| 1. |
- Alsén, Samuel, et al.
(författare)
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Antigen-Presenting B Cells Program the Efferent Lymph T Helper Cell Response
- 2022
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Ingår i: Frontiers in Immunology. - : Frontiers Media SA. - 1664-3224. ; 13
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Tidskriftsartikel (refereegranskat)abstract
- B cells interact with T follicular helper (Tfh) cells in germinal centers (GCs) to generate high-affinity antibodies. Much less is known about how cognate T-B-cell interactions influence Th cells that enter circulation and peripheral tissues. Therefore, we generated mice lacking MHC-II expressing B cells and, by thoracic duct cannulation, analyzed Th cells in the efferent lymph at defined intervals post-immunization. Focusing on gut-draining mesenteric lymph nodes (MLNs), we show that antigen-specific alpha(4)beta(+)(7) gut-homing effector Th cells enter the circulation prior to CXCR5(+)PD-1(+) Tfh-like cells. B cells appear to have no or limited impact on the early generation and egress of gut-homing Th cells but are critical for the subsequent appearance of Tfh-like cells that peak in the lymph before GCs have developed. At this stage, antigen-presenting B cells also reduce the proportion of alpha(4)beta(+)(7) Th cells in the MLN and efferent lymph. Furthermore, cognate B-cell interaction drives a broad transcriptional program in Th cells, including IL-4 that is confined to the Tfh cell lineage. The IL-4-producing Tfh-like cells originate from Bcl6(+) precursors in the LNs and have gut-homing capacity. Hence, B cells program the efferent lymph Th cell response within a limited window of time after antigenic challenge.
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| 2. |
- Fernández-Santoscoy, Maria, et al.
(författare)
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A reduced population of CD103(+)CD11b(+) dendritic cells has a limited impact on oral Salmonella infection
- 2016
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Ingår i: Immunology Letters. - : Elsevier BV. - 0165-2478. ; 176, s. 72-80
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Tidskriftsartikel (refereegranskat)abstract
- CD103(+)CD11b(+) dendritic cells (DC) are the major migratory DC subset in the small intestine lamina propria (siLP) and their survival is dependent on the transcription factor interferon regulatory factor 4 (IRF4). Mice with a DC-specific deletion of irf4 (CD11c-cre.Irf4 mice) have reduced mucosal CD103(+)CD11b(+) DC and altered T cell differentiation to protein antigen. The influence of CD103(+)CD11b(+) DC on oral infection with the gastrointestinal pathogen Salmonella, however, is poorly understood and is investigated here. We show that, despite being infected with Salmonella, CD11c-cre.lrf4 mice (called Cre(+) mice) conserve the reduction in CD103(+)CD11b(+) DC observed in naive Cre(+) mice, particularly in the mesenteric lymph nodes (MLN) but also in the siLP at day 3 post infection. Moreover, Salmonella-infected Cre(+) mice have a similar bacterial burden in intestinal tissues (siLP, MLN and Peyer's patches) as well as the spleen compared to infected Cre-controls. The T cell compartment, including the frequency of IFN-gamma and IL-17-producing T cells, is not altered in intestinal tissues of Salmonella-infected Cre(+) mice relative to infected Cre-controls. In addition, no difference between infected Cre(+) and Cre-mice was observed in either the concentration of IL-6 or IL-17 in whole tissue lysates of siLP, MLN or Peyer's patches or in the serum concentration of Salmonella-specific IgG and IgM. Overall the data suggest that the reduction of CD103(+)CD11b(+) DC in Cre(+) mice has little if any impact on Salmonella burden in infected tissues or eliciting effector functions important in host survival at later stages of the infection. (C) 2016 European Federation of Immunological Societies. Published by Elsevier B.V. All rights reserved.
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| 3. |
- Fernández-Santoscoy, Maria, et al.
