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1.	Lingblom, Christine, 1984, et al. (author) Topical Corticosteroids Do Not Revert the Activated Phenotype of Eosinophils in Eosinophilic Esophagitis but Decrease Surface Levels of CD18 Resulting in Diminished Adherence to ICAM-1, ICAM-2, and Endothelial Cells. 2014 In: Inflammation. - : Springer Science and Business Media LLC. - 1573-2576 .- 0360-3997. ; 37:6, s. 1932-1944 Journal article (peer-reviewed)abstract Swallowed topical corticosteroids are the standard therapy for eosinophilic esophagitis (EoE) in adults. Eosinophils in the blood of untreated EoE patients have an activated phenotype. Our aim was to determine if corticosteroids restore the phenotype of eosinophils to a healthy phenotype and if certain cell-surface molecules on blood eosinophils correlate with eosinophilic infiltration of the esophagus. Levels of eight surface markers on eosinophils from treated and untreated EoE patients were determined by flow cytometry and analyzed using multivariate methods of pattern recognition. Corticosteroid-treated EoE patients' eosinophils had decreased levels of CD18 compared to both untreated patients and healthy controls, but maintained their activated phenotype. CD18 expression correlated positively with eosinophil numbers in the esophagus and promoted the adherence of eosinophils to ICAM-1, ICAM-2, and to endothelial cells. The diminished expression of CD18 may be one mechanism behind the reduced entry of eosinophils into the esophagus in corticosteroid-treated EoE patients.
2.	Ahlmanner, Filip, et al. (author) CD39+ regulatory T cells accumulate in colon adenocarcinomas and display markers of increased suppressive function 2018 In: Oncotarget. - : Impact Journals, LLC. - 1949-2553. ; 9:97, s. 36993-37007 Journal article (peer-reviewed)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.
3.	Akeus, Paulina, et al. (author) Altered chemokine production and accumulation of regulatory T cells in intestinal adenomas of APC(Min/+) mice. 2014 In: Cancer immunology, immunotherapy : CII. - : Springer Science and Business Media LLC. - 1432-0851 .- 0340-7004. ; 63:8, s. 807-19 Journal article (peer-reviewed)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.
4.	Akeus, Paulina, et al. (author) Regulatory T cells control endothelial chemokine production and migration of T cells into intestinal tumors of APC(min/+) mice 2018 In: Cancer Immunology Immunotherapy. - : Springer Science and Business Media LLC. - 0340-7004 .- 1432-0851. ; 67:7, s. 1067-1077 Journal article (peer-reviewed)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.
5.	Akeus, Paulina, et al. (author) Regulatory T cells reduce endothelial neutral sphingomyelinase 2 to prevent T-cell migration into tumors 2021 In: European Journal of Immunology. - : Wiley. - 0014-2980 .- 1521-4141. ; 51:9, s. 2317-2329 Journal article (peer-reviewed)abstract Endothelial cells are key regulators of transendothelial migration and their secretion of chemokines and expression of adhesion molecules facilitates lymphocyte entry into tissues. Previously, we demonstrated that Tregs can reduce transendothelial migration of T cells into tumors by decreasing endothelial CXCL10 secretion, but the mechanism by which this occurs is still not known. In this study, we aimed to define how Tregs decrease transendothelial migration into tumors. mRNA sequencing of intestinal tumor endothelial cells from Treg depleted mice identified neutral sphingomyelinase 2 (nSMase2) as a gene downregulated in the presence of Tregs. nSMase2 is expressed in human umbilical vein endothelial cells (HUVECs) and was decreased after coculture with Tregs. Furthermore, blocking of nSMase2 activity in vitro decreased VCAM1, CX3CL1, and CXCL10 expression in HUVECs, mirroring the same decrease found in Treg cocultures. In the APC(min/+) mouse model of intestinal cancer, nSMase2 is lower in tumor endothelial cells than in unaffected small intestine and chronic treatment with a nSMase2 inhibitor suppressed the increased migration that is otherwise seen in the absence of Tregs. We conclude that nSMase2 is an important mediator in endothelial cells supporting transendothelial migration, which may be targeted by Tregs to reduce T-cell migration into tumors.
