| 1. |
- Akter, S., et al.
(författare)
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The frequency of circulating integrin alpha 4 beta 7(+) cells correlates with protection against Helicobacter pylori infection in immunized mice
- 2019
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Ingår i: Helicobacter. - : Wiley. - 1083-4389 .- 1523-5378. ; 24:6
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Tidskriftsartikel (refereegranskat)abstract
- Background Chronic Helicobacter pylori infection is the cause of peptic ulcers in a subpopulation of individuals and a risk factor for the development of gastric cancer. A vaccine against H pylori infection can prevent the acquisition of the infection and protect against reinfections. Clinical trials to date evaluating the efficacy of H pylori vaccines in human challenge models have shown moderate to poor protection with difficulties in predicting efficacy. Thus, while further studies are needed to design an effective vaccine, we also need to find relevant correlates for vaccine efficacy. Objective To find immune correlates to vaccine efficacy, the frequencies of neutrophils, eosinophils and inflammatory monocytes and CD4(+) T-cell memory and mucosa homing integrin alpha 4 beta 7(+) cells were assessed by flow cytometry in the blood of mice after vaccination. Materials and Methods H pylori antigens and cholera toxin or the multiple mutant CT (mmCT) were administered via the sublingual (SL) and intragastric route (IG). The vaccinated mice were infected with H pylori strain SS1 bacteria, and colonization in the stomach and immune responses were evaluated. Results The H pylori vaccine was effective in reducing bacterial load in the stomach of mice and enhancing immune responses compared to unvaccinated infection controls. In the blood of mice after SL or IG route of vaccination, we observed changes in frequencies of innate and adaptive immune cell subsets compared to infection controls. Remarkably, the frequency of circulating mucosal homing alpha 4 beta 7(+)CD4(+) T cells after vaccination correlated with low bacterial load in the stomach of individual mice irrespective of the immunization route. Conclusions Our study shows that the innate and adaptive immune cell subsets can be measured in the blood after vaccination and that increased frequency of alpha 4 beta 7(+)CD4(+) in the blood after immunization could be used as a predictive marker for the efficacy of vaccine against H pylori infection.
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| 2. |
- Dahlén, Rahil, et al.
(författare)
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Infliximab Inhibits Activation and Effector Functions of Peripheral Blood T Cells in vitro from Patients with Clinically Active Ulcerative Colitis
- 2013
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Ingår i: Scandinavian Journal of Immunology. - : Wiley. - 0300-9475. ; 78:3, s. 275-284
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Tidskriftsartikel (refereegranskat)abstract
- Many patients with inflammatory bowel disease (IBD) are undergoing therapy with infliximab, an antibody specific for TNF. However, the exact mechanisms of action of infliximab are not completely understood. The aim of this study was to determine the in vitro effects of infliximab on blood T cells derived from anti-TNF therapy-naive ulcerative colitis (UC) patients with clinically active disease. Peripheral blood mononuclear cells were stimulated polyclonally or by antigen in the presence or absence of infliximab. The T cell phenotype was investigated by flow cytometry, cytokine secretion was determined by ELISA, and cell proliferation was determined by thymidine assay or CFSE dye. Presence of infliximab resulted in reduced expression of CD25 in CD4(+) and CD8(+) T cell populations and inhibited secretion of IFN-, IL-13, IL-17A, TNF as well as granzyme A. Infliximab also suppressed CD4(+) and CD8(+) T cell proliferation. These effects of infliximab were recorded both in T cells activated by polyclonal and antigen-specific stimulation. The effects of infliximab on T cell apoptosis and induction of FOXP3(+)CD4(+) T regulatory cells were ambiguous and depended on the originating cellular source and/or the stimulation mode and strength. In conclusion, infliximab is able to reduce T cell activation as measured by CD25, proliferation and cytokine secretion in vitro from UC patients with clinically active disease. These data suggest that suppression of T cell activity may be important for infliximab-mediated disease remission in patients with UC.
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| 3. |
- Dutta, Nikita, 1992, et al.
