Purification of Immunoglobulin A Using Mesoporous Zirconia Particles Coated with Phosphate.

Immunoglobulin A (IgA) is the most abundant antibody in the human body and plays a critical role in defending against bacteria and viruses that invade through mucosal surfaces. Leveraging this property, recombinant IgA has been developed as a preventive drug for infectious diseases such as COVID-19, influenza, and tuberculosis. Recombinant IgA is typically purified using columns packed with protein-immobilized resins, such as jacalin, Protein L, or nanobody-based materials.

Mosquito-borne alphaviruses in Zambia: Isolation and characterization of Eilat and Sindbis viruses.

Alphaviruses in the family Togaviridae include zoonotic arthropod-borne viruses, including Sindbis virus (SINV), chikungunya virus, as well as insect-specific viruses such as Eilat virus (EILV). Previous investigations of alphaviruses in Zambia have identified a novel insect-specific alphavirus, Mwinilunga alphavirus in mosquitoes. Further ongoing surveillance resulted in the isolation of EILV and SINV for the first time in Zambia.

Development of a novel plate reader-based antibody-dependent enhancement (ADE) assay for orthoflavivirus infections.

Antibody-dependent enhancement (ADE) is one of the mechanisms associated with severe clinical outcomes in infections caused by certain viruses, including dengue virus (DENV). Several ADE assay systems have been established, including flow cytometric assays using live viruses, enzyme-linked immuno-sorbent assay (ELISA) for the detection of viral NS1, and luciferase reporter gene assays. Among these, the flow cytometric assay is the most commonly used to evaluate ADE activity; however, it has limitations such as high operational costs due to fixation and immunostaining procedures, as well as a long analysis time.

African lineage 1a West Nile virus isolated from crocodiles exhibits low neuroinvasiveness in mice.

West Nile virus (WNV) is a mosquito-borne flavivirus that causes encephalitis in humans and infects crocodiles, resulting in rashes and neurological signs. In Zambia, two distinct lineages of WNV have been detected in neighbouring areas: lineage 2 in mosquitoes and lineage 1a in farmed crocodiles. Considering the risk of direct or vector-mediated WNV transmission from crocodiles to mammals, it is necessary to elucidate the pathogenicity of WNV strains derived from crocodiles.

Development of flavivirus subviral particles with low cross-reactivity by mutations of a distinct antigenic domain.

The most conserved fusion loop (FL) domain present in the flavivirus envelope protein has been reported as a dominant epitope for cross-reactive antibodies to mosquito-borne flaviviruses (MBFVs). As a result, establishing accurate serodiagnosis for MBFV infections has been difficult as anti-FL antibodies are induced by both natural infection and following vaccination. In this study, we modified the most conserved FL domain to overcome this cross-reactivity.

Impact of Imprinted Immunity Induced by mRNA Vaccination in an Experimental Animal Model.

The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variants has led to concerns that ancestral SARS-CoV-2-based vaccines may not be effective against newly emerging Omicron subvariants. The concept of "imprinted immunity" suggests that individuals vaccinated with ancestral virus-based vaccines may not develop effective immunity against newly emerging Omicron subvariants, such as BQ.1.

Morphogenesis of Bullet-Shaped Rabies Virus Particles Regulated by TSG101.

Viral protein assembly and virion budding are tightly regulated to enable the proper formation of progeny virions. At this late stage in the virus life cycle, some enveloped viruses take advantage of the host endosomal sorting complex required for transport (ESCRT) machinery, which contributes to the physiological functions of membrane modulation and abscission. Bullet-shaped viral particles are unique morphological characteristics of rhabdoviruses; however, the involvement of host factors in rhabdovirus infection and, specifically, the molecular mechanisms underlying virion formation are not fully understood.

A high-affinity aptamer with base-appended base-modified DNA bound to isolated authentic SARS-CoV-2 strains wild-type and B.1.617.2 (delta variant).

Simple, highly sensitive detection technologies for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are crucial for the effective implementation of public health policies. We used the systematic evolution of ligands by exponential enrichment with a modified DNA library, including a base-appended base (uracil with a guanine base at its fifth position), to create an aptamer with a high affinity for the receptor-binding domain (RBD) of the SARS-CoV-2 spike glycoprotein. The aptamer had a dissociation constant of 1.

Glu in rabies virus glycoprotein is involved in virus attenuation through astrocyte infection and interferon responses.

The amino acid residue at position 333 of the rabies virus (RABV) glycoprotein (G333) is a major determinant of RABV pathogenicity. Virulent RABV strains possess Arg, whereas the attenuated strain HEP-Flury (HEP) possesses Glu. To investigate the potential attenuation mechanism dependent on a single amino acid at G333, comparative analysis was performed between HEP and HEPR mutant with Arg.

SARS-CoV-2 Bearing a Mutation at the S1/S2 Cleavage Site Exhibits Attenuated Virulence and Confers Protective Immunity.

Severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) possesses a discriminative polybasic cleavage motif in its spike protein that is recognized by the host furin protease. Proteolytic cleavage activates the spike protein, thereby affecting both the cellular entry pathway and cell tropism of SARS-CoV-2. Here, we investigated the impact of the furin cleavage site on viral growth and pathogenesis using a hamster animal model infected with SARS-CoV-2 variants bearing mutations at the furin cleavage site (S gene mutants).

Host serine proteases TMPRSS2 and TMPRSS11D mediate proteolytic activation and trypsin-independent infection in group A rotaviruses.

Group A rotaviruses (RVAs) are representative enteric virus species and major causes of diarrhea in humans and animals. The RVA virion is a triple-layered particle, and the outermost layer consists of the glycoprotein VP7 and spike protein VP4. To increase the infectivity of RVA, VP4 is proteolytically cleaved into VP5* and VP8* subunits by trypsin; and these subunits form a rigid spike structure on the virion surface.