6.	Akeus, Paulina, et al. (author) Treg-cell depletion promotes chemokine production and accumulation of CXCR3(+) conventional T cells in intestinal tumors. 2015 In: European journal of immunology. - : Wiley. - 1521-4141 .- 0014-2980. ; 45:6, s. 1654-66 Journal article (peer-reviewed)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.
7.	Andersson Lundell, Anna-Carin, 1976, et al. (author) Development of gut-homing receptors on circulating B cells during infancy. 2011 In: Clinical immunology. - : Elsevier BV. - 1521-7035 .- 1521-6616. ; 138:1, s. 97-106 Journal article (peer-reviewed)abstract B cell gut-homing is mainly mediated by α4β7, CCR9 and CCR10. We here studied the expression of these receptors on B cells from cord blood and from peripheral blood at 1, 4, 18 and 36months of age in a prospective cohort of Swedish infants. The proportion of all B cells expressing α4β7 as well as the fraction of CCR10+ B cells expressing α4β7 was highest in early infancy. Nearly all naïve B cells in all age groups expressed α4β7, whereas the expression on class-switched B cells decreased with age. Moreover, the proportion of both IgA+ and IgG+ B cells expressing α4β7, CCR9 and CCR10 were higher during the first months when compared to adults. In conclusion, the high fraction of circulating IgA+ and IgG+ B cells expressing CCR9 and CCR10 in the first months of life indicates activation of naïve B cells in the gut, coinciding with bacterial colonization.
8.	Andric, Fanny, et al. (author) Immune Microenvironment in Sporadic Early-Onset versus Average-Onset Colorectal Cancer 2023 In: Cancers. - : MDPI AG. - 2072-6694. ; 15:5 Journal article (peer-reviewed)abstract Simple Summary The incidence of non-hereditary cancer in the left colon and rectum is increasing in young patients worldwide for unknown reasons. To understand this phenomenon, the biology of early-onset colorectal cancer needs to be established. Here, we investigated the immune response to tumors by selecting a highly representative group of patients younger than 45 years matched to those aged 70-75 years, excluding hereditary cases. Both T-cell distribution in tumors and expression of 770 immune-related genes were overall similar between the groups. The findings suggest that the immune response in cancer of the left colon and rectum is not dependent on age and that early-onset colorectal cancer is likely not related to immune response deficiencies. The incidence of left-sided colon and rectal cancer in young people are increasing worldwide, but its causes are poorly understood. It is not clear if the tumor microenvironment is dependent on age of onset, and little is known about the composition of tumor-infiltrating T cells in early-onset colorectal cancer (EOCRC). To address this, we investigated T-cell subsets and performed gene expression immune profiling in sporadic EOCRC tumors and matched average-onset colorectal cancer (AOCRC) tumors. Left-sided colon and rectal tumors from 40 cases were analyzed; 20 EOCRC (<45 years) patients were matched 1:1 to AOCRC (70-75 years) patients by gender, tumor location, and stage. Cases with germline pathogenic variants, inflammatory bowel disease or neoadjuvant-treated tumors were excluded. For T cells in tumors and stroma, a multiplex immunofluorescence assay combined with digital image analysis and machine learning algorithms was used. Immunological mediators in the tumor microenvironment were assessed by NanoString gene expression profiling of mRNA. Immunofluorescence revealed no significant difference between EOCRC and AOCRC with regard to infiltration of total T cells, conventional CD4(+) and CD8(+) T cells, regulatory T cells, or gamma delta T cells. Most T cells were located in the stroma in both EOCRC and AOCRC. Immune profiling by gene expression revealed higher expression in AOCRC of the immunoregulatory cytokine IL-10, the inhibitory NK cell receptors KIR3DL3 and KLRB1 (CD161), and IFN-a7 (IFNA7). In contrast, the interferon-induced gene IFIT2 was more highly expressed in EOCRC. However, in a global analysis of 770 tumor immunity genes, no significant differences could be detected. T-cell infiltration and expression of inflammatory mediators are similar in EOCRC and AOCRC. This may indicate that the immune response to cancer in left colon and rectum is not related to age of onset and that EOCRC is likely not driven by immune response deficiency.