(författare)
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Combinatory analysis of immune cell subsets and tumor-specific genetic variants predict clinical response to PD-1 blockade in patients with non-small cell lung cancer
- 2023
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Ingår i: Frontiers in Oncology. - : Frontiers Media SA. - 2234-943X. ; 12
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Tidskriftsartikel (refereegranskat)abstract
- Immunotherapy by blocking programmed death protein-1 (PD-1) or programmed death protein-ligand1 (PD-L1) with antibodies (PD-1 blockade) has revolutionized treatment options for patients with non-small cell lung cancer (NSCLC). However, the benefit of immunotherapy is limited to a subset of patients. This study aimed to investigate the value of combining immune and genetic variables analyzed within 3-4 weeks after the start of PD-1 blockade therapy to predict long-term clinical response.Blood collected from patients with NSCLC were analyzed for changes in the frequency and concentration of immune cells using a clinical flow cytometry assay. Next-generation sequencing (NGS) was performed on DNA extracted from archival tumor biopsies of the same patients. Patients were categorized as clinical responders or non-responders based on the 9 months' assessment after the start of therapy.We report a significant increase in the post-treatment frequency of activated effector memory CD4+ and CD8+ T-cells compared with pre-treatment levels in the blood. Baseline frequencies of B cells but not NK cells, T cells, or regulatory T cells were associated with the clinical response to PD-1 blockade. NGS of tumor tissues identified pathogenic or likely pathogenic mutations in tumor protein P53, Kirsten rat sarcoma virus, Kelch-like ECH-associated protein 1, neurogenic locus notch homolog protein 1, and serine/threonine kinase 11, primarily in the responder group. Finally, multivariate analysis of combined immune and genetic factors but neither alone, could discriminate between responders and non-responders.Combined analyses of select immune cell subsets and genetic mutations could predict early clinical responses to immunotherapy in patients with NSCLC and after validation, can guide clinical precision medicine efforts.
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| 4. |
- Navabi, Nazanin, 1969, et al.
(författare)
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Helicobacter pylori Infection Impairs the Mucin Production Rate and Turnover in the Murine Gastric Mucosa
- 2013
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Ingår i: Infection and Immunity. - 0019-9567. ; 81:3, s. 829-837
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Tidskriftsartikel (refereegranskat)abstract
- To protect the surface of the stomach, the epithelial cells secrete a mucus layer, which is mainly comprised of the MUC5AC mucin. Further protection is provided by a thick glycocalyx on the apical surface of the epithelial cell, with the cell surface mucin MUC1 as a major component. Here, we investigate the production rate and turnover of newly synthesized mucin in mice and analyze the effects of early colonization and chronic infection with H. pylori. Metabolic incorporation of an azido GalNAc analog (GalNAz) was used as a nonradioactive method to perform pulse experiments in the whole animal. First, the subcellular movement of newly synthesized mucin and mucin turnover was determined in uninfected mice. Based on the time line for mucin transport and dissemination, 2, 6, and 12 h after GalNAz injection was selected to collect the stomachs from mice infected with H. pylori strain SS1 during early colonization (7 days) and chronic infection (90 days). The results demonstrated that the speed from the start of glycosylation to the final destination is faster for the membrane-bound mucin to reach the glycocalyx (2 h) than for the secretory mucins to become secreted into the mucus layer (5 h). Furthermore, infection with H. pylori reduces the rate of mucin turnover and decreases the levels of Muc1. Since H. pylori colonizes this mucus niche, the decreased turnover rate indicates that H. pylori creates a more stable and favorable environment for itself by impairing the defense mechanism for clearing the mucosal surface of pathogens by mucus flow.
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| 5. |
- Adamsson, Jenni, 1977, et al.
(författare)
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Gastric expression of IL-17A and IFNγ in Helicobacter pylori infected individuals is related to symptoms
- 2017
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Ingår i: Cytokine. - : Elsevier BV. - 1043-4666. ; 99, s. 30-34
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Tidskriftsartikel (refereegranskat)abstract
- Background: Chronic infection with Helicobacter pylori leads to gastritis and in a subpopulation of infected individuals to ulcers and cancer. Bacterial virulence factors and host immune inflammatory responses are risk factors related to disease. CD4+ T cells secrete cytokines that promote inflammation and an anti-bacterial response in the gastric mucosa during infection. The aim of the study was to investigate the pattern of expression of CD4+ T cell derived cytokines, IL-17A and IFNγ in paired antrum and corpus biopsies and correlate it to H. pylori infection outcome. Methods: Gene and protein expression of IL-17A and IFNγ was analyzed in gastric biopsies from H. pylori infected subjects with non-ulcer dyspepsia (NUD) or gastric ulcer; and for comparison uninfected individuals. Results: Upregulation of IL-17A and IFNγ gene expression was seen in corpus and antrum biopsies of H. pylori infected individuals with NUD compared to in uninfected controls. The expression of these cytokines correlated significantly with each other. Immunofluorescence staining revealed increased frequencies of IL-17A+ and IFNγ+ cells in antrum biopsies of gastric ulcer patients compared to of H. pylori infected NUD individuals; positive cells were not detected in any of the biopsies of uninfected controls. The frequencies of IFNγ and IL-17A+ cells correlated positively with inflammation in the antrum, but not the corpus, of H. pylori infected individuals. In the antrum, while there was no significant evidence of correlation between IFNγ and bacterial score, a positive correlation between bacterial score and IL-17A+ cells was seen. Conclusions: In H. pylori infected individuals, the frequencies of IFNγ and IL-17A+ cells were increased in the antrum, particularly in patients with H. pylori induced gastric ulcers. Even though H. pylori colonized both the corpus and antrum regions of the stomach, the cytokine responses and subsequent pathology were mainly detected in the antrum. © 2017 Elsevier Ltd
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| 6. |
- Ahlmanner, Filip, et al.
