OP0079 SYNOVIAL FIBROBLASTS – T CELL INTERACTIONS ARE MAJOR DRIVERS OF INFLAMMATION: A CLOSER LOOK INTO THE JOINT

Background

Rheumatoid Arthritis (RA) is a chronic inflammatory disease, which is characterized by synovial inflammation resulting in bone and cartilage destruction. Crosstalk between activated fibroblast-like synoviocytes (FLS) and immune cells, such as CD4+ T cells, within the synovium might amplify synovial inflammation and joint destruction.

Objectives

To define the interaction profile of activated FLS and CD4+ T cells within an inflammatory setting and to elucidate its consequence on synovial inflammation.

Methods

To screen for factors that activate FLS in RA, isolated FLS were treated with different inflammatory cytokines and transcriptomic changes were measured with RNA-seq. Fluorescence activated cell sorting (FACS) purified naïve CD4+ T-cells from the same patients were co-cultured with the cytokine pre-treated FLS. Automated fluorescence microscopy and downstream bioinformatic image analysis allowed visualization and quantification of cell-cell interactions. After co-culture T-cells were isolated and T-cell activation, proliferation and differentiation was determined by flow cytometry.

Results

To model the in vivo situation, FLS were pre-stimulated with different pro- and anti-inflammatory cytokines. RNA-seq revealed cytokine specific activation patterns of FLS. Correspondingly, we observed distinct CD4+ T cells – FLS interaction profiles depending on the cytokine used for FLS activation. In line with distinct interaction profiles, specific patterns in CD4+ T cells activation, proliferation and differentiation of naïve T cells into CD62Lhigh CD45ROhigh memory T cells could be detected. Signatures of cytokine-stimulated FLS could be identified in transcriptomic data from synovial tissue samples.

Conclusion

Within this study, we describe how cytokine induced CD4+ T cells – FLS interactions impact on T-cell proliferation, activation and differentiation.

References

[1]Zhang F, Wei K, Slowikowski K, Fonseka CY, Rao DA, Kelly S, et al. Defining inflammatory cell states in rheumatoid arthritis joint synovial tissues by integrating single-cell transcriptomics and mass cytometry. Nat Immunol. 2019.

[2]Smolen JS, Aletaha D, Barton A, Burmester GR, Emery P, Firestein GS, et al. Rheumatoid arthritis. Nat Rev Dis Primers. 2018;4:18001.

[3]Smolen JS, Aletaha D, McInnes IB. Rheumatoid arthritis. The Lancet. 2016;388(10055):2023-38.

[4]Bartok B, Firestein GS. Fibroblast-like synoviocytes: key effector cells in rheumatoid arthritis. Immunol Rev. 2010;233(1):233-55.

[5]Zhang F, Wei K, Slowikowski K, Fonseka CY, Rao DA, Kelly S, et al. Defining inflammatory cell states in rheumatoid arthritis joint synovial tissues by integrating single-cell transcriptomics and mass cytometry. Nat Immunol. 2019.

Disclosure of Interests

None declared.

OP0032 ERAP1-MEDIATED IMMUNOGENICITY AND IMMUNE-PHENOTYPES IN HLA-B51+ BEHÇET’S DISEASE POINT TO PATHOGENIC CD8 T CELL EFFECTOR RESPONSES

Background:

HLA-B51 is a definite risk factor for Behçet’s disease (BD). A coding variant of ERAP1, Hap10 – with low peptide-trimming activity – vastly potentiates this risk, but is mechanistically unclear1,2).

Objectives:

To test the hypothesis that low or absent ERAP1 activity alters CD8 T cell immunogenicity through changes in the HLA-B51 peptidome and shapes the CD8 T cell immune response in affected subjects.