9.	Banerjee, Debashish, et al. (author) Epithelial MUC1/Muc1 Promotes Cell migration, Reduces Apoptosis and Affects Levels of Mucosal Modulators During Acetylsalicylic Acid (Aspirin) Induced Gastropathy. 2015 In: The Biochemical journal. - 1470-8728. ; 465:3, s. 423-431 Journal article (peer-reviewed)abstract MUC1 is a transmembrane mucin highly expressed in the stomach. While extensive research has uncovered many of its roles in cancer, knowledge about the functions of MUC1 in normal tissues is limited. Here we showed that acetylsalicylic acid (Aspirin, ASA) upregulated MUC1/Muc1 expression in the gastric mucosa of humans and wild type mice. ASA induced mucosal injury in all mice to a similar extent, however wild type animals and those chimeras with Muc1 on the epithelia recovered faster than Muc1 knock-out mice and chimeras carrying Muc1 on haematopoietic but not epithelial cells. MUC1 enhanced proliferation and migration of the human gastric cell line MKN-7, and increased resistance to apoptosis. The repeated treatment regime used caused a reduction in cyclooxygenase-1 expression, though wild type animals returned faster towards pre-treatment levels, and had increased cyclooxygenase-2 and vascular endothelial growth factor levels during recovery. Thus, we found that epithelial Muc1 is more important for the healing process than haematopoetic Muc1, and Muc1/MUC1 facilitates wound healing by enhancing cell migration and proliferation, protecting against apoptosis and mediating expression of mucosal modulators. Thus, MUC1 plays essential roles during wound healing, and development of treatment modalities targeting enhanced expression of MUC1 may be beneficial to treat mucosal wounds.
10.	Bergin, Philip, 1975, et al. (author) Gastric gelatinase B/matrix metalloproteinase-9 is rapidly increased in Helicobacter felis-induced gastritis. 2008 In: FEMS immunology and medical microbiology. - 0928-8244. ; 52:1, s. 88-98 Journal article (peer-reviewed)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.
11.	Bergin, Philip, 1975, et al. (author) Increased production of matrix metalloproteinases in Helicobacter pylori-associated human gastritis. 2004 In: Helicobacter. - : Wiley. - 1083-4389 .- 1523-5378. ; 9:3, s. 201-10 Journal article (peer-reviewed)abstract BACKGROUND AND AIMS: Helicobacter pylori infection results in an active, chronic inflammation of the gastric mucosa. Previous studies have highlighted the importance of matrix metalloproteinases (MMPs) in diseases involving mucosal inflammation, prompting us to investigate MMP activity in H. pylori-induced gastritis. METHODS: Gastric biopsies were obtained from H. pylori-infected and uninfected volunteers, and MMP activity was assessed using substrate gel electrophoresis. MMP production was also evaluated by immunohistochemistry and real time-polymerase chain reaction. In parallel, tissue inhibitors of MMPs (TIMP) levels and TIMP-MMP complexes were examined in corresponding tissues using enzyme-linked immunosorbent assays and Western blotting. Finally, MMP production by gastric macrophages was determined after stimulation with H. pylori. RESULTS: Antral mucosa of H. pylori-infected subjects demonstrated a 19-fold higher MMP-9 activity than that of uninfected individuals. MMP-2 was present at lower levels, but was also increased in H. pylori-infected individuals, while there was no difference in the total levels of TIMP-1 and TIMP-2 between the groups of volunteers. Significant numbers of MMP-9-containing cells were only found in the H. pylori-infected antral mucosa. Tissue-resident macrophages were significantly increased in H. pylori-infected individuals, and double-staining showed MMP-9 colocalized to macrophages. Furthermore, gastric macrophages secreted MMP-9 in response to H. pylori bacteria. A corresponding 10-fold increase of gene expression of MMP-9 was seen in patients infected with H. pylori compared to uninfected individuals. CONCLUSIONS: Helicobacter pylori infection results in a substantial increase in MMP-9 and MMP-2 activity in the gastric mucosa, probably contributed to in large part by tissue-resident macrophages, while no changes were seen in the TIMP levels. The net increase in gastric MMP activity is likely to contribute to tissue damage during H. pylori-associated gastritis.
