BACKGROUND: To determine differences in the blood innate gene expression signatures of systemic lupus erythematosus (SLE) patients across various organ manifestations and disease activity, with a focus on lupus nephritis (LN) and central nervous system (CNS) involvement. METHODS: Toll-like receptor family (TLR 1-10) mRNA expression was investigated in peripheral blood mononuclear cells from patients with SLE (n = 74) and healthy controls (n = 34). We compared patients with histologically confirmed active LN or neuropsychiatric systemic lupus erythematosus (NPSLE) with patients without these symptoms. The expression of TLR mRNA was determined by RT‒qPCR using a high-throughput SmartChip Real-Time-qPCR system (WaferGen). Multivariate analysis and nonparametric statistics were used for data analysis to assess the associations between TLRs and disease activity and severity. RESULTS: TLR4 (0.044 vs. 0.081, p = 0.012) was upregulated and TLR10 (0.009 vs. 0.006, p = 0.0007) was downregulated in the whole cohort of SLE patients compared to healthy controls. A comparison of the active LN group with participants without kidney involvement revealed increased expression of TLR2 (0.078 vs. 0.03, p = 0.009), and TLR5 (0.035 vs. 0.017, p = 0.03). Moreover, a significant difference was observed in TLR9 expression between inactive LN and the control group (0.014 vs. 0.009, p = 0.01), together with borderline correlation in TLR2 expression (0.04 vs. 0.03, p = 0.06). Receiver operating characteristic (ROC) curve analysis revealed that TLR1 and TLR2 expression were the best potential diagnostic markers for active LN. The NPSLE group showed upregulation of TLR1 (0.088 vs. 0.048, p = 0.01), TLR4 (0.173 vs. 0.066, p = 0.0003) and TLR6 (0.087 vs. 0.036, 0.007). Our correlation analysis supported the close relationships among the expression of individual TLRs in the whole lupus cohort and its subgroups. CONCLUSION: Our study revealed differences in TLR expression between a lupus cohort and healthy controls. Additionally, our analysis provides insight into specific TLR expression in cases with severe organ manifestations, such as LN and NPSLE. The multiple mutual relationships of TLRs demonstrate the activation of innate immunity in SLE and suggest promising targets for future therapies or diagnostics.

3 Interni Klinika Nefrologicka Revmatologicka a Endokrinologicka Fakultni Nemocnice Olomouc Zdravotniku 248 7 Olomouc 779 00 Czech Republic

Department of Computer Science Faculty of Electrical Engineering and Computer Science Technical University of Ostrava Ostrava Czech Republic

Department of Immunology Faculty of Medicine and Dentistry Palacky University Olomouc and University Hospital Olomouc Czech Republic

Department of Internal Medicine 3 Nephrology Rheumatology and Endocrinology Faculty of Medicine and Dentistry Palacky University Olomouc and University Hospital Olomouc Czech Republic

Department of Medical Biophysics Czech Republic Faculty of Medicine and Dentistry Palacky University Olomouc and University Hospital Olomouc Czech Republic

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Akhil A, Bansal R, Anupam K, et al. Systemic lupus erythematosus: latest insight into etiopathogenesis. Rheumatol Int. 2023;43(8):1381–93. 10.1007/s00296-023-05346-x. Epub 2023 May 24. PMID: 37226016; PMCID: PMC10208557. PubMed PMC

Pan L, Lu MP, Wang JH, et al. Immunological pathogenesis and treatment of systemic lupus erythematosus. World J Pediatr. 2020;16(1):19–30. 10.1007/s12519-019-00229-3. Epub 2019 Feb 22. PMID: 30796732; PMCID: PMC7040062. PubMed PMC

Takeuchi O, Akira S. Toll-like receptors; their physiological role and signal transduction system. Int Immunopharmacol. 2001;1(4):625– 35. 10.1016/s1567-5769(01)00010-8. PMID: 11357875. PubMed

Fillatreau S, Manfroi B, Dörner T. Toll-like receptor signalling in B cells during systemic lupus erythematosus. Nat Rev Rheumatol. 2021;17:98–108. 10.1038/s41584-020-00544-4. PubMed PMC

García-Ortiz H, Velázquez-Cruz R, Espinosa-Rosales F, et al. Association of TLR7 copy number variation with susceptibility to childhood-onset systemic lupus erythematosus in Mexican population. Ann Rheum Dis. 2010;69:1861–5. PubMed

Devarapu SK, Anders HJ. Toll-like receptors in lupus nephritis. J Biomed Sci. 2018;25(1):35. 10.1186/s12929-018-0436-2. PMID: 29650017; PMCID: PMC5898010. PubMed PMC

Manno A, Honda T, Kuwata C et al. Targeting Toll-Like receptor 7 with DS-7011a, a promising novel antagonistic antibody for the treatment of systemic lupus erythematosus [abstract]. Arthritis Rheumatol 2023; 75 (suppl 9).

