Biology subjects

Gerke, C.

Publications and source records attributed to Gerke, C..

6 recordsLinked to original sources

bioRxiv2024

Contribution of the Type 3 Secretion System to immunogenicity of a live Yersinia pseudotuberculosis plague vaccine

The causative agent of plague, Yersinia pestis, remains a treat for public health worldwide. In the perspective to develop effective and safe vaccines, we present here a derived version of our Y. pseudotuberculosis VTnF1 live attenuated vaccine candidate that lacks the pYV virulence plasmid coding for the Type 3 Secretion system (T3SS) and no antibiotic resistance cassettes. This strain, called VpYV-, was safe for immunodeficient mice, and thus can be considered as deeply attenuated. It still has tropism for lymphatic tissues (Peyers patches, Mesenteric lymph nodes) but hardly reaches the spleen and liver. It elicits IgG to the F1 antigen as efficiently as VTnF1 but less directed to other Yersinia antigens. A single oral dose induced 100% protection against bubonic and pneumonic forms of plague, but this protection decreased faster with time than that of VTnF1. In the same line, VpYV-was 30% less protective against a F1-negative Y. pestis, revealing that the tools encoded by pYV are mandatory to obtain a large spectrum protection. Finally, VTnF1 like the Y. pestis vaccine EV76 can induce protection against co-infected Y. pestis relying on host iron nutritional immunity", indicating a potential use as therapeutics of recent infection. In contrast VpYV-failed to do so, revealing an importance of the T3SS in this mechanism. Overall, VpYV- and its parental strain VTnF1 offer a choice between more attenuation and safety or vaccine performances. They give an alternative and may represent useful tools to prevent and treat Y. pestis infection in healthy or immunosuppressed individuals.

microbiology↗

bioRxiv2023

Multimodal HLA-I genotype regulation by human cytomegalovirus US10 and resulting surface patterning

To control human cytomegalovirus (HCMV) infection, NK cells and CD8+ T-cells are crucial. HLA class I (HLA-I) molecules play a central role for both NK and T-cell responses and are targets of multifaceted HCMV-encoded immunoevasins. A so far insufficiently studied HLA-I immunoevasin is the glycoprotein US10. It was shown that US10 targets HLA-G, but it is unknown whether US10 contributes also to escape from classical HLA-I antigen presentation. Our biochemical analysis revealed that early during maturation, all investigated HLA-I (HLA-A/B/C/E/G) heavy chains are recognized and bound by US10. Remarkably, the consequences of this initial binding strongly depended on both the HLA-I geno- and allotypes: i) HLA-A molecules escaped down-regulation by US10, ii) tapasin-dependent HLA-B molecules exhibited impaired recruitment to the peptide loading complex and maturation, iii) HLA-C and HLA-G, but not HLA-A/B/E, strongly bound US10 also in their {beta}2m-assembled form. Thus, US10 senses geno- and allotypic differences in a so far unparalleled and multimodal manner, suggestive of adaptation to HLA-I genotype differences. At a further level of complexity, in HCMV-infected fibroblasts inhibition of overlapping US10 and US11 transcription revealed an additional HLA-I specificity, suggesting targeting of HLA-I in a synergistically arranged manner. Our study unveils the exceptional HLA-I selectivity of HCMV-encoded US10 and underlines its contribution to immune escape.

microbiology↗

bioRxiv2022

An intranasal lentiviral booster broadens immune recognition of SARS-CoV-2 variants and reinforces the waning mRNA vaccine-induced immunity that it targets to lung mucosa

