Interplay between the heterotrimeric G-protein subunits Gαq and Gαi2 sets the threshold for chemotaxis and TCR activation

<p>Abstract</p> <p>Background</p> <p>TCR and CXCR4-mediated signaling appears to be reciprocally regulated pathways. TCR activation dampens the chemotactic response towards the CXCR4 ligand CXCL12, while T cells exposed to CXCL12 are less prone to subsequent TCR-activation. The heterotrimeric G proteins G_αqand G_αi2have been implicated in CXCR4-signaling and we have recently also reported the possible involvement of G_αqin TCR-dependent activation of Lck (Ngai et al., Eur. J. Immunol., 2008, 38: 32083218). Here we examined the role of G_αqin migration and TCR activation.</p> <p>Results</p> <p>Pre-treatment of T cells with CXCL12 led to significantly reduced Lck Y394 phosphorylation upon TCR triggering indicating heterologous desensitization. We show that knockdown of G_αqsignificantly enhanced basal migration in T cells and reduced CXCL12-induced SHP-1 phosphorylation whereas G_αi2knockdown inhibited CXCL12-induced migration.</p> <p>Conclusion</p> <p>Our data suggest that G_αi2confers migration signals in the presence of CXCL12 whereas G_αqexerts a tonic inhibition on both basal and stimulated migrational responses. This is compatible with the notion that the level of G_αqactivation contributes to determining the commitment of the T cell either to migration or activation through the TCR.</p

Cell-based therapy in prophylaxis and treatment of chronic graft-versus-host disease

Copyright © 2022 Doglio, Crossland, Alho, Penack, Dickinson, Stary, Lacerda, Eissner and Inngjerdingen. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.Hematopoietic allogeneic stem cell transplantation (allo-SCT) is a curative option for patients with hematological malignancies. However, due to disparities in major and minor histocompatibility antigens between donor and recipient, severe inflammatory complications can occur, among which chronic graft-versus-host disease (cGVHD) can be life-threatening. A classical therapeutic approach to the prevention and treatment of cGVHD has been broad immunosuppression, but more recently adjuvant immunotherapies have been tested. This review summarizes and discusses immunomodulatory approaches with T cells, including chimeric antigen receptor (CAR) and regulatory T cells, with natural killer (NK) cells and innate lymphoid cells (ILCs), and finally with mesenchymal stromal cells (MSC) and extracellular vesicles thereof. Clinical studies and pre-clinical research results are presented likewise.This work was supported by COST (European Cooperation in Science and Technology). www.cost.eu - COST Action 17138 EUROGRAFT.info:eu-repo/semantics/publishedVersio

Innate lymphoid cell characterization in the rat and their correlation to gut commensal microbes.

Innate lymphoid cells (ILCs) are important for tissue immune homeostasis, and are thoroughly characterized in mice and humans. Here, we have performed in-depth characterization of rat ILCs. Rat ILCs were identified based on differential expression of transcription factors and lack of lineage markers. ILC3s represented the major ILC population of the small intestine, while ILC2s were infrequent but most prominent in liver and adipose tissue. Two major subsets of group 1 ILCs were defined. Lineage- T-bet+ Eomes+ cells were identified as conventional NK cells, while lineage- T-bet+ Eomes- cells were identified as the probable rat counterpart of ILC1s based on their selective expression of the ILC marker CD200R. Rat ILC1s were particularly abundant in liver and intestinal tissues, and were functionally similar to NK cells. Single-cell transcriptomics of spleen and liver cells confirmed the main division of NK cells and ILC1-like cells, and demonstrated Granzyme A as an additional ILC1 marker. We further report differential distributions of NK cells and ILCs along the small and large intestines, and the association of certain bacterial taxa to frequencies of ILCs. In conclusion, we provide a framework for future studies of ILCs in diverse rat experimental models, and novel data on the potential interplay between commensals and intestinal ILCs

