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Coxsackievirus A24 variant (CVA24v) and human adenovirus 37 (HAdV-37) are leading causative agents of the severe and highly contagious ocular infections acute hemorrhagic conjunctivitis and epidemic keratoconjunctivitis, respectively. Currently, neither vaccines nor antiviral agents are available for treating these diseases, which affect millions of individuals worldwide. CVA24v and HAdV-37 utilize sialic acid as attachment receptors facilitating entry into host cells. Previously, we and others have shown that derivatives based on sialic acid are effective in preventing HAdV-37 binding and infection of cells. Here, we designed and synthesized novel pentavalent sialic acid conjugates and studied their inhibitory effect against CVA24v and HAdV-37 binding and infection of human corneal epithelial cells. The pentavalent conjugates are the first reported inhibitors of CVA24v infection and proved efficient in blocking HAdV-37 binding. Taken together, the pentavalent conjugates presented here form a basis for the development of general inhibitors of these highly contagious ocular pathogens.

Salivary agglutinin is a high molecular mass component of human saliva that binds Streptococcus mutans, an oral bacterium implicated in dental caries. To study its protein sequence, we isolated the agglutinin from human parotid saliva. After trypsin digestion, a portion was analyzed by matrix-assisted laser/desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS), which gave the molecular mass of 14 unique peptides. The remainder of the digest was subjected to high performance liquid chromatography, and the separated peptides were analyzed by MALDI-TOF/post-source decay; the spectra gave the sequences of five peptides. The molecular mass and peptide sequence information showed that salivary agglutinin peptides were identical to sequences in lung (lavage) gp-340, a member of the scavenger receptor cysteine-rich protein family. Immunoblotting with antibodies that specifically recognized either lung gp-340 or the agglutinin confirmed that the salivary agglutinin was gp-340. Immunoblotting with an antibody specific to the sialyl Lexcarbohydrate epitope detected expression on the salivary but not the lung glycoprotein, possible evidence of different glycoforms. The salivary agglutinin also interacted with Helicobacter pylori, implicated in gastritis and peptic ulcer disease,Streptococcus agalactiae,implicated in neonatal meningitis, and several oral commensal streptococci. These results identify the salivary agglutinin as gp-340 and suggest it binds bacteria that are important determinants of either the oral ecology or systemic diseases.

Earlier studies have demonstrated that the genes of the human carcinoembryonic antigen (CEA) family can be divided into three subgroups, the CEA subgroup (n = 12), the pregnancy-specific glycoprotein (PSG) subgroup (n = 11), and a third subgroup (n = 6). To further characterize the CEA gene family, we have determined the genomic structures of CGM9 and CGM11, analyzed the promoter regions of all eleven PSGs, studied the CGM15-PSG13 intergenic region and the evolutionary relationships beween the CEA family genes. CGM9, a typical CEA subgroup member, was a pseudogene with the exon structure [5′UTR-L-L/N-TM-Cyt-3′UTR]. CGM11 contained a mixture of exons derived from CEA and PSG subgroup genes. The formula of the CGM11 pseudogene was [5′UTR-L-L/N-C-3′UTR]. Thus both genes lacked the IgC2-like domains typically found in CEA subfamily members. The upstream promoter regions of all eleven PSGs were characterized. All PSG promoters lacked the classical TATA and CCAAT elements, but had putative PEA3 box(es), CACCC box(es), a RARE box, and poly (dG-dT) repeats of different lengths. Five PSGs also had an SP1 site. The complete 10-kb intergenic region between CGM15 and PSG13 was sequenced. Clusters of different types of repetitive sequences were seen. The time of divergence of the CEA and PSG subfamilies was estimated to be 107.7 ± 17.1 million years, or at about the time of human-rodent divergence. Models for the evolution of CEA and PSG and the third family subgroup genes are proposed.

To elucidate which of the seven transcriptionally active genes of the carcinoembryonic antigen (CEA) subfamily are expressed in human colon, we first examined mRNA expression using reverse transcriptase PCR. The result showed the CEA, nonspecific crossreacting antigen 50/90 (NCA), biliary glycoprotein (BGP), and carcinoembryonic antigen gene family member 2 (CGM2) mRNAs were expressed in the colon. To determine the cellular sources of these members within normal colonic mucosa, in situ hybridization and immunocytochemistry were then performed. CEA and NCA mRNAs were clearly detectable in the cytoplasm of columnar and goblet cells at the free luminal surface and the upper crypts with low hybridization in the mid crypt and the crypt base. In contrast, BGP and CGM2 mRNAs were restricted only to columnar cells at the upper third of the crypts and the luminal surface. Colon epithelium expression of CEA, NCA, BGP and CGM2 coincided with that of corresponding mRNAs. Ultrastructurally, CEA, NCA, BGP and CGM2 were localized mainly to the apical surface glycocalyx, the fuzzy coat, of columnar cells. Interestingly, these molecules were localized in different microdomains within the fuzzy coat. Furthermore, BGP was highly expressed in the fuzzy coat of cryptal caveolated cells. As integral components of the fuzzy coat, CEA, NCA, BGP and CGM2 can hardly function as intercellular adhesion molecules; they possibly play an important role in epithelial-microbial interactions.

Wie wär's mit einem dritten Arm?Geschadet hat Ähnliches einem Inhibitor mit drei Sialinsäuregruppen auf jeden Fall nicht: Er blockierte alle drei Bindetaschen eines trimeren adenoviralen Fiber‐Knob‐Proteins und verhinderte dadurch die Anlagerung und anschließende Infektion bei menschlichen Corneaepithelzellen. Das Bild zeigt die terminalen Sialinsäure‐Einheiten des Inhibitors gebunden an das Peptid (C gelb, O rot, N blau; das Molekülgerüst ist nicht abgebildet).

Wouldn′t it be useful to have three arms?It came in handy for a trivalent sialic acid inhibitor, which blocked all three binding pockets of a trimeric adenoviral fiber‐knob protein and thus prevented cell attachment and the subsequent infection of human corneal epithelial cells. The picture shows the terminal sialic acid moietes of the inhibitor bound to the top of the fiber head (C yellow, O red, N blue; the spacers and scaffold are not shown).