| 1. |
|
|
| 2. |
|
|
| 3. |
- Anderson, Per, et al.
(författare)
-
Differential activation of signal transducer and activator of transcription (STAT)3 and STAT5 and induction of suppressors of cytokine signalling in T(h)1 and T(h)2 cells
- 2003
-
Ingår i: International Immunology. - : Oxford University Press (OUP). - 1460-2377. ; 15:11, s. 1309-1317
-
Tidskriftsartikel (refereegranskat)abstract
- Cytokines direct the differentiation of naive CD4(+) T cells into either IFN-gamma-producing T(h)1 cells or IL-4-producing T(h)2 cells. In this study, we analyzed the activation of signal transducer and activator of transcription (STAT)1, STAT3 and STAT5 (together with STAT4 and STAT6), and the expression of the recently identified suppressor of cytokine signalling (SOCS) proteins, in differentiated T(h)1 and T(h)2 cells, both before and after re-stimulation with anti-CD3 and anti-CD28. In addition to the polarized activation of STAT4 in T(h)1 cells and STAT6 in T(h)2 cells, we found that STAT3 and STAT5 are selectively activated in T(h)1 cells after differentiation. This activation of STAT3 and STAT5 was maintained after TCR re-stimulation. The selective activation of STAT3 and STAT5 in T(h)1 cells was associated with differential induction of SOCS molecules. After restimulation, SOCS1 expression was significantly increased in T(h)2 cells, but not in T(h)1 and nonpolarized 'T-h' cells. Additionally, the level of CIS was higher in T(h)2 cells compared with T(h)1 and T-h cells. In contrast, the expression of SOCS3 was higher in T(h)1 cells. The differential induction of SOCS proteins was paralleled by the differential expression of cytokines in re-stimulated T(h)1 and T(h)2 cells (IFN-gamma and IL-4/IL-13 respectively). Our results suggests that STAT3 and STAT5, possibly regulated by the SOCS proteins, may play a role in the differentiation of T-h cells, and in the maintenance of the T(h)1 and T(h)2 phenotype.
|
|
| 4. |
- Andersson, Mattias K., et al.
(författare)
-
The extended substrate cleavage specificity of the human mast cell chymase reveals a serine protease with well-defined substrate recognition profile
- 2009
-
Ingår i: International Immunology. - : Oxford University Press (OUP). - 0953-8178 .- 1460-2377. ; 21:1, s. 95-104
-
Tidskriftsartikel (refereegranskat)abstract
- The human chymase (HC) is a major granule constituent of mast cells (MCs) residing in the connective tissue and the sub-mucosa. Although many potential substrates have been described for this important MC enzyme, its full range of in vivo substrates has most likely not yet been identified. A major step toward a better understanding of the function of the HC is therefore to determine its extended cleavage specificity. Using a phage-displayed random nonapeptide library, we show that the HC has a rather stringent substrate recognition profile. Only aromatic amino acids (aa) are accepted in position P1, with a strong preference for Tyr and Phe over Trp. Aliphatic aa are preferred in positions P2 to P4 N-terminal of the cleaved bond. In the P1' position C-terminal of the cleaved bond, Ser is clearly over-represented and acidic aa Asp and Glu are strongly preferred in the P2' position. In P3', the small aliphatic aa Ala, Val and Gly were frequently observed. The consensus sequence, from P4 to P3': Gly/Leu/Val-Val/Ala/Leu-Ala/Val/Leu-Tyr/Phe-Ser-Asp/Glu-Ala/Val/Gly, provides an instrument for the identification of novel in vivo substrates for the HC. Interestingly, a very similar cleavage specificity was recently reported for the major chymase in mouse connective tissue mast cells (CTMCs), the beta-chymase mouse mast cell protease-4, suggesting functional homology between these two enzymes. This indicates that a rather stringent chymotryptic substrate recognition profile has been evolutionary conserved for the dominant CTMC chymase in mammals.
|
|
| 5. |
|
|
| 6. |
|
|
| 7. |
- Cai, Yan, et al.