12.	Bergin, Philip, 1975, et al. (author) Secretion of matrix metalloproteinase-9 by macrophages, in vitro, in response to Helicobacter pylori. 2005 In: FEMS immunology and medical microbiology. - : Oxford University Press (OUP). - 0928-8244 .- 1574-695X. ; 45:2, s. 159-69 Research review (peer-reviewed)abstract We have previously shown that matrix metalloproteinase-9 (MMP-9) activity is greatly enhanced within the active chronic inflammation of Helicobacter pylori infected individuals, of which a major fraction derives from macrophages in the tissue. Here, we have investigated the ability of macrophages to secrete MMPs in response to H. pylori. Human macrophages secrete MMP-9 in response to live and inactivated H. pylori, as well as to specific bacterial products. Protein kinase C, phosphatiolylinositol 3-kinase and calcium uptake channels all play a role in MMP-9 secretion, whereas neither tumour necrosis factor alpha, interleukin-8, nor interleukin-1beta autocrine stimulation appear to contribute. We conclude that human macrophages have the ability to react directly against several H. pylori derived factors, utilising several signalling pathways.
13.	Brisslert, Mikael, 1974, et al. (author) Helicobacter pylori induce neutrophil transendothelial migration: role of the bacterial HP-NAP 2005 In: FEMS Microbiol Lett. ; 249:1, s. 95-103 Journal article (peer-reviewed)abstract Continuous recruitment of neutrophils into the inflamed gastric mucosal tissue is a hallmark of Helicobacter pylori infection in humans. In this study, we examined the ability of H. pylori to induce transendothelial migration of neutrophils using a transwell system consisting of a cultured monolayer of human endothelial cells as barrier between two chambers. We showed for the first time that live H. pylori, but not formalin-killed bacteria, induced a significantly increased transendothelial migration of neutrophils. H. pylori conditioned culture medium also induced significantly increased transendothelial migration, whereas heat-inactivated culture filtrates had no effect, suggesting that the chemotactic factor was proteinaceous. Depletion of H. pylori-neutrophil activating protein (HP-NAP) from the culture filtrates resulted in significant reduction of the transmigration. Culture filtrates from isogenic HP-NAP deficient mutant bacteria also induced significantly less neutrophil migration than culture filtrates obtained from wild-type bacteria. HP-NAP did not induce endothelial cell activation, suggesting that HP-NAP acts directly on the neutrophils. In conclusion, our results demonstrate that secreted HP-NAP is one of the factors resulting in H. pylori induced neutrophil transendothelial migration. We propose that HP-NAP contributes to the continuous recruitment of neutrophils to the gastric mucosa of H. pylori infected individuals.
14.	Börgeson, Emma, et al. (author) AICAR ameliorates high-fat diet-associated pathophysiology in mouse and ex vivo models, independent of adiponectin. 2017 In: Diabetologia. - : Springer Science and Business Media LLC. - 1432-0428 .- 0012-186X. ; 60:4, s. 729-739 Journal article (peer-reviewed)abstract In this study, we aimed to evaluate the therapeutic potential of 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR), an activator of AMP-activated protein kinase, for ameliorating high-fat diet (HFD)-induced pathophysiology in mice. We also aimed to determine whether the beneficial effects of AICAR were dependent on adiponectin. Furthermore, human adipose tissue was used to examine the effect of AICAR ex vivo.Six-week-old male C57BL/6J wild-type and Adipoq (-/-) mice were fed a standard-fat diet (10% fat) or an HFD (60% fat) for 12weeks and given vehicle or AICAR (500μg/g) three times/week from weeks 4-12. Diet-induced pathophysiology was examined in mice after 11 weeks by IPGTT and after 12 weeks by flow cytometry and western blotting. Human adipose tissue biopsies from obese (BMI 35-50kg/m(2)) individuals were incubated with vehicle or AICAR (1mmol/l) for 6h at 37°C, after which inflammation was characterised by ELISA (TNF-α) and flow cytometry.AICAR attenuated adipose inflammation in mice fed an HFD, promoting an M1-to-M2 macrophage phenotype switch, while reducing infiltration of CD8(+) T cells. AICAR treatment of mice fed an HFD partially restored glucose tolerance and attenuated hepatic steatosis and kidney disease, as evidenced by reduced albuminuria (p<0.05), urinary H2O2 (p<0.05) and renal superoxide levels (p<0.01) in both wild-type and Adipoq (-/-) mice. AICAR-mediated protection occurred independently of adiponectin, as similar protection was observed in wild-type and Adipoq (-/-) mice. In addition, AICAR promoted an M1-to-M2 macrophage phenotype switch and reduced TNF-α production in tissue explants from obese human patients.AICAR may promote metabolic health and protect against obesity-induced systemic diseases in an adiponectin-independent manner. Furthermore, AICAR reduced inflammation in human adipose tissue explants, suggesting by proof-of-principle that the drug may reduce obesity-induced complications in humans.ClinicalTrials.gov NCT02322073.
