Transcriptional and translational regulation of IL-1 alpha and IL-1 beta account for the control of IL-1 in experimental yersiniosis.
Interleukin 1 (IL-1) gene expression was investigated in mice following oral infection with Yersinia enterocolitica 08. In Peyer's patches (PP), the primary site of bacterial invasion, induction of IL-1 alpha mRNA was delayed when compared to IL-1 beta mRNA. As shown by in situ hybridization. IL-1 alpha and IL-1 beta mRNA were found to be expressed within different cell types. These results indicate that expression of the two forms of IL-1 is regulated in a cell-specific manner at the transcriptional level. Moreover, IL-1 (alpha and beta) mRNA was increased in other organs such as spleen and lung. In spleens, IL-1 beta mRNA was found within the red pulp, and IL-1 alpha mRNA was located to the marginal zone confirming that differential expression of IL-1 alpha and IL-1 beta mRNA does not represent a tissue-specific event. However, as revealed by immunohistochemistry and measuring IL-1 activity in tissue homogenates, synthesis of IL-1 proteins was not detectable in spleens, unless mice were challenged with LPS. Because IL-1 synthesis was inducible in spleen cells following actinomycin D treatment, the results indicate that at distant sites of infection IL-1 (alpha and beta) mRNA is expressed but not translated into protein. It is concluded that cell-specific transcription of IL-1 alpha and IL-1 beta as well as dissociation between IL-1 mRNA and protein synthesis are two mechanisms effective in regulating the production of IL-1 during infection.
Rausch
U P
UP
Institute for Clinical Microbiology, University of Erlangen/Nürnberg, Germany.
Jordan
M
M
Rödel
F
F
Aigner
T
T
Otterness
I G
IG
Beuscher
N
N
Röllinghoff
M
M
Beuscher
H U
HU
D000818:Animals; D015152:Blotting, Northern; D003609:Dactinomycin / Q000494:pharmacology; D005260:Female; D005786:Gene Expression Regulation / Q000187:drug effects; D007124:Immunoenzyme Techniques; D017403:In Situ Hybridization; D007375:Interleukin-1 / Q000096:biosynthesis*; D007700:Kinetics; D008099:Liver / Q000276:immunology; D008168:Lung / Q000276:immunology; D008214:Lymphocytes / Q000187:drug effects / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D009928:Organ Specificity; D010581:Peyer's Patches / Q000276:immunology*; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000096:biosynthesis; D013154:Spleen / Q000276:immunology; D014158:Transcription, Genetic / Q000187:drug effects; D015009:Yersinia Infections / Q000276:immunology* / Q000378:metabolism; D015008:Yersinia enterocolitica
D007375:Interleukin-1; D012333:RNA, Messenger; D003609:Dactinomycin