As the COVID-19 pandemic continues and new SARS-CoV-2 variants of concern emerge, the adaptive immunity initially induced by the first-generation COVID-19 vaccines wains and needs to be strengthened and broadened in specificity. Vaccination by the nasal route induces mucosal humoral and cellular immunity at the entry point of SARS-CoV-2 into the host organism and has been shown to be the most effective for reducing viral transmission. The lentiviral vaccination vector (LV) is particularly suitable for this route of immunization because it is non-cytopathic, non-replicative and scarcely inflammatory. Here, to set up an optimized cross-protective intranasal booster against COVID-19, we generated an LV encoding stabilized Spike of SARS-CoV-2 Beta variant (LV::SBeta-2P). mRNA vaccine-primed and -boosted mice, with waning primary humoral immunity at 4 months post-vaccination, were boosted intranasally with LV::SBeta-2P. Strong boost effect was detected on cross-sero-neutralizing activity and systemic T-cell immunity. In addition, mucosal anti-Spike IgG and IgA, lung resident B cells, and effector memory and resident T cells were efficiently induced, correlating with complete pulmonary protection against the SARS-CoV-2 Delta variant, demonstrating the suitability of the LV::SBeta-2P vaccine candidate as an intranasal booster against COVID-19.

immunology↗

bioRxiv2021

A measles-vectored COVID-19 vaccine induces long-term immunity and protection from SARS-CoV-2 challenge in mice

In light of the expanding SARS-CoV-2 pandemic, developing efficient vaccines that can provide sufficient coverage for the world population is a global health priority. The measles virus (MV)-vectored vaccine is an attractive candidate given the measles vaccines extensive safety history, well-established manufacturing process, and induction of strong, long-lasting immunity. We developed an MV-based SARS-CoV-2 vaccine using either the full-length spike (S) or S2 subunit as the antigen. While the S2 antigen failed to induce neutralizing antibodies, the prefusion-stabilized, full-length S (MV-ATU2-SF-2P-dER) construct proved to be an attractive vaccine candidate, eliciting strong Th1-dominant T-cell and neutralizing antibody responses against the S antigen while minimizing reactivity to the vector itself. Neutralizing antibody titers remained high three months after homologous prime-boost immunization, and infectious virus was undetectable in all animals after challenge with a mouse-adapted SARS-CoV-2 virus.

immunology↗

bioRxiv2020

PAKC: A novel Panel of HLA class I Antigen presentation machinery Knockout Cells from the same genetic origin

With the emergence of immunotherapies, the understanding of functional HLA class I antigen presentation to T cells is more relevant than ever. Current knowledge on antigen presentation is based on decades of research in a wide variety of cell types with varying antigen presentation machinery (APM) expression patterns, proteomes and HLA haplotypes. This diversity complicates the establishment of individual APM contributions to antigen generation, selection and presentation. Therefore, we generated a novel Panel of APM Knockout Cell lines (PAKC) from the same genetic origin. After CRISPR/Cas9 genome-editing of ten individual APM components in a human cell line, we derived clonal cell lines and confirmed their knockout status and phenotype. We then show how PAKC will accelerate research on the functional interplay between APM components and their role in antigen generation and presentation. This will lead to improved understanding of peptide-specific T cell responses in infection, cancer and autoimmunity. Key pointsO_LIWe generated a panel of cell lines to study HLA class I antigen presentation C_LIO_LIWe show how this will spark research in infection, tumor biology and autoimmunity C_LI

immunology↗

bioRxiv2019

Subcutaneous vaccination with a live attenuated Yersinia pseudotuberculosis plague vaccine

A single oral inoculation to mice of the live attenuated Yersinia pseudotuberculosis VTnF1 strain producing an F1 pseudocapsule protects against bubonic and pneumonic plague. However oral vaccination can fail in humans exposed to frequent intestinal infections. We evaluated in mice the efficacy of subcutaneous vaccine injection as an alternative way to induce protective immunity, while reducing the dose and avoiding strain release in nature. A single subcutaneous dose of up to 108 CFU induced dose-dependent antibody production. At the dose of 107 CFU, i.e. 10 times less than via the oral route, it caused a modest skin reaction and protected 100% against bubonic and 80% against pneumonic plague, caused by high doses of Yersinia pestis. Bacteria migrating to lymph nodes and spleen, but not feces, were rapidly eliminated. Thus, subcutaneous injection of VTnF1 would represent a good alternative when dissemination in nature and human intestinal responsiveness are limitations.

immunology↗