40L) expressed on activated T cells. This activates deletional switch recombination. We review the molecular mechanisms of IL-4 and CD40 signaling that lead to IgE isotype switching and discuss the implications for intervening to abort or suppress the IgE antibody response.
Collapse
Affiliation(s)
- L B Bacharier
- Division of Immunology, Children's Hospital, Department of Pediatrics, Harvard Medical School, Boston, MA 02115, USA
| | | |
Collapse
|
7
|
Morio T, Hanissian SH, Bacharier LB, Teraoka H, Nonoyama S, Seki M, Kondo J, Nakano H, Lee SK, Geha RS, Yata J. Ku in the cytoplasm associates with CD40 in human B cells and translocates into the nucleus following incubation with IL-4 and anti-CD40 mAb. Immunity 1999; 11:339-48. [PMID: 10514012 DOI: 10.1016/s1074-7613(00)80109-0] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
CD40 plays a critical role in survival, growth, differentiation, and class switching of B lymphocytes. Although Ku is required for immunoglobulin class switching, how CD40 signal transduction is coupled to Ku is still unknown. Here, we show that CD40 directly interacts with Ku through the membrane-proximal region of cytoplasmic CD40. Ku was confined to the cytoplasm in human primary B cells, and the engagement of CD40 on the B cells cultured in the presence of IL-4 resulted in the dissociation of Ku from CD40, translocation of Ku into the nucleus, and increase in the activity of DNA-dependent protein kinase. These findings indicate that Ku is involved in the CD40 signal transduction pathway and may play an important role in the CD40-mediated events.
Collapse
Affiliation(s)
- T Morio
- Department of Pediatrics, Tokyo Medical and Dental University School of Medicine, Japan.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
8
|
Jeppson JD, Patel HR, Sakata N, Domenico J, Terada N, Gelfand EW. Requirement for Dual Signals by Anti-CD40 and IL-4 for the Induction of Nuclear Factor-κB, IL-6, and IgE in Human B Lymphocytes. THE JOURNAL OF IMMUNOLOGY 1998. [DOI: 10.4049/jimmunol.161.4.1738] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
Stimulation of human peripheral B cells via the CD40 receptor and IL-4R together lead to IgE synthesis and secretion, but the intracellular signaling mechanisms by which these signals lead to IgE production are unclear. Roles for the transcription factor NF-κB and IL-6 have been postulated in the induction of IgE synthesis by IL-4/CD40. We found that neither anti-CD40 Ab nor IL-4 alone was able to induce significant proliferation of human B cells. However, the combination of anti-CD40 and IL-4 was a potent inducer of B cell proliferation in addition to IgE production from purified human B cells. Furthermore, IL-4 and anti-CD40 synergized for the production of IL-6. While neither IL-4 alone nor anti-CD40 alone was able to induce significant NF-κB DNA binding activity, the combination of IL-4 and anti-CD40 induced a strong activation of NF-κB, a transcription factor that regulates IL-6 production. These data indicate that both IL-4 and anti-CD40 are required to induce NF-κB activation and IL-6 transcription and production, and implicate these events in a signaling pathway augmenting IgE production in human B lymphocytes.
Collapse
Affiliation(s)
- John D. Jeppson
- Division of Basic Sciences, Department of Pediatrics, National Jewish Medical and Research Center, Denver, CO 80206
| | - Hiren R. Patel
- Division of Basic Sciences, Department of Pediatrics, National Jewish Medical and Research Center, Denver, CO 80206
| | - Naoki Sakata
- Division of Basic Sciences, Department of Pediatrics, National Jewish Medical and Research Center, Denver, CO 80206
| | - Joanne Domenico
- Division of Basic Sciences, Department of Pediatrics, National Jewish Medical and Research Center, Denver, CO 80206
| | - Naohiro Terada
- Division of Basic Sciences, Department of Pediatrics, National Jewish Medical and Research Center, Denver, CO 80206
| | - Erwin W. Gelfand
- Division of Basic Sciences, Department of Pediatrics, National Jewish Medical and Research Center, Denver, CO 80206
| |
Collapse
|
9
|
|
10
|
Kurup VP, Grunig G, Knutsen AP, Murali PS. Cytokines in allergic bronchopulmonary aspergillosis. RESEARCH IN IMMUNOLOGY 1998; 149:466-77; discussion 515-6. [PMID: 9720964 DOI: 10.1016/s0923-2494(98)80770-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- V P Kurup
- Allergy-Immunology Division, Medical College of Wisconsin and VA Medical Center, Milwaukee 53295, USA
| | | | | | | |
Collapse
|
11
|
Loh RK, Jabara HH, Geha RS. Mechanisms of inhibition of IgE synthesis by nedocromil sodium: nedocromil sodium inhibits deletional switch recombination in human B cells. J Allergy Clin Immunol 1996; 97:1141-50. [PMID: 8626993 DOI: 10.1016/s0091-6749(96)70269-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