(författare)
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The Gut Microbiota Reduces Colonization of the Mesenteric Lymph Nodes and IL-12-Independent IFN-gamma Production During Salmonella Infection
- 2015
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Ingår i: Frontiers in Cellular and Infection Microbiology. - : Frontiers Media SA. - 2235-2988. ; 5
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Tidskriftsartikel (refereegranskat)abstract
- The intestinal commensal microbiota is essential for many host physiological processes, but its impact on infectious diseases is poorly understood. Here we investigate the influence of the gut microbiota during oral Salmonella infection. We report a higher bacterial burden in mesenteric lymph nodes (MLN) of intragastrically infected germ-free (GF) mice compared to conventionally-raised (CONV-R) animals, despite similar inflammatory phagocyte recruitment. Salmonella penetration into the lamina propria of the small intestine and splenic bacterial burden were not altered in the absence of the microbiota. Intragastrically infected GF mice also displayed a higher frequency of IFN-gamma-producing NK, NKT, CD4(+), and CD8(+) T cells in the MLN despite IL-12 levels similar to infected CONV-R mice. However, infecting mice intraperitoneally abrogated the difference in MLN bacterial load and IFN-gamma-producing cells observed in intragastrically-infected animals. Moreover, mice treated with antibiotics (ABX) and intragastrically infected with Salmonella had a greater bacterial burden and frequency of IFN-gamma-producing cells in the MLN. In ABX mice the number of Salmonella correlated with the frequency of IFN-gamma-producing lymphocytes in the MLN, while no such correlation was observed in the MLN of infected GF mice. Overall, the data show that the lack of the microbiota influences pathogen colonization of the MLN, and the increased IFN-gamma in the MLN of infected GF mice is not only due to the absence of commensals at the time of infection but the lack of immune signals provided by the microbiota from birth.
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| 4. |
- Crauwels, P., et al.
(författare)
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Cathelicidin Contributes to the Restriction of Leishmania in Human Host Macrophages
- 2019
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Ingår i: Frontiers in Immunology. - : Frontiers Media SA. - 1664-3224. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- In cutaneous Leishmaniasis the parasitic control in human host macrophages is still poorly understood. We found an increased expression of the human cathelicidin CAMP in skin lesions of Ethiopian patients with cutaneous leishmaniasis. Vitamin D driven, Cathelicidin-type antimicrobial peptides (CAMP) play an important role in the elimination of invading microorganisms. Recombinant cathelicidin was able to induce cell-death characteristics in Leishmania in a dose dependent manner. Using human primary macrophages, we demonstrated pro-inflammatory macrophages (hMDM1) to express a higher level of human cathelicidin, both on gene and protein level, compared to anti-inflammatory macrophages (hMDM2). Activating the CAMP pathway using Vitamin D in hMDM1 resulted in a cathelicidin-mediated-Leishmania restriction. Finally, a reduction of cathelicidin in hMDM1, using a RNA interference (RNAi) approach, increased Leishmania parasite survival. In all, these data show the human cathelicidin to contribute to the innate immune response against Leishmaniasis in a human primary cell model.
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| 5. |
- Grdic Eliasson, Dubravka, et al.
(författare)
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M2e-tetramer-specific memory CD4 T cells are broadly protective against influenza infection.
- 2018
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Ingår i: Mucosal immunology. - : Elsevier BV. - 1935-3456 .- 1933-0219. ; 11:1, s. 273-289
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Tidskriftsartikel (refereegranskat)abstract
- Matrix protein 2 ectodomain (M2e) is considered an attractive component of a broadly protective, universal influenza A vaccine. Here we challenge the canonical view that antibodies against M2e are the prime effectors of protection. Intranasal immunizations of Balb/c mice with CTA1-3M2e-DD-generated M2e-specific memory CD4 T cells that were I-Ad restricted and critically protected against infection, even in the complete absence of antibodies, as observed in JhD mice. Whereas some M2e-tetramer-specific memory CD4 T cells resided in spleen and lymph nodes, the majority were lung-resident Th17 cells, that rapidly expanded upon a viral challenge infection. Indeed, immunized IL-17A-/- mice were significantly less well protected compared with wild-type mice despite exhibiting comparable antibody levels. Similarly, poor protection was also observed in congenic Balb/B (H-2b) mice, which failed to develop M2e-specific CD4 T cells, but exhibited comparable antibody levels. Lung-resident CD69+ CD103low M2e-specific memory CD4 T cells were αβ TCR+ and 50% were Th17 cells that were associated with an early influx of neutrophils after virus challenge. Adoptively transferred M2e memory CD4 T cells were strong helper T cells, which accelerated M2e- but more importantly also hemagglutinin-specific IgG production. Thus, for the first time we demonstrate that M2e-specific memory CD4 T cells are broadly protective.Mucosal Immunology advance online publication 15 March 2017. doi:10.1038/mi.2017.14.
