{"id":383,"date":"2006-11-16T09:49:03","date_gmt":"2006-11-16T07:49:03","guid":{"rendered":"http:\/\/www.wjst.de\/blog\/2006\/11\/16\/unripe\/"},"modified":"2006-11-23T13:53:38","modified_gmt":"2006-11-23T11:53:38","slug":"unripe","status":"publish","type":"post","link":"https:\/\/www.wjst.de\/blog\/sciencesurf\/2006\/11\/unripe\/","title":{"rendered":"Unripe"},"content":{"rendered":"

A key event in the vitamin D hypothesis of allergy induction is the immature state of dendritic cells. So far, maturity has been mainly described in terms of reduced expression of cell surface marker like CD80. A new study in Nature<\/a> now further unravels how the capacity of DC to present antigen may be disturbed. Ubiquitination – the covalent attachment of ubiquitin polymers – of the MHC II \u00df chain ceases on maturation allowing the transport from endosomal compartments to the plasma membrane. Immature cells seem to be capable to some level of peptide-MHC interaction (at least for some selected antigens) although this process is greatly enhanced by maturation of DCs. Semi-maturity is believed to be an important inetrim stage where at least an earlier review<\/a> argued<\/p>\n

\nwe propose a model in which steady-state migration and partial maturation (semi-maturation) of DCs is embedded as a major component within immune homeostasis, established for permanent and active tolerance induction against self-antigens derived from peripheral tissues by inducing antigen-specific CD4+ Tr cells. Semi-maturation induced by proinflammatory cytokines, such as TNF-alpha, seems to represent a unique developmental tolerogenic stage for DCs, which is based on the absence of proinflammatory cytokine production, despite high expression of MHC II and costimulatory molecules.\n<\/p><\/blockquote>\n

Another interesting study in the J Immunol – coined “alternatively activated dendritic cells<\/a>” the authors probably talk about the same immature cells (compare with my cartoon summarizing a 2002 paper in Trend Mol Med<\/a>). These immature DCs secrete high levels of IL10 (a paradox discussed in my most recent paper<\/a>). In addition these DCs produce low amounts of IL12p70, TLR4 and CCR7. What was new to me, was an impressive list of pharmacological agents that suppress DC development: aspirin (also paracetamol?), corticosteroids, cyclosporine A, rapamycin (also other antibiotics?), and finally mycophenolate mofetil.<\/p>\n

There is also an update of the IL10 paradox<\/a>: Allergic sensitization may be down regulated by CD40 AGONISTs independent of IL10!<\/p>\n

Finally, I would like to understand what immature really do after encountering allergen exposure. A new paper in nature immunology<\/a> says that<\/p>\n

\nimmature DC are also thought to carry antigen to lymph nodes and to interact with naive T cells but without a previous maturation stimulus, those interactions result in abortive activation of the T cells, which can be eliminated, rendered unresponsive or induced to differentiate into regulatory T cells.\n<\/p><\/blockquote>\n

which still does not answer my question.<\/p>\n

Vitamin D actions<\/em>
\n\"vd_immun.png\"<\/p>\n

Yea, yea.<\/p>\n\n

 <\/p>\n

\n CC-BY-NC Science Surf , accessed 14.04.2026<\/span>\n <\/div>","protected":false},"excerpt":{"rendered":"

A key event in the vitamin D hypothesis of allergy induction is the immature state of dendritic cells. So far, maturity has been mainly described in terms of reduced expression of cell surface marker like CD80. A new study in Nature now further unravels how the capacity of DC to present antigen may be disturbed. … Continue reading Unripe<\/span> →<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[10],"tags":[200,201,94,199,204,202,203,205],"class_list":["post-383","post","type-post","status-publish","format-standard","hentry","category-sunshine-vitamin","tag-hla","tag-mhc","tag-vitamin-sunshine","tag-allergy","tag-cell_surface_marker","tag-dendritic-cells","tag-dendritic_cells","tag-immature_state"],"_links":{"self":[{"href":"https:\/\/www.wjst.de\/blog\/wp-json\/wp\/v2\/posts\/383","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.wjst.de\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.wjst.de\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.wjst.de\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.wjst.de\/blog\/wp-json\/wp\/v2\/comments?post=383"}],"version-history":[{"count":0,"href":"https:\/\/www.wjst.de\/blog\/wp-json\/wp\/v2\/posts\/383\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.wjst.de\/blog\/wp-json\/wp\/v2\/media?parent=383"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.wjst.de\/blog\/wp-json\/wp\/v2\/categories?post=383"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.wjst.de\/blog\/wp-json\/wp\/v2\/tags?post=383"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}