Self-Assembled TLR7/8 Agonist-Mannose Conjugate as An Effective Vaccine Adjuvant for SARS-CoV-2 RBD Trimer.

Small synthetic TLR7/8-agonists can be used as vaccine adjuvants to enhance cell and humoral-mediated immune responses to specific antigens. Despite their potency, after local injection they can be dispersed to undesired body parts causing high reactogenicity, limiting their clinical applications. Here we describe a vaccination strategy that employs the covalent conjugate of a mannose and TLR7/8 agonist as a vaccine adjuvant to take advantage of mannose binding C-type lectins on dendritic cells to enhance the vaccine's immunogenicity.

Efficient synthesis of α-galactosylceramide and its C-6 modified analogs.

The synthesis of α-galactosylceramide (KRN7000) and its C-6 modified analogs remains a challenge due to the difficult α-1,2--glycosidic bond. A non-participating benzyl (Bn) protecting group has been commonly used to favor the α-glycosylation product. Here, we report the α-selective glycosylation by using a bulky 4,6-O-di--butylsilylene (DTBS) galactosyl donor, regardless of the 2-benzoyl (Bz) participating group.

Conjugate of structurally reassigned pneumococcal serotype 31 polysaccharide with CRM197 elicited potent immune response.

Around 100 Streptococcus pneumonia (Spn) serotypes have been discovered, 90% of the severe diseases in children are caused by 13 serotypes. With the success of pneumococcal bacterial polysaccharide conjugate vaccines (PCVs), the burden of pneumococcal disease has been significantly reduced. Serotype 31 is a non-vaccine serotype and has increased in prevalence.