Aringer M. EULAR/ACR classification criteria for SLE. Semin Arthritis Rheum. 2019;49(3S):S14-S17. 10.1016/j.semarthrit.2019.09.009. PMID: 31779843. PubMed

Gladman DD, Ibañez D, Urowitz MB. Systemic lupus erythematosus disease activity index 2000. J Rheumatol. 2002;29(2):288–91. PMID: 11838846. PubMed

Gladman DD, Goldsmith CH, Urowitz MB, et al. The systemic lupus international collaborating clinics/american college of rheumatology (SLICC/ACR) damage index for systemic lupus erythematosus international comparison. J Rheumatol. 2000;27(2):373–6. PMID: 10685799. PubMed

Mina R, Abulaban K, Klein-Gitelman MS, et al. Validation of the lupus nephritis clinical indices in Childhood-Onset systemic lupus erythematosus. Arthritis Care Res (Hoboken). 2016;68(2):195–202. 10.1002/acr.22651. PMID: 26213987; PMCID: PMC4720587. PubMed PMC

The American College of Rheumatology nomenclature and case definitions for neuropsychiatric lupus syndromes. Arthritis Rheum. 1999;42(4):599–608. 10.1002/1529-0131(199904)42:4<599::AID-ANR2>3.0.CO;2-F. PMID: 10211873. PubMed

Petrackova A, Horak P, Radvansky M et al. Revealed heterogeneity in rheumatoid arthritis based on multivariate innate signature analysis. Clin Exp Rheumatol 2020 Mar-Apr;38(2):289–98. 10.55563/clinexprheumatol/qb2ha3. Epub 2019 Aug 3. PMID: 31376255. PubMed

Youden WJ. Index for rating diagnostic tests. Cancer. 1950;3(1):32– 5. doi: 10.1002/1097-0142(1950)3:1<32::aid-cncr2820030106>3.0.co;2-3. PMID: 15405679. PubMed

Zhou XH, Obuchowski NA. McClish DK Statistical methods in diagnostic medicine. Wiley-Interscience. 2002;(1). Print ISBN:9780471347729|Online ISBN:9780470317082|DOI:10.1002/9780470317082.

Souyris M, Cenac C, Azar P et al. JC. TLR7 escapes X chromosome inactivation in immune cells. Sci Immunol. 2018;3(19):eaap8855. 10.1126/sciimmunol.aap8855. PMID: 29374079. PubMed

Jenks SA, Cashman KS, Zumaquero E et al. Distinct Effector B Cells Induced by Unregulated Toll-like Receptor 7 Contribute to Pathogenic Responses in Systemic Lupus Erythematosus. Immunity. 2018;49(4):725–739.e6. 10.1016/j.immuni.2018.08.015. Epub 2018 Oct 9. Erratum in: Immunity. 2020;52(1):203. PMID: 30314758; PMCID: PMC6217820. PubMed PMC

Anders HJ. Toll-like receptors and danger signaling in kidney injury. J Am Soc Nephrol. 2010;21(8):1270-4. 10.1681/ASN.2010030233. Epub 2010 Jul 22. PMID: 20651159. PubMed

Liu Y, Liao J, Zhao M, et al. Increased expression of TLR2 in CD4(+) T cells from SLE patients enhances immune reactivity and promotes IL-17 expression through histone modifications. Eur J Immunol. 2015;45(9):2683–93. 10.1002/eji.201445219. Epub 2015 Jun 26. PMID: 26079624. PubMed

Lee TP, Huang JC, Liu CJ et al. Interactions of surface-expressed TLR-4 and endosomal TLR-9 accelerate lupus progression in anti-dsDNA antibody transgenic mice. Exp Biol Med (Maywood). 2014;239(6):715– 23. 10.1177/1535370214525299. PMID: 24719374. PubMed

Hayashi F, Smith KD, Ozinsky A et al. The innate immune response to bacterial flagellin is mediated by Toll-like receptor 5. Nature. 2001;410(6832):1099– 103. 10.1038/35074106. PMID: 11323673. PubMed

Gharbia OM, Bassiouni SAR, Zaki MES, et al. Toll-like receptor 5 and Toll-like receptor 9 single nucleotide polymorphisms and risk of systemic lupus erythematosus and nephritis in Egyptian patients. Egypt Rheumatol Rehabil. 2021;48:49. 10.1186/s43166-021-00093-y.

