OBJECTIVE: To determine gene expression of the interleukin-17 (IL-17) family members (IL-17A-F) in rheumatoid subcutaneous nodules, and to assess the cytokines involved in regulating IL-17A expression. METHODS: Total RNA was isolated from 19 nodules obtained from 16 different patients with rheumatoid arthritis (RA). Reverse transcription-polymerase chain reaction (PCR) was used to screen for gene expression of the IL-17 subtypes (IL-17A-F) in all nodules. Quantitative real-time PCR was used to measure the expression of interferon-gamma (IFN gamma), IL-6, IL-23, IL-12, and transforming growth factor beta (TGFbeta), relative to GAPDH as control, in a subset of 10 nodules. RESULTS: IL-17A gene expression was present in only 1 of 19 nodules, IL-17B in 17 of 19 nodules, IL-17C in 18 of 19 nodules, IL-17D in 16 of 19 nodules, and IL-17E in 3 of 19 nodules. IL-17F was absent in all samples. Cytokines that stimulate IL-17A production (IL-6, IL-23) as well as those that inhibit IL-17A production (IL-12, IFN gamma, TGFbeta) were present in the majority of nodules. Quantitative real-time PCR showed a similar pattern of gene expression for the individual cytokines between the different nodules. The mean +/- SD expression of IL-6 relative to GAPDH was 2.28 +/- 2.2 ng, and that of TGFbeta was 2.96 +/- 1.14 ng. There was a lower relative expression of IL-23 (0.05 +/- 0.05 ng), while the expression of IFN gamma was 0.67 +/- 0.68 ng and that of IL-12 was 0.48 +/- 0.23 ng. CONCLUSION: IL-17 family members are varyingly expressed in rheumatoid nodules. The paucity of IL-17A in nodules suggests an important difference from that observed in the synovium. The expression of IL-23 below a critical threshold level seems the most likely explanation for the virtual absence of IL-17A. The presence of tissue destruction within the nodule despite the absence of IL-17A suggests that IL-17A may be an important amplifier rather than an absolute requirement for inflammation in RA.
OBJECTIVE: To determine gene expression of the interleukin-17 (IL-17) family members (IL-17A-F) in rheumatoid subcutaneous nodules, and to assess the cytokines involved in regulating IL-17A expression. METHODS: Total RNA was isolated from 19 nodules obtained from 16 different patients with rheumatoid arthritis (RA). Reverse transcription-polymerase chain reaction (PCR) was used to screen for gene expression of the IL-17 subtypes (IL-17A-F) in all nodules. Quantitative real-time PCR was used to measure the expression of interferon-gamma (IFN gamma), IL-6, IL-23, IL-12, and transforming growth factor beta (TGFbeta), relative to GAPDH as control, in a subset of 10 nodules. RESULTS:IL-17A gene expression was present in only 1 of 19 nodules, IL-17B in 17 of 19 nodules, IL-17C in 18 of 19 nodules, IL-17D in 16 of 19 nodules, and IL-17E in 3 of 19 nodules. IL-17F was absent in all samples. Cytokines that stimulate IL-17A production (IL-6, IL-23) as well as those that inhibit IL-17A production (IL-12, IFN gamma, TGFbeta) were present in the majority of nodules. Quantitative real-time PCR showed a similar pattern of gene expression for the individual cytokines between the different nodules. The mean +/- SD expression of IL-6 relative to GAPDH was 2.28 +/- 2.2 ng, and that of TGFbeta was 2.96 +/- 1.14 ng. There was a lower relative expression of IL-23 (0.05 +/- 0.05 ng), while the expression of IFN gamma was 0.67 +/- 0.68 ng and that of IL-12 was 0.48 +/- 0.23 ng. CONCLUSION:IL-17 family members are varyingly expressed in rheumatoid nodules. The paucity of IL-17A in nodules suggests an important difference from that observed in the synovium. The expression of IL-23 below a critical threshold level seems the most likely explanation for the virtual absence of IL-17A. The presence of tissue destruction within the nodule despite the absence of IL-17A suggests that IL-17A may be an important amplifier rather than an absolute requirement for inflammation in RA.
Authors: William F N Chan; Christopher J Atkins; David Naysmith; Nicholas van der Westhuizen; Janet Woo; J Lee Nelson Journal: Arthritis Rheum Date: 2012-02
Authors: X Xu; H-C Hsu; J Chen; W E Grizzle; W W Chatham; C R Stockard; Q Wu; P A Yang; V M Holers; J D Mountz Journal: Scand J Immunol Date: 2009-09 Impact factor: 3.487
Authors: Rossella Talotta; Fabiola Atzeni; Alberto Batticciotto; Maria Chiara Ditto; Maria Chiara Gerardi; Piercarlo Sarzi-Puttini Journal: J Med Case Rep Date: 2018-06-03