(författare)
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CD39+ regulatory T cells accumulate in colon adenocarcinomas and display markers of increased suppressive function
- 2018
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Ingår i: Oncotarget. - : Impact Journals, LLC. - 1949-2553. ; 9:97, s. 36993-37007
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Tidskriftsartikel (refereegranskat)abstract
- Increasing knowledge of the function and regulation of tumor-infiltrating lymphocytes has led to new insights in cancer immunotherapy. Regulatory T cells (Treg) accumulate in colon tumors, and we recently showed that CD39+ Treg from cancer patients inhibit transendothelial migration of conventional T cells. CD39 mediates the hydrolysis of ATP to immunosuppressive adenosine and adds to the immunosuppressive effects of Treg. Here, we further investigated the regulatory features of intratumoral CD39+ Treg in colon cancer. Using flow cytometry analyses of cells from 46 colon cancer patients, we confirm the accumulation of CD39+ Treg in the tumor tissue compared to unaffected colon tissue, and also show that tumor-infiltrating Treg express more CD39 and Foxp3 on a per cell basis. Furthermore, CD39+ Treg in tumors express markers indicating increased turnover and suppressive ability. In particular, tumor-infiltrating CD39+ Treg have high expression of surface molecules related to immunosuppression, such as ICOS, PD-L1 and CTLA-4. Functional suppression assays also indicate potent suppressive capacity of CD39+ Treg on proliferation and IFN-γ secretion by conventional T cells. In conclusion, our results identify tumor-infiltrating CD39+ Treg as a numerous and potentially important immunosuppressive subset, and suggest that immunotherapy aimed at reducing the activity of CD39+ Treg may be particularly useful in the setting of colon cancer. © 2018 Ahlmanner et al.
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| 7. |
- Akeus, Paulina, et al.
(författare)
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Altered chemokine production and accumulation of regulatory T cells in intestinal adenomas of APC(Min/+) mice.
- 2014
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Ingår i: Cancer immunology, immunotherapy : CII. - : Springer Science and Business Media LLC. - 1432-0851 .- 0340-7004. ; 63:8, s. 807-19
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Tidskriftsartikel (refereegranskat)abstract
- Tumor progression in the colon moves from aberrant crypt foci to adenomatous polyps to invasive carcinomas. The composition of the tumor-infiltrating leukocyte population affects the ability of the immune system to fight the tumor. T cell infiltration into colorectal adenocarcinomas, particularly T helper 1 (Th1) type T cells as well as increased regulatory T cell (Treg) frequencies, is correlated with improved prognosis. However, whether Th1 cells and Tregs are already present at the adenoma stage is not known. In this study, the APC(Min/+) mouse model of intestinal adenomatous polyposis was used to investigate tumor-associated lymphocyte subsets and the mechanisms of their accumulation into gastrointestinal adenomas. Compared to unaffected tissue, adenomas accumulated CD4(+)FoxP3(+) putative Treg in parallel with lower frequencies of conventional T cells and B cells. The accumulation of Treg was also observed in human adenomatous polyps. Despite high Treg numbers, the function of conventional T cells present in the APC(Min/+) adenomas was not different from those in the unaffected tissue. Adenomas displayed an altered chemokine balance, with higher CCL17 and lower CXCL11 and CCL25 expression than in the unaffected tissue. In parallel, CXCR3(+) Tregs were largely absent from adenomas. The data indicate that already in early stages of tumor development, the balance of lymphocyte-recruiting chemokines is altered possibly contributing to the observed shift toward higher frequencies of Treg.
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| 8. |
- Akeus, Paulina, et al.