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| 6. |
- Guo, Manman, et al.
(författare)
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Triggering MSR1 promotes JNK-mediated inflammation in IL-4-activated macrophages.
- 2019
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Ingår i: The EMBO journal. - : EMBO. - 1460-2075 .- 0261-4189. ; 38:11
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Tidskriftsartikel (refereegranskat)abstract
- Alternatively activated M2 macrophages play an important role in maintenance of tissue homeostasis by scavenging dead cells, cell debris and lipoprotein aggregates via phagocytosis. Using proteomics, we investigated how alternative activation, driven by IL-4, modulated the phagosomal proteome to control macrophage function. Our data indicate that alternative activation enhances homeostatic functions such as proteolysis, lipolysis and nutrient transport. Intriguingly, we identified the enhanced recruitment of the TAK1/MKK7/JNK signalling complex to phagosomes of IL-4-activated macrophages. The recruitment of this signalling complex was mediated through K63 polyubiquitylation of the macrophage scavenger receptor 1 (MSR1). Triggering of MSR1 in IL-4-activated macrophages leads to enhanced JNK activation, thereby promoting a phenotypic switch from an anti-inflammatory to a pro-inflammatory state, which was abolished upon MSR1 deletion or JNK inhibition. Moreover, MSR1K63 polyubiquitylation correlated with the activation of JNK signalling in ovarian cancer tissue from human patients, suggesting that it may be relevant for macrophage phenotypic shift invivo Altogether, we identified that MSR1 signals through JNK via K63 polyubiquitylation and providesevidence for the receptor's involvement in macrophage polarization.
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| 7. |
- Lebrero-Fernandez, Cristina, et al.
(författare)
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Altered expression of Butyrophilin (BTN) and BTN-like (BTNL) genes in intestinal inflammation and colon cancer
- 2016
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Ingår i: Immunity Inflammation and Disease. - : Wiley. - 2050-4527. ; 4:2, s. 191-200
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Tidskriftsartikel (refereegranskat)abstract
- Several Butyrophilin (BTN) and Btn-like (BTNL) molecules control T lymphocyte responses, and are genetically associated with inflammatory disorders and cancer. In this study, we present a comprehensive expression analysis of human and murine BTN and BTNL genes in conditions associated with intestinal inflammation and cancer. Using real-time PCR, expression of human BTN and BTNL genes was analyzed in samples from patients with ulcerative colitis, irritable bowel syndrome, and colon tumors. Expression of murine Btn and Btnl genes was examined in mouse models of spontaneous colitis (Muc2(-/-)) and intestinal tumorigenesis (Apc(Min/+)). Our analysis indicates a strong association of several of the human genes with ulcerative colitis and colon cancer; while especially BTN1A1, BTN2A2, BTN3A3, and BTNL8 were significantly altered in inflammation, colonic tumors exhibited significantly decreased levels of BTNL2, BTNL3, BTNL8, and BTNL9 as compared to unaffected tissue. Colonic inflammation in Muc2(-/-) mice significantly down-regulated the expression of particularly Btnl1, Btnl4, and Btnl6 mRNA, and intestinal polyps derived from Apc(Min/+) mice displayed altered levels of Btn1a1, Btn2a2, and Btnl1 transcripts. Thus, our data present an association of BTN and BTNL genes with intestinal inflammation and cancer and represent a valuable resource for further studies of this gene family.
