Cloning and polymorphism analysis of IL-4 proximal promoter in asthmatic children.
OBJECTIVE
To clone and study the polymorphism within interleukin-4 (IL-4) proximal promoter of asthmatic children.


METHODS
The IL-4 proximal promoter segments were amplified and selected by polymerase chain reaction (PCR) and single strand conformation polymorphism (SSCP) with genomic DNA from ten healthy children and forty patients with dominantly allergic familial histories as templates. The selected PCR segments were cloned into recombinant plasmids pIL-4-Jx2. The PCR inserts were sequenced by dideoxy chain termination method.


RESULTS
Seven aberrant bands were found in SSCP analysis from forty asthmatic patients. The sequencing results showed that four variant sites were found within or adjacent to the known IL-4 regulatory element. A C to A transversion located at -229 position was just within the positive regulatory element-I (PRE-I) in one patient. A C to T transition adjacent to the negative regulatory element-II (NRE-II) and an extra G adjacent to TATA box were found in two patients. A five base nucleotide deletion was found near signal transducers and activators of transcription-6 responsive element (STAT-6 RE) in one patient.


CONCLUSIONS
There were polymorphisms within the IL-4 proximal promoter of allergic asthmatic patients and these polymorphisms might result in aberrant expression of IL-4 gene and asthma.
Zhou
Yufeng
Y
Department of Molecular Immunology, Institute of Shenzhen Children's Hospital, Shenzhen 518026, China. yufengzh@hotmail.com
Fu
Jinrong
J
Wu
Jianmin
J
Li
Chengrong
C
D001249:Asthma / Q000235:genetics*; D001483:Base Sequence; D002648:Child; D002675:Child, Preschool; D003001:Cloning, Molecular; D006801:Humans; D015847:Interleukin-4 / Q000235:genetics*; D008969:Molecular Sequence Data; D010957:Plasmids; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D018807:Polymorphism, Single-Stranded Conformational; D011401:Promoter Regions, Genetic; D050800:STAT6 Transcription Factor; D015534:Trans-Activators / Q000378:metabolism
D050800:STAT6 Transcription Factor; C494101:STAT6 protein, human; D015534:Trans-Activators; D015847:Interleukin-4