Methods:

We generated HLA-B51+ERAP1 KO LCL clones using CRISPR-Cas9, performed mass spectrometry of the immunoprecipitated MHC-class I peptidome with subsequent computational deconvolution for HLA-B51-binding peptides. We then assessed single cell (ICS), bulk (ELISA) and proliferative (CFSE) CD8 effector (IFNg, granzyme B, perforin) T cell responses through stimulation of allogeneic donor cells with WT vs KO LCL and determined ERAP1 haplotypes in 49 untreated Turkish BD subjects with ocular and/ or major vascular involvement as well as healthy donors (HD) whose PBMC were profiled using 6 multicolour flow cytometry panels.

Results:

WT and KO peptidomes differed significantly (p<0.0005 Fisher’s exact test) with a distinctive shift of peptide length frequencies exceeding 9-mer (binding optimum) in the KO vs WT. This held true for computationally deconvoluted HLA-B51 binders. IFNg secretion from CD8 T cells stimulated with KO LCL was significantly different from WT (ICS, p=0.0006; ELISA, p=0.0059) as were CD8 T cell proliferation and ICS of perforin/granzyme B+CD8 T cells. Analysis of 133 T, B, NK and monocyte cell populations revealed predominance of CD8 T and NKT cell subset in HLA-B51+/Hap10+ BD vs HLA-B51+/Hap10- BD and HD, accounting for 80% of all populations reaching significance (p<0.05, Mann-Whitney). Naive and effector memory CD8 T cell subsets were inversely correlated. Cohen’s effect sizes were large (>0.8) or very large (>1.2).

Conclusion:

We show that absence of functional ERAP1 alters human CD8 T cell immunogenicity. This is mediated by an HLA-class I peptidome with propensity for longer peptides above 9mer and suggests loss or de-novo presentation of peptide-HLA-B51 complexes to cognate CD8 TCR. The reciprocal changes in antigen- experienced vs naive CD8 T cell subsets in affected subjects point to biologic significance of HLA-B51/Hap10 in BD. Collectively, our findings suggest that an altered HLA-B51 peptidome modulates immunogenicity of CD8 effector T cells in ERAP1-Hap10 carriers with BD and identify targets for future drug development.

References:

[1]Kirino, Y., G. Bertsias, Y. Ishigatsubo, N. Mizuki, I. Tugal-Tutkun, E. Seyahi, Y. Ozyazgan, F. S. Sacli, B. Erer, H. Inoko, Z. Emrence, A. Cakar, N. Abaci, D. Ustek, C. Satorius, A. Ueda, M. Takeno, Y. Kim, G. M. Wood, M. J. Ombrello, A. Meguro, A. Gul, E. F. Remmers, and D. L. Kastner. 2013. ‘Genome-wide association analysis identifies new susceptibility loci for Behcet’s disease and epistasis between HLA-B*51 and ERAP1’,Nat Genet, 45: 202-7.

[2]Takeuchi, M., M. J. Ombrello, Y. Kirino, B. Erer, I. Tugal-Tutkun, E. Seyahi, Y. Ozyazgan, N. R. Watts, A. Gul, D. L. Kastner, and E. F. Remmers. 2016. ‘A single endoplasmic reticulum aminopeptidase-1 protein allotype is a strong risk factor for Behcet’s disease in HLA-B*51 carriers’,Ann Rheum Dis, 75: 2208-11.

Disclosure of Interests:

Arshed F. Al-Obeidi: None declared, Ann Cavers: None declared, Yesim Ozguler: None declared, Olivier Manches: None declared, Hua Zhong: None declared, Berna Yurttas: None declared, Beatrix Ueberheide: None declared, Gulen Hatemi Grant/research support from: BMS, Celgene Corporation, Silk Road Therapeutics – grant/research support, Consultant of: Bayer, Eli Lilly – consultant, Speakers bureau: AbbVie, Mustafa Nevzat, Novartis, UCB – speaker, Matthias Kugler: None declared, Johannes Nowatzky: None declared

