Interaction with monocytes enhances IL-5 gene transcription in peripheral T cells of asthmatic patients.
BACKGROUND
The regulatory mechanisms of IL-5 gene transcription in human peripheral T cells are unclear because the transfection efficiency of plasmid constructs into nontransformed T cells is very low.


METHODS
Concanavalin A (ConA)-stimulated blastocytes derived from peripheral blood lymphocytes of asthmatic subjects were transiently transfected with the human IL-5 gene promoter/enhancer-luciferase gene construct, pIL-5 (-511)Luc, and cultured with THP-1 cells (human monocytoid cells) and anti-CD3 monoclonal antibody (mAb). IL-5 level in the culture medium was determined by an enzyme-linked immunosorbent assay. Transcriptional activity of the IL-5 gene was measured by luciferase reporter analysis.


RESULTS
ConA-blast lymphocytes of asthmatic patients produced a significant amount of IL-5 upon combined stimulation with anti-CD3 mAb and THP-1 cells, but not with anti-CD3 mAb alone. Costimulation with anti-CD28 mAb also enhanced the anti-CD3 mAb- induced IL-5 production. Accordingly, luciferase activity induced by anti-CD3 mAb stimulation in pIL-5(-511)Luc-transfected ConA-blast lymphocytes was increased 1.9- and 3.4-fold by the addition of anti-CD28 mAb and THP-1 cells, respectively. Serial 5' deletion analysis of the reporter gene demonstrated that the cis-regulatory element located at -119 to -80 is critical for anti-CD3 mAb-induced IL-5 gene transcription.


CONCLUSIONS
Our present findings provide a useful model reflecting IL-5 gene transcription in human peripheral T cells in vivo, and clearly demonstrate that an interaction with monocytes enhances IL-5 gene transcription.
Ogawa
Koji
K
Clinical Research Center for Allergy and Rheumatology, National Sagamihara Hospital, Kanagawa, Japan. k-ogawa@tanabe.co.jp
Kaminuma
Osamu
O
Kikkawa
Hideo
H
Akiyama
Kazuo
K
Mori
Akio
A
D000328:Adult; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D001249:Asthma / Q000235:genetics* / Q000378:metabolism; D015815:Cell Adhesion Molecules / Q000096:biosynthesis / Q000235:genetics; D003208:Concanavalin A / Q000494:pharmacology; D015536:Down-Regulation / Q000187:drug effects / Q000235:genetics; D017353:Gene Deletion; D005786:Gene Expression Regulation / Q000187:drug effects / Q000235:genetics; D006801:Humans; D015848:Interleukin-5 / Q000235:genetics* / Q000378:metabolism; D008875:Middle Aged; D009000:Monocytes / Q000187:drug effects / Q000502:physiology*; D011401:Promoter Regions, Genetic / Q000187:drug effects / Q000235:genetics; D011948:Receptors, Antigen, T-Cell / Q000235:genetics / Q000378:metabolism; D013268:Stimulation, Chemical; D013601:T-Lymphocytes / Q000187:drug effects / Q000502:physiology*; D014158:Transcription, Genetic / Q000187:drug effects / Q000235:genetics*
D000911:Antibodies, Monoclonal; D015815:Cell Adhesion Molecules; D015848:Interleukin-5; D011948:Receptors, Antigen, T-Cell; D003208:Concanavalin A