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| 8. |
- Schussek, Sophie, et al.
(författare)
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The CTA1-DD adjuvant strongly potentiates follicular dendritic cell function and germinal center formation, which results in improved neonatal immunization
- 2020
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Ingår i: Mucosal Immunology. - : Elsevier BV. - 1933-0219. ; 13, s. 545-557
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Tidskriftsartikel (refereegranskat)abstract
- Vaccination of neonates and young infants is hampered by the relative immaturity of their immune systems and the lack of safe and efficacious vaccine adjuvants. Immaturity of the follicular dendritic cells (FDCs), in particular, appears to play a critical role for the inability to stimulate immune responses. Using the CD21mT/mG mouse model we found that at 7 days of life, FDCs exhibited a mature phenotype only in the Peyer ' s patches (PP), but our unique adjuvant, CTA1-DD, effectively matured FDCs also in peripheral lymph nodes following systemic, as well as mucosal immunizations. This was a direct effect of complement receptor 2-binding to the FDC and a CTA1-enzyme-dependent enhancing effect on gene transcription, among which CR2, IL-6, ICAM-1, IL-1 beta, and CXCL13 encoding genes were upregulated. This way we achieved FDC maturation, increased germinal center B-cell- and Tfh responses, and enhanced specific antibody levels close to adult magnitudes. Oral priming immunization of neonates against influenza infection with CTA1-3M2e-DD effectively promoted anti-M2e-immunity and significantly reduced morbidity against a live virus challenge infection. To the best of our knowledge, this is the first study to demonstrate direct effects of an adjuvant on FDC gene transcriptional functions and the subsequent enhancement of neonatal immune responses.
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| 9. |
- Sjökvist Ottsjö, Louise, 1986, et al.
(författare)
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Induction of mucosal immune responses against Helicobacter pylori infection after sublingual and intragastric route of immunization
- 2017
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Ingår i: Immunology. - : Wiley. - 0019-2805. ; 150:2, s. 172-183
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Tidskriftsartikel (refereegranskat)abstract
- There is a current lack of effective mucosal vaccines against major gastroenteric pathogens and particularly against Helicobacter pylori, which causes a chronic infection that can lead to peptic ulcers and gastric cancer in a subpopulation of infected individuals. Mucosal CD4(+) T-cell responses have been shown to be essential for vaccine-induced protection against H. pylori infection. The current study addresses the influence of the adjuvant and site of mucosal immunization on early CD4(+) T-cell priming to H. pylori antigens. The vaccine formulation consisted of H. pylori lysate antigens and mucosal adjuvants, cholera toxin (CT) or a detoxified double-mutant heat-labile enterotoxin from Escherichia coli (dmLT), which were administered by either the sublingual or intragastric route. We report that in vitro, adjuvants CT and dmLT induce up-regulation of pro-inflammatory gene expression in purified dendritic cells and enhance the H. pylori-specific CD4(+) T-cell response including interleukin-17A (IL-17A), interferon-gamma (IFN-gamma) and tumour necrosis factor-alpha (TNF-alpha) secretion. In vivo, sublingual immunization led to an increased frequency of IL-17A(+), IFN-gamma(+) and TNF-alpha(+) secreting CD4(+) T cells in the cervical lymph nodes compared with in the mesenteric lymph nodes after intragastric immunization. Subsequently, IL-17A(+) cells were visualized in the stomach of sublingually immunized and challenged mice. In summary, our results suggest that addition of an adjuvant to the vaccine clearly activated dendritic cells, which in turn, enhanced CD4(+) T-cell cytokines IL-17A, IFN-gamma and TNF-alpha responses, particularly in the cervical lymph nodes after sublingual vaccination.
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| 10. |
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| 11. |
- Tam, Miguel A., 1976, et al.