Band Structure of Helimagnons in MnSi Resolved by Inelastic Neutron Scattering

A magnetic helix realizes a one-dimensional magnetic crystal with a period given by the pitch length λh. Its spin-wave excitations-the helimagnons-experience Bragg scattering off this periodicity, leading to gaps in the spectrum that inhibit their propagation along the pitch direction. Using high-resolution inelastic neutron scattering, the resulting band structure of helimagnons was resolved by preparing a single crystal of MnSi in a single magnetic-helix domain. At least five helimagnon bands could be identified that cover the crossover from flat bands at low energies with helimagnons basically localized along the pitch direction to dispersing bands at higher energies. In the low-energy limit, we find the helimagnon spectrum to be determined by a universal, parameter-free theory. Taking into account corrections to this low-energy theory, quantitative agreement is obtained in the entire energy range studied with the help of a single fitting parameter.

Monitoring of the booster biocide dichlofluanid in water and marine sediment of Greek marinas

Dichlofluanid (N-dichlorofluoromethylthio-N'-dimethyl-N-phenylsulphamide) is used as booster biocide in antifouling paints. The occurrence of dichlofluanid and its metabolite DMSA (N'-dimethyl-N-phenyl-sulphamide) was monitored in seawater and marine sediment from three Greek marinas. Seawater and sediment samples were collected at three representative positions and one suspected hotspot in each marina and shipped to the laboratory for chemical analysis. As part of the project, an analytical method had been developed and validated. Furthermore, some additional experiments were carried out to investigate the potential contribution of paint particle bound dichlofluanid on the total concentration in the sediment. As expected, given its known high hydrolytic degradation rate, no detectable concentrations of dichlofluanid were measured in any of the seawater samples. DMSA was detected in seawater samples at very low concentrations varying from <3 ng l(-1) (LOD) to 36 ng l(-1). During method validation, it had already been demonstrated that dichlofluanid is unstable in sediment and can therefore only be determined as its metabolite DMSA. In a separate experiment, in which marine sediment was spiked with artificial paint particles containing dichlofluanid and then analysed according to the validated method, it was demonstrated that if there is any dichlofluanid originating from paint particles, this would be determined as DMSA. No DMSA was detected in any of the sediment samples. It could therefore be concluded that there were no significant concentrations of dichlofluanid in the sediment samples.

[Incorrect positioning of a catheter for continuous block of the nervus suprascapularis. A case report]

The case of a 55-year-old woman is described where shoulder pain was successfully treated with a suprascapular catheter. During arthroscopy of the shoulder the catheter was detected in the subacromial space. The reasons and consequences of an abnormal position of the suprascapular catheter are discussed.

Vortex imaging in the pi band of magnesium diboride

We report scanning tunneling spectroscopy imaging of the vortex lattice in single crystalline MgB2. By tunneling parallel to the c axis, a single superconducting gap (Delta=2.2 meV) associated with the pi band is observed. The vortices in the pi band have a large core size compared to estimates based on H(c2) and show an absence of localized states in the core. Furthermore, superconductivity between the vortices is rapidly suppressed by an applied field. These results suggest that superconductivity in the pi band is, at least partially, induced by the intrinsically superconducting sigma band.

[Development of macroglossia associated with neurosurgery in a seated position]

A case report is presented in which post-operatively a distinct macroglossia including an additional swelling running up to the trachea developed within the framework of a neurosurgical intervention in a seated position. Pathomechanisms and possible therapeutic methods are described and discussed with the help of a review of the literature.

[Opioid rotation in pain therapy. Case report]

The use of opioids in the treatment of chronic pain is sometimes accompanied by inadequate pain relief and opioid-specific side-effects. Opioid rotation is a therapeutic approach, that can improve analgesia and provide a more advantageous analgesia and toxicity relationship. This article presents a case report and discusses the mechanisms, indications and possibilities of opioid rotation.

