Respiratory Disease Surveillance in the Middle East and Latin America during the COVID-19 Pandemic, 2020-2022.

Characterizing the epidemiology of circulating respiratory pathogens during the COVID-19 pandemic could clarify the burden of acute respiratory infections and monitor outbreaks of public health and military relevance. The US Department of Defense supported 2 regions for influenza-like illness and severe acute respiratory infections surveillance, one in the Middle East through US Naval Medical Research Unit EURAFCENT, and another in Latin America through US Naval Medical Research Unit SOUTH. During 2020‒2022, coinciding with the COVID-19 pandemic, we collected a total of 16,146 nasopharyngeal and oropharyngeal swab samples from sentinel sites in Jordan (n = 11,305) and Latin America (n = 4,841).

Profiling Germinal Center-like B Cell Responses to Conjugate Vaccines Using Synthetic Immune Organoids.

Glycoengineered bacteria have emerged as a cost-effective platform for rapid and controllable biosynthesis of designer conjugate vaccines. However, little is known about the engagement of such conjugates with naïve B cells to induce the formation of germinal centers (GC), a subanatomical microenvironment that converts naïve B cells into antibody-secreting plasma cells. Using a three-dimensional biomaterials-based B-cell follicular organoid system, we demonstrate that conjugates triggered robust expression of hallmark GC markers, B cell receptor clustering, intracellular signaling, and somatic hypermutation.

A modular vaccine platform enabled by decoration of bacterial outer membrane vesicles with biotinylated antigens.

Engineered outer membrane vesicles (OMVs) derived from Gram-negative bacteria are a promising technology for the creation of non-infectious, nanoparticle vaccines against diverse pathogens. However, antigen display on OMVs can be difficult to control and highly variable due to bottlenecks in protein expression and localization to the outer membrane of the host cell, especially for bulky and/or complex antigens. Here, we describe a universal approach for avidin-based vaccine antigen crosslinking (AvidVax) whereby biotinylated antigens are linked to the exterior of OMVs whose surfaces are remodeled with multiple copies of a synthetic antigen-binding protein (SNAP) comprised of an outer membrane scaffold protein fused to a biotin-binding protein.

Shotgun scanning glycomutagenesis: A simple and efficient strategy for constructing and characterizing neoglycoproteins.

As a common protein modification, asparagine-linked (linked) glycosylation has the capacity to greatly influence the biological and biophysical properties of proteins. However, the routine use of glycosylation as a strategy for engineering proteins with advantageous properties is limited by our inability to construct and screen large collections of glycoproteins for cataloguing the consequences of glycan installation. To address this challenge, we describe a combinatorial strategy termed shotgun scanning glycomutagenesis in which DNA libraries encoding all possible glycosylation site variants of a given protein are constructed and subsequently expressed in glycosylation-competent bacteria, thereby enabling rapid determination of glycosylatable sites in the protein.

On-demand biomanufacturing of protective conjugate vaccines.

Conjugate vaccines are among the most effective methods for preventing bacterial infections. However, existing manufacturing approaches limit access to conjugate vaccines due to centralized production and cold chain distribution requirements. To address these limitations, we developed a modular technology for in vitro conjugate vaccine expression (iVAX) in portable, freeze-dried lysates from detoxified, nonpathogenic Upon rehydration, iVAX reactions synthesize clinically relevant doses of conjugate vaccines against diverse bacterial pathogens in 1 hour.

Interplay of Carbohydrate and Carrier in Antibacterial Glycoconjugate Vaccines.

Bacterial infections are a serious health concern and are responsible for millions of illnesses and deaths each year in communities around the world. Vaccination is an important public health measure for reducing and eliminating this burden, and regions with comprehensive vaccination programs have achieved significant reductions in infection and mortality. This is often accomplished by immunization with bacteria-derived carbohydrates, typically in conjunction with other biomolecules, which induce immunological memory and durable protection against bacterial human pathogens.

Immunization with outer membrane vesicles displaying conserved surface polysaccharide antigen elicits broadly antimicrobial antibodies.

Many microbial pathogens produce a β-(1→6)-linked poly--acetyl-d-glucosamine (PNAG) surface capsule, including bacterial, fungal, and protozoan cells. Broadly protective immune responses to this single conserved polysaccharide antigen in animals are possible but only when a deacetylated poly--acetyl-d-glucosamine (dPNAG; <30% acetate) glycoform is administered as a conjugate to a carrier protein. Unfortunately, conventional methods for natural extraction or chemical synthesis of dPNAG and its subsequent conjugation to protein carriers can be technically demanding and expensive.

Outer membrane vesicles displaying engineered glycotopes elicit protective antibodies.

The O-antigen polysaccharide (O-PS) component of lipopolysaccharides on the surface of gram-negative bacteria is both a virulence factor and a B-cell antigen. Antibodies elicited by O-PS often confer protection against infection; therefore, O-PS glycoconjugate vaccines have proven useful against a number of different pathogenic bacteria. However, conventional methods for natural extraction or chemical synthesis of O-PS are technically demanding, inefficient, and expensive.

Spherical micelles assembled from variants of recombinant oleosin.

An emerging field in biomaterials is the creation and engineering of protein surfactants made by recombinant biotechnology. Protein surfactants made by recombinant biotechnology allow for complete control of the molecular weight and chemical sequence of the surfactant. The proteins are monodisperse in molecular weight, and functionalization with bioactive amino acid sequences is straightforwardly achieved through genetic engineering.