POS0349 SEQUENCE COMPLEMENTARITY BETWEEN SARS-CoV-2 GENOME AND HUMAN NONCODING RNAS ASSOCIATED WITH IMMUNOLOGICAL DISORDERS: AN IN SILICO PIVOTAL STUDY

Background:

Recent evidence shows that human cells may produce several noncoding (nc)RNAs in response to viral infections. Among them, a central role has been attributed to long noncoding (lnc)RNAs, more than 200 nucleotides in length, which are also crucially involved in cancer and autoimmunity. LncRNAs epigenetically control the transcription of genes presiding over cell proliferation, differentiation, migration and apoptosis, by directly or indirectly binding cellular or foreign nucleic acids, including viral genomes.

Objectives:

The objectives of this study were to evaluate in silico the presence of a nucleotide sequence complementarity between the RNA genome of Severe Acute Respiratory Syndrome CoronaVirus-2 (SARS-CoV-2) and human ncRNA genes and to analyze any associations between SARS-CoV-2 gene-matching ncRNAs and human diseases.

Methods:

The FASTA sequence of each of the 11 SARS-CoV-2 isolate Wuhan-Hu-1 genes (ORF1ab, ORF3a, ORF6, ORF7a, ORF7b, ORF8, ORF10, S, E, M, N) was retrieved from NCBI.nlm.nih.gov/gene (reference sequence NC_045512.2). The ensembl.org library for human ncRNA genes was interrogated for any base-pair match and detected human ncRNAs analyzed for their functional activity. Finally, the associations between ncRNAs and human diseases were searched on GWAS databases (https://www.ebi.ac.uk/gwas and https://www.genecards.org).

Results:

A total of 252 matches between SARS-CoV-2 genes and human ncRNAs were recorded (ORF1ab: 28; ORF3a: 9; ORF6: 50; ORF7a: 31; ORF7b: 16; ORF8: 23; ORF10: 5; S: 24; E: 17; M: 32; N: 17). With the exception of two small nuclear RNAs (RNVU1-4 and RNU4-74P corresponding to ORF6 and ORF10, respectively), all of them were lncRNAs, mostly expressed in testis and central nervous system under physiological conditions. Percentage of alignment ranged from 91.30% to 100%, with a mean nucleotide alignment length of 17.5±2.4. Polymorphic variants of these transcripts have mostly been reported in patients with neuropsychiatric disorders, cancer and dysmetabolism. Of note, we found 13 and 15 complementarities with lncRNAs associated with immune-mediated diseases Table 1. and immunological pathways (IL-2, IL-6, IL-12, IL-12R, IL-13, IL-17, M-CSF, CXCL-10, TRAIL-R2 and IgG glycosylation), respectively.

Conclusion:

This pivotal study shows that SARS-CoV-2 genes contain complementary sequences to human ncRNAs in turn associated with several diseases, including autoimmunity. The biological effects of this interaction remain to be elucidated.

Table 1.

SARS-CoV-2 complementary ncRNAs and associated immunological disorders

SARS-CoV-2 geneLncRNAGenomic locationNucleotide alignment lengthAlignment percentageAssociated immunological disorderSXACTX:113705866-11370588318100%Crohn’s diseaseNLINC013581:59082428-5908257417100%Acute Graft-versus-Host DiseaseECOX10-AS117:14029229-1402924517100%Systemic lupus erythematosusORF8AC093765.34:116752764-1167527842195.24%Ulcerative colitisORF6CDKN2B-AS19:22033529-2203354618100%Multiple sclerosisCHROMR2:178433948-1784339682195.24%Multiple sclerosisPsoriasisAtopic eczemaWAKMAR26:137857643-13785765715100%Atopic eczemaHay feverAllergic rhinitisMultiple sclerosisPsoriasisSystemic sclerosisSystemic lupus erythematosusRheumatoid arthritisAC008691.15:159362809-159362828(promoter flank)2095%SarcoidosisPsoriasisPsoriatic arthritisSclerosing cholangitisCeliac diseaseType I diabetes mellitusSystemic lupus erythematosusJuvenile idiopathic arthritisUlcerative colitisCrohn’s diseaseTakayasu arteritisMultiple sclerosisLMCD1-AS13:7953602-7953616(enhancer)15100%Systemic sclerosisMLINC019342:181403969-18140398416100%Multiple sclerosisAnkylosing spondylitisCeliac diseaseRheumatoid arthritisORF7bXACTX:113959816-11395983116100%Crohn’s diseaseLINC0262110:62289643-6230233515100%Rheumatoid arthritisLINC019913:187966255-18796626915100%IgA deficitAtopic asthmaAllergic rhinitis

Disclosure of Interests:

None declared

Collectin liver 1 and collectin kidney 1 and other complement-associated pattern recognition molecules in systemic lupus erythematosus

The objective of this study was to explore the involvement of collectin liver 1 (CL-L1) and collectin kidney 1 (CL-K1) and other pattern recognition molecules (PRMs) of the lectin pathway of the complement system in a cross-sectional cohort of systemic lupus erythematosus (SLE) patients. Concentrations in plasma of CL-L1, CL-K1, mannan-binding lectin (MBL), M-ficolin, H-ficolin and L-ficolin were determined in 58 patients with SLE and 65 healthy controls using time-resolved immunoflourometric assays. The SLE patients' demographic, diagnostic, clinical and biochemical data and collection of plasma samples were performed prospectively during 4 months. CL-L1, CL-K1 and M-ficolin plasma concentrations were lower in SLE patients than healthy controls (P-values < 0.001, 0.033 and < 0.001, respectively). H-ficolin concentration was higher in SLE patients (P < 0.0001). CL-L1 and CL-K1 plasma concentrations in the individuals correlated in both patients and controls. Patients with low complement component 3 (C3) demonstrated a negative correlation between C3 and CL-L1 and CL-K1 (P = 0.022 and 0.031, respectively). Patients positive for anti-dsDNA antibodies had lower levels of MBL in plasma than patients negative for anti-dsDNA antibodies (P = 0.02). In a cross-sectional cohort of SLE patients, we found differences in the plasma concentrations of CL-L1, CL-K1, M-ficolin and H-ficolin compared to a group of healthy controls. Alterations in plasma concentrations of the PRMs of the lectin pathway in SLE patients and associations to key elements of the disease support the hypothesis that the lectin pathway plays a role in the pathogenesis of SLE.