Genetic association and differential expression of HLAComplexGroup lncRNAs in pemphigus.

Authors:
Amanda Salviano-Silva, Mareike Becker, Danillo G Augusto, Hauke Busch, Gabriel Adelman Cipolla, Ticiana D-J Farias, Valéria Bumiller-Bini, Verónica Calonga-Solís, Matthias Munz, Andre Franke, Michael Wittig, Carolina M Camargo, Matthias Goebeler, Jennifer Elisabeth Hundt, Claudia Günther, Regine Gläser, Eva Hadaschik, Claudia Pföhler, Miklós Sárdy, Nina Van Beek, Margitta Worm, Detlef Zillikens, Angelica B W Boldt, Enno Schmidt, Maria Luiza Petzl-Erler, Saleh Ibrahim, Danielle Malheiros
Year of publication:
2021
Volume:
123
Issue:
-
Issn:
0896-8411
Journal title abbreviated:
J AUTOIMMUN
Journal title long:
Journal of autoimmunity
Impact factor:
14.511
Abstract:
<h4>Background</h4>Pemphigus is a group of bullous diseases characterized by acantholysis and skin blisters. As for other autoimmune diseases, the strongest genetic associations found so far for pemphigus foliaceus (PF) and vulgaris (PV) are with alleles of HLA genes. However, apart from protein-coding genes, the MHC region includes a set of poorly explored long non-coding RNA (lncRNA) genes, the HLA complex group (HCG).<h4>Objectives</h4>To investigate if HCG lncRNA alleles are associated with pemphigus susceptibility.<h4>Methods and results</h4>We analyzed SNPs in 13 HCG lncRNA genes, both in PV (Germany: 241 patients; 1,188 controls) and endemic PF (Brazil: 227 patients; 194 controls), applying multivariate logistic regression. We found 55 associations with PV (p<sub>corr</sub> < 0.01) and nine with endemic PF (p<sub>corr</sub> < 0.05), the majority located in TSBP1-AS1 (which includes HCG23) and HCG27 lncRNA genes, independently of HLA alleles previously associated with pemphigus. The association of TSBP1-AS1 rs3129949*A allele was further replicated in sporadic PF (p = 0.027, OR = 0.054; 75 patients and 150 controls, all from Germany). Next, we evaluated the expression levels of TSBP1-AS1, TSBP1, HCG23, and HCG27 in blood mononuclear cells of Brazilian patients and controls. HCG27 was upregulated in endemic PF (p = 0.035, log<sub>2</sub> FC = 1.3), while TSBP1-AS1 was downregulated in PV (p = 0.029, log<sub>2</sub> FC = -1.29). The same expression patterns were also seen in cultured keratinocytes stimulated with IgG antibodies from patients and controls from Germany. TSBP1 mRNA levels were also decreased in endemic PF blood cells (p = 0.042, log<sub>2</sub> FC = -2.14). TSBP1-AS1 and HCG27 were also observed downregulated in CD19<sup>+</sup> cells of endemic PF (p < 0.01, log<sub>2</sub> FC = -0.226 and -0.46 respectively).<h4>Conclusions</h4>HCG lncRNAs are associated with susceptibility to pemphigus, being TSBP1-AS1 and HCG27 also differentially expressed in distinct cell populations. These results suggest a role for HCG lncRNAs in pemphigus autoimmunity.