(författare)
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Regulatory T cells control endothelial chemokine production and migration of T cells into intestinal tumors of APC(min/+) mice
- 2018
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Ingår i: Cancer Immunology Immunotherapy. - : Springer Science and Business Media LLC. - 0340-7004 .- 1432-0851. ; 67:7, s. 1067-1077
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Tidskriftsartikel (refereegranskat)abstract
- Tumor-infiltrating lymphocytes are crucial for anti-tumor immunity. We have previously shown that regulatory T cells (Treg) are able to reduce T-cell transendothelial migration in vitro and accumulation of effector T cells in intestinal tumors in vivo. Treg depletion also resulted in increased levels of the chemokines CXCL9 and CXCL10 specifically in the tumors. In this study, we investigated the mechanisms for Treg mediated suppression of T-cell migration into intestinal tumors in the APC(min/+) mouse model. By breeding APC(min/+) mice with DEREG mice, which harbour a high affinity diphtheria toxin receptor under the control of the FOXP3 promoter, we were able to deplete Treg in tumor-bearing mice. Using adoptive transfer experiments, we could document a markedly increased migration of T cells specifically into Treg depleted tumors, and that Treg depletion results in increased production of the CXCR3 ligand CXCL10 from endothelial cells in the tumors. Furthermore, we were able to demonstrate that T cells use CXCR3 to migrate into intestinal tumors. In addition, human colon adenocarcinomas express high levels of mRNA CXCR3 ligands and tumor endothelial cells produce CXCL9 and CXCL10 ex vivo. In conclusion, this study demonstrates that Treg reduce endothelial CXCL10 production, inhibit T-cell migration into tumors and that CXCR3 mediated signalling is crucial for lymphocyte accumulation in intestinal tumors. Thus, immunotherapy aimed at Treg depletion may be effective by increasing not only T effector cell activity, but also their accumulation in tumors.
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| 9. |
- Akeus, Paulina, et al.
(författare)
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Treg-cell depletion promotes chemokine production and accumulation of CXCR3(+) conventional T cells in intestinal tumors.
- 2015
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Ingår i: European journal of immunology. - : Wiley. - 1521-4141 .- 0014-2980. ; 45:6, s. 1654-66
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Tidskriftsartikel (refereegranskat)abstract
- Colorectal cancer (CRC) is one of the most prevalent tumor types worldwide and tumor-infiltrating T cells are crucial for anti-tumor immunity. We previously demonstrated that Treg cells from CRC patients inhibit transendothelial migration of conventional T cells. However, it remains unclear if local Treg cells affect lymphocyte migration into colonic tumors. By breeding APC(Min/+) mice with depletion of regulatory T cells mice, expressing the diphtheria toxin receptor under the control of the FoxP3 promoter, we were able to selectively deplete Treg cells in tumor-bearing mice, and investigate the impact of these cells on the infiltration of conventional T cells into intestinal tumors. Short-term Treg-cell depletion led to a substantial increase in the frequencies of T cells in the tumors, attributed by both increased infiltration and proliferation of T cells in the Treg-cell-depleted tumors. We also demonstrate a selective increase of the chemokines CXCL9 and CXCL10 in Treg-cell-depleted tumors, which were accompanied by accumulation of CXCR3(+) T cells, and increased IFN-γ mRNA expression. In conclusion, Treg-cell depletion increases the accumulation of conventional T cells in intestinal tumors, and targeting Treg cells could be a possible anti-tumor immunotherapy, which not only affects T-cell effector functions, but also their recruitment to tumors.
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| 10. |
- Bergin, Philip, 1975, et al.
(författare)
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Gastric gelatinase B/matrix metalloproteinase-9 is rapidly increased in Helicobacter felis-induced gastritis.
- 2008
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Ingår i: FEMS immunology and medical microbiology. - 0928-8244. ; 52:1, s. 88-98
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Tidskriftsartikel (refereegranskat)abstract
- It has previously been shown that matrix metalloproteinase-9 (MMP-9) levels, originating from macrophages, are considerably increased in human Helicobacter pylori-associated gastritis. Here, the early kinetics of the MMP-9 response resulting from Helicobacter infection in C57BL/6 and MMP-9 knock-out mice using the murine Helicobacter felis model were examined. H. felis infection induced severe gastritis in the murine stomach at just 2 weeks after infection. Before gastritis, an increase was observed in MMP-9-positive cells detected by immunohistochemistry in the basal lamina propria. This finding was corroborated by gelatin zymography of stomach samples. As the gastritis increased so did the concentration of MMP-9 and the incidence of gastric MMP-9-positive cells, their location corresponding to that of macrophages. In contrast, systemic levels of MMP-9 remained unchanged. When MMP-9-deficient mice were infected with H. felis, no significant difference in gastritis development was detected compared with disease development in wild-type animals. We conclude that MMP-9 production is an early event in the response to gastric Helicobacter infection, a feature that may favor the recruitment of immune cells early during infection. At later stages, however, the increased levels of MMP-9 may damage the integrity of the stomach mucosa.
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