(författare)
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Plasmacytoid dendritic cells mature independently of MyD88 and IFN-alpha beta R in response to Listeria and stimulate CD8 T cells
- 2011
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Ingår i: IMMUNOLOGY LETTERS. - 0165-2478. ; 138:2, s. 104-112
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Tidskriftsartikel (refereegranskat)abstract
- Abstract: Plasmacytoid dendritic cells (pDCs) are a subpopulation of dendritic cells specialized in the production of IFN-alpha/beta, particularly during viral infections. In this way pDCs directly impact antiviral immunity and influence T cell activation. However, despite their role as modulators of the immune response, their function as antigen-presenting cells (APCs) remains poorly understood. Indeed, their capacity as APCs during bacterial infections is unexplored. Here we investigate the importance of MyD88 and IFN-alpha/beta in upregulating costimulatory molecules on pDCs during Listeria infection and their impact on activation of naive CD8 T cells. We show that pDCs efficiently upregulate CD80 and CD86 during systemic Listeria infection, yet express lower levels of these molecules than conventional dendritic cells (cDCs). Furthermore, pDCs are able to stimulate CD8 T cell proliferation and IFN-gamma production, although less efficiently than cDCs. Despite these differences, the influence of MyD88 and IFN-alpha/beta on CD80 and CD86 expression on pDCs and cDCs is similar. Thus, our data show for the first time the potential of pDCs to activate CD8 T cells in response to a bacterial infection. (C) 2011 Elsevier B.V. All rights reserved.
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| 12. |
- Wenzel, Ulf Alexander, 1975, et al.
(författare)
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CD103(+)CD11b(+) Dendritic Cells Induce T(h)17 T Cells in Muc2-Deficient Mice with Extensively Spread Colitis
- 2015
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Ingår i: Plos One. - : Public Library of Science (PLoS). - 1932-6203. ; 10:6
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Tidskriftsartikel (refereegranskat)abstract
- Mucus alterations are a feature of ulcerative colitis (UC) and can drive inflammation by compromising the mucosal barrier to luminal bacteria. The exact pathogenesis of UC remains unclear, but CD4(+) T cells reacting to commensal antigens appear to contribute to pathology. Given the unique capacity of dendritic cells (DCs) to activate naive T cells, colon DCs may activate pathogenic T cells and contribute to disease. Using Muc2(-/-) mice, which lack a functional mucus barrier and develop spontaneous colitis, we show that colitic animals have reduced colon CD103(+)CD11b(-) DCs and increased CD103(-)CD11b(+) phagocytes. Moreover, changes in colonic DC subsets and distinct cytokine patterns distinguish mice with distally localized colitis from mice with colitis spread proximally. Specifically, mice with proximally spread, but not distally contained, colitis have increased IL-1 beta, IL-6, IL-17, TNF alpha, and IFN gamma combined with decreased IL-10 in the distal colon. These individuals also have increased numbers of CD103(+)CD11b(+) DCs in the distal colon. CD103(+)CD11b(+) DCs isolated from colitic but not noncolitic mice induced robust differentiation of Th17 cells but not Th1 cells ex vivo. In contrast, CD103(-)CD11b(+) DCs from colitic Muc2(-/-) mice induced Th17 as well as Th1 differentiation. Thus, the local environment influences the capacity of intestinal DC subsets to induce T cell proliferation and differentiation, with CD103(+)CD11b(+) DCs inducing IL-17-producing T cells being a key feature of extensively spread colitis.
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| 13. |
- Wenzel, Ulf Alexander, 1975, et al.