T Cell Specific Adapter Protein (TSAd) Interacts with Tec Kinase ITK to Promote CXCL12 Induced Migration of Human and Murine T Cells

The chemokine CXCL12/SDF-1α interacts with its G-protein coupled receptor CXCR4 to induce migration of lymphoid and endothelial cells. T cell specific adapter protein (TSAd) has been found to promote migration of Jurkat T cells through interaction with the G protein β subunit. However, the molecular mechanisms for how TSAd influences cellular migration have not been characterized in detail. We show that TSAd is required for tyrosine phosphorylation of the Lck substrate IL2-inducible T cell kinase (Itk). Presence of Itk Y511 was necessary to boost TSAd\u27s effect on CXCL12 induced migration of Jurkat T cells. In addition, TSAd\u27s ability to promote CXCL12-induced actin polymerization and migration of Jurkat T lymphocytes was dependent on the Itk-interaction site in the proline-rich region of TSAd. Furthermore, TSAd-deficient murine thymocytes failed to respond to CXCL12 with increased Itk phosphorylation, and displayed reduced actin polymerization and cell migration responses. We propose that TSAd, through its interaction with both Itk and Lck, primes Itk for Lck mediated phosphorylation and thereby regulates CXCL12 induced T cell migration and actin cytoskeleton rearrangements

Distinguishing left ventricular hypertrophy from hypertrophic cardiomyopathy in adolescents: A longitudinal observation study

This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial License (https://creativecommons.org/licenses/by-nc/4.0/), which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is properly cited.Aims: Echocardiographic characteristics to distinguish physiological left ventricular (LV) hypertrophy from pathology are warranted in early adolescent athletes. This study aimed to explore the phenotype, progression, and potential grey zone of LV hypertrophy during adolescence in athletes and hypertrophic cardiomyopathy (HCM) genotype–positive patients. Methods and results: In this longitudinal observation study, we compared seventy-six 12-year-old athletes with 55 age-matched and sex-matched HCM genotype–positive patients. Echocardiographic parameters were evaluated by using paediatric reference values (Z-scores). Hypertrophic cardiomyopathy genotype–positive patients were included if they had no or mild LV hypertrophy [maximum wall thickness <13 mm, Z-score <6 for interventricular septum diameter (ZIVSd), or posterior wall thickness]. We collected clinical data, including data on cardiac events. The mean follow-up-time was 3.2 ± 0.8 years. At baseline, LV hypertrophy was found in 28% of athletes and 21% of HCM genotype–positive patients (P = 0.42). Septum thickness values were similar (ZIVSd 1.4 ± 0.9 vs. 1.0 ± 1.3, P = 0.08) and increased only in HCM genotype–positive patients {ZIVSd progression rate −0.17 [standard error (SE) 0.05], P = 0.002 vs. 0.30 [SE 0.10], P = 0.001}. Left ventricular volume Z-scores (ZLVEDV) were greater in athletes [ZLVEDV 1.0 ± 0.6 vs. −0.1 ± 0.8, P < 0.001; ZLVEDV progression rate −0.05 (SE 0.04), P = 0.21 vs. −0.06 (SE 0.04), P = 0.12]. Cardiac arrest occurred in two HCM genotype–positive patients (ages 13 and 14), with ZIVSd 8.2–11.5. Conclusion: Left ventricular hypertrophy was found in a similar proportion in early adolescence but progressed only in HCM genotype–positive patients. A potential grey zone of LV hypertrophy ranged from a septum thickness Z-score of 2.0 to 3.3. Left ventricular volumes remained larger in athletes. Evaluating the progression of wall thickness and volume may help clinicians distinguish physiological LV hypertrophy from early HCM.publishedVersionInstitutt for fysisk prestasjonsevne / Department of Physical Performanc

In vivo induction of leukemia-specific adaptive and innate immune cells by treatment of aml-diseased rats and therapy-refractory AML patients with blast modulating response modifiers

