The recombinant human TSLP Protein represents a mammalian cell-expressed variant of thymic stromal lymphopoietin engineered through arginine-to-alanine substitution site-directed mutagenesis at residues 127 and 130 within its 29-159 amino acid sequence. This lyophilized preparation demonstrates dual verification of purity exceeding 95% through both SDS-PAGE and SEC-HPLC, coupled with a C-terminal 10xHis tag that streamlines immobilized metal affinity chromatography purification. Functional validation via surface-bound interaction assays reveals its capacity to bind the anti-TSLP recombinant antibody (CSB-RA025141MA2HU) with an EC50 of 52.55-58.67 ng/mL when immobilized at 2 μg/mL, indicating preserved epitope presentation despite the arginine-to-alanine substitutions at critical positions. The mammalian expression system ensures native-like glycosylation patterns essential for proper tertiary structure formation, making this engineered TSLP variant particularly valuable for mechanistic studies requiring precise control over receptor activation thresholds and antibody neutralization assays in therapeutic development contexts.
Human TSLP is a crucial cytokine involved in various immunological processes. It is expressed in diverse human cells, including epithelial and stromal cells. It promotes type 2 immune responses [1][2]. TSLP is particularly important in the differentiation of naïve T cells into Th2 cells, which are associated with allergic responses and asthma pathology [2][3].
TSLP functions primarily through its interaction with a heterodimeric receptor complex composed of the TSLPR and the soluble sIL-7Rα. This signaling mechanism activates downstream JAK/STAT pathways, particularly involving STAT5, which is critical for the Th2 cytokine response [4]. The presence of TSLP in both healthy and diseased tissues, such as in chronic rhinosinusitis and asthma, underscores its relevance in inflammatory diseases [5][6]. In asthma, for example, elevated levels of TSLP have been observed in the airways of patients, where it is produced by bronchial epithelial cells and contributes to the recruitment and activation of immune cells like dendritic cells and mast cells [6].
Interestingly, TSLP has also been implicated in the effects of environmental factors like UV radiation and infections, which can enhance its expression through various signaling pathways [7]. For instance, exposure to respiratory syncytial virus can induce TSLP in airway epithelial cells, which further promotes an allergic type 2 response to infection [8]. Moreover, recent studies have shown that TSLP can influence the behavior of nerve cells, linking it to the sensation of itch, particularly relevant in skin conditions such as atopic dermatitis [9].
TSLP's role extends to its function as a mediator in conditions like systemic sclerosis and interstitial lung disease, driving fibrosis and highlighting its significance in chronic inflammatory diseases [10]. Additionally, the therapeutic potential of targeting TSLP in allergic diseases has been explored; monoclonal antibodies that block TSLP, such as tezepelumab, are being developed to mitigate type 2 inflammation effectively [11].
References:
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[5] D. Nagarkar, J. Poposki, et al. Thymic stromal lymphopoietin activity is increased in nasal polyps of patients with chronic rhinosinusitis. Journal of Allergy and Clinical Immunology, vol. 132, no. 3, p. 593-600.e12, 2013. https://doi.org/10.1016/j.jaci.2013.04.005
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[7] Y. Jang, S. Jeong, et al. Uvb induces hif-1α-dependent tslp expression via the jnk and erk pathways. Journal of Investigative Dermatology, vol. 133, no. 11, p. 2601-2608, 2013. https://doi.org/10.1038/jid.2013.203
[8] H. Lee, M. Headley, et al. Thymic stromal lymphopoietin is induced by respiratory syncytial virus–infected airway epithelial cells and promotes a type 2 response to infection. Journal of Allergy and Clinical Immunology, vol. 130, no. 5, p. 1187-1196.e5, 2012. https://doi.org/10.1016/j.jaci.2012.07.031
[9] S. Wilson, L. Thé, et al. The epithelial cell-derived atopic dermatitis cytokine tslp activates neurons to induce itch. Cell, vol. 155, no. 2, p. 285-295, 2013. https://doi.org/10.1016/j.cell.2013.08.057
[10] A. Datta, R. Alexander, et al. Evidence for a functional thymic stromal lymphopoietin signaling axis in fibrotic lung disease. The Journal of Immunology, vol. 191, no. 9, p. 4867-4879, 2013. https://doi.org/10.4049/jimmunol.1300588
[11] N. Syabbalo. Aerosol biologics for the treatment of eosinophilic asthma. Journal of Thoracic Disease and Cardiothoracic Surgery, vol. 3, no. 1, p. 01-05, 2022. https://doi.org/10.31579/2693-2156/035
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