| 1. |
- Rose Mathew, Nimitha, 1987, et al.
(författare)
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Single-cell BCR and transcriptome analysis after influenza infection reveals spatiotemporal dynamics of antigen-specific B cells
- 2021
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Ingår i: Cell Reports. - : Elsevier BV. - 2211-1247. ; 35:12
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Tidskriftsartikel (refereegranskat)abstract
- B cell responses are critical for antiviral immunity. However, a comprehensive picture of antigen-specific B cell differentiation, clonal proliferation, and dynamics in different organs after infection is lacking. Here, by combining single-cell RNA and B cell receptor (BCR) sequencing of antigen-specific cells in lymph nodes, spleen, and lungs after influenza infection in mice, we identify several germinal center (GC) B cell subpopulations and organ-specific differences that persist over the course of the response. We discover transcriptional differences between memory cells in lungs and lymphoid organs and organ-restricted clonal expansion. Remarkably, we find significant clonal overlap between GC-derived memory and plasma cells. By combining BCR-mutational analyses with monoclonal antibody (mAb) expression and affinity measurements, we find that memory B cells are highly diverse and can be selected from both low- and high-affinity precursors. By linking antigen recognition with transcriptional programming, clonal proliferation, and differentiation, these finding provide important advances in our understanding of antiviral immunity.
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| 2. |
- Rodin, William, 1994, et al.
(författare)
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Exhaustion in tumor-infiltrating Mucosal-Associated Invariant T (MAIT) cells from colon cancer patients
- 2021
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Ingår i: Cancer Immunology Immunotherapy. - : Springer Science and Business Media LLC. - 0340-7004 .- 1432-0851. ; 70, s. 3461-3475
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Tidskriftsartikel (refereegranskat)abstract
- Mucosal-associated invariant T (MAIT) cells are unconventional T cells recognizing microbial metabolites, presented by the invariant MR1 protein. Upon activation, MAIT cells rapidly secrete cytokines and exert cytotoxic functions, and may thus be highly relevant also in tumor immunity. MAIT cells accumulate in colon tumors, but in contrast to other cytotoxic T cell subsets, their presence in tumors has been associated with worse patient outcome. Here we investigated if exhaustion may contribute to reduced anti-tumor immunity by MAIT cells. Freshly isolated lymphocytes from colon tumors, unaffected tissue and blood from the same patients were analyzed by flow cytometry to detect MAIT cells with effector functions that are relevant for tumor immunity, and their expression of inhibitory receptors and other exhaustion markers. Our studies show that MAIT cells with a PD-1(high)Tim-3(+)CD39(+) terminally exhausted phenotype and an increased proliferation accumulate in colon tumors. The exhausted MAIT cells have reduced polyfunctionality with regard to production of important anti-tumor effector molecules, and blocking antibodies to PD-1 partly improved activation of tumor-infiltrating MAIT cells in vitro. We conclude that the tumor microenvironment leads to exhaustion not only of conventional T cells, but also MAIT cells, and that checkpoint blockade therapy may be useful also to reinvigorate tumor-infiltrating MAIT cells.
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| 3. |
- Rodin, William, 1994, et al.
(författare)
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Isolation and Characterization of MAIT Cells from Tumor Tissues
- 2020
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Ingår i: MAIT Cells. Methods and Protocols. Helen KaipeIsabelle Magalhaes (red.). - New York, NY : Springer. - 9781071602065 ; , s. 39-53
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Mucosal-associated invariant T (MAIT) cell infiltration has been demonstrated in colorectal and hepatocellular carcinoma, and their ability to produce Th1- and Th17-associated cytokines, as well as their cytotoxic function, suggests that MAIT cells may have important functions in both reducing and promoting protective tumor immunity. Here, we describe enzymatic methods to isolate intraepithelial and lamina propria lymphocyte single cell suspensions from colon tissue and tumors containing viable MAIT cells, which can be used for further purification, flow cytometry analysis, or culture.
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| 4. |
- Rodin, William, 1994
(författare)
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Unconventional T cells in colon adenocarcinomas
- 2023
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Many factors influence the initiation and growth of tumours. The infiltration and activity of immune cells in the tumour microenvironment are widely recognised as key factors affecting the clinical outcome of cancer. In this context, conventional T cells have been studied thoroughly but much less is known about the enigmatic populations of unconventional T cells. Of particular interest are the gd and mucosal-associated invariant T (MAIT) cells as they, among other things, are (relatively) abundant in humans, possess the ability to recognise transformed host cells, and secrete cytokines, as well as cytotoxic effector proteins. The aim of this thesis was to investigate the potential role of unconventional T cells in the immune response to tumours and specifically if they possess the ability to kill tumour cells. We used tissue from colon tumours, unaffected colon mucosa, and blood from patients undergoing curative resection surgery at the Sahlgrenska University Hospital, along with blood samples from healthy blood donors, to investigate the phenotype and effector functions of MAIT and gd T cells. We demonstrated that MAIT cells accumulate in colon tumours while gd T cell infiltration is reduced. The gd T cells present in colon tumours contained a subset of Vd1-Vd2- cells with potential tumour-promoting properties. Furthermore, we showed that a portion of the tumour-infiltrating MAIT cells were functionally impaired and characterised by expression of PD-1 and Tim3. The PD-1+Tim3high MAIT cells had a reduced capacity to produce cytokines and effector proteins, compared to their PD-1-Tim3- counterparts. We also showed that these functionally impaired, or exhausted, MAIT cells could be partially re-activated in the presence of monoclonal antibodies towards PD-1 (Pembrolizumab). In a third study, we demonstrated that circulating and tumour-infiltrating MAIT cells from patients and circulating MAIT cells from healthy donors can be readily expanded in vitro. Expanded MAIT cells regardless of tissue origin were highly cytotoxic and effectively killed both epithelial cancer cell lines as well as primary tumour cells derived from colon cancer patients. Lastly, we also showed that the cytotoxicity of expanded MAIT cells was partly dependent on the activity of one or more serine proteases, as blocking the activity of all serine protease activity reduced the cytotoxicity of expanded MAIT cells. In conclusion, this thesis highlights some of the complexities of gd and MAIT cell responses in tumour immunity, but also that specific subsets, such as MAIT cells, can be expanded and potentially used as future treatments against colon cancer.
