Modulation of T Lymphocyte Proliferation in Mice Infected with Schistosoma mansoni: VIP Suppresses Mitogen- and Antigen-Induced T Cell Proliferation Possibly by Inhibiting IL-2 Production

1993 ◽  
Vol 149 (1) ◽  
pp. 11-23 ◽  
Author(s):  
Ahmed Metwali ◽  
Arthur Blum ◽  
Ranjit Mathew ◽  
Matyas Sandor ◽  
Richard G. Lynch ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
T Cell ◽  
Schistosoma Mansoni ◽  
T Lymphocyte ◽  
Lymphocyte Proliferation ◽  
T Cell Proliferation ◽  
T Lymphocyte Proliferation

scholarly journals Surfactant protein A inhibits T cell proliferation via its collagen-like tail and a 210-kDa receptor

1998 ◽  
Vol 275 (4) ◽  
pp. L679-L686 ◽  
Author(s):  
Paul Borron ◽  
Francis X. McCormack ◽  
Baher M. Elhalwagi ◽  
Zissis C. Chroneos ◽  
James F. Lewis ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
T Cell ◽  
T Lymphocyte ◽  
Lymphocyte Proliferation ◽  
Pulmonary Surfactant ◽  
Protein A ◽  
T Cell Proliferation ◽  
T Lymphocyte Proliferation ◽  
Human T Lymphocyte

Investigation of possible mechanisms to describe the hyporesponsiveness of pulmonary leukocytes has led to the study of pulmonary surfactant and its constituents as immune suppressive agents. Pulmonary surfactant is a phospholipid-protein mixture that reduces surface tension in the lung and prevents collapse of the alveoli. The most abundant protein in this mixture is a hydrophilic molecule termed surfactant-associated protein A (SP-A). Previously, we showed that bovine (b) SP-A can inhibit human T lymphocyte proliferation and interleukin-2 production in vitro. Results presented in this investigation showed that different sources of human SP-A and bSP-A as well as recombinant rat SP-A inhibited human T lymphocyte proliferation in a dose-dependent manner. A structurally similar collagenous protein, C1q, did not block the in vitro inhibitory action of SP-A. The addition of large concentrations of mannan to SP-A-treated cultures also did not disrupt inhibition, suggesting that the effect is not mediated by the carbohydrate recognition domain of SP-A. Use of recombinant mutant SP-As revealed that a 36-amino acid Arg-Gly-Asp (RGD) motif-containing span of the collagen-like domain was responsible for the inhibition of T cell proliferation. A polyclonal antiserum directed against an SP-A receptor (SP-R210) completely blocked the inhibition of T cell proliferation by SP-A. These results emphasize a potential role for SP-A in dampening lymphocyte responses to exogenous stimuli. The data also provide further support for the concept that SP-A maintains a balance between the clearance of inhaled pathogens and protection against collateral immune-mediated damage.

scholarly journals ILA, a member of the human nerve growth factor/tumor necrosis factor receptor family, regulates T-lymphocyte proliferation and survival

Blood ◽  
1996 ◽  
Vol 87 (7) ◽  
pp. 2839-2845 ◽  
Author(s):  
H Schwarz ◽  
FJ Blanco ◽  
J von Kempis ◽  
J Valbracht ◽  
M Lotz
Keyword(s):  
Cell Proliferation ◽  
T Cell ◽  
T Lymphocyte ◽  
Cho Cells ◽  
Lymphocyte Proliferation ◽  
Tumor Necrosis Factor Receptor ◽  
T Cell Proliferation ◽  
T Lymphocyte Proliferation ◽  
Human Nerve ◽  
Necrosis Factor

ILA, a gene induced by lymphocyte activation, is a member of the human nerve growth factor tumor necrosis factor receptor family and the human homologue of murine 4–1BB. The present study analyzed the role of ILA in the regulation of human peripheral blood T-lymphocyte function. Antibodies raised against different fusion proteins recognized ILA on activated lymphocytes. These antibodies significantly increased anti- CD3--induced T-lymphocyte proliferation. When anti-CD3--stimulated cells were incubated on ILA-expressing CHO cells, proliferation was inhibited. CHO cells transfected with a control construct and not expressing ILA did not reduce T-cell proliferation. A purified fusion protein containing the extracellular domain of ILA and the constant domain of human IgG (ILA-IgG) also inhibited lymphocyte proliferation. Results obtained by 3H-thymidine incorporation were confirmed by cell cycle analysis that showed a decrease in the number of lymphocytes in S phase. Lymphocyte morphology in cultures with ILA-expressing CHO cells was suggestive of apoptosis. Flow cytometry on propidium iodide-stained cells showed a time-dependent increase in the number of hypodiploid apoptotic cells when lymphocytes were cultured on ILA-expressing CHO cells. Internucleosomal DNA cleavage was seen in these cultures, but not in the presence of ILA-negative CHO cells. Studies on the mechanism by which ILA regulates T-cell function showed that ILA-IgG inhibited anti-CD3-induced T-cell proliferation when presented in immobilized but not in soluble form. These results suggest that ILA may act by cross- linking its ligand and thereby inhibit T-cell proliferation.