Scanning tunneling spectroscopy of Bi(2)Sr(2)CuO(6+delta): new evidence for the common origin of the pseudogap and superconductivity

Using scanning tunneling spectroscopy, we investigated the temperature dependence of the quasiparticle density of states of overdoped Bi(2)Sr(2)CuO(6+delta) between 275 mK and 82 K. Below T(c) = 10 K, the spectra show a gap with well-defined coherence peaks at +/-Delta(p) approximately 12 meV, which disappear at T(c). Above T(c), the spectra display a clear pseudogap of the same magnitude, gradually filling up and vanishing at T(*) approximately 68 K. The comparison with Bi(2)Sr(2)CaCu(2)O(8+delta) demonstrates that the pseudogap and the superconducting gap scale with each other, providing strong evidence that they have a common origin.

Frequency data for the STR loci HumFibra (FGA) and HumACTBP2 (SE33) in a population of Germans and Turks from South-West Germany

Population studies were carried out on German and Turkish individuals from South-West Germany using the short tandem repeat (STR) systems HumFibra (n = 138 Turkish and 1161 German individuals) and HumACTBP2 (n = 202 Turkish and 1338 German individuals). After electrophoresis 19 alleles could be identified for HumFibra and 55 for HumACTBP2. No significant deviations from Hardy-Weinberg equilibrium were observed.

The Partridge nylon cerclage: its use as a supplementary fixation of difficult femoral fractures in the elderly

We report on our early experience with the use of the Partridge nylon cerclage. This system was employed as a supplementary fixation in 18 femoral fractures in elderly patients (average age, 78 years). Indications of its use were reduction of comminuted fragments and enhancement of the grip of the main fixation device on osteoporotic femora or in femora with a prosthesis in situ. All fractures but one healed primarily. At an average follow-up time of 25 months, 15 of the 18 patients were ambulatory. Radiographic review showed that the cerclage did not cause cortical avascularity and that none of the straps used failed. We concluded that the internal fixation of difficult femoral fractures in the elderly can be easily and effectively strengthened by the use of this cerclage system.

Rhizocticin A, an antifungal phosphono-oligopeptide of Bacillus subtilis ATCC 6633: biological properties

Rhizocticin A, the main component of the antifungal, hydrophilic phosphono-oligopeptides of Bacillus subtilis ATCC 6633, was used for sensitivity testing and experiments into the molecular mechanism of the antibiotic action. Budding and filamentous fungi as well as the cultivated nematode Caenorhabditis elegans were found to be sensitive, whereas bacteria and the protozoon Paramecium caudatum were insensitive. Rhizoctonia solani was inhibited in agar dilution tests but not in diffusion tests. The antifungal effect of rhizocticin A was neutralized by a variety of amino acids and oligopeptides. Oligopeptide influence was mainly understood as transport antagonism, and it was concluded that the antibiotic enters the recipient cell via the peptide transport system. L- and D-cystine were also identified as potent, general antagonists of the oligopeptide transport. The rhizocticin-antagonism of four other amino acids was taken as a clue to the site of action. Provided that rhizocticin A is split by peptidases of the target cell into inactive L-arginine and toxic L-2-amino-5-phosphono-3-cis-pentenoic acid (L-APPA), the latter may interfere with the threonine or threonine-related metabolism.

Enhancement of nitro reduction in rat liver microsomes by haemin and haemoproteins

1. Reductive metabolism of p-nitrobenzoic acid and neoprontosil in rat liver microsomes was studied in the presence of haemin, haemoglobin and myoglobin. 2. Microsomal nitro reduction is enhanced 4-fold in the presence of haemoglobin, whereas azo reduction is not affected. 3. Microsomal nitro reduction is enhanced to a similar extent by haemoglobin, haemin and boiled haemoglobin, whereas myoglobin is about half as active. 4. Maximal enhancement of microsomal nitro reductase activity by haemoglobin is achieved at high substrate concentration (6 mM) and low microsomal protein concentration (0.5--1.0 mg/ml). 5. Control microsomal nitro reduction as well as the haemoglobin-enhanced microsomal nitro reduction are inhibited completely by O2 and CO whereas potassium azide as a ligand of ferric haem iron is a less potent inhibitor.