{"id":53894,"date":"2026-01-19T12:42:01","date_gmt":"2026-01-19T11:42:01","guid":{"rendered":"https:\/\/inmuno.es\/index.php\/2026\/01\/19\/basal-activation-of-erk1-2-blunts-the-antimicrobial-activity-of-neutrophils-from-old-hosts-against-antibody-opsonized-streptococcus-pneumoniaeshaunna-r-simmons-on-19-de-january-de-2026-at-1\/"},"modified":"2026-01-19T12:42:01","modified_gmt":"2026-01-19T11:42:01","slug":"basal-activation-of-erk1-2-blunts-the-antimicrobial-activity-of-neutrophils-from-old-hosts-against-antibody-opsonized-streptococcus-pneumoniaeshaunna-r-simmons-on-19-de-january-de-2026-at-1","status":"publish","type":"post","link":"https:\/\/inmuno.es\/index.php\/2026\/01\/19\/basal-activation-of-erk1-2-blunts-the-antimicrobial-activity-of-neutrophils-from-old-hosts-against-antibody-opsonized-streptococcus-pneumoniaeshaunna-r-simmons-on-19-de-january-de-2026-at-1\/","title":{"rendered":"Basal activation of ERK1\/2 blunts the antimicrobial activity of neutrophils from old hosts against antibody-opsonized Streptococcus pneumoniae\u200bShaunna R Simmons   on 19 de January de 2026 at 11:00"},"content":{"rendered":"<div>\n<p><b>J Leukoc Biol<\/b>. 2026 Jan 19:qiag011. doi: 10.1093\/jleuko\/qiag011. Online ahead of print.<\/p>\n<p><b>ABSTRACT<\/b><\/p>\n<p>Age-related decline in neutrophil function reduces vaccine protection against Streptococcus pneumoniae. In vaccinated hosts, neutrophil activation via complement and Fc\u03b3 receptors mediates bacterial uptake and killing. Mechanisms behind age-related changes in signaling of these receptors is unknown. Using neutrophils from young and old mice, we found opsonin-dependent differences in MAPK activation. Neutrophils from old mice had higher basal phosphorylation of MAPK proteins compared to young controls, including a 15-fold increase in phosphorylated ERK1\/2, but failed to increase phosphorylation upon infection with antibody-opsonized bacteria. Inhibition of ERK1\/2 signaling blunted killing of antibody-opsonized pneumococci by neutrophils from young mice but improved killing in old mice. In young adult human participants, inhibition of ERK1\/2 signaling in neutrophils decreased pneumococcal killing, but only in vaccinated hosts, demonstrating the clinical relevance of this pathway. This study demonstrates that balanced activation of ERK1\/2 is crucial for neutrophil antimicrobial activity against antibody-opsonized bacteria but is disrupted in old hosts.<\/p>\n<p>PMID:<a href=\"https:\/\/pubmed.ncbi.nlm.nih.gov\/41549468\/?utm_source=SimplePie&amp;utm_medium=rss&amp;utm_content=8405628&amp;ff=20260119064159&amp;v=2.18.0.post22+67771e2\">41549468<\/a> | DOI:<a href=\"https:\/\/doi.org\/10.1093\/jleuko\/qiag011\">10.1093\/jleuko\/qiag011<\/a><\/p>\n<\/div>","protected":false},"excerpt":{"rendered":"<p>J Leukoc Biol. 2026 Jan 19:qiag011. doi: 10.1093\/jleuko\/qiag011. Online ahead of print. ABSTRACT Age-related decline in neutrophil function reduces vaccine protection against Streptococcus pneumoniae. In vaccinated hosts, neutrophil activation via complement and Fc\u03b3 receptors mediates bacterial uptake and killing. Mechanisms behind age-related changes in signaling of these receptors is unknown. Using neutrophils from young and &#8230; <a title=\"Basal activation of ERK1\/2 blunts the antimicrobial activity of neutrophils from old hosts against antibody-opsonized Streptococcus pneumoniae\u200bShaunna R Simmons   on 19 de January de 2026 at 11:00\" class=\"read-more\" href=\"https:\/\/inmuno.es\/index.php\/2026\/01\/19\/basal-activation-of-erk1-2-blunts-the-antimicrobial-activity-of-neutrophils-from-old-hosts-against-antibody-opsonized-streptococcus-pneumoniaeshaunna-r-simmons-on-19-de-january-de-2026-at-1\/\" aria-label=\"Read more about Basal activation of ERK1\/2 blunts the antimicrobial activity of neutrophils from old hosts against antibody-opsonized Streptococcus pneumoniae\u200bShaunna R Simmons   on 19 de January de 2026 at 11:00\">Read more<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[86,42],"tags":[],"class_list":["post-53894","post","type-post","status-publish","format-standard","hentry","category-journal-of-leukocyte-biology","category-publicaciones"],"_links":{"self":[{"href":"https:\/\/inmuno.es\/index.php\/wp-json\/wp\/v2\/posts\/53894","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/inmuno.es\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/inmuno.es\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/inmuno.es\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/inmuno.es\/index.php\/wp-json\/wp\/v2\/comments?post=53894"}],"version-history":[{"count":0,"href":"https:\/\/inmuno.es\/index.php\/wp-json\/wp\/v2\/posts\/53894\/revisions"}],"wp:attachment":[{"href":"https:\/\/inmuno.es\/index.php\/wp-json\/wp\/v2\/media?parent=53894"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/inmuno.es\/index.php\/wp-json\/wp\/v2\/categories?post=53894"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/inmuno.es\/index.php\/wp-json\/wp\/v2\/tags?post=53894"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}