IgE synthesis requires IL-4 and a T cell-B cell interaction that involves the B-cell antigen CD40 and its ligand expressed on activated T cells. Nedocromil sodium (NS), an effective prophylactic agent in asthma, inhibits IgE synthesis by human B cells. In this report we examined the mechanisms of this inhibition. NS targeted the B cells because it inhibited IgE synthesis induced by anti-CD40 and IL-4 in highly purified B cells (greater than 98% CD19+). NS had no effect on the induction of epsilon-germline transcripts by IL-4 but strongly inhibited CD40-mediated S mu --> S epsilon deletional switch recombination. The effect of NS was not specific for CD40 because it inhibited IgE synthesis in B cells stimulated with hydrocortisone plus IL-4. Moreover, the effect of NS was not specific for IgE because it inhibited CD40/IL-4-driven IgG4 synthesis by B cells sorted for lack of surface expression of IgG4. NS caused only modest inhibition of spontaneous IgE synthesis by B cells from patients with hyper-IgE syndrome, suggesting that it has little effect on B cells that have already undergone isotype switching. These results strongly suggest that NS inhibits IgE isotype switching by inhibiting deletional switch recombination and that NS has a novel potential mechanism for the prevention of asthma and other allergic diseases.
Collapse
Affiliation(s)
- R K Loh
- Children's Hospital/Department of Pediatrics, Harvard Medical School, Boston, MA 02115, USA
| | | | | |
Collapse
|
12
|
Brodie C, Oshiba A, Renz H, Bradley K, Gelfand EW. Nerve growth-factor and anti-CD40 provide opposite signals for the production of IgE in interleukin-4-treated lymphocytes. Eur J Immunol 1996; 26:171-8. [PMID: 8566063 DOI: 10.1002/eji.1830260127] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Nerve growth factor (NGF) is a well-known neurotrophic factor acting on both the peripheral and the central nervous systems. In addition, it has been shown to play a role in the function of the immune system through specific receptors. Both high-affinity and low-affinity NGF receptors (NGFR) are expressed on human B lymphocytes. The low-affinity NGFR has been shown to have structural homology with another specific B cell surface molecule, CD40, which plays an important role in IgE production. In view of the structural similarities of the p75 NGFR and CD40 we examined whether NGF may also be involved in the regulation of IgE production. We found that NGF and anti-CD40 exerted opposite effects on the induction of IgE by IL-4 in peripheral blood mononuclear cells. NGF inhibited the induction of IgE by IL-4 and this inhibition was not mediated through blocking of the induction of CD23 nor through inhibition of IL-4R expression. The inhibition of IL-4-dependent IgE production was observed on surface (s)IgE+ and sIgE-/sIgM+ B lymphocytes. Anti-CD40 on the other hand, exerted an enhancing effect on IgE production and its addition to IL-4 provided a signal that was resistant to the inhibitory effect of NGF. Antagonistic effects of NGF and IL-4 were also observed for other Ig isotypes since IL-4 prevented the increase in IgA and IgM production induced by NGF. These data indicate that although NGFR and CD40 belong to the same receptor superfamily and exert similar proliferative effects on B lymphocytes, they interact differently with IL-4 in the regulation of IgE production.
Collapse
Affiliation(s)
- C Brodie
- Department of Pediatrics, National Jewish Center for Immunology and Respiratory Medicine, Denver, CO 80206, USA
| | | | | | | | | |
Collapse
|
13
|
Harun RB, Markham AF, Morrison JF. Identification of differentially expressed genes in CD19+ve B lymphocytes in allergic asthma. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1996; 409:375-80. [PMID: 9095268 DOI: 10.1007/978-1-4615-5855-2_53] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- R B Harun
- Molecular Medicine Unit, St James's University Hospital, Leeds, United Kingdom
| | | | | |
Collapse
|
14
|
Morio T, Hanissian S, Geha RS. Characterization of a 23-kDa protein associated with CD40. Proc Natl Acad Sci U S A 1995; 92:11633-6. [PMID: 8524818 PMCID: PMC40456 DOI: 10.1073/pnas.92.25.11633] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
CD40 is a 45-kDa glycoprotein member of the tumor necrosis factor receptor (TNFR) family expressed on B cells, thymic epithelial cells, dendritic cells, and some carcinoma cells. The unique capacity of CD40 to trigger immunoglobulin isotype switching is dependent on the activation of protein-tyrosine kinases, yet CD40 possesses no kinase domain and no known consensus sequences for binding to protein-tyrosine kinases. Recently, an intracellular protein (CD40bp/LAP-1/CRAF-1) which belongs to the family of TNFR-associated proteins was reported to associate with CD40. We describe a 23-kDa cell surface protein (p23) which is specifically associated with CD40 on B cells and on urinary bladder transitional carcinoma cells. Protein microsequencing revealed that p23 shows no homology to any known protein. A rabbit antibody raised against a peptide derived from p23 recognized a 23-kDa protein in CD40 immunoprecipitates. In contrast to CD40bp/LAP-1/CRAF-1, p23 was not associated with TNFR p80 (CD120b). These findings suggest that p23 is a novel member of the CD40 receptor complex.
