Autor: |
Quinones, Marlon, Ahuja, Sunil K., Melby, Peter C., Pate, Lyle, Reddick, Robert L., Ahuja, Seema S. |
Zdroj: |
The Journal of Experimental Medicine; August 2000, Vol. 192 Issue: 4 p507-516, 10p |
Abstrakt: |
The prevailing paradigm is that production of the interleukin (IL)-12 p70 heterodimer, a critical T helper cell type 1 (Th1)–inducing cytokine, depends on the induced transcription of the p40 subunit. Concordant with this paradigm, we found that dendritic cells (DCs) produced IL-12 p70 only after at least 2–4 h of stimulation with lipopolysaccharide plus interferon γ. However, using several complementary experimental approaches, including electron and confocal microscopy, we now show that resting murine and human myeloid cells, including macrophages/DCs and DC-rich tissues, contain a novel source of bioactive IL-12 that is preformed and membrane associated. These preformed, membrane-associated IL-12 p70 stores are released within minutes after in vitro or in vivo contact with Leishmania donovani, an intracellular pathogen. Our findings highlight a novel source of bioactive IL-12 that is readily available for the rapid initiation of Th1 host responses to pathogens such as Leishmania species. |
Databáze: |
Supplemental Index |
Externí odkaz: |
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