15.	Calander, Ann-Marie, 1957, et al. (author) Matrix metalloproteinase-9 (gelatinase B) deficiency leads to increased severity of Staphylococcus aureus-triggered septic arthritis. 2006 In: Microbes and infection / Institut Pasteur. - : Elsevier BV. - 1286-4579. ; 8:6, s. 1434-9 Journal article (peer-reviewed)abstract Matrix metalloproteinases constitute a family of structurally related endopeptidases that are crucial for the normal turnover of the extracellular matrix. Elevated levels of MMP-9 have been demonstrated in synovial fluids of rheumatoid arthritis patients, and a correlation with the severity of the disease has been described. The aim of this study was to explore the impact of MMP-9 expression on joint inflammation and destruction in a model of bacterially induced septic arthritis. MMP-9 knock-out mice and C57Bl6 congenic controls were inoculated intravenously or intra-articularly with Staphylococcus aureus. Arthritis was evaluated clinically and by means of histology. Zymographic analyses were performed to study ex vivo induction of MMP-9 following exposure to S. aureus. The MMP-9 knock-out mice displayed a significantly higher frequency and severity, but not destructivity, of arthritis than did the wild-type mice. The knock-out mice also proved to harbour an increased number of bacteria locally in joints and systemically in kidneys, possibly by impaired extravasation and recruitment of leukocytes and a deficient early defence against infection. Our findings indicate that deficiency in MMP-9 increases the degree of joint inflammation due to decreased bacterial clearance.
16.	Cardeno, Ana, et al. (author) Activated T follicular helper-like cells are released into blood after oral vaccination and correlate with vaccine specific mucosal B-cell memory 2018 In: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 8 Journal article (peer-reviewed)abstract T follicular helper (Tfh)-like cells with potent B-cell helping ability are mobilized into human circulation after parenteral vaccination and are generally held to reflect ongoing germinal center reactions. However, whether mucosal vaccination induces systemic Tfh responses and how such responses may relate to IgA production are unknown. We investigated the frequencies, phenotype and function of circulating Tfh-like CD4(+) CXCR5(+) T cells (cTfh) in adults receiving an oral inactivated enterotoxigenic Escherichia coli vaccine. Subjects were classified as vaccine responders or weak/non-responders based on their intestine-derived antibody-secreting cell (ASC) IgA responses to major vaccine antigens. Oral immunization induced significantly increased proportions of cTfh cells expressing the cTfh activation marker inducible costimulator (ICOS) in ASC responders, but not in weak/non-responders. Vaccination also enhanced the expression of IL-21, Th17 markers and integrin beta 7 by activated cTfh cells, supporting functionality and gut homing potential. cTfh cells promoted total and vaccine specific IgA production from cocultured B cells. Magnitudes of cTfh responses assessed within a week after primary vaccinations correlated with memory intestine-derived vaccine specific IgA responses 1-2 years later. We conclude that activated ICOS+ Tfh-like cells are mobilized into blood after oral vaccination and may be used as biomarkers of vaccine specific mucosal memory in humans.
17.	Das, S., et al. (author) beta 7 integrins contribute to intestinal tumor growth in mice 2018 In: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 13:9 Journal article (peer-reviewed)abstract The gut homing receptor integrin alpha 4 beta 7 is essential for the migration of pro-inflammatory T cells into the gut mucosa. Since intestinal neoplasia has been associated with chronic inflammation, we investigated whether interfering with gut-homing affects intestinal tumorigenesis. Using chemically induced and spontaneous intestinal tumor models we showed that lack of beta 7 integrin significantly impairs tumor growth without affecting tumor frequencies, with a mild translatable effect on overall survival. This correlates with human data showing lower MAdCAM-1 expression and disease-free survival in colorectal cancer patients. Thus, paradoxically in contrast to extra-intestinal tumors, blocking migration of immune cells into the gut might have a positive therapeutic effect on intestinal neoplasia.
