{"title":"Development of an immunoassay for quantification of soluble human CD40L (CD154) in plasma and serum samples","authors":"Kathrine Pedersen , Nick Stub Laursen , Annette Gudmann Hansen , Yaseelan Palarasah , Steffen Thiel","doi":"10.1016/j.jim.2024.113710","DOIUrl":null,"url":null,"abstract":"<div><p>When the membrane protein CD40 ligand (CD40L) on activated T cells binds the receptor CD40 on B-cells, it provides a co-stimulatory signal for B cell activation. Dysregulation of the CD40L:CD40 axis is associated with inflammatory and autoimmune diseases. The presence of soluble CD40L (sCD40L) in plasma is implicated in several diseases, from cardiovascular and autoimmune diseases to different types of cancer, and sCD40L has been suggested as a valuable marker of disease. If sCD40L is to be used as a biomarker, being able to precisely measure and quantify the levels of sCD40L in human blood samples is of utmost importance. We demonstrate the development of a sandwich-type time-resolved immunofluorometric assay for quantification of sCD40L in plasma or serum samples. For this, we generate 29 monoclonal anti-CD40L antibodies, and from these, we select the optimal combination of capture antibody and detection antibody. A number of variables were tested: the influence of the type of sample (comparing 3 different blood collection tubes for serum sampling and 4 different types of tubes for plasma sampling), the influence of freeze-thaw cycles, the influence of sampling time during night and day, and the influence of centrifugation of the samples. We found a very similar level of sCD40L in paired EDTA plasma and serum samples. Out of 100 healthy blood donor samples 61 had a level of sCD40L below the detection level of the assay, whereas the remaining 39 samples had ranging levels of sCD40L from 1.14 to 33.14 ng/mL. In summary, we present a time-resolved immunofluorometric assay based on paired monoclonal antibodies, ensuring high specificity, sensitivity, and homogeneity. The Eu<sup>3+</sup>-based assay additionally provides consistent assay readouts due to the extended decay time not seen in standard enzyme-linked immunosorbent assays. The assay paves the way for specific and consistent quantification of sCD40L in human plasma and serum samples.</p></div>","PeriodicalId":16000,"journal":{"name":"Journal of immunological methods","volume":"531 ","pages":"Article 113710"},"PeriodicalIF":1.6000,"publicationDate":"2024-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of immunological methods","FirstCategoryId":"3","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0022175924000954","RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"BIOCHEMICAL RESEARCH METHODS","Score":null,"Total":0}
引用次数: 0
Abstract
When the membrane protein CD40 ligand (CD40L) on activated T cells binds the receptor CD40 on B-cells, it provides a co-stimulatory signal for B cell activation. Dysregulation of the CD40L:CD40 axis is associated with inflammatory and autoimmune diseases. The presence of soluble CD40L (sCD40L) in plasma is implicated in several diseases, from cardiovascular and autoimmune diseases to different types of cancer, and sCD40L has been suggested as a valuable marker of disease. If sCD40L is to be used as a biomarker, being able to precisely measure and quantify the levels of sCD40L in human blood samples is of utmost importance. We demonstrate the development of a sandwich-type time-resolved immunofluorometric assay for quantification of sCD40L in plasma or serum samples. For this, we generate 29 monoclonal anti-CD40L antibodies, and from these, we select the optimal combination of capture antibody and detection antibody. A number of variables were tested: the influence of the type of sample (comparing 3 different blood collection tubes for serum sampling and 4 different types of tubes for plasma sampling), the influence of freeze-thaw cycles, the influence of sampling time during night and day, and the influence of centrifugation of the samples. We found a very similar level of sCD40L in paired EDTA plasma and serum samples. Out of 100 healthy blood donor samples 61 had a level of sCD40L below the detection level of the assay, whereas the remaining 39 samples had ranging levels of sCD40L from 1.14 to 33.14 ng/mL. In summary, we present a time-resolved immunofluorometric assay based on paired monoclonal antibodies, ensuring high specificity, sensitivity, and homogeneity. The Eu3+-based assay additionally provides consistent assay readouts due to the extended decay time not seen in standard enzyme-linked immunosorbent assays. The assay paves the way for specific and consistent quantification of sCD40L in human plasma and serum samples.
期刊介绍:
The Journal of Immunological Methods is devoted to covering techniques for: (1) Quantitating and detecting antibodies and/or antigens. (2) Purifying immunoglobulins, lymphokines and other molecules of the immune system. (3) Isolating antigens and other substances important in immunological processes. (4) Labelling antigens and antibodies. (5) Localizing antigens and/or antibodies in tissues and cells. (6) Detecting, and fractionating immunocompetent cells. (7) Assaying for cellular immunity. (8) Documenting cell-cell interactions. (9) Initiating immunity and unresponsiveness. (10) Transplanting tissues. (11) Studying items closely related to immunity such as complement, reticuloendothelial system and others. (12) Molecular techniques for studying immune cells and their receptors. (13) Imaging of the immune system. (14) Methods for production or their fragments in eukaryotic and prokaryotic cells.
In addition the journal will publish articles on novel methods for analysing the organization, structure and expression of genes for immunologically important molecules such as immunoglobulins, T cell receptors and accessory molecules involved in antigen recognition, processing and presentation. Submitted full length manuscripts should describe new methods of broad applicability to immunology and not simply the application of an established method to a particular substance - although papers describing such applications may be considered for publication as a short Technical Note. Review articles will also be published by the Journal of Immunological Methods. In general these manuscripts are by solicitation however anyone interested in submitting a review can contact the Reviews Editor and provide an outline of the proposed review.