BACKGROUND: IL-13 plays a key regulatory role in asthmatic responses and immunity to parasitic infection. In vivo, IL-13R-alpha2 is a critical modulator of IL-13 bioactivity. When inducibly expressed on the surface of fibroblasts and other cell types under inflammatory conditions, IL-13R-alpha2 contributes to resolution of IL-13 responses. A soluble form of IL-13R-alpha2 (sIL-13R-alpha2) can be detected in murine circulation, and functions as a regulator of IL-13 bioactivity. In humans, sIL-13R-alpha2 has been more difficult to detect. Recently, novel assay systems have been described to quantitate sIL-13R-alpha2 in human circulation, and revealed unexpectedly high levels of sIL-13R-alpha2 in healthy subjects. OBJECTIVE: To verify sIL-13R-alpha2 quantitation in human plasma samples under stringent conditions of signal verification and false-positive detection. METHODS: A standard ELISA protocol was evaluated for specificity using false-positive detection reagents. A more stringent ELISA protocol was developed by optimizing the composition of blocking and dilution buffers. RESULTS: Using the stringent assay protocol, endogenous sIL-13R-alpha2 was undetectable in plasma samples from a total of 120 asthmatics and 20 healthy subjects, and in bronchoalveolar lavage fluid from 10 asthmatics and eight healthy subjects undergoing allergen challenge. CONCLUSION: These results underscore the necessity to perform rigorous assay controls in the biological matrix to be tested. Because the soluble form could not be demonstrated, our findings question a role for sIL-13R-alpha2 in the regulation of IL-13 bioactivity, and highlight the potentially important contribution of the membrane-bound form of IL-13R-alpha2 in humans.
BACKGROUND:IL-13 plays a key regulatory role in asthmatic responses and immunity to parasitic infection. In vivo, IL-13R-alpha2 is a critical modulator of IL-13 bioactivity. When inducibly expressed on the surface of fibroblasts and other cell types under inflammatory conditions, IL-13R-alpha2 contributes to resolution of IL-13 responses. A soluble form of IL-13R-alpha2 (sIL-13R-alpha2) can be detected in murine circulation, and functions as a regulator of IL-13 bioactivity. In humans, sIL-13R-alpha2 has been more difficult to detect. Recently, novel assay systems have been described to quantitate sIL-13R-alpha2 in human circulation, and revealed unexpectedly high levels of sIL-13R-alpha2 in healthy subjects. OBJECTIVE: To verify sIL-13R-alpha2 quantitation in human plasma samples under stringent conditions of signal verification and false-positive detection. METHODS: A standard ELISA protocol was evaluated for specificity using false-positive detection reagents. A more stringent ELISA protocol was developed by optimizing the composition of blocking and dilution buffers. RESULTS: Using the stringent assay protocol, endogenous sIL-13R-alpha2 was undetectable in plasma samples from a total of 120 asthmatics and 20 healthy subjects, and in bronchoalveolar lavage fluid from 10 asthmatics and eight healthy subjects undergoing allergen challenge. CONCLUSION: These results underscore the necessity to perform rigorous assay controls in the biological matrix to be tested. Because the soluble form could not be demonstrated, our findings question a role for sIL-13R-alpha2 in the regulation of IL-13 bioactivity, and highlight the potentially important contribution of the membrane-bound form of IL-13R-alpha2 in humans.
Authors: Marion T Kasaian; Debra D Donaldson; Lioudmila Tchistiakova; Kimberly Marquette; Xiang-Yang Tan; Ashfaq Ahmed; Bruce A Jacobson; Angela Widom; Timothy A Cook; Xin Xu; Anthony B Barry; Samuel J Goldman; William M Abraham Journal: Am J Respir Cell Mol Biol Date: 2006-10-05 Impact factor: 6.914
Authors: J Bernard; D Treton; C Vermot-Desroches; C Boden; P Horellou; E Angevin; P Galanaud; J Wijdenes; Y Richard Journal: Lab Invest Date: 2001-09 Impact factor: 5.662
Authors: Allison-Lynn Andrews; Tosia Nasir; Fabio Bucchieri; John W Holloway; Stephen T Holgate; Donna E Davies Journal: J Allergy Clin Immunol Date: 2006-09-08 Impact factor: 10.793
Authors: Julia Kellner; Fernando Gamarra; Ulrich Welsch; Rudolf A Jörres; Rudolf M Huber; Albrecht Bergner Journal: Int Arch Allergy Immunol Date: 2006-11-13 Impact factor: 2.749
Authors: Allison-Lynn Andrews; Fabio Bucchieri; Kazuhiko Arima; Kenji Izuhara; Stephen T Holgate; Donna E Davies; John W Holloway Journal: J Allergy Clin Immunol Date: 2007-06-08 Impact factor: 10.793
Authors: Vahe Badalyan; Robert Thompson; Kezia Addo; Lee A Borthwick; Andrew J Fisher; Tatiana Ort; Timothy G Myers; Thomas A Wynn; Thirumalai R Ramalingam Journal: J Allergy Clin Immunol Date: 2014-06-20 Impact factor: 10.793
Authors: Fred D Finkelman; Simon P Hogan; Gurjit K Khurana Hershey; Marc E Rothenberg; Marsha Wills-Karp Journal: J Immunol Date: 2010-02-15 Impact factor: 5.422
Authors: James D Nolin; Ryan C Murphy; Michael H Gelb; William A Altemeier; William R Henderson; Teal S Hallstrand Journal: Biochim Biophys Acta Mol Cell Biol Lipids Date: 2018-12-05 Impact factor: 4.698
Authors: Weiguo Chen; Umasundari Sivaprasad; Yasuhiro Tabata; Aaron M Gibson; Matthew T Stier; Fred D Finkelman; Gurjit K Khurana Hershey Journal: J Immunol Date: 2009-12-15 Impact factor: 5.422
Authors: Maya Arai; Sadhana Jain; Amy A Weaver; Andrew A Hill; Yongjing Guo; Andrea G Bree; Michael F Smith; Scott W Allen; Edward R LaVallie; Deborah Young; Laird Bloom; Karissa Adkins; Margot O'Toole Journal: J Transl Med Date: 2010-05-28 Impact factor: 5.531
Authors: Weiguo Chen; Umasundari Sivaprasad; Aaron M Gibson; Mark B Ericksen; Christie M Cunningham; Stacey A Bass; Kayla G Kinker; Fred D Finkelman; Marsha Wills-Karp; Gurjit K Khurana Hershey Journal: J Allergy Clin Immunol Date: 2013-06-12 Impact factor: 10.793