Lee YH, Choi SJ, Ji JD, et al. Association between toll-like receptor polymorphisms and systemic lupus erythematosus: a meta-analysis update. Lupus. 2016;25(6):593–601. 10.1177/0961203315622823. PubMed

Klonowska-Szymczyk A, Wolska A, Robak T, et al. Expression of toll-like receptors 3, 7, and 9 in peripheral blood mononuclear cells from patients with systemic lupus erythematosus. Mediators Inflamm. 2014;2014:381418. 10.1155/2014/381418. Epub 2014 Feb 25. PMID: 24692849; PMCID: PMC3955595. PubMed PMC

Wang CM, Chang SW, Wu YJ, et al. Genetic variations in Toll-like receptors (TLRs 3/7/8) are associated with systemic lupus erythematosus in a Taiwanese population. Sci Rep. 2014;4:3792. 10.1038/srep03792. PMID: 24445780; PMCID: PMC3896912. PubMed PMC

Young NA, Wu LC, Burd CJ, et al. Estrogen modulation of endosome-associated toll-like receptor 8: an IFNα-independent mechanism of sex-bias in systemic lupus erythematosus. Clin Immunol. 2014;151(1):66–77. 10.1016/j.clim.2014.01.006. Epub 2014 Jan 24. PMID: 24525049; PMCID: PMC4066385. PubMed PMC

Young NA, Valiente GR, Hampton JM, et al. Estrogen-regulated STAT1 activation promotes TLR8 expression to facilitate signaling via microRNA-21 in systemic lupus erythematosus. Clin Immunol. 2017;176:12–22. 10.1016/j.clim.2016.12.005. Epub 2016 Dec 27. PMID: 28039018; PMCID: PMC5815376. PubMed PMC

Desnues B, Macedo AB, Roussel-Queval A, et al. TLR8 on dendritic cells and TLR9 on B cells restrain TLR7-mediated spontaneous autoimmunity in C57BL/6 mice. Proc Natl Acad Sci U S A. 2014;111(4):1497–502. 10.1073/pnas.1314121111. Epub 2014 Jan 13. PMID: 24474776; PMCID: PMC3910605. PubMed PMC

Nündel K, Green NM, Shaffer AL, et al. Cell-intrinsic expression of TLR9 in autoreactive B cells constrains BCR/TLR7-dependent responses. J Immunol. 2015;194(6):2504–12. 10.4049/jimmunol.1402425. Epub 2015 Feb 13. PMID: 25681333; PMCID: PMC4382804. PubMed PMC

Hess NJ, Felicelli C, Grage J, et al. TLR10 suppresses the activation and differentiation of monocytes with effects on DC-mediated adaptive immune responses. J Leukoc Biol. 2017;101(5):1245–52. 10.1189/jlb.3A1116-492R. Epub 2017 Feb 24. PMID: 28235773; PMCID: PMC5380377. PubMed PMC

Oosting M, Cheng SC, Bolscher JM, et., Al. Human TLR10 is an anti-inflammatory pattern-recognition receptor. Proc Natl Acad Sci U S A. 2014;111(42):E4478–84. 10.1073/pnas.1410293111. Epub 2014 Oct 6. PMID: 25288745; PMCID: PMC4210319. PubMed PMC

Fore F, Indriputri C, Mamutse J, et al. TLR10 and its unique Anti-Inflammatory properties and potential use as a target in therapeutics. Immune Netw. 2020;20(3):e21. 10.4110/in.2020.20.e21. PMID: 32655969; PMCID: PMC7327153. PubMed PMC

Umare V, Pradhan V, Nadkar M, et al. Effect of Proinflammatory cytokines (IL-6, TNF-α, and IL-1β) on clinical manifestations in Indian SLE patients. Mediators Inflamm. 2014;2014:385297. 10.1155/2014/385297. Epub 2014 Dec 7. PMID: 25548434; PMCID: PMC4273527. PubMed PMC

Petrackova A, Horak P, Radvansky M, et al. Cross-Disease innate gene signature: emerging diversity and abundance in RA comparing to SLE and SSc. J Immunol Res. 2019;2019:3575803. 10.1155/2019/3575803. PMID: 31396542; PMCID: PMC6664489. PubMed PMC

Lai Y, Xue C, Liao Y et al. Differential Expression of Toll-Like Receptor Signaling Pathway Is Associated with Microscopic Polyangiitis in Peripheral Blood Neutrophils. Immunol Invest. 2017;46(4):375–384. 10.1080/08820139.2017.1288236. Epub 2017 Apr 4. PMID: 28375762. PubMed

