Type 2 cytokine gene activation and its relationship to extent of disease in patients with tuberculosis.
The extent of type 2 cytokine gene expression in patients with pulmonary tuberculosis (TB) was studied by use of quantitative nested reverse-transcription polymerase chain reaction on freshly isolated peripheral blood mononuclear cells. Interleukin (IL)-4 and IL-13 mRNA expression was significantly greater in patients-median mRNA copy numbers were 1.7 and 1.1 log10 higher, respectively-than in matched tuberculin-positive control subjects. Significant correlations with radiologic extent of disease and serum IgE levels supported the biologic significance of these results. Interferon-gamma mRNA copy numbers exceeded those of type 2 cytokines but were only marginally lower in patients than in control subjects. Gene expression of an IL-4 splice variant (IL-4delta2) was bimodally distributed in both patient and control groups. Patients with greater IL-4delta2 expression also expressed more IL-4 mRNA and had more extensive disease. Type 2 cytokines are associated with immunopathologic changes in TB patients but could be a cause or consequence of disease.
Seah
G T
GT
Department of Bacteriology, Windeyer Institute of Medical Sciences, Royal Free and University College Medical School, London, United Kingdom.
Scott
G M
GM
Rook
G A
GA
D000293:Adolescent; D000328:Adult; D017398:Alternative Splicing; D005786:Gene Expression Regulation; D006801:Humans; D007371:Interferon-gamma / Q000235:genetics; D018793:Interleukin-13 / Q000235:genetics*; D015847:Interleukin-4 / Q000235:genetics*; D008875:Middle Aged; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015533:Transcriptional Activation; D014397:Tuberculosis, Pulmonary / Q000276:immunology* / Q000473:pathology
D018793:Interleukin-13; D012333:RNA, Messenger; D015847:Interleukin-4; D007371:Interferon-gamma