18.	Enarsson, Karin, 1975, et al. (author) CD4+ CD25high regulatory T cells reduce T cell transendothelial migration in cancer patients. 2007 In: European journal of immunology. - : Wiley. - 0014-2980 .- 1521-4141. ; 37:1, s. 282-91 Journal article (peer-reviewed)abstract Cell-mediated immunity is thought to be the main mechanism of anti-tumour responses of the host, but it is not known if cancer disease affects T cell recruitment from blood to tissues. Therefore, we compared Heliobacter pylori-induced T cell transendothelial migration (TEM) in H. pylori-infected gastric carcinoma patients, colon and lung carcinoma patients and healthy volunteers. H. pylori induced significant T cell migration from all groups. However, there was a dramatic reduction of T cell TEM in gastric carcinoma patients (80%) compared to healthy individuals. A similarly reduced transmigration was also seen in colon and lung carcinoma patients. We found significantly increased frequencies of T(reg) cells in the blood of gastric carcinoma patients compared to healthy individuals, and depletion of T(reg) cells from the blood of these patients prior to TEM restored T cell migration. The effect of T(reg) cells was largely dependent on cell-cell contact, but not on IL-10 or TGF-beta. In addition, the presence of T(reg) cells led to reduced T cell attachment to endothelium and decreased production of T cell-recruiting chemokines during TEM. In conclusion, T(reg) cell-mediated reduction of T cell TEM may reduce T cell recruitment in patients with epithelial malignancies, thereby hampering anti-tumour responses.
19.	Enarsson, Karin, 1975, et al. (author) Differential mechanisms for T lymphocyte recruitment in normal and neoplastic human gastric mucosa 2006 In: Clin Immunol. - : Elsevier BV. ; 118:1, s. 24-34 Research review (peer-reviewed)abstract Worldwide, gastric adenocarcinoma (GC) is the second most common cause of death from malignant disease. The reason why immune responses are unable to clear the tumour is not fully understood, although aberrant lymphocyte recruitment to the tumour site might be one factor. Therefore, we investigated the homing phenotype of mucosal T lymphocytes in GC, compared to tumour-free mucosa. We could detect significantly decreased frequencies of mucosal homing alpha4beta7+ T cells in the tumour tissues and increased frequencies of L-selectin+ T cells. This was probably due to the correlated decrease in MAdCAM-1 positive and increase in PNAd positive blood vessels in the tumour mucosa. There were also fewer CXCR3+ T lymphocytes in the tumour tissue. These findings provide evidence that endothelial cells within tumours arising at mucosal sites do not support extravasation of typical mucosa-infiltrating T cells. This may be of major relevance for future immunotherapeutic strategies for treatment of GC.
20.	Enarsson, Karin, 1975, et al. (author) Function and recruitment of mucosal regulatory T cells in human chronic Helicobacter pylori infection and gastric adenocarcinoma. 2006 In: Clinical immunology (Orlando, Fla.). - : Elsevier BV. - 1521-6616. ; 121:3, s. 358-68 Journal article (peer-reviewed)abstract CD4(+)CD25(high) FOXP3-expressing regulatory T cells (Treg) can suppress immune responses to infections and tumors, thereby promoting microbial persistence and tumor progression. However, little is known about the phenotype and function of human mucosal Treg. Therefore, we analyzed the suppressive activity and homing phenotype of Treg in gastric mucosa of Helicobacter pylori-infected gastric adenocarcinoma patients. We found increased numbers of CD4(+)FOXP3(+) Treg in the tumor compared to tumor-free gastric mucosa. Gastric Treg cells were able to suppress H. pylori-induced T cell proliferation and IFN-gamma production. Furthermore, gastric Treg expressed increased levels of l-selectin and CCR4, compared to non-Treg cells, suggesting that these receptors contribute to Treg recruitment. The presence of functional antigen-specific Treg in H. pylori-infected gastric mucosa supports an important role for these cells in suppression of mucosal effector T cell responses, which probably contribute to bacterial persistence and possibly also to gastric tumor progression.