scholarly journals T-cell mediated autoimmunity to the insulinoma-associated protein 2 islet tyrosine phosphatase in type 1 diabetes mellitus

1999 ◽  
pp. 272-278 ◽  
Author(s):  
F Dotta ◽  
S Dionisi ◽  
V Viglietta ◽  
C Tiberti ◽  
MC Matteoli ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Type 1 Diabetes ◽  
T Cell ◽  
T Lymphocyte ◽  
Tyrosine Phosphatase ◽  
T Cell Response ◽  
T Cell Proliferation ◽  
Diabetic Patients ◽  
Hla Dr

The target molecules of the T-cell response in type 1 diabetes, despite their pathogenic importance, remain largely uncharacterized, especially in humans. Interestingly, molecules such as insulin and glutamic acid decarboxylase (GAD) have been shown to be a target not only of autoantibodies, but also of autoreactive T-lymphocytes both in man and in the non-obese diabetic (NOD) mouse. In the present study we aimed to determine the existence of a specific T-cell response towards the insulinoma-associated protein 2 (IA-2) islet tyrosine phosphatase, a recently identified autoantigen which is the target of autoantibodies strongly associated with diabetes development. Human recombinant IA-2 produced in Escherichia coli, was tested for its reactivity with peripheral blood lymphocytes obtained from 16 newly diagnosed type 1 diabetic patients and from 25 normal controls, 15 of whom were HLA-DR-matched. A T-cell proliferation assay was performed in triplicate employing freshly isolated cells in the absence or in the presence of the antigen to be tested (at two different concentrations: 2 microg/ml and 10 microg/ml). A specific T-cell proliferation (defined as a stimulation index (S.I.) >/=3) was observed against IA-2 used at a concentration of 10 microg/ml (but not of 2 microg/ml) in 8/16 diabetic patients, in 1/15 HLA-DR-matched control subjects (P<0.01 by Fisher exact test) and in 0/10 of the remaining normal individuals. A statistically significant difference (P<0.003 by Mann-Whitney U test) was also observed in S.I. values between patients (3.1+/-1.4) and HLA-DR-matched controls (1.7+/-0.54) employing IA-2 at a concentration of 10 microg/ml. However, when IA-2 was used at a concentration of 2 microg/ml, the difference in S. I. between patients (1.65+/-0.8) and controls (1.0+/-0.3) did not reach statistical significance. In conclusion, these data show the presence of a specific, dose-dependent T-lymphocyte response against the IA-2 islet tyrosine phosphatase at the onset of type 1 diabetes. Consequently, this molecule appears to be a target not only at the B-lymphocyte but also at the T-lymphocyte level, reinforcing the potential pathogenic role of this autoantigen in the islet destructive process.

RecombinantPseudomonasexoenzyme S and exoenzyme S fromPseudomonas aeruginosaDG1 share the ability to stimulate T lymphocyte proliferation

1999 ◽  
Vol 45 (7) ◽  
pp. 607-611 ◽  
Author(s):  
Tony F Bruno ◽  
Donald E Woods ◽  
Douglas G Storey ◽  
Christopher H Mody
Keyword(s):  
Pseudomonas Aeruginosa ◽  
T Cell ◽  
T Cell Activation ◽  
T Lymphocyte ◽  
Lymphocyte Proliferation ◽  
Cell Activation ◽  
Lymphocyte Activation ◽  
Activation Markers ◽  
Exoenzyme S ◽  
T Lymphocyte Proliferation

Exoenzyme S from P. aeruginosa DG1 and recombinant exoenzyme S derived from strain 388 have distinct characteristics, which has led to a controversy about their homology and their pathophysiologic consequences. We have been investigating the ability of exoenzyme S to activate T lymphocytes, and therefore performed studies to determine whether exoenzyme S from P. aeruginosa DG1 and recombinant exoenzyme S derived from strain 388 and expressed in Pseudomonas aeruginosa PA103 or in E. coli BL21(DE3), could induce T lymphocyte activation and proliferation. Both preparations were able to activate T cells and induce lymphocyte proliferation at similar levels as measured by flow cytometry of surface-activation markers and DNA synthesis, respectively. Further, a monoclonal antibody raised against exoenzyme S from strain DG1 partially neutralized T cell activation induced by recombinant exoenzyme S and bound to it in an immunoblot suggesting that the epitope responsible for T cell activation is shared by exoenzyme S from strain DG1 and recombinant exoenzyme S. These data suggest that the two different preparations of exoenzyme S, despite biochemical differences, share the characteristic that is responsible for T lymphocyte activation.Key words: exoenzyme S, Pseudomonas aeruginosa, T lymphocyte, cystic fibrosis.

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