{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,13]],"date-time":"2026-07-13T12:04:50Z","timestamp":1783944290505,"version":"3.55.0"},"reference-count":33,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,1,14]],"date-time":"2026-01-14T00:00:00Z","timestamp":1768348800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Immunol."],"abstract":"<jats:p>Multiple p38 MAP kinase inhibitors have been developed for the treatment of inflammatory diseases such as rheumatoid arthritis, but their effectiveness has been limited due to toxicity and tachyphylaxis, leading to a lack of clinical benefit. Efforts have been made to circumvent this limitation by targeting individual substrates downstream of p38, including MK2 and MK5. This approach has failed to yield clinical benefit despite preclinical evidence of a therapeutic effect. We hypothesized that there is redundancy in the MAPK activating kinase family that would necessitate blocking multiple kinases to sufficiently impact inflammatory processes. We used heterobifunctional protein degraders that either specifically degraded MK2 selectively or degraded MK2\/3\/5 simultaneously to test the hypothesis, in addition to genetic approaches to enable knockdown. In human PBMCs, elimination of MK2\/3\/5 with heterobifunctional degraders resulted in full reduction of TLR4 or TLR7\/8 induced TNF\u03b1, whereas MK2-specific degradation only attenuated TNF\u03b1 biosynthesis. In contrast, both specific MK2 degradation and broad MK2\/3\/5 degradation inhibited TGF-\u03b2-induced collagen production in human fibroblasts. This observation was consistent with genetic deletions of MK2, MK3 and MK5 (singly and in combination) whereby single deletion of MK2, MK3 or MK5 attenuated lipopolysaccharide (LPS) induced TNF\u03b1 production and had no effect on R848-induced TNF\u03b1 production. Double deletion of MK2 and MK3 or MK2 and MK5 or MK2\/3\/5 triple deletion had a significantly greater effect on TNF\u03b1 production regardless of stimulus. The combined data suggest cooperativity between MK2 and either MK3 or MK5 for efficient, cell context-dependent modulation of inflammatory responses.<\/jats:p>","DOI":"10.3389\/fimmu.2025.1712589","type":"journal-article","created":{"date-parts":[[2026,1,14]],"date-time":"2026-01-14T06:40:02Z","timestamp":1768372802000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":1,"title":["Targeted degradation of MK2 is insufficient to block inflammatory cytokine production in human cells due to cooperativity with MK3 and MK5"],"prefix":"10.3389","volume":"16","author":[{"given":"Bin","family":"Yang","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Guoqiang","family":"Fang","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Isaac","family":"Marx","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Guang","family":"Liu","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Stephanie","family":"Skouras","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kirti","family":"Sharma","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Dirk M.","family":"Walther","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sarah","family":"Bollinger Martinez","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Cedric","family":"Hubeau","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yatao","family":"Shi","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Chris","family":"De Savi","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xin","family":"Huang","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Annissa","family":"Huhn","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Rupa","family":"Sawant","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"William R.","family":"Proctor","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Vaishali S.","family":"Dixit","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Huijun","family":"Dong","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Matthew M.","family":"Weiss","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nello","family":"Mainolfi","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Anthony","family":"Slavin","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Andrew J.","family":"Long","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Juliet A.","family":"Williams","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Fergus R.","family":"Byrne","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2026,1,14]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","first-page":"797","DOI":"10.1124\/jpet.110.166173","article-title":"A benzothiophene inhibitor of mitogen-activated protein kinase-activated protein kinase 2 inhibits tumor necrosis factor alpha production and has oral anti-inflammatory efficacy in acute and chronic models of inflammation","volume":"333","author":"Mourey","year":"2010","journal-title":"J Pharmacol Exp Ther"},{"key":"B2","doi-asserted-by":"publisher","DOI":"10.3899\/jrheum.100602","article-title":"A 