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Background and Objectives: Systemic lupus erythematosus (SLE) is an inflammatory disease. The sera of SLE patients contain antibodies-abzymes hydrolyzing myelin basic protein (MBP), DNA, nucleotides, and oligosaccharides. The blood of SLE patients contains an increased amount of some specific miRNAs. This study aimed to analyze a possible hydrolysis of eight microRNAs found in the blood of SLE patients with high frequency by blood antibodies-abzymes. Patients and Methods: Using affinity chromatography of the serum proteins of SLE patients and healthy donors on protein G-Sepharose and following FPLC gel filtration, electrophoretically homogeneous IgG preparations containing no impurities of canonical RNases were obtained. These preparations were used to analyze their activity in the hydrolysis of eight miRNAs. Results: It was shown that SLE IgGs hydrolyze very efficiently four neuroregulatory miRNAs (miR-219-2-3p, miR-137, miR-219a-5p, and miR-9-5p) and four immunoregulatory miRNAs (miR-326, miR-21-3p, miR-155-5p, and miR-146a-3p). To demonstrate that the miRNAs hydrolysis is an intrinsic property of SLE IgGs, several rigid criteria were checked. Only some IgGs of healthy donors showed very weak, but reliably detectable activity in the hydrolysis miRNAs. The average activity of SLE patients IgGs according to median values is statistically significant 84.8-fold higher than that of healthy donors. The maximum and comparable average activity (RA) was observed in the hydrolysis of three miRAs: miR-9-5p, miR-155-5p, and miR-326. MiR-9-5p plays an important role in the development of lupus nephritis, while miR-326 activates the production of antibodies by B cells. The major and moderate specific sites of the hydrolysis of each miRNA were revealed. The hydrolysis of eight microRNAs was mostly site specific. Several SLE IgGs hydrolyzed some miRNAs demonstrating a combination of site-specific and non-specific splitting. Conclusion: Since inflammatory processes in SLE are associated with the change in miRNAs expression, the decrease in their concentration due to hydrolysis by autoantibodiesabzymes may be important for SLE pathogenesis.

Homeostatic proliferation (HP) is a physiological process that reconstitutes the T cell pool after lymphopenia involving Interleukin-7 and 15 (IL-7 and IL-15), which are the key cytokines regulating the process. However, there is no evidence that these cytokines influence the function of regulatory T cells (Tregs). Since lymphopenia often accompanies autoimmune diseases, we decided to study the functional activity of Tregs stimulated by HP cytokines from patients with rheumatoid arthritis as compared with that of those from healthy donors. Since T cell receptor (TCR) signal strength determines the intensity of HP, we imitated slow HP using IL-7 or IL-15 and fast HP using a combination of IL-7 or IL-15 with anti-CD3 antibodies, cultivating Treg cells with peripheral blood mononuclear cells (PBMCs) at a 1:1 ratio. We used peripheral blood from 14 patients with rheumatoid arthritis and 18 healthy volunteers. We also used anti-CD3 and anti-CD3 + IL-2 stimulation as controls. The suppressive activity of Treg cells was evaluated in each case by the inhibition of the proliferation of CD4+ and CD8+ cells. The phenotype and proliferation of purified CD3+CD4+CD25+CD127lo cells were assessed by flow cytometry. The suppressive activity of the total pool of Tregs did not differ between the rheumatoid arthritis and healthy donors; however, it significantly decreased in conditions close to fast HP when the influence of HP cytokines was accompanied by anti-CD3 stimulation. The Treg proliferation caused by HP cytokines was lower in the rheumatoid arthritis (RA) patients than in the healthy individuals. The revealed decrease in Treg suppressive activity could impact the TCR landscape during lymphopenia and lead to the proliferation of potentially self-reactive T cell clones that are able to receive relatively strong TCR signals. This may be another explanation as to why lymphopenia is associated with the development of autoimmune diseases. The revealed decrease in Treg proliferation under IL-7 and IL-15 exposure can lead to a delay in Treg pool reconstitution in patients with rheumatoid arthritis in the case of lymphopenia.

