MASP-2, mannose-binding protein-associated serine protease 2, is a key enzyme in the lectin pathway of complement activation. Hyperactivation this protein by human coronaviruses SARS-CoV, MERS-CoV and SARS-CoV-2 has been found to contribute aberrant activation patients, leading aggravated lung injury with potentially fatal consequences. This hyperactivation triggered lungs through conserved, di...

Hemocyanins are used as immunomodulators in clinical applications because they induce a strong Th1-biased cell-mediated immunity, which has beneficial effects. They multiligand glycosylated molecules with abundant and complex mannose-rich structures. It remains unclear whether these structures influence hemocyanin-induced immunostimulatory processes human APCs. We have previously shown that hem...

We have investigated the interactions of the plant toxin ricin with sinusoidal endothelial rat liver cells (EC). In these cells, ricin can be bound and internalized via either cell surface galactosyl residues or mannose receptors. Binding and uptake via galactosyl residues and mannose receptors was studied in the presence of mannan (1 mg/ml) and lactose (50 mM) respectively. Whereas most of the...

The development of anti-human immunodeficiency virus (HIV) microbicides for either topical or ex vivo use is of considerable interest, mainly due to the difficulties in creating a vaccine that would be active against multiple clades of HIV. Cyanovirin-N (CV-N), an 11-kDa protein from the cyanobacterium (blue-green algae) Nostoc ellipsosporum with potent virucidal activity, was identified in the...

Mycobacterium tuberculosis (Mtb) infection induces the expression of matrix metalloproteinase-9 (MMP-9) in mouse lungs. In cultured human monocytic cells, Mtb bacilli and the cell wall glycolipid lipoarabinomannan (LAM) stimulate high levels of MMP-9 activity. Here, we explore the cellular mechanisms involved in the induction of MMP-9 by Mtb. We show that infection of THP-1 cells with Mtb cause...

We have isolated a novel lectin, named HRL40 from the green alga Halimeda renschii. In hemagglutination-inhibition test and oligosaccharide-binding experiment with 29 pyridylaminated oligosaccharides, HRL40 exhibited a strict binding specificity for high-mannose N-glycans having an exposed (α1-3) mannose residue in the D2 arm of branched mannosides, and did not have an affinity for monosacchari...

The carbohydrate-rich coating of human tissues and cells provide a first point of contact for colonizing and invading bacteria. Commensurate with N-glycosylation being an abundant form of protein glycosylation that has critical functional roles in the host, some host-adapted bacteria possess the machinery to process N-linked glycans. The human pathogen Streptococcus pneumoniae depolymerizes com...

Mannose-binding lectin from champedak (Artocarpus integer) is a homotetramer with a single-monomer molecular weight of 16 800 Da. Previous work has shown it to bind IgE and IgM, as well as being a mitogen of T cells in humans. Champedak mannose-binding lectin has successfully been used to detect altered glycosylation states of serum proteins. The protein was crystallized at 293 K in space group...

A differential-display PCR procedure identified the capsular assembly gene kpsD after Escherichia coli type 1 fimbrial binding to mannose-coated Sepharose beads. Limiting-dilution reverse-transcribed PCRs confirmed down-regulation of the kpsD gene, and Northern blot and lacZ fusion analyses showed down-regulation of the kpsFEDUCS region 1 operon. KpsD protein levels fell, and an agglutination t...

In vitro infection by the human immunodeficiency virus (HIV) of CD4+ H9 lymphoblasts is inhibited by a mannose-binding protein (MBP) purified from human serum. In addition, MBP is able to selectively bind to HIV-infected H9 cells and HIV-infected cells from the monocyte cell line U937. These results indicate MBP most likely recognizes high mannose glycans known to be present on gp120 in the dom...