There is a high medical need to develop new strategies for the treatment of patients with acute myeloid leukemia (AML) refractory to conventional therapy. In vitro, the combinations of the blast-modulatory response modifiers GM-CSF + Prostaglandin E1, (summarized as Kit M) have been shown to convert myeloid leukemic blasts into antigen-presenting dendritic cells of leukemic origin (DCleu) that were able to (re-)activate the innate and adaptive immune system, direct it specifically against leukemic blasts, and induce memory cells. This study aimed to investigate the immune modulatory capacity and antileukemic efficacy of Kit M in vivo. Brown Norway rats suffering from AML were treated with Kit M (twofold application). Blasts and immune cells were monitored in peripheral blood (PB) and spleen. Upon the observation of promising immune modulatory effects in the treated animals, two patients with AML refractory to multiple lines of therapy were offered treatment with Kit M on an individualized basis. Safety, as well as immunological and clinical effects, were monitored. Samples obtained from a third patient in similar clinical conditions not receiving Kit M were used as controls for immune monitoring tests. Animal experiments: Drugs were well tolerated by the treated animals. After 9 days of treatment, DCleu and memory-like T cells increased in the peripheral blood, whereas regulatory T cells, especially blasts, decreased in treated as compared to untreated control animals. Clinical courses: No severe side effects were observed. In patient 1482, PB blasts remained under the detection threshold during 27 days of treatment, thrombocytes were normalized, and (leukemia specific) immune effector cells of the adaptive and innate immune system increased up to 800-fold compared to the start of treatment. Patient 1601 responded with a 12% reduction in blasts in PB immediately after Kit M treatment. Several subtypes of (leukemia-specific) immune effector cells in PB increased up to four-fold during the 19 days of treatment. In contrast, immune-reactive cells decreased under mild chemotherapy in the PB of control patient 1511 with comparably refractory AML. Within the limitation of low numbers in both animal experiments and clinical applications, our data suggest that Kit M treatment of AML-diseased rats and patients is feasible and may induce leukemia-specific immune reactions and clinical improvement. A larger series and a prospective clinical trial will be required to confirm our observations. Beyond optimized doses and schedules of the applied compounds, the combination with other antileukemic strategies or the application of Kit M in less proliferative stages of the myeloid diseases need to be discussed. If effects are confirmed, the concept may add to the armamentarium of treatments for highly aggressive blood cancer

Polysaccharides from the South African medicinal plant Artemisia afra: Structure and activity studies

Artemisia afra (Jacq. Ex. Willd), is an indigenous plant in South Africa and other parts of the African continent, where it is used as traditional medicine mostly for respiratory conditions. The objective of this study was to investigate the structural features of the polysaccharides from the leaves of this plant, as well as the biological activities of the polysaccharide fractions against the complement assay. Leaves of Artemisia afra were extracted sequentially with organic solvents (dichloromethane and methanol), 50% aqueous ethanol, and water at 50 and 100 °C respectively. The polysaccharide extracts were fractionated by ion exchange chromatography and the resulting fractions were tested for biological activity against the complement fixation assay. Active fractions were further fractionated using gel filtration. Monosaccharide compositions and linkage analyses were determined for the relevant fractions. Polysaccharides were shown to be of the pectin type, and largely contain arabinogalactan, rhamnogalacturonan and homogalacturonan structural features. The presence of arabinogalactan type II features as suggested by methylation analysis was further confirmed by the ready precipitation of the relevant polysaccharides with the Yariv reagent. An unusual feature of some of these polysaccharides was the presence of relatively high levels of xylose as one of its monosaccharide constituents. Purified polysaccharide fractions were shown to possess higher biological activity than the selected standard in the complement assay. Digestion of these polysaccharides with an endo-polygalacturonase enzyme resulted in polymers with lower molecular weights as expected, but still with biological activity which exceeded that of the standard. Thus on the basis of these studies it may be suggested that immunomodulating properties probably contribute significantly to the health-promoting effects of this medicinal plant