Monocytes are one of the key inflammatory cells recruited to xenografts and play an important role in delayed xenograft rejection. Previous studies have demonstrated the ability of monocytes to bind to the major xenoantigen Gal-alpha(1,3)Gal-beta(1,4)GlcNAc-R; however, the receptor that mediates this interaction has yet to be identified. We provide evidence that it is Galectin-3, a approximately 30-kDa lectin that recognizes beta-galactosides (Gal-beta(1-3/4)GlcNAc) and plays diverse roles in many physiological and pathological events. Human monocyte binding is strikingly increased on porcine aortic endothelial cells (PAEC), which express high levels of Gal-alpha(1,3)Gal-beta(1,4)GlcNAc-R, compared with human aortic endothelial cells. Human monocytes obtained from healthy donors bind to Gal-alpha(1,3)Gal-beta(1,4)GlcNAc-R at variable intensities. This variation of binding intensity was consistent and reproducible in individual donors. Galectin-3 is mainly expressed in human monocytes, not lymphocytes. Purified Galectin-3 is able to bind directly to Gal-alpha(1,3)Gal-beta(1,4)GlcNAc-R. Galectin-3 can also be affinity isolated from monocytes (and not lymphocytes) using an Gal-alpha(1,3)Gal-beta(1,4)GlcNAc-R-biotin/streptavidin-bead pull-down system. Soluble Galectin-3 binds preferentially to PAEC vs human aortic endothelial cells, and this binding can be inhibited by lactose, indicating dependence on the carbohydrate recognition domain of Galectin-3. Gal-alpha(1,3)Gal-beta(1,4)GlcNAc-R is at least partly responsible for this phenomenon, as binding decreased after digestion of PAEC with alpha-galactosidase. Furthermore, monocytes pretreated with a blocking anti-Galectin-3 Ab show decreased adhesion to PAEC when compared with isotype control in a parallel plate flow chamber perfusion assay. Thus, we conclude that Galectin-3 expressed in human monocytes is a receptor for the major xenoantigen (Gal-alpha(1,3)Gal-beta(1,4)GlcNAc-R), expressed on porcine endothelial cells.
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http://dx.doi.org/10.4049/jimmunol.177.2.1289 | DOI Listing |
Eur J Med Res
January 2025
Department of General, Visceral and Thoracic Surgery, German Armed Forces Central Hospital, Koblenz, Germany.
Liquid biomarkers are essential in trauma cases and critical care and offer valuable insights into the extent of injury, prognostic predictions, and treatment guidance. They can help assess the severity of organ damage (OD), assist in treatment decisions and forecast patient outcomes. Notably, small extracellular vesicles, particularly those involved in splenic trauma, have been overlooked.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2025
Department of Signaling and Gene Expression, La Jolla Institute for Allergy and Immunology, La Jolla, CA 92037.
is one of the three most frequently mutated genes in age-related clonal hematopoiesis (CH), alongside and (. CH can progress to myeloid malignancies including chronic monomyelocytic leukemia (CMML) and is also strongly associated with inflammatory cardiovascular disease and all-cause mortality in humans. DNMT3A and TET2 regulate DNA methylation and demethylation pathways, respectively, and loss-of-function mutations in these genes reduce DNA methylation in heterochromatin, allowing derepression of silenced elements in heterochromatin.
View Article and Find Full Text PDFPLoS One
January 2025
Division of Cell- and Neurobiology, Department of Biomedical and Clinical Sciences, Faculty of Medicine and Health Sciences, Linköping University, Linköping, Sweden.
Emerging evidence suggests that fusion of cancer cells with leucocytes, such as macrophages, plays a significant role in cancer metastasis and results in tumor hybrid cells that acquire resistance to chemo- and radiation therapy. However, the precise mechanisms behind the leukocyte-cancer cell fusion remain unclear. The present in vitro study explores the presence of fusion between the monocyte cell line (THP-1) and the breast cancer cell line (MCF-7) in relation to the expression of CD36 and phosphatidylserine with and without treatment of these cells with ionizing radiation.
View Article and Find Full Text PDFSci Adv
January 2025
Department of Chemical Engineering, University of Michigan, Ann Arbor, MI 48109, USA.
Particle elasticity has widely been established to substantially influence immune cell clearance and circulation time of vascular-targeted carriers (VTCs). However, prior studies have primarily investigated interactions with macrophages, monocytic cell lines, and in vivo murine models. Interactions between particles and human neutrophils remain largely unexplored, although they represent a critical aspect of VTC performance.
View Article and Find Full Text PDFPLoS One
January 2025
Lawrence Livermore National Laboratory, Physical and Life Science Directorate, Livermore, CA, United States of America.
Post-traumatic osteoarthritis (PTOA) is a painful joint disease characterized by the degradation of bone, cartilage, and other connective tissues in the joint. PTOA is initiated by trauma to joint-stabilizing tissues, such as the anterior cruciate ligament, medial meniscus, or by intra-articular fractures. In humans, ~50% of joint injuries progress to PTOA, while the rest spontaneously resolve.
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