(författare)
-
Infliximab alleviates inflammation and ex vivo airway hyperreactivity in asthmatic E3 rats
- 2011
-
Ingår i: International Immunology. - : Oxford University Press (OUP). - 1460-2377 .- 0953-8178. ; 23:7, s. 443-451
-
Tidskriftsartikel (refereegranskat)abstract
- Tumor necrosis factor-alpha (TNF-alpha) has been implicated in the pathogenesis of asthma, and neutralization of TNF-alpha is an effective therapy for inflammatory diseases. The present study tested the idea that a TNF-alpha antibody, infliximab, may be useful in the management of asthma. E3 rats were immunized with ovalbumin (OVA)/alum and received infliximab intra-peritoneally. Two weeks later, OVA-PBS was instilled intranasally daily for 7 days. Bronchoalveolar lavage fluids (BALFs), serum and lung homogenates were collected for analysis of cells and inflammatory mediators. Contractile responses of lobar-bronchus segments to agonists were functionally tested. Pulmonary tissues were investigated using histological examination. The results showed that the sensitized 'model E3 rats' exhibited an increase in the total amount of inflammatory cells, primarily eosinophils, in BALF and pulmonary tissue, as well as epithelial damage. Serum levels of IgE increased and so did the levels of nitric oxide, inducible nitric oxide synthase, TNF-alpha and IL-4, IL-5 and IL-13 in lung homogenate and serum. Furthermore, the contractile responses in bronchi induced by endothelin-1, sarafotoxin 6c and bradykinin increased and isoprenaline-induced relaxations decreased. All these changes induced by the sensitization procedure were reduced by the infliximab treatment. The results suggest that infliximab prevents the development of local airway inflammation and antagonizes changes of the bronchial smooth muscle receptor phenotype, thereby blocking the development of airway smooth muscle hyperreactivity of asthmatic rats.
|
|
| 8. |
- Chen, S, et al.
(författare)
-
Functional association of cytokine-induced SH2 protein and protein kinase C in activated T cells
- 2003
-
Ingår i: International Immunology. - : Oxford University Press (OUP). - 1460-2377. ; 15:3, s. 403-409
-
Tidskriftsartikel (refereegranskat)abstract
- TCR signaling is mediated by intracellular signaling molecules and nuclear transcription factors, which are tightly regulated by interaction with regulatory proteins such as Grb2 and SLAP. We reported recently that TCR stimulation induces the expression of cytokine-induced SH2 protein (CIS). The expression of CIS promotes TCR-mediated activation. We have now found specific interactions between CIS and activated protein kinase C (PKC) alpha, beta and theta in TCR-stimulated T cells. CIS was shown by in vitro kinase assay to associate with activated PKC. In CIS-expressing T cells isolated from CIS-transgenic mice, the amount of activated PKC associated with CIS was found to increase following TCR stimulation. By immunohistochemical analysis, CIS was also found to co-localize with PKCtheta at the plasma membrane of activated T cells. In addition to the interaction and intracellular co-localization of the CIS and PKC, an increase in the activation of AP-1 and NF-kappaB was noted in CIS-expressing T cells, after stimulation by either anti-CD3/CD28 or phorbol myristate acetate + ionomycin. These results suggest that CIS regulates PKC activation, and that this may be important for the activation of both the AP-1 and NF-kappaB pathways in TCR signaling.
|
|
| 9. |
|
|
| 10. |
- Corthay, Alexandre, et al.
(författare)
-
Collagen-induced arthritis development requires alpha beta T cells but not gamma delta T cells: studies with T cell-deficient (TCR mutant) mice
- 1999
-
Ingår i: International Immunology. - 1460-2377. ; 11:7, s. 1065-1073
-
Tidskriftsartikel (refereegranskat)abstract
- Collagen type II (CII)-induced arthritis (CIA) in mice is a model for rheumatoid arthritis (RA) in which the role of T lymphocytes remains controversial. To clarify this, we have bred a targeted gene deletion of TCR beta or delta loci into two mouse strains susceptible to CIA, the B10.Q and DBA/1 strains. The TCRbeta-/- mice lacked alphabeta T cells, which was compensated by an expansion of B cells, gammadelta T cells and NK cells. The beta-/- mice, but not control beta+/- littermates, were completely resistant to CIA. The production of anti-CII IgG antibodies was also abolished in beta-/- mice, revealing a strict alphabeta T cell dependency. In contrast, beta-/- mice produced reduced, but significant, anti-CII IgM titers after immunization with either CII or ovalbumin, indicating a multispecificity for these alphabeta T cell-independent IgM antibodies. The TCRdelta-/- mice lacked gammadelta T cells but had no other significant changes in lymphocyte or monocyte subsets. The cytokine response (IL-2, IL-4, IL-10 and IFN-gamma) in delta-/- mice, quantified by flow cytometry staining of mitogen-stimulated lymphocytes, was indistinguishable from normal mice. Likewise, no statistically significant differences were observed in CIA between mice lacking gammadelta T cells and control littermates, considering arthritis incidence, day of disease onset, maximum arthritic score, anti-CII IgG titers and disease course. We conclude that alphabeta T cells are necessary for CIA development and for an IgG response towards CII, whereas gammadelta T cells are neither necessary nor sufficient for development of CIA.
|
|