24-week, randomized, double-blind, placebo-controlled, parallel group study of the efficacy of oral SCIO-469, a p38 mitogen-activated protein kinase inhibitor, in patients with active rheumatoid arthritis","volume":"38","author":"Genovese","year":"2011","journal-title":"J Rheumatol"},{"key":"B3","doi-asserted-by":"publisher","DOI":"10.1093\/emboj\/cdg552","article-title":"Feedback control of the protein kinase TAK1 by SAPK2a\/p38alpha","volume":"22","author":"Cheung","year":"2003","journal-title":"EMBO J"},{"key":"B4","doi-asserted-by":"publisher","DOI":"10.1084\/jem.20172063","article-title":"Selective inhibition of the p38\u03b1 MAPK-MK2 axis inhibits inflammatory cues including inflammasome priming signals","volume":"215","author":"Wang","year":"2018","journal-title":"J Exp Med"},{"key":"B5","doi-asserted-by":"publisher","DOI":"10.4049\/jimmunol.177.3.1913","article-title":"MAPKAP kinase 2-deficient mice are resistant to collagen-induced arthritis","volume":"177","author":"Hegen","year":"2006","journal-title":"J Immunol"},{"key":"B6","doi-asserted-by":"publisher","DOI":"10.1111\/j.1471-4159.2008.05310.x","article-title":"MAPKAP kinase 2-deficiency prevents neurons from cell death by reducing neuroinflammation\u2014relevance in a mouse model of Parkinson\u2019s disease","volume":"105","author":"Thomas","year":"2008","journal-title":"J Neurochem"},{"key":"B7","doi-asserted-by":"publisher","DOI":"10.1161\/CIRCRESAHA.107.156075","article-title":"Systemic deficiency of the MAP kinase-activated protein kinase 2 reduces atherosclerosis in hypercholesterolemic mice","volume":"101","author":"Jagavelu","year":"2007","journal-title":"Circ Res"},{"key":"B8","doi-asserted-by":"publisher","first-page":"e0246600","DOI":"10.1371\/journal.pone.0246600","article-title":"Allosteric MAPKAPK2 inhibitors improve plaque stability in advanced atherosclerosis","volume":"16","author":"Ozcan","year":"2021","journal-title":"PLoS One"},{"key":"B9","doi-asserted-by":"publisher","DOI":"10.3389\/fimmu.2023.1212100","article-title":"MK2 drives progression of pancreas and colon cancers by suppressing CD8+ T cell cytotoxic function and is a potential immunotherapy target","volume":"14","author":"Jacenik","year":"2023","journal-title":"Front Immunol"},{"key":"B10","doi-asserted-by":"publisher","DOI":"10.1093\/intbio\/zyz025","article-title":"Substrate-based kinase activity inference identifies MK2 as driver of colitis","volume":"11","author":"Strasser","year":"2019","journal-title":"Integr Biol (Camb)"},{"key":"B11","doi-asserted-by":"publisher","DOI":"10.1016\/j.joca.2008.05.001","article-title":"Mitogen-activated protein kinase-activated protein kinase 2 (MK2) modulates key biological pathways associated with OA disease pathology","volume":"17","author":"Jones","year":"2009","journal-title":"Osteoarthritis Cartilage"},{"key":"B12","doi-asserted-by":"publisher","first-page":"47","DOI":"10.1016\/j.jconrel.2020.04.007","article-title":"Thermoresponsive, hollow, degradable core-shell nanoparticles for intra-articular delivery of anti-inflammatory peptide","volume":"323","author":"Deloney","year":"2020","journal-title":"J Control Release"},{"key":"B13","doi-asserted-by":"publisher","DOI":"10.2174\/1389450119666180816121323","article-title":"Novel therapeutic potential of mitogen-activated protein kinase activated protein kinase 2 (MK2) in chronic airway inflammatory disorders","volume":"20","author":"Singh","year":"2019","journal-title":"Curr Drug Targets"},{"key":"B14","doi-asserted-by":"publisher","DOI":"10.1165\/rcmb.2018-0033OC","article-title":"Mitogen-activated protein kinase-activated protein kinase 2 inhibition attenuates fibroblast invasion and severe lung fibrosis","volume":"60","author":"Liang","year":"2019","journal-title":"Am J Respir Cell Mol Biol"},{"key":"B15","doi-asserted-by":"publisher","DOI":"10.1074\/jbc.C100685200","article-title":"MK2 targets AU-rich elements and regulates biosynthesis of tumor necrosis factor and interleukin-6 independently at different post-transcriptional levels","volume":"277","author":"Neininger","year":"2002","journal-title":"J Biol Chem"},{"key":"B16","doi-asserted-by":"publisher","DOI":"10.1038\/10061","article-title":"MAPKAP kinase 2 is essential for LPS-induced TNF-alpha biosynthesis","volume":"1","author":"Kotlyarov","year":"1999","journal-title":"Nat Cell Biol"},{"key":"B17","doi-asserted-by":"publisher","DOI":"10.1128\/MCB.01456-06","article-title":"The mitogen-activated protein kinase (MAPK)-activated protein kinases MK2 and MK3 cooperate in stimulation of tumor necrosis factor biosynthesis and stabilization of p38 MAPK","volume":"27","author":"Ronkina","year":"2007","journal-title":"Mol Cell Biol"},{"key":"B18","doi-asserted-by":"publisher","DOI":"10.1038\/s41591-023-02635-7","article-title":"IRAK4 degrader in hidradenitis suppurativa and atopic dermatitis: a phase 1 trial","volume":"29","author":"Ackerman","year":"2023","journal-title":"Nat