An engineered recombinant protein containing three structural domains in SARS-CoV-2 S2 protein has potential to act as a pan-human coronavirus entry inhibitor or vaccine antigen.

The threat to global health caused by three highly pathogenic human coronaviruses (HCoV), SARS-CoV-2, MERS-CoV and SARS-CoV, calls for the development of pan-HCoV therapeutics and vaccines. This study reports the design and engineering of a recombinant protein designated HR1LS. It contains three linked molecules, each consisting of three structural domains, including a heptad repeat 1 (HR1), a central helix (CH), and a stem helix (SH) region, in the S2 subunit of SARS-CoV-2 spike (S) protein. It was found that HR1LS protein automatically formed a trimer able to bind with heptad repeat 2 (HR2) region in the SARS-CoV-2 S2 subunit, thus potently inhibiting HCoV fusion and entry into host cells. Furthermore, immunization of mice with HR1LS, when combined with CF501 adjuvant, resulted in the production of neutralizing antibodies against infection of SARS-CoV-2 and its variants, as well as SARS-CoV, MERS-CoV, HCoV-229E, HCoV-NL63 and MjHKU4r-CoV-1. These results suggest that HR1LS is a promising candidate for further development as a novel HR1-trimer-based pan-HCoV entry inhibitor or vaccine for the treatment and prevention of infection by SARS-CoV-2 and its variants, but also other HCoVs with the potential to cause future emerging and re-emerging infectious coronavirus diseases.

Potential cross-species transmission of highly pathogenic avian influenza H5 subtype (HPAI H5) viruses to humans calls for the development of H5-specific and universal influenza vaccines.

In recent years, highly pathogenic avian influenza H5 subtype (HPAI H5) viruses have been prevalent around the world in both avian and mammalian species, causing serious economic losses to farmers. HPAI H5 infections of zoonotic origin also pose a threat to human health. Upon evaluating the global distribution of HPAI H5 viruses from 2019 to 2022, we found that the dominant strain of HPAI H5 rapidly changed from H5N8 to H5N1. A comparison of HA sequences from human- and avian-derived HPAI H5 viruses indicated high homology within the same subtype of viruses. Moreover, amino acid residues 137A, 192I, and 193R in the receptor-binding domain of HA1 were the key mutation sites for human infection in the current HPAI H5 subtype viruses. The recent rapid transmission of H5N1 HPAI in minks may result in the further evolution of the virus in mammals, thereby causing cross-species transmission to humans in the near future. This potential cross-species transmission calls for the development of an H5-specific influenza vaccine, as well as a universal influenza vaccine able to provide protection against a broad range of influenza strains.

An Artificial Peptide-Based Bifunctional HIV-1 Entry Inhibitor That Interferes with Viral Glycoprotein-41 Six-Helix Bundle Formation and Antagonizes CCR5 on the Host Cell Membrane.

Human immunodeficiency virus type 1 (HIV-1) is characterized by high variability and drug resistance. This has necessitated the development of antivirals with a new chemotype and therapy. We previously identified an artificial peptide with non-native protein sequence, AP3, with the potential to inhibit HIV-1 fusion through targeting hydrophobic grooves on the N-terminal heptad repeat trimer of viral glycoprotein gp41. Here, a small-molecule HIV-1 inhibitor targeting chemokine coreceptor CCR5 on the host cell was integrated into the AP3 peptide, producing a novel dual-target inhibitor with improved activity against multiple HIV-1 strains including those resistant to the currently used anti-HIV-1 drug enfuvirtide. Its superior antiviral potency in comparison with the respective pharmacophoric moieties is in consonance with the dual binding of viral gp41 and host factor CCR5. Therefore, our work provides a potent artificial peptide-based bifunctional HIV-1 entry inhibitor and highlights the multitarget-directed ligands approach in the development of novel therapeutic anti-HIV-1 agents.

Multitargeted drug design strategy for discovery of short-peptide-based HIV-1 entry inhibitors with high potency.

The development of short-peptide-based inhibitors to prevent HIV-1 entry into the host cell has been rewarded with limited success. Herein, we report a multitarget-directed ligand strategy to generate a series of short-peptide HIV-1 entry inhibitors that integrated the pharmacological activities of a peptide fusion inhibitor able to disrupt HIV-1 gp41 glycoprotein hexameric coiled-coil assembly and a small-molecule CCR5 antagonist that blocks the interaction between HIV-1 and its coreceptor. Among these inhibitors, dual-target 23-residue peptides SP12T and SP12L displayed dramatically increased inhibitory activities against HIV-1 replication as compared to the marketed 36-residue peptide T20. Moreover, results suggested that SP12T and SP12L successfully performed a dual-targeting mechanism. It can be concluded that these short-peptide-based HIV-1 entry inhibitors have potential for further development as candidates for a novel multitarget therapy to treat HIV-1 infection.

Mobile Health in China: Well Integrated or a New Divide?

The application of mobile health holds promises of achieving greater accessibility in the evolving health care sector. The active engagement of private actors drives its growth, while the challenges that exist between health care privatization and equitable access are a concern. This article selects the private internet hospital in China as a case study. It indicates that a market-oriented regulatory mechanism of private mobile health will contribute little to improving health equity from the perspectives of egalitarians and libertarians. By integrating the capability approach and the right to health, it is claimed that mobile health is a means of accessing health care for everyone, where substantive accessibility should be emphasized. With this view, this article provides policy recommendations that reinforce private sector engagement for mobile health, recognizing liberty, equity, and collective responsibility in the Chinese context.