Zhang Y, Cao R, Ying H et al. Increased Expression of TLR10 in B Cell Subsets Correlates with Disease Activity in Rheumatoid Arthritis. Mediators Inflamm. 2018;2018:9372436. 10.1155/2018/9372436. Erratum in: Mediators Inflamm. 2019;2019:8419439. PMID: 30686934; PMCID: PMC6327257. PubMed PMC

Tang H, Cheng Z, Ma W, et al. TLR10 and NFKBIA contributed to the risk of hip osteoarthritis: systematic evaluation based on Han Chinese population. Sci Rep. 2018;8:10243. 10.1038/s41598-018-28597-2. PubMed PMC

Pryor KP, Barbhaiya M, Costenbader KH, et al. Disparities in lupus and lupus nephritis care and outcomes among US medicaid beneficiaries. Rheum Dis Clin North Am. 2021;47(1):41–53. 10.1016/j.rdc.2020.09.004. Epub 2020 Oct 29. PMID: 34042053; PMCID: PMC8171807. PubMed PMC

Patole PS, Pawar RD, Lech M et al. Expression and regulation of Toll-like receptors in lupus-like immune complex glomerulonephritis of MRL-Fas(lpr) mice. Nephrol Dial Transplant. 2006;21(11):3062-73. 10.1093/ndt/gfl336. Epub 2006 Sep 5. PMID: 16954173. PubMed

Imaizumi T, Aizawa T, Segawa C, et al. Toll-like receptor 3 signaling contributes to the expression of a neutrophil chemoattractant, CXCL1 in human mesangial cells. Clin Exp Nephrol. 2015;19(5):761–70. 10.1007/s10157-014-1060-4. Epub 2014 Dec 4. PMID: 25471749. PubMed

Elloumi N, Fakhfakh R, Abida O, Ayadi L, Marzouk S, Hachicha H, Fourati M, Bahloul Z, Mhiri MN, Kammoun K, Masmoudi H. Relevant genetic polymorphisms and kidney expression of Toll-like receptor (TLR)-5 and TLR-9 in lupus nephritis. Clin Exp Immunol. 2017;190(3):328–39. 10.1111/cei.13022. Epub 2017 Aug 30. PMID: 28763101; PMCID: PMC5680057. PubMed PMC

Yavuz S, Bianchi M, Kozyrev S, et al. Toll-like receptors revisited; a possible role for TLR1 in lupus nephritis. Ann Rheum Dis. 2021;80(3):404–6. 10.1136/annrheumdis-2020-218373. Epub 2020 Sep 29. PMID: 32994161; PMCID: PMC7892377. PubMed PMC

Rahman S, Shering M, Ogden NH, et al. Toll-like receptor cascade and gene polymorphism in host-pathogen interaction in Lyme disease. J Inflamm Res. 2016;9:91–102. 10.2147/JIR.S104790. PMID: 27330321; PMCID: PMC4898433. PubMed PMC

Kawai T, Akira S. The role of pattern-recognition receptors in innate immunity: update on Toll-like receptors. Nat Immunol. 2010;11(5):373–84. 10.1038/ni.1863. Epub 2010 Apr 20. PMID: 20404851. PubMed

Oliveira-Nascimento L, Massari P, Wetzler LM. The role of TLR2 in infection and immunity. Front Immunol. 2012;3:79. 10.3389/fimmu.2012.00079. PMID: 22566960; PMCID: PMC3342043. PubMed PMC

Sarwar S, Mohamed AS, Rogers S, et al. Neuropsychiatric systemic lupus erythematosus: A 2021 update on diagnosis, management, and current challenges. Cureus. 2021;13(9):e17969. 10.7759/cureus.17969. PMID: 34667659; PMCID: PMC8516357. PubMed PMC

Lindblom J, Mohan C, Parodis I. Biomarkers in neuropsychiatric systemic lupus erythematosus: A systematic literature review of the last decade. Brain Sci. 2022;12:192. 10.3390/brainsci12020192. PubMed PMC

Huang Q, Shen S, Qu H, et al. Expression of HMGB1 and TLR4 in neuropsychiatric systemic lupus erythematosus patients with seizure disorders. Ann Transl Med. 2020;8(1):9. 10.21037/atm.2019.12.44. PMID: 32055600; PMCID: PMC6995744. PubMed PMC

Birmingham DJ, Irshaid F, Zou X, et al. The complex nature of serum C3 and C4 as biomarkers of renal flare. Lupus. 2010;19:1272–80. 10.1177/0961203310371154. PubMed PMC