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We have previously reported that multi-cellular heteroaggregates comprising murine pancreatic α (αTC1.6) and β (MIN6-m9) cell lines spontaneously acquired islet-like architecture and displayed higher insulin secretion rates. However, the mechanisms of self-organization remain unclear. The objective of this study is to examine the possibility that a sugar chain participates in the mutual recognition of the cells during reconstitution of the islet-like structure in vitro . Using a lectin-binding assay, we identified Erythrina cristagalli agglutinin (ECA), which particularly recognizes the β-galactoside structure on the surfaces of MIN6-m9 cells. The self-organization of αTC1.6 and MIN6-m9 was obstructed using ECA-bound MIN6-m9 cells. Lactose neutralized the ECA's inhibitory effect on the autonomous rearrangement of αTC1.6 and MIN6-m9 cells, indicating that the inhibition of cell arrangement by ECA was mediated via β-galactoside. We concluded that a β-galactoside sugar chain was central to the reconstitution of the pancreatic islet-like architecture in vitro .

Ricin, a highly toxic plant-derived toxin, is considered a potential weapon in biological warfare due to its high availability and ease of preparation. Pulmonary exposure to ricin results in the generation of an acute edematous inflammation followed by respiratory insufficiency and death. Passive immunization with polyclonal anti-ricin antibodies conferred protection against pulmonary ricinosis, however, at clinically-relevant time points for treatment, survival rates were limited. In this study, intranasal instillation of a lethal dose of ricin to mice, served as a lung challenge model for the evaluation and comparison of different therapeutic modalities against pulmonary ricinosis. We show that treatment with doxycycline resulted in a significant reduction of pro-inflammatory cytokines, markers of oxidative stress and capillary permeability in the lungs of the mice. Moreover, survival rates of mice intoxicated with ricin and treated 24 h later with anti-ricin antibody were significantly improved by co-administration of doxycycline. In contrast, co-administration of the steroid drug dexamethasone with anti-ricin antibodies did not increase survival rates when administered at late hours after intoxication, however dexamethasone did exert a positive effect on survival when applied in conjunction with the doxycycline treatment. These studies strongly suggest that combined therapy, comprised of neutralizing anti-ricin antibodies and an appropriate anti-inflammatory agent, can promote high-level protection against pulmonary ricinosis at clinically-relevant time points post-exposure.

Green algae have a great potential as biofactories for the production of proteins. Chlamydomonas reinhardtii, a representative of eukaryotic microalgae, has been extensively used as a model organism to study light-induced gene expression, chloroplast biogenesis, photosynthesis, light perception, cell-cell recognition, and cell cycle control. However, little is known about the glycosylation machinery and N-linked glycan structures of green algae. In this study, we performed mass spectrometry analysis of N-linked oligosaccharides released from total extracts of Chlamydomonas reinhardtii and demonstrated that C. reinhardtii algae possess glycoproteins with mammalian-like sialylated N-linked oligosaccharides. These findings suggest that C. reinhardtii may be an attractive system for expression of target proteins.