21.	Enarsson, Karin, 1975, et al. (author) Helicobacter pylori induces transendothelial migration of activated memory T cells. 2005 In: Infection and immunity. - 0019-9567. ; 73:2, s. 761-9 Research review (peer-reviewed)abstract Helicobacter pylori infection is associated with pronounced infiltration of granulocytes and lymphocytes into the gastric mucosa, resulting in active chronic gastritis that may develop into duodenal ulcer disease or gastric adenocarcinoma. Infiltrating T cells play a major role in the pathology of these diseases, but the signals involved in recruitment of T cells from blood to H. pylori-infected tissues are not well understood. We therefore examined H. pylori-induced T-cell transendothelial migration (TEM). The Transwell system, employing a monolayer of human umbilical vein endothelial cells, was used as a model to study TEM. H. pylori induced a significant T-cell migration, compared to spontaneous migration. CD4+ and CD8+ T cells migrated to the same extent in response to H. pylori, whereas there was significantly larger transmigration of memory T cells compared to naive T cells. Both H. pylori culture filtrate and urease induced migration, and the presence of the H. pylori cag pathogenicity island increased TEM. T-cell TEM was mediated by LFA-1-ICAM-1 interactions in accordance with an increased ICAM-1 expression on the endothelial cells after contact with H. pylori. Migrating T cells had increased expression of activation marker CD69 and chemokine receptors CXCR3, CCR4, and CCR9. Furthermore, T cells migrating in response to H. pylori secreted Th1 but not Th2 cytokines upon stimulation. In conclusion, our data indicate that live H. pylori and its secreted products contribute to T-cell recruitment to the gastric mucosa and that the responding T cells have an activated memory Th1 phenotype.
22.	Friman, Vanda, 1952, et al. (author) Intestinal and circulating antibody-forming cells in IgA-deficient individuals after oral cholera vaccination. 1994 In: Clinical and experimental immunology. - 0009-9104. ; 95:2, s. 222-6 Journal article (peer-reviewed)abstract In search for a possible explanation for the different susceptibility to mucosal infections in IgA-deficient (IgAd) individuals, the frequency of total immunoglobulin-secreting cells (ISC) and vaccine-specific antibody-secreting cells (ASC) in intestinal mucosa and peripheral blood was determined by the enzyme-linked immunospot (ELISPOT) assay before and after peroral vaccination with a B subunit-whole cell cholera vaccine. Two groups of IgAd individuals, frequently infected and non-infected respectively, and normal controls were studied. Before cholera vaccination there were significantly higher frequencies of total IgM and IgG ISC in the gut, but not in the blood, in the IgAd individuals than in the controls. However, there were no significant differences between healthy and infection-prone IgAd individuals in this respect. In response to oral cholera vaccination, intestinal cholera toxin (CT)-specific IgG and IgM ASC were significantly more abundant among the IgAd individuals with a history of frequent infections than among the healthy IgAd individuals and controls. A similar difference in IgG and IgM ASC, although not significant, was also noted in blood. In IgAd individuals with frequent infections the vaccine induced variable anti-CT IgM ASC responses in the gut, ranging from no increase to a few strikingly high responses. In the controls, the CT-specific responses were dominated by IgA ASC. The data show that oral cholera vaccination evoked strong CT-specific IgG ASC responses, and in some cases also strong IgM ASC responses in the intestinal mucosa of IgAd patients with a history of frequent infections. The healthy IgAd individuals unexpectedly responded with lower numbers of CT-specific IgG ASC and did not show any increase of CT-specific IgM ASC in the intestinal mucosa. Thus, inability to mount a mucosal immune response to an oral antigen cannot in itself explain recurrent infections among many IgAd individuals.