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| 5. |
- Sundström, Patrik, et al.
(författare)
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Immune checkpoint blockade improves the activation and function of circulating mucosal-associated invariant T (MAIT) cells in patients with non-small cell lung cancer
- 2024
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Ingår i: OncoImmunology. - 2162-4011 .- 2162-402X. ; 13:1
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Tidskriftsartikel (refereegranskat)abstract
- Mucosal-associated invariant T (MAIT) cells constitute one of the most numerous unconventional T cell subsets, and are characterized by rapid release of Th1- and Th17-associated cytokines and increased cytotoxic functions following activation. MAIT cells accumulate in tumor tissue but show an exhausted phenotype. Here, we investigated if immune checkpoint blockade (ICB) with antibodies to PD-1 or PD-L1 affects the function of circulating MAIT cells from non-small cell lung cancer patients. ICB increased the proliferation and co-expression of the activation markers HLA-DR and CD38 on MAIT cells in most patients after the first treatment cycle, irrespective of treatment outcome. Furthermore, production of cytokines, especially TNF and IL-2, also increased after treatment, as did MAIT cell polyfunctionality. These results indicate that MAIT cells respond to ICB, and that MAIT cell reinvigoration may contribute to tumor regression in patients undergoing immune checkpoint therapy.
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| 6. |
- Szeponik, Louis, et al.
(författare)
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Intratumoral regulatory T cells from colon cancer patients comprise several activated effector populations
- 2021
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Ingår i: Bmc Immunology. - : Springer Science and Business Media LLC. - 1471-2172. ; 22:1
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Tidskriftsartikel (refereegranskat)abstract
- Background Intratumoral regulatory T cells (Treg) in colon cancer are a heterogeneous cell population, with potential impact on patient outcome. Generally, a high Treg infiltration has been correlated to a worse patient outcome, but it is still unclear how the composition of different Treg subsets affects patient relapse and survival. In this study, we used mass and flow cytometry to characterize Treg in colon tumors and corresponding unaffected tissue, followed by a correlation to clinical parameters and patient outcome. Results Using mass cytometry, we defined 13 clusters of intestinal Treg, three of which were enriched in the tumors. The two most enriched clusters were defined by their expression of the proliferation marker Ki67 and CD56, respectively. The Treg accumulating in the tumors expressed inducible T-cell co-stimulator (ICOS), OX-40, and CD39, indicating that they were effector Treg (eTreg). Intratumoral CD39(+) Treg also had a higher expression of Foxp3, suggesting a higher suppressive activity, and we subsequently used CD39 as a marker for eTreg. Our further studies showed that colon tumors can be divided into two tumor groups, based on the proportion of CD39(+) putative eTreg in the tumors. This property was independent of both tumor microsatellite status and tumor stage, which are important factors in predicting cancer disease progression. In a prospective study of forty-four colon cancer patients, we also showed that patients with a high CD39 expression on tumor-infiltrating Treg have a tendency towards a less favorable patient outcome in terms of cumulative cancer-specific survival. Conclusions This study uncovers novel subsets of tumor-infiltrating Treg in colon cancer, and suggests that CD39 may be a potential therapeutic target in patients with microsatellite stable colon tumors, which are usually refractory to checkpoint blockade therapy.
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| 7. |
- Szeponik, Louis, et al.
(författare)
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Regulatory T cells specifically suppress conventional CD8 alpha beta T cells in intestinal tumors of APC(Min/+) mice
- 2020
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Ingår i: Cancer Immunology, Immunotherapy. - : Springer Science and Business Media LLC. - 0340-7004 .- 1432-0851. ; 69, s. 1279-1292
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Tidskriftsartikel (refereegranskat)abstract
- The presence of activated T cells in colorectal cancer tissues is a strong predictor of patient survival. Our previous studies have 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 in the murine APC(Min/+) model for microsatellite stable intestinal tumors. In this study, we investigated the effect of Treg depletion on the density and effector functions of different TCR alpha beta(+) and TCR gamma delta(+) T cell populations in intestinal tumors. We used the APC(Min/+)\DEREG mouse model, which harbor a diphtheria toxin receptor under the control of the FOXP3 promoter, to deplete Treg in tumor bearing mice. We found that the density of conventional TCR alpha beta(+)CD8 alpha beta(+) T cells was significantly increased in Treg-depleted tumors in comparison with Treg-proficient tumors. Furthermore, TCR alpha beta(+)CD8 alpha beta(+) T cells showed increased proliferation and activation as well as increased Granzyme B and IFN-gamma production in Treg-depleted tumors. In sharp contrast, the densities and effector functions of TCR alpha beta(+)CD8 alpha alpha(+) T cells and TCR gamma delta(+) T cells remained unchanged by Treg depletion. We also documented a distinct population of IL-17A(+)TNF(+) TCR gamma delta(+)CD8(-) T cells in tumors, which were not affected by Treg depletion. We conclude that Treg depletion affects only conventional TCR alpha beta(+)CD8 alpha beta(+) T cells in intestinal tumors, while unconventional T cells and T cells in unaffected tissue are not altered. Immunotherapies aimed at depleting Treg from tumors may thus be a viable option for reinvigoration of conventional cytotoxic T cells with a Th1 cytokine profile.
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