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Kikkeri, R.

Publications and source records attributed to Kikkeri, R..

2 recordsLinked to original sources

Nanoparticle Shape Governs Immunomodulation of MUC1 Antigen to Develop Anti-cancer Vaccine

T-cell-dependent immunomodulation of carbohydrate antigens under benign conditions is the most promising approach for carbohydrate-based vaccine development. However, to achieve such adaptive immune responses, well-defined multifunctional nanocarriers loaded with immunogenic materials must be explored. Current efforts to use gold nanoparticles (AuNPs) as antigen carriers in vaccine development have conveniently introduced considerable diversity. Here, we show that the shape of AuNPs markedly influences carbohydrate-based antigen processing in murine dendritic cells (mDCs) and subsequent T-cell activation. In the study, CpG-adjuvant coated sphere-, rod-, and star-shaped AuNPs were conjugated to the tripodal Tn-glycopeptide antigen to study their DC uptake and the activation of T-cells in the DCs/T-cell co-culture assay. Our results showed that sphere- and star-shaped AuNPs displayed relatively weak receptor-mediated uptake but induced a high level of T helper-1 (Th1) biasing immune responses compared with rod-shaped AuNPs, showing that receptor-mediated uptake and cytokine secretion of nanostructures are two independent mechanisms. Significantly, the shapes of AuNPs and antigen/adjuvant conjugation synergistically work together to modulate the effective anti-Tn-glycopeptide immunoglobulin (IgG) antibody response after in vivo administration of the AuNPs. These results show that by varying the shape parameter, one can alter the immunomodulation, leading to the development of carbohydrate vaccines.

immunology↗

Therapeutic antibodies, targeting the SARS-CoV-2 spike N-terminal domain, protect lethally infected K18-hACE2 mice

Since the onset of the current COVID-19 pandemic, high priority is given to the development of neutralizing antibodies, as a key approach for the design of therapeutic strategies to countermeasure and eradicate the disease. Previously, we reported the development of human therapeutic monoclonal antibodies (mAbs) exhibiting very high protective ability. These mAbs recognize epitopes on the spike receptor binding domain (RBD) of SARS-CoV-2 that is considered to represent the main rout of receptor engagement by the SARS-CoV-2 virus. The recent emergence of viral variants emphasizes the notion that efficient antibody treatments need to rely on mAbs against several distinct key epitopes in order to circumvent the occurrence of therapy escape-mutants. Here we report the isolation and characterization of 12 neutralizing mAbs, identified by screening a phage-display library constructed from lymphatic cells collected from severe COVID-19 patients. The antibodies target three distinct epitopes on the spike N-terminal domain (NTD) of SARS-CoV-2, one of them defining a major site of vulnerability of the virus. Extensive characterization of these mAbs suggests a neutralization mechanism which relies both on amino-acid and N-glycan recognition on the virus, and involvement of receptors other than the hACE2 on the target cell. Two of the selected mAbs, which demonstrated superior neutralization potency in vitro, were further evaluated in vivo, demonstrating their ability to fully protect K18-hACE2 transgenic mice even when administered at low doses and late after infection. The study demonstrates the high potential of the mAbs for therapy of SARS-CoV-2 infection and underlines the possible role of the NTD in mediating infection of host cells via alternative cellular portals other than the canonical ACE2 receptor.

immunology↗