Joerg Hamann

Learn More
BACKGROUND Polarization of macrophages by specific micro-environmental conditions impacts upon their function following subsequent activation. This study aimed to systematically validate robust phenotypic markers for in vitro polarized human macrophages in order to facilitate the study of macrophage subsets in vivo. METHODS Human peripheral blood(More)
CD97 is an activation-induced antigen on leukocytes with a seven-span transmembrane (7-TM) region homologous to the secretin receptor superfamily. However, in contrast to this group of peptide hormone receptors, CD97 has an extended extracellular region with three EGF domains at the NH2 terminus, two of them with a calcium binding site. By demonstrating(More)
Using multivalent protein probes, an evolutionarily conserved endogenous ligand for EMR2, a human myeloid cell-restricted EGF-TM7 receptor, was identified on the surface of a number of adherent cell lines. In addition, in situ staining of the ligand has revealed specific in vivo patterns consistent with a connective tissue distribution. The interaction is(More)
Much is still unknown about mechanisms underlying the phenotypical and functional versatility of human microglia. Therefore, we developed a rapid procedure to isolate pure microglia from postmortem human brain tissue and studied their immediate ex vivo phenotype and responses to key inflammatory mediators. Microglia were isolated, along with macrophages(More)
Adhesion-type heterotrimeric guanine nucleotide-binding protein (G protein)-coupled receptors (Adhesion-GPCRs) comprise a class of widely distributed seven-transmembrane spanning (7TM) receptors with unusual layout and properties. The key to understanding the function of Adhesion-GPCRs appears to be their hybrid architecture: They have an extracellular(More)
The molecular repertoire of macrophages in health and disease can provide novel biomarkers for diagnosis, prognosis, and treatment. Th2-IL-4–activated macrophages (M2) have been associated with important diseases in mice, yet no specific markers are available for their detection in human tissues. Although mouse models are widely used for macrophage(More)
The epidermal growth factor (EGF)-TM7 proteins [EMR1, (EGF-like molecule containing mucin-like hormone receptor 1) F4/80, and CD97] constitute a recently defined class B GPCR subfamily and are predominantly expressed on leukocytes. These molecules possess N-terminal EGF-like domains coupled to a seven-span transmembrane (7TM) moiety via a mucin-like spacer(More)
The Adhesion family forms a large branch of the pharmacologically important superfamily of G protein-coupled receptors (GPCRs). As Adhesion GPCRs increasingly receive attention from a wide spectrum of biomedical fields, the Adhesion GPCR Consortium, together with the International Union of Basic and Clinical Pharmacology Committee on Receptor Nomenclature(More)
CD69 is a very early activation Ag of T lymphocytes. It is a cell surface glycoprotein that can only be detected after stimulation of lymphocytes. Despite extensive studies on its biologic activities, little is known about its molecular function. To investigate the latter in more detail, we have cloned a cDNA encoding CD69 on the basis of its expression in(More)
The expression of CD97, a member of the EGF-TM7 family with adhesive properties, is proportional to the aggressiveness and lymph node involvement in thyroid tumors. CD97 has never been systematically investigated in other tumors. First, we examined colorectal carcinoma cell lines (n = 18) for CD97 expression and regulation. All cell lines were(More)