The IL-3, IL-5, and GM-CSF common receptor beta chain mediates oncogenic activity of FLT3-ITD-positive AML

FLT3-ITD is the most predominant mutation in AML being expressed in about one-third of AML patients and is associated with a poor prognosis. Efforts to better understand FLT3-ITD downstream signaling to possibly improve therapy response are needed. We have previously described FLT3-ITD-dependent phosphorylation of CSF2RB, the common receptor beta chain of IL-3, IL-5, and GM-CSF, and therefore examined its significance for FLT3-ITD-dependent oncogenic signaling and transformation. We discovered that FLT3-ITD directly binds to CSF2RB in AML cell lines and blasts isolated from AML patients. A knockdown of CSF2RB in FLT3-ITD positive AML cell lines as well as in a xenograft model decreased STAT5 phosphorylation, attenuated cell proliferation, and sensitized to FLT3 inhibition. Bone marrow from CSF2RB-deficient mice transfected with FLT3-ITD displayed decreased colony formation capacity and delayed disease onset together with increased survival upon transplantation into lethally irradiated mice. FLT3-ITD-dependent CSF2RB phosphorylation required phosphorylation of the FLT3 juxtamembrane domain at tyrosines 589 or 591, whereas the ITD insertion site and sequence were of no relevance. Our results demonstrate that CSF2RB participates in FLT3-ITD-dependent oncogenic signaling and transformation in vitro and in vivo. Thus, CSF2RB constitutes a rational treatment target in FLT3-ITD-positive AML.

COVID-19:Attacks the 1-Beta Chain of Hemoglobin and Captures the Porphyrin to Inhibit Human Heme Metabolism

The novel coronavirus pneumonia is a contagious acute respiratory disease caused by the SARS-COV-2 coronavirus. The pathogenic mechanism of the novel coronavirus is unknown, which presents a significant impediment to the patient rescue. A conserved domain search strategy was utilized in this work to determine that a large number of viral proteins could bind to hemoglobin. S could bind to extracellular hemoglobin. SARS-COV-2 virus proteins interacted with porphyrins. SARS-COV-2 viruses could synthesize heme from porphobilinogen and encode all the similar enzymes required for the process. Both E and ORF3a contained heme-binding sites. ORF3a's Arg134 and E's Cys44 were the heme-iron binding sites, respectively. ORF3a also contained homologous domains to human cytochrome C reductase and bacterial EFeB protein. The molecular docking analysis revealed that ORF3a and ORF8 proteins were shown to be capable of attacking hemoglobin's 1-beta chain, whereas ORF3a was found to be effective in capturing heme for dissociation to iron and porphyrin. Deoxyhemoglobin was more susceptible to viral attack than oxidized hemoglobin. In summary, the combination of viral proteins to porphyrins and their metal compounds would improve the ability to permeate cell membranes and generate oxygen free radicals (ROS). It may be associated with viral infections and epidemic transmission. Viral proteins regulated the production and function of NO, CO and CO2 by inhibiting the activity of hemoglobin, thereby affecting immune cell function. Viral proteins' attack on hemoglobin could result in symptoms such as respiratory distress and blood clotting, damage to numerous organs and tissues, and disruption of normal human heme metabolism.

AB0735 POLYMORPHISMS OF GENES CD14, C-REACTIVE PROTEIN, FIBRINOGEN BETA CHAIN, ASSOCIATED WITH THE DEVELOPMENT OF KAWASAKI DISEASE AND CORONARY ARTERY ANEURYSMS IN CHILDREN FROM CENTRAL RUSSIA

Background:Kawasaki disease (KD) is a multifactorial disease with a genetic predisposition, systemic vasculitis complicated by the formation of coronary artery aneurysms (CAA). Its pathogenesis is based on immune inflammation with an increase in the concentration of pro-inflammatory cytokines, the level of C-reactive protein (CRP), and coagulation disorder.Objectives:to search for polymorphisms of genes cluster of differentiation CD14, CRP, fibrinogen beta chain (FGB), associated with the KD development and a predisposition to the CAA formation among patients with KD living in Moscow and the Moscow region.Methods:genotyping for gene polymorphisms CD14 –159 C>T (rs2569190), CRP 3872 C>T (rs1205), FGB – 455 G>A (rs1800790) by PCR in 31 children 1 month – 10 years old (median age 19 months [9,0; 38,5]) with KD, among them, in 10 patients the disease was complicated by CAA formation according to echocardiography, and 30 children of the control group.Results:Three out of six investigated SNPs showed statistically significant difference in genotype and allele distribution: СRP C3872T, CD14 C159T and FGB G455A. CRP gene polymorphism: in patients with KD significantly less frequent is homozygous type TT (RR 0,22, 95% CI: 0,05–0,91, p=0,0168).CD14 gene polymorphism: in control group heterozygous genotype CT is predominant, (RR 0,58, 95% CI: 0,4–0,83, p=0,0017) among patients with KD homozygous genotypes CC and TT are predominant. (RR 3,61, 95% CI: 1,14–11,49, p=0,0057).FGB gene polymorphism: genotype GA is predominant in control group (RR 0,48, 95% CI: 0,26–0,9, p=0,0149). In patients with KD significantly less frequent is homozygous type GG (RR 1,69, 95% CI: 1,03–2,8, p=0,0297).We didn’t find any significant difference in genotype and allele distribution in KD patients with and without CA lesions.Conclusion:statistically significant differences (p<0,05) were revealed in the distribution of genotypes for polymorphisms of the CD14 –159 C>T, CRP 3872 C>T and FGB –455 G>A genes among patients with KD and children of the control group; when comparing the results of KD patients with CAA and the control group, statistically significant differences (p<0,05) were revealed only in the polymorphism CD14 –159 C>T. It can be assumed that these polymorphisms are associated with the development of KD and CAA in these patients.Disclosure of Interests:None declared

