Production of biologically active recombinant human soluble CD23 and its effect on PBMCs isolated from hyper-IgE blood.
A recombinant form of human soluble CD23 (sCD23), the low affinity receptor for IgE (FcepsilonRII), was produced by PCR cloning the lectin-binding domain sequence into a bacterial expression vector. After renaturation and purification, the sCD23 bound IgE and divalent metal ions, indicating its activity. The recombinant human sCD23 exhibited similar proinflammatory properties as the native protein. Although interleukin-1beta, tumour necrosis factor-alpha, and nuclear factor-kappaB appeared not to be enhanced significantly in unstimulated RPMI 8866 B-lymphoblastoid and U937 promonocytic cell lines with 24 h incubation of recombinant sCD23, they were produced in both healthy and hyper-IgE-derived peripheral blood mononuclear cells, especially tumour necrosis factor-alpha. This study concludes that while recombinant and chimeric sCD23 may be useful in blocking IgE binding to immune cells and decreasing IgE synthesis by B-lymphocytes, the production of proinflammatory cytokines, particularly tumour necrosis factor-alpha will enhance immune responses in cases of asthma, allergy, and hyper-IgE syndrome.
Daniels
Brodie B
BB
Department of Biochemistry and Microbiology, Nelson Mandela Metropolitan University, P.O. Box 77000, Port Elizabeth 6031, South Africa.
Askew
Sandra L
SL
van de Venter
Maryna
M
Oosthuizen
Vaughan
V
D000328:Adult; D002478:Cells, Cultured; D006801:Humans; D007375:Interleukin-1 / Q000276:immunology; D007589:Job Syndrome / Q000097:blood*; D007963:Leukocytes, Mononuclear / Q000276:immunology*; D016328:NF-kappa B / Q000378:metabolism; D017455:Receptors, IgE / Q000235:genetics / Q000276:immunology*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000276:immunology; D011994:Recombinant Proteins / Q000235:genetics / Q000276:immunology*; D014409:Tumor Necrosis Factor-alpha / Q000276:immunology
D007375:Interleukin-1; D016328:NF-kappa B; D017455:Receptors, IgE; D011993:Recombinant Fusion Proteins; D011994:Recombinant Proteins; D014409:Tumor Necrosis Factor-alpha