23.	Gonzales, Lucia, et al. (author) Alkaline pH Is a Signal for Optimal Production and Secretion of the Heat Labile Toxin, LT in Enterotoxigenic Escherichia Coli (ETEC) 2013 In: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 8:9 Journal article (peer-reviewed)abstract Enterotoxigenic Escherichia coli (ETEC) cause secretory diarrhea in children and travelers to endemic areas. ETEC spreads through the fecal-oral route. After ingestion, ETEC passes through the stomach and duodenum before it colonizes the lower part of the small intestine, exposing bacteria to a wide range of pH and environmental conditions. This study aimed to determine the impact of external pH and activity of the Cyclic AMP receptor protein (CRP) on the regulation of production and secretion of heat labile (LT) enterotoxin. ETEC strain E2863wt and its isogenic mutant E2863ΔCRP were grown in LBK media buffered to pH 5, 7 and 9. GM1 ELISA, cDNA and cAMP analyses were carried out on bacterial pellet and supernatant samples derived from 3 and 5 hours growth and from overnight cultures. We confirm that CRP is a repressor of LT transcription and production as has been shown before but we show for the first time that CRP is a positive regulator of LT secretion both in vitro and in vivo. LT secretion increased at neutral to alkaline pH compared to acidic pH 5 where secretion was completely inhibited. At pH 9 secretion of LT was optimal resulting in 600 percent increase of secreted LT compared to unbuffered LBK media. This effect was not due to membrane leakage since the bacteria were viable at pH 9. The results indicate that the transition to the alkaline duodenum and/or exposure to high pH close to the epithelium as well as activation of the global transcription factor CRP are signals that induce secretion of the LT toxin in ETEC.
24.	Grindebacke, Hanna, 1977, et al. (author) Dynamic development of homing receptor expression and memory cell differentiation of infant CD4+CD25high regulatory T cells. 2009 In: Journal of immunology (Baltimore, Md. : 1950). - : The American Association of Immunologists. - 1550-6606 .- 0022-1767. ; 183:7, s. 4360-70 Journal article (peer-reviewed)abstract Migration of CD4+CD25+FOXP3+ regulatory T cells (Treg) is important for suppressing immune responses in different tissues. Previous studies show that the majority of Treg at birth express gut homing receptor alpha(4)beta(7) and that only few express CCR4, while the reverse pattern is found in adults. The age at which homing receptor switch occurs in vivo is not known. In this study, we show, in a prospective study of human infants from birth to 3 years of age, that homing receptor switch from alpha(4)beta(7) to CCR4 commences between 1 1/2 and 3 years of age and that Treg at that age also had started their switch to a memory phenotype. The majority of naive Treg express alpha(4)beta(7) in infants but not in adults, while the majority of memory Treg express CCR4 both infants and adults. The homing receptor expression on Treg corresponds to their actual migration properties, because Treg from cord blood migrate foremost toward the gut-associated chemokine CCL25. CD4+FOXP3+ T cell numbers increase rapidly in the circulation during the first days of life indicating conversion to suppressive Treg from CD25(high) Treg precursors. These findings suggest that the gut is the primary site of Treg stimulation to exogenous Ags during the first 18 mo of life and that homing receptor switch toward a more extra-intestinal phenotype occurs thereafter.
25.	Hansson, Malin, 1967, et al. (author) CCL28 is increased in human Helicobacter pylori induced gastritis and mediates recruitment of gastric IgA-secreting cells. 2008 In: Infection and Immunity. - 0019-9567. ; 76:7, s. 3304-11 Journal article (peer-reviewed)abstract Human Helicobacter pylori infection gives rise to an active chronic gastritis and is a major risk factor for the development of duodenal ulcer disease and gastric adenocarcinoma. The infection is accompanied by a large accumulation of immunoglobulin A (IgA)-secreting cells in the gastric mucosa, and following mucosal immunization only H. pylori-infected volunteers mounted a B-cell response in the gastric mucosa. To identify the signals for recruitment of gastric IgA-secreting cells, we investigated the gastric production of CCL28 (mucosa-associated epithelial chemokine) and CCL25 (thymus-expressed chemokine) in H. pylori-infected and uninfected individuals and the potential of gastric B-cell populations to migrate toward these chemokines. Gastric tissue from H. pylori-infected individuals contained significantly more CCL28 protein and mRNA than that from uninfected individuals, while CCL25 levels remained unchanged. Chemokine-induced migration of gastric lamina propria lymphocytes isolated from patients undergoing gastric resection was then assessed using the Transwell system. IgA-secreting cells and IgA+ memory B cells from H. pylori-infected tissues migrated toward CCL28 but not CCL25, while the corresponding cells from uninfected patients did not. Furthermore, IgG-secreting cells from H. pylori-infected patients did not migrate to CCL28 but instead to CXCL12 (SDF-1). However, chemokine receptor expression did not correlate to the migratory pattern of the different B-cell populations. These studies are the first to show increased CCL28 production during gastrointestinal infection in humans and provide an explanation for the large influx of IgA-secreting cells to the gastric mucosa in H. pylori-infected individuals.

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