(författare)
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Leishmania major parasite stage-dependent host cell invasion and immune evasion
- 2012
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Ingår i: FASEB Journal. - : Wiley. - 0892-6638 .- 1530-6860. ; 26, s. 29-39
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Tidskriftsartikel (refereegranskat)abstract
- Leishmania pathogenesis is primarily studied using the disease-inducing promastigote stage of Leishmania major. Despite many efforts, all attempts so far have failed to culture the disease-relevant multiplying amastigote stage of L. major. Here, we established a stably growing axenic L. major amastigote culture system that was characterized genetically, morphologically, and by stage-specific DsRed protein expression. We found parasite stage-specific disease development in resistant C57BL/6 mice. Human neutrophils, as first host cells for promastigotes, do not take up amastigotes. In human macrophages, we observed an amastigote-specific complement receptor 3-mediated, endocytotic entry mechanism, whereas promastigotes are taken up by complement receptor 1-mediated phagocytosis. Promastigote infection of macrophages induced the inflammatory mediators TNF, CCL3, and CCL4, whereas amastigote infection was silent and resulted in significantly increased parasite numbers: from 7.1 ± 1.4 (after 3 h) to 20.1 ± 7.9 parasites/cell (after 96 h). Our study identifies Leishmania stage-specific disease development, host cell preference, entry mechanism, and immune evasion. Since the amastigote stage is the disease-propagating form found in the infected mammalian host, the newly developed L. major axenic cultures will serve as an important tool in better understanding the amastigote-driven immune response in leishmaniasis. © FASEB.
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| 14. |
- Wenzel, Ulf Alexander, 1975, et al.
(författare)
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Spontaneous colitis in Muc2-deficient mice reflects clinical and cellular features of active ulcerative colitis.
- 2014
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Ingår i: PloS one. - : Public Library of Science (PLoS). - 1932-6203. ; 9:6
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Tidskriftsartikel (refereegranskat)abstract
- The colonic mucus layer plays a critical role in intestinal homeostasis by limiting contact between luminal bacteria and the mucosal immune system. A defective mucus barrier in animal models allows bacterial contact with the intestinal epithelium and results in spontaneous colitis. A defective mucus barrier is also a key feature of active ulcerative colitis (UC). Alterations in the immune compartment due to intestinal bacterial breach in mice lacking the colon mucus barrier have not been characterized and correlated to active UC.
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| 15. |
- Wenzel, Ulf Alexander, 1975, et al.
(författare)
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Synergy between CD40 and MyD88 does not influence host survival to Salmonella infection
- 2015
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Ingår i: Frontiers in Immunology. - : Frontiers Media SA. - 1664-3224. ; 6
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Tidskriftsartikel (refereegranskat)abstract
- Previous studies using purified toll-like receptor (TLR) ligands plus agonistic anti-CD40 antibodies showed that TLRs and CD40 can act synergistically on dendritic cells (DCs) to optimize T cell activation and Th1 differentiation. However, a synergistic effect of TLRs and CD40 during bacterial infection is not known. Here, we show that mice lacking the TLR adaptor MyD88 alone, or lacking both MyD88 and CD40 [double knockout (DKO) mice], are compromised in survival to Salmonella infection but have intact recruitment of neutrophils and inflammatory monocytes as well as unaltered abundance of DC subsets and DC activation in infected tissues. In contrast to infected wildtype and CD40(-/-) mice, both MyD88(-/-) mice and DKO mice lack detectable serum IFN-gamma and have elevated IL-10. A synergistic effect of TLRs and CD40 was revealed in co-culture experiments where 01-11 T cell proliferation was compromised when DKO DCs were pulsed with OVA protein and OVA(323-339) peptide, but not with heat-killed Salmonella expressing OVA (HKSOVA), relative to MyD88(-/-) DCs. By contrast, MyD88(-/-) or DKO DCs pulsed with any of the antigens had a similar ability to induce IFN-gamma that was lower than WT or CD40(-/-) DCs. DKO DCs pulsed with HKSOVA, but not with OVA or OVA(323-339), had increased IL-10 relative to MyD88(-/-) DCs. Finally, HKSHKSOVA-pulsed MyD88(-/-) and DKO DCs had similar and low induction of NF kappa B-dependent and independent genes upon co-culture with 01-11 cells. Overall, our data revealed that synergistic effects of CD40 and MyD88 do not influence host survival to Salmonella infection or serum levels of IFN-gamma or IL-10. However, synergistic effects of MyD88 and CD40 may be apparent on some (IL-10 production) but not all (01-11 proliferation and IFN-gamma production) DC functions and depend on the complexity of the antigen. Indeed, synergistic effects observed using purified ligands and well-defined antigens may not necessarily apply when complex antigens, such as live bacteria, challenge the immune system.
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