Med"},{"key":"B19","author":"Yang","year":"2023"},{"key":"B20","doi-asserted-by":"publisher","first-page":"50","DOI":"10.1128\/MMBR.00031-10","article-title":"Activation and function of the MAPKs and their substrates, the MAPK-activated protein kinases","volume":"75","author":"Cargnello","year":"2011","journal-title":"Microbiol Mol Biol Rev"},{"key":"B21","doi-asserted-by":"publisher","DOI":"10.1074\/jbc.M111.235275","article-title":"Distinct functions of the mitogen-activated protein kinase-activated protein (MAPKAP) kinases MK2 and MK3: MK2 mediates lipopolysaccharide-induced signal transducers and activators of transcription 3 (STAT3) activation by preventing negative regulatory effects of MK3","volume":"286","author":"Ehlting","year":"2011","journal-title":"J Biol Chem"},{"key":"B22","doi-asserted-by":"publisher","DOI":"10.1002\/jcb.21154","article-title":"Smooth muscle alpha-actin expression and myofibroblast differentiation by TGFbeta are dependent upon MK2","volume":"100","author":"Sousa","year":"2007","journal-title":"J Cell Biochem"},{"key":"B23","doi-asserted-by":"publisher","first-page":"47","DOI":"10.1165\/rcmb.2012-0389OC","article-title":"Peptide-mediated inhibition of mitogen-activated protein kinase-activated protein kinase-2 ameliorates bleomycin-induced pulmonary fibrosis","volume":"49","author":"Vittal","year":"2013","journal-title":"Am J Respir Cell Mol Biol"},{"key":"B24","doi-asserted-by":"publisher","DOI":"10.2741\/3095","article-title":"MK2 and MK3\u2014a pair of isoenzymes","volume":"13","author":"Ronkina","year":"2008","journal-title":"Front Biosci"},{"key":"B25","doi-asserted-by":"publisher","DOI":"10.4049\/jimmunol.1801221","article-title":"The role of TTP phosphorylation in the regulation of inflammatory cytokine production by MK2\/3","volume":"203","author":"Ronkina","year":"2019","journal-title":"J Immunol"},{"key":"B26","doi-asserted-by":"publisher","DOI":"10.1038\/ni1517","article-title":"The MAPK-activated kinase Rsk controls an acute Toll-like receptor signaling response in dendritic cells and is activated through two distinct pathways","volume":"8","author":"Zaru","year":"2007","journal-title":"Nat Immunol"},{"key":"B27","doi-asserted-by":"publisher","DOI":"10.1016\/j.cellsig.2010.03.002","article-title":"Mitogen-activated protein kinase p38 and MK2, MK3 and MK5: m\u00e9nage \u00e0 trois or m\u00e9nage \u00e0 quatre","volume":"22","author":"Shiryaev","year":"2010","journal-title":"Cell Signal"},{"key":"B28","doi-asserted-by":"publisher","first-page":"e54239","DOI":"10.1371\/journal.pone.0054239","article-title":"Crucial roles of the protein kinases MK2 and MK3 in a mouse model of glomerulonephritis","volume":"8","author":"Guess","year":"2013","journal-title":"PLoS One"},{"key":"B29","doi-asserted-by":"publisher","first-page":"49","DOI":"10.1016\/j.trsl.2022.06.005","article-title":"Discovery of CC-99677, a selective targeted covalent MAPKAPK2 (MK2) inhibitor for autoimmune disorders","volume":"249","author":"Malona","year":"2022","journal-title":"Transl Res"},{"key":"B30","doi-asserted-by":"publisher","first-page":"199","DOI":"10.1186\/s13075-022-02850-6","article-title":"CC-99677, a novel, oral, selective covalent MK2 inhibitor, sustainably reduces pro-inflammatory cytokine production","volume":"24","author":"Gaur","year":"2022","journal-title":"Arthritis Res Ther"},{"key":"B31","doi-asserted-by":"publisher","DOI":"10.2147\/CPAA.S305308","article-title":"Safety, tolerability, pharmacokinetics, and pharmacodynamics of the MK2 inhibitor ATI-450 in healthy subjects: a placebo-controlled, randomized phase 1 study","volume":"13","author":"Gordon","year":"2021","journal-title":"Clin Pharmacol"},{"key":"B32","doi-asserted-by":"publisher","first-page":"63","DOI":"10.1002\/acr2.11517","article-title":"Selective inhibition of the MK2 pathway: data from a phase iIa randomized clinical trial in rheumatoid arthritis","volume":"5","author":"Gordon","year":"2023","journal-title":"ACR Open Rheumatol"},{"key":"B33","doi-asserted-by":"publisher","DOI":"10.1136\/annrheumdis-2012-202221","article-title":"Oral administration of GLPG0259, an inhibitor of MAPKAPK5, a new target for the treatment of rheumatoid arthritis: a phase II, randomised, double-blind, placebo-controlled, multicentre trial","volume":"72","author":"Westhovens","year":"2013","journal-title":"Ann Rheum Dis"}],"container-title":["Frontiers in Immunology"],"original-title":[],"link":[{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fimmu.2025.1712589\/full","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,1,14]],"date-time":"2026-01-14T06:40:03Z","timestamp":1768372803000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fimmu.2025.1712589\/full"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,1,14]]},"references-count":33,"alternative-id":["10.3389\/fimmu.2025.1712589"],"URL":"https:\/\/doi.org\/10.3389\/fimmu.2025.1712589","relation":{},"ISSN":["1664-3224"],"issn-type":[{"value":"1664-3224","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,1,14]]},"article-number":"1712589"}}