Contribution of T Cell Receptor Alpha and Beta CDR3, MHC Typing, V and J Genes to Peptide Binding Prediction

IntroductionPredicting the binding specificity of T Cell Receptors (TCR) to MHC-peptide complexes (pMHCs) is essential for the development of repertoire-based biomarkers. This affinity may be affected by different components of the TCR, the peptide, and the MHC allele. Historically, the main element used in TCR-peptide binding prediction was the Complementarity Determining Region 3 (CDR3) of the beta chain. However, recently the contribution of other components, such as the alpha chain and the other V gene CDRs has been suggested. We use a highly accurate novel deep learning-based TCR-peptide binding predictor to assess the contribution of each component to the binding.MethodsWe have previously developed ERGO-I (pEptide tcR matchinG predictiOn), a sequence-based T-cell receptor (TCR)-peptide binding predictor that employs natural language processing (NLP) -based methods. We improved it to create ERGO-II by adding the CDR3 alpha segment, the MHC typing, V and J genes, and T cell type (CD4+ or CD8+) as to the predictor. We then estimate the contribution of each component to the prediction.Results and DiscussionERGO-II provides for the first time high accuracy prediction of TCR-peptide for previously unseen peptides. For most tested peptides and all measures of binding prediction accuracy, the main contribution was from the beta chain CDR3 sequence, followed by the beta chain V and J and the alpha chain, in that order. The MHC allele was the least contributing component. ERGO-II is accessible as a webserver at http://tcr2.cs.biu.ac.il/ and as a standalone code at https://github.com/IdoSpringer/ERGO-II.

Clusterin in Alzheimer's disease: an amyloidogenic inhibitor of amyloid formation

Clusterin is a heterodimeric glycoprotein (alpha- and beta-chain), which has been described as an extracellular molecular chaperone. In humans, clusterin is an amyloid associated protein, co-localizing with fibrillar deposits in several amyloidoses, including Alzheimer's disease. To clarify its potential implication in amyloid formation, we located aggregation-prone regions within the sequence of clusterin a-chain, via computational methods. We had peptide-analogues of each region chemically synthesized and experimentally demonstrated that all of them can form amyloid-like fibrils. We also provide evidence that the same peptide-analogues can inhibit amyloid-beta fibril formation. These findings elucidate parts of the molecular mechanism in which clusterin inhibits amyloid formation. At the same time, they hint that molecular chaperones with amyloidogenic properties might have a role in the regulation of amyloid formation, essentially acting as functional amyloids.

POLYMORPHISMS OF GENES INTERLEUKIN-6, VASCULAR ENDOTHELIAL GROWTH FACTOR A, CD14, C-REACTIVE PROTEIN, FIBRINOGEN BETA CHAIN, ASSOCIATED WITH THE DEVELOPMENT OF KAWASAKI DISEASE AND CORONARY ARTERY ANEURYSMS IN CHILDREN LIVING IN MOSCOW AND THE MOSCOW REGION

Kawasaki disease (KD) is a multifactorial disease with a genetic predisposition, systemic vasculitis complicated by the formation of coronary artery aneurysms (CAA). Its pathogenesis is based on immune inflammation with an increase in the concentration of pro-inflammatory cytokines, the level of C-reactive protein (CRP), and coagulation disorder. Objective of the study: to search for polymorphisms of genes interleukin-6 (IL6), vascular endothelial growth factor A (VEGFA), cluster of differentiation CD14, CRP, fibrinogen beta chain (FGB), associated with the KD development and a predisposition to the CAA formation among patients with KD living in Moscow and the Moscow region. Materials and methods: genotyping for gene polymorphisms IL6 –174G>C (rs1800795), VEGFA –634 C>G (rs2010963), CD14 –159 C>T (rs2569190), CRP 3872 C>T (rs1205), FGB – 455 G>A (rs1800790) by PCR in 31 children 1 month – 10 years old (median age 19 months [9,0; 38,5]) with KD, among them, in 10 patients the disease was complicated by CAA formation according to echocardiography, and 30 children of the control group. Results: statistically significant differences (p<0,05) were revealed in the distribution of genotypes for polymorphisms of the CD14 –159 C>T, CRP 3872 C>T and FGB –455 G>A genes among patients with KD and children of the control group; when comparing the results of KD patients with CAA and the control group, statistically significant differences (p<0,05) were revealed only in the polymorphism CD14 –159 C>T. Conclusion: it can be assumed that these polymorphisms are associated with the development of KD and CAA in these patients.

Breast cancer is marked by specific, Public T-cell receptor CDR3 regions shared by mice and humans

The partial success of tumor immunotherapy induced by checkpoint blockade, which is not antigen-specific, suggests that the immune system of some patients contain antigen receptors able to specifically identify tumor cells. Here we focused on T-cell receptor (TCR) repertoires associated with spontaneous breast cancer. We studied the alpha and beta chain CDR3 domains of TCR repertoires of CD4 T cells using deep sequencing of cell populations in mice and applied the results to published TCR sequence data obtained from human patients. We screened peripheral blood T cells obtained monthly from individual mice spontaneously developing breast tumors by 5 months. We then looked at identical TCR sequences in published human studies; we used TCGA data from tumors and healthy tissues of 1,256 breast cancer resections and from 4 focused studies including sequences from tumors, lymph nodes, blood and healthy tissues, and from single cell dataset of 3 breast cancer subjects. We now report that mice spontaneously developing breast cancer manifest shared, Public CDR3 regions in both their alpha and beta and that a significant number of women with early breast cancer manifest identical CDR3 sequences. These findings suggest that the development of breast cancer is associated, across species, with biomarker, exclusive TCR repertoires.