Paired Ig-like type 2 receptors (PILRs) are one of the paired receptor families, which consist of two functionally opposite members, inhibitory (PILRalpha) and activating (PILRbeta) receptors. PILRs are widely expressed in immune cells and recognize the sialylated O-glycosylated ligand CD99, which is expressed on activated T cells, to regulate immune responses. To date, their biophysical properties have not yet been examined. Here we report the affinity, kinetic, and thermodynamic analyses of PILR-CD99 interactions using surface plasmon resonance (SPR) together with site-directed mutagenesis. The SPR analysis clearly demonstrated that inhibitory PILRalpha can bind to CD99 with low affinity (K(d) approximately 2.2 microm), but activating PILRbeta binds with approximately 40 times lower affinity (K(d) approximately 85 microm). In addition to our previous mutagenesis study (Wang, J., Shiratori, I., Saito, T., Lanier, L. L., and Arase, H. (2008) J. Immunol. 180, 1686-1693), the SPR analysis showed that PILRalpha can bind to each Ala mutant of the two CD99 O-glycosylated sites (Thr-45 and Thr-50) with similar binding affinity to wild-type CD99. This indicated that both residues act as independent and equivalent PILRalpha binding sites, consistent with the highly flexible structure of CD99. On the other hand, it is further confirmed that PILRbeta can bind the T50A mutant, but not the T45A mutant, indicating a recognition difference between PILRalpha and PILRbeta. Kinetic studies demonstrated that the PILR-CD99 interactions show fast dissociation rates, typical of cell-cell recognition receptors. Thermodynamic analyses revealed that the PILRalpha-CD99 interaction is enthalpically driven with a large entropy loss (-TDeltaS = 8.9 kcal.mol(-1)), suggesting the reduction of flexibility upon complex formation. This is in contrast to the entropically driven binding of selectins to sugar-modified ligands involved in leukocyte rolling and infiltration, which may reflect their functional differences.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1074/jbc.M709793200 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Characterization of two novel MCSFR paralogues in rainbow trout Oncorhynchus mykiss: New insights into the molecular mechanism underlying macrophage differentiation and modulation in fish.
Fish Shellfish Immunol
January 2025
Scottish Fish Immunology Research Centre, School of Biological Sciences, The University of Aberdeen, Aberdeen AB24 2TZ United Kingdom.
Article Synopsis
- The study investigates the colony-stimulating factor-1 receptor (MCSFR) in rainbow trout, identifying four gene variants, including two previously unrecognized, and explores their expression levels in various tissues.
- The protein structure of MCSFRs includes five immunoglobulin-like domains and suggests a conserved function across species.
- Following infection with Yersinia ruckeri, different MCSFR paralogues exhibit unique expression patterns, showing complex regulatory mechanisms influenced by various stimuli, enhancing the understanding of immune responses in fish.
Development of CD33-Targeted Dual Drug-Loaded Nanoparticles for the Treatment of Pediatric Acute Myeloid Leukemia.
Biomacromolecules
October 2024
The Patrick G Johnston Centre for Cancer Research, School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast, Belfast BT9 7AE, U.K.
Paediatric acute myeloid leukemia (AML) is a heterogeneous hematological malignancy still heavily reliant on traditional chemotherapeutic approaches. Combination treatments have shown to be a superior approach, but their success is often hindered by side effects and different drugs' pharmacokinetics. Here, we investigated ABT-737 and Purvalanol A as a potential drug pairing for pediatric AML and described the development of CD33-targeted polymeric nanoparticles (NPs) to enable their simultaneous targeted codelivery.
View Article and Find Full Text PDFIntra-patient spatial comparison of non-metastatic and metastatic lymph nodes reveals the reduction of CD169 macrophages by metastatic breast cancers.
EBioMedicine
September 2024
Department of Breast Surgery, Kyoto University Hospital, Graduate School of Medicine, Shogoin Sakyo-ku, Kyoto 606-8507, Japan; Department of Breast Surgery, Breast Center, Mie University, Mie 514-0102, Japan. Electronic address:
Background: Breast cancer cells suppress the host immune system to efficiently invade the lymph nodes; however, the underlying mechanism remains incompletely understood. Here, we aimed to comprehensively characterise the effects of breast cancers on immune cells in the lymph nodes.
Methods: We collected non-metastatic and metastatic lymph node samples from 6 patients with breast cancer with lymph node metastasis.
A bioinspired supramolecular nanoprodrug for precision therapy of B-cell non-Hodgkin's lymphoma.
J Nanobiotechnology
August 2024
College of Pharmacy, Key Laboratory of Research and Application of Ethnic Medicine Processing and Preparation on the Qinghai-Tibet Plateau, Southwest Minzu University, Chengdu, 610041, China.
Fludarabine (FA) is still considered as a first-line chemotherapy drug for hematological tumors related to B lymphocytes. However, it is worth noting that the non-specific distribution and non-different cytotoxicity of FA may lead to irreversible consequences such as central nervous system damage such as blindness, coma, and even death. Therefore, it is very important to develop a system to targeting delivery FA.
View Article and Find Full Text PDFAlloantigen Infusion Activates the Transcriptome of Type 2 Conventional Dendritic Cells.
Immunohorizons
October 2023
Department of Pathology, Northwestern University Feinberg School of Medicine, Chicago, IL.
Recent studies have revealed novel molecular mechanisms by which innate monocytic cells acutely recognize and respond to alloantigen with significance to allograft rejection and tolerance. What remains unclear is the single-cell heterogeneity of the innate alloresponse, particularly the contribution of dendritic cell (DC) subsets. To investigate the response of these cells to exposure of alloantigen, C57BL/6J mice were administered live allogenic BALB/cJ splenic murine cells versus isogenic cells.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!