Changes in cytokine profiles and cytokine networks are known to be a hallmark of autoimmune diseases, including systemic lupus erythematosus (SLE) and multiple sclerosis (MS). However, cytokine profiles research studies are usually based on the analysis of a small number of cytokines and give conflicting results. In this work, we analyzed cytokine profiles of 41 analytes in patients with SLE and MS compared with healthy donors using multiplex immunoassay. The SLE group included treated patients, while the MS patients were drug-free. Levels of 11 cytokines, IL-1b, IL-1RA, IL-6, IL-9, IL-10, IL-15, MCP-1/CCL2, Fractalkine/CX3CL1, MIP-1a/CCL3, MIP-1b/CCL4, and TNFa, were increased, but sCD40L, PDGF-AA, and MDC/CCL22 levels were decreased in SLE patients. Thus, changes in the cytokine profile in SLE have been associated with the dysregulation of interleukins, TNF superfamily members, and chemokines. In the case of MS, levels of 10 cytokines, sCD40L, CCL2, CCL3, CCL22, PDGF-AA, PDGF-AB/BB, EGF, IL-8, TGF-a, and VEGF, decreased significantly compared to the control group. Therefore, cytokine network dysregulation in MS is characterized by abnormal levels of growth factors and chemokines. Cross-disorder analysis of cytokine levels in MS and SLE showed significant differences between 22 cytokines. Protein interaction network analysis showed that all significantly altered cytokines in both SLE and MS are functionally interconnected. Thus, MS and SLE may be associated with impaired functional relationships in the cytokine network. A cytokine correlation networks analysis revealed changes in correlation clusters in SLE and MS. These data expand the understanding of abnormal regulatory interactions in cytokine profiles associated with autoimmune diseases.

Курочкина Ю.Д., Леплина О.Ю., Тихонова М.А., Тыринова Т.В., Баторов Е.В., Сизиков А.Э., Останин А.А., Черных Е.Р. ФГБНУ «Научно-исследовательский институт фундаментальной и клинической иммунологии», г. Новосибирск, РоссияРезюме. Интерфероны I типа являются мощными индукторами дифференцировки моноцитов в дендритные клетки (ДК), однако чувствительность таких ДК к толерогенному эффекту глюкокор-тикоидов ранее не исследовалась. Целью работы явилось изучение влияния дексаметазона на со-зревание и функции интерферон-альфа-индуцированных ДК (IFN-ДК) здоровых доноров. ДК генерировали из моноцитов крови, которые культивировали в течение 5 суток с GM-CSF и IFNα в отсутствие и присутствии декасаметазона (10 -6 M), вносимого на 3 сутки. Добавление дексаметазо-на блокировало созревание IFN-ДК, что проявлялось возрастанием доли CD14 + клеток и снижени-ем содержания CD83 + клеток. Дексаметазон не оказывал значимого влияния на экспрессию HLA-DR, CD86 и B7-H1, однако 2-кратно усиливал экспрессию толерогенной молекулы TLR-2. Наряду с подавлением созревания IFN-ДК, дексаметазон ингибировал продукцию ими провоспалитель-ных/Th1-цитокинов (TNFα, IL-1, IL-2, IFNγ, IL-12) и хемокинов (MIP-1α, RANTES). IFN-ДК, ге-нерированные в присутствии дексаметазона, отличались 2-кратным снижением аллостимуляторной активности в смешанной культуре лимфоцитов (СКЛ). При этом способность IFN-ДК стимулиро-вать пролиферативный ответ Т-клеток в алло-СКЛ прямо коррелирует с экспрессией на ДК моле-кулы CD83 и обратно -с экспрессией СD14 и TLR-2. Оценка Th1-/Th2-поляризующей активности IFN-ДК показала, что дексаметазон оказывал выраженное ингибирующее влияние на способность ДК стимулировать Т-клетки к продукции IFNγ, тогда как супрессорный эффект на способность ДК стимулировать продукцию IL-6 был менее выраженным, что свидетельствует о доминировании Th2-поляризующей активности IFN-ДК под влиянием дексаметазона. В целом показано, что IFN-ДК чувствительны к толерогенному действию дексаметазона и, следовательно, могут опосредовать им-муномодулирующий эффект глюкокортикоидной терапии, а также рассматриваться в качестве но-вых кандидатов для разработки толерогенных лечебных ДК-вакцин при аутоиммунной патологии.