{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,5]],"date-time":"2026-02-05T20:01:35Z","timestamp":1770321695274,"version":"3.49.0"},"reference-count":41,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,2,5]],"date-time":"2026-02-05T00:00:00Z","timestamp":1770249600000},"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. Microbiol."],"abstract":"<jats:sec>\n                    <jats:title>Background<\/jats:title>\n                    <jats:p>\n                      Brucellosis remains the most prevalent zoonotic disease globally and can cause chronic persistent infection, which in turn results in prolonged recovery challenges. Myeloid-derived suppressor cells (MDSCs) are pathologically activated neutrophils and monocytes with strong immunosuppressive activity. Toll-like receptor 4 (TLR4) can initiate the body\u2019s inflammatory response, leading to an inflammatory cytokine storm. Programmed death ligand 1 (PD-L1) modulates the strength and duration of the immune response, diminishing the immune system\u2019s ability to eliminate pathogens and subsequently affecting disease progression and prognosis. However, the clinical significance of TLR4\n                      <jats:sup>+<\/jats:sup>\n                      MDSC and PD-L1\n                      <jats:sup>+<\/jats:sup>\n                      MDSC in\n                      <jats:italic>Brucella<\/jats:italic>\n                      infection remains unclear.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>\n                      A total of 88 patients with acute brucellosis infection (ABI), 66 patients with chronic brucellosis infection (CBI), and 82 healthy controls (HC) subjects were enrolled. Flow cytometry was used to detect TLR4\n                      <jats:sup>+<\/jats:sup>\n                      MDSCs and PD-L1\n                      <jats:sup>+<\/jats:sup>\n                      MDSCs of patients. ELISA was used to detect ALT, AST, Arg1 and iNOS in the patient\u2019s serum. We characterized a mouse model of\n                      <jats:italic>Brucella<\/jats:italic>\n                      , and determined the effects of TLR4\n                      <jats:sup>+<\/jats:sup>\n                      MDSCs and PD-L1\n                      <jats:sup>+<\/jats:sup>\n                      MDSCs in this model.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>\n                      Our study found that the frequency of MDSC in CBI group was significantly elevated. The levels of Arg1 and iNOS were also positively correlated with the levels of TLR4\n                      <jats:sup>+<\/jats:sup>\n                      MDSCs and PD-L1\n                      <jats:sup>+<\/jats:sup>\n                      MDSCs. The levels of AST and ALT had elevated may reflect liver function. In addition, we also found that the number of TLR4\n                      <jats:sup>+<\/jats:sup>\n                      MDSCs and PD-L1\n                      <jats:sup>+<\/jats:sup>\n                      MDSCs increased in model mice with chronic brucellosis.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion<\/jats:title>\n                    <jats:p>\n                      These findings expand the current understanding of persistent Brucella infection, and highlight that TLR4\n                      <jats:sup>+<\/jats:sup>\n                      and PD-L1\n                      <jats:sup>+<\/jats:sup>\n                      MDSCs hold potential as candidate biomarkers for assessing the severity and progression of brucellosis.\n                    <\/jats:p>\n                  <\/jats:sec>","DOI":"10.3389\/fmicb.2026.1730300","type":"journal-article","created":{"date-parts":[[2026,2,5]],"date-time":"2026-02-05T06:45:18Z","timestamp":1770273918000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["Myeloid-derived suppressor cells and their subsets serve as potential biomarkers for the progression of brucellosis"],"prefix":"10.3389","volume":"17","author":[{"given":"Juan","family":"Shi","sequence":"first","affiliation":[{"name":"Clinical Laboratory Center, The First Affiliated Hospital of Xinjiang Medical University","place":["Urumqi, China"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yibeibaihan","family":"Maimaiti","sequence":"additional","affiliation":[{"name":"Department of Medical Laboratory, Hospital of Xinjiang Production and Construction Corps\/Second Affiliated Hospital of Shihezi University School of Medicine","place":["Urumqi, China"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Xinxin","family":"Qi","sequence":"additional","affiliation":[{"name":"Post-doctoral Research station of the Clinical Medicine, The First Affiliated Hospital of Xinjiang Medical University","place":["Urumqi, China"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Na","family":"Chen","sequence":"additional","affiliation":[{"name":"Clinical Laboratory Center, The First Affiliated Hospital of Xinjiang Medical University","place":["Urumqi, China"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Huidong","family":"Shi","sequence":"additional","affiliation":[{"name":"Clinical Laboratory Center, The First Affiliated Hospital of Xinjiang Medical University","place":["Urumqi, China"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jianbing","family":"Ding","sequence":"additional","affiliation":[{"name":"Clinical Laboratory Center, The First Affiliated Hospital of Xinjiang Medical University","place":["Urumqi, China"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yuejie","family":"Zhu","sequence":"additional","affiliation":[{"name":"Reproductive Medicine Center, The First Affiliated Hospital of Xinjiang Medical University","place":["Urumqi, China"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Fengbo","family":"Zhang","sequence":"additional","affiliation":[{"name":"Clinical Laboratory Center, The First Affiliated Hospital of Xinjiang Medical University","place":["Urumqi, China"]}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1965","published-online":{"date-parts":[[2026,2,5]]},"reference":[{"key":"ref1","doi-asserted-by":"publisher","first-page":"333","DOI":"10.3201\/eid2902.220725","article-title":"Novel species of Brucella causing human brucellosis, French Guiana","volume":"29","author":"About","year":"2023","journal-title":"Emerg. 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