Collapse
Affiliation(s)
- T Morio
- Division of Immunology, Children's Hospital, Boston, MA, USA
| | | | | |
Collapse
|
15
|
Ramesh N, Morio T, Fuleihan R, Worm M, Horner A, Tsitsikov E, Castigli E, Geha RS. CD40-CD40 ligand (CD40L) interactions and X-linked hyperIgM syndrome (HIGMX-1). CLINICAL IMMUNOLOGY AND IMMUNOPATHOLOGY 1995; 76:S208-13. [PMID: 7554470 DOI: 10.1016/s0090-1229(95)90252-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Interactions between the B cell surface antigen CD40 and its ligand (CD40L) expressed on activated T cells play a critical role in isotype switching. This is illustrated by failure of isotype switching in patients with X-linked hyperIgM syndrome in whom the CD40L gene is mutated and by failure of isotype switching of CD40-deficient mice in response to T-cell-dependent antigens. We review these findings and discuss the signaling mechanisms of CD40 and the developmental control and transcriptional regulation of CD40L expression.
Collapse
Affiliation(s)
- N Ramesh
- Division of Immunology, Children's Hospital, Boston, Massachusetts 02115, USA
| | | | | | | | | | | | | | | |
Collapse
|
16
|
Worm M, Geha RS. CD40-mediated lymphotoxin alpha expression in human B cells is tyrosine kinase dependent. Eur J Immunol 1995; 25:2438-44. [PMID: 7589108 DOI: 10.1002/eji.1830250905] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The cytokine lymphotoxin (LT)alpha is known to play a role in B cell activation. As the engagement of the B cell antigen CD40 is known to lead to B cell proliferation and differentiation, we studied LT alpha expression in human B cells after CD40 ligation. We demonstrate that anti-CD40 monoclonal antibody (mAb) induces strong LT alpha mRNA and surface-expression in human tonsil B cells. Induction of LT alpha mRNA and surface expression by CD40 ligation is inhibited by the protein tyrosine kinase (PTK) inhibitors herbimycin and genistein in a dose-dependent manner. The protein kinase C (PKC)-specific inhibitors sphingosine and bis-indolylmaleimide caused negligible inhibition of anti-CD40-induced LT alpha mRNA and surface expression. No inhibition is observed with the protein kinase (PKA) inhibitors H89 and HA1004. Cross-linking of the transmembrane phosphatase CD45 to CD40 by using goat-anti-mouse F(ab')2 fragments strongly inhibits CD40-mediated LT alpha expression in human B cells, confirming the role of PTK activation in CD40-mediated induction of LT alpha expression. Inhibitors of the serine/threonine protein phosphatases PP1 and PP2A, okadaic acid and calyculin induce LT alpha mRNA expression. In contrast, cyclosporin A, an inhibitor of the serine/threonine phosphatase calcineurin has no effect on anti-CD40-induced LT alpha expression. These results suggest that induction of LT alpha expression in B cells following engagement of CD40 involves activation of protein tyrosine kinases.
Collapse
Affiliation(s)
- M Worm
- Children's Hospital/Department of Pediatrics, Harvard Medical School, Boston, MA 02115, USA
| | | |
Collapse
|
17
|
Fuleihan R, Ramesh N, Geha RS. X-linked agammaglobulinemia and immunoglobulin deficiency with normal or elevated IgM: immunodeficiencies of B cell development and differentiation. Adv Immunol 1995; 60:37-56. [PMID: 8607374 DOI: 10.1016/s0065-2776(08)60583-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- R Fuleihan
- Division of Immunology, Children's Hospital, Boston, Massachusetts 02115, USA
| | | | | |
Collapse
|