A novel cyclic γ-AApeptide-based long-acting pan-coronavirus fusion inhibitor with potential oral bioavailability by targeting two sites in spike protein.

The receptor-binding domain (RBD) in S1 subunit and heptad repeat 1 (HR1) domain in S2 subunit of SARS-CoV-2 spike (S) protein are the targets of neutralizing antibodies (nAbs) and pan-coronavirus (CoV) fusion inhibitory peptides, respectively. However, neither nAb- nor peptide-based drugs can be used orally. In this study, we screened a one-bead-two-compound (OBTC) cyclic γ-AApeptide library against SARS-CoV-2 S protein and identified a hit: S-20 with potent membrane fusion inhibitory activity, but moderate selectivity index (SI). After modification, one derivative, S-20-1, exhibited improved fusion inhibitory activity and SI (>1000). S-20-1 could effectively inhibit infection by pseudotyped and authentic SARS-CoV-2 and pseudotyped variants of concern (VOCs), including B.1.617.2 (Delta) and B.1.1.529 (Omicron), as well as MERS-CoV, SARS-CoV, HCoV-OC43, HCoV-229E, and HCoV-NL63. It could also inhibit infection of a pseudotyped SARS-related coronavirus WIV1 (SARSr-CoV-WIV1) from bats. Intranasal application of S-20-1 to mice before or after challenge with HCoV-OC43 or SARS-CoV-2 provided significant protection from infection. Importantly, S-20-1 was highly resistant to proteolytic degradation, had long half-life, and possessed favorable oral bioavailability. Mechanistic studies suggest that S-20-1 binds with high affinity to RBD in S1 and HR1 domain in S2 of SARS-CoV-2 S protein. Thus, with its pan-CoV fusion and entry inhibitory activity by targeting two sites in S protein, desirable half-life, and promising oral bioavailability, S-20-1 is a potential candidate for further development as a novel therapeutic and prophylactic drug against infection by SARS-CoV-2 and its variants, as well as future emerging and reemerging CoVs.

Comparative mass spectrometry analysis of N-glycans from the glycoproteins of eight allergy-inducing plants.

Extensive cross-allergic reactivity exists among food-borne plants. As most allergens are glycoproteins, protein sensitization has been extensively studied. However, little attention has been given to the glycan component of glycoproteins. Here, we qualitatively and quantitatively compared the N-glycans of eight cross-reactive plant glycoproteins derived from peach pollen, soy, pine nut, cashew nut, pistachio, walnut, almond, and hazelnut. Cross-reactive carbohydrate determinants (CCDs) were widely present in the allergic glycoproteins according to the following order: pollen > soybean > pistachios > pine nuts > walnuts > cashews > hazelnuts > almonds. The N-glycan structure presented clear differences between the germplasm and vegetative tissue. Importantly, fucosylation and xylosylation levels correlated positively with extensive cross-reactivity between plants, which suggests that CCDs may be one of the causes of cross-allergy. This result provides the foundation for mechanistic studies on plant-derived CCDs as a source of food cross-allergies.

Online LC-UV-ESI-MS/MS Comparative Analysis of Changes in Goat Colostrum N/O-Glycopatterns at Different Parities.

Goat milk oligosaccharides are complex carbohydrates with a variety of biological functions. Free oligosaccharides from goat milk show more similarity to human milk than cow milk. At present, changes in goat milk glycoconjugates at different parities remain poorly studied. Herein, we qualitatively and quantitatively compared the goat milk glycoprotein N/O-glycome at different parities using a stable isotope labeling followed by electrospray ionization mass spectrometry and online hydrophilic interaction chromatography. N-Glycans were mainly fucosylated and nonfucosylated nonsialylated, and both fucosylation and sialylation gradually increased with parity, amounting (at the third parity) to 1.25 times and 3.3 times those of the first parity, respectively. O-Glycans were mostly nonfucosylated and nonsialylated, and sialylation increased with increasing parity, and Neu5Ac-sialylated was up to 9 times higher in the third parity than in the first parity, whereas Neu5Gc-sialylated was 5.5 times higher. This study provides a reference for exploring an alternative milk source closest to human milk and for the development of humanized formula milk.

Mass Spectrometry Analysis of Changes in Human Milk N/O-Glycopatterns at Different Lactation Stages.

Human milk oligosaccharides are complex carbohydrates with multibiofunctional health benefits to newborns. Human milk free oligosaccharides (HMOs) are well characterized. However, changes in the N/O-glycome during lactation are poorly reported. Herein, we qualitatively and quantitatively investigated N/O-glycome profiles and their alteration in human milk at different lactation stages. N-Glycans were mainly fucosylated and nonsialylated, nonfucosylated throughout lactation. O-Glycans mainly consisted of sialylated and nonsialylated, nonfucosylated in colostrum and transitional milk, and fucosylated and nonfucosylated, nonsialylated in mature milk. Fucosylated and sialylated N-glycans gradually decreased and increased, respectively, as lactation progressed; O-glycans showed the reverse. Interestingly, changes in HMO abundance decreased during lactation, complementing HMG N/O-glycome changes. In conclusion, temporal HMG glycosylation changes provide the groundwork for developing infant formula that is closer to breast milk at different lactation stages.