Biology subjects

Wardemann, H.

Publications and source records attributed to Wardemann, H..

10 recordsLinked to original sources

bioRxiv2026

B Lymphocyte Protein Factories produced by Hematopoietic Stem Cell Gene Editing

Long-term in vivo production of therapeutic proteins and development of vaccines that elicit protective levels of broadly neutralizing antibodies (bNAbs) against major pathogens face challenges. Here we report on an alternative gene-editing approach using small numbers of hematopoietic stem and progenitor cells (HSPCs) to direct long-term, high-level expression of antibodies or cargo proteins. Edited B lymphocyte offspring can be activated by cognate antigen to undergo clonal expansion and develop into specific antibody or