Variant size- and glycoforms of the scavenger receptor cysteine-rich protein gp-340 with differential bacterial aggregation.
Glycoprotein gp-340 aggregates bacteria in saliva as part of innate defence at mucosal surfaces. We have detected size- and glycoforms of gp-340 between human saliva samples (n = 7) and lung gp-340 from a proteinosis patient using antibodies and lectins in Western blots and ELISA measurements. Western blots of saliva samples, and of gp-340 purified, from the seven donors using a gp-340 specific antibody distinguished four gp-340 size variants, designated I to IV (n = 2,2,2 and 1). While saliva gp-340 variants I to III had single bands of increasing sizes, variant IV and lung gp-340 had double bands. Purified I to IV proteins all revealed a N-terminal sequence TGGWIP upon Edman degradation. Moreover, purified gp-340 from the seven donors and lung gp-340 shared N-glycans, sialylated Galbeta1-3GalNAc and (poly)lactosamine structures. However, the larger size gp-340 grouping II/III (n = 4) and smaller size grouping I/IV correlated with a secretor, Se(+), and a non secretor, Se(-), dependent glycoform of gp-340, respectively (p = 0.03). The Se(+) glycoforms contained ABH, Le(b), Le(y) and polylactosamine structures, while the Se(-) glycoforms lacked ABH antigens but expressed Le(a), Le(x) and lactosamine structures. By contrast, lung gp-340 completely lacked ABH, Le(a/b), Le(x/y) or sLe(x) structures. Gp-340 and secretor typing of saliva from additional donors (n = 29) showed gp-340 glycoforms I to IV for 6, 16, 4 and 0 donors, respectively, and 3 non-typeable donors, and verified that gp-340 glycoforms I and II/III correlate with Se(-) and Se(+) phenotypes, respectively (p < 0.0001). The glycoforms of saliva and lung gp-340 mediated differential aggregation of Le(b)- (Helicobacter pylori), sialylpolylactosamine- (Streptococcus suis) or sialic acid- (Streptococcus mutans) binding bacteria. In conclusion, variant size- and glycoforms of gp-340 are expressed by different individuals and may modulate the biological properties of gp-340 pertinent to health and disease.
Eriksson
Christer
C
Department of Odontology/Cariology, Umeå University, SE 901 87, Umeå, Sweden. Nicklas.Stromberg@odont.umu.se
Frängsmyr
Lars
L
Danielsson Niemi
Liza
L
Loimaranta
Vuokko
V
Holmskov
Ulf
U
Bergman
Tomas
T
Leffler
Hakon
H
Jenkinson
Howard F
HF
Strömberg
Nicklas
N
D000595:Amino Acid Sequence; D001422:Bacterial Adhesion / Q000276:immunology*; D002135:Calcium-Binding Proteins; D004268:DNA-Binding Proteins; D006031:Glycosylation; D016480:Helicobacter pylori / Q000276:immunology; D006801:Humans; D007071:Immunoglobulin A, Secretory / Q000737:chemistry / Q000378:metabolism; D066298:In Vitro Techniques; D008168:Lung / Q000276:immunology; D008970:Molecular Weight; D011956:Receptors, Cell Surface / Q000737:chemistry* / Q000378:metabolism*; D011971:Receptors, Immunologic / Q000737:chemistry* / Q000378:metabolism*; D051116:Receptors, Scavenger / Q000737:chemistry* / Q000378:metabolism*; D012463:Saliva / Q000276:immunology / Q000382:microbiology; D013295:Streptococcus mutans / Q000276:immunology; D017011:Streptococcus suis / Q000276:immunology; D025521:Tumor Suppressor Proteins
D002135:Calcium-Binding Proteins; C108174:DMBT1 protein, human; D004268:DNA-Binding Proteins; D007071:Immunoglobulin A, Secretory; D011956:Receptors, Cell Surface; D011971:Receptors, Immunologic; D051116:Receptors, Scavenger; D025521:Tumor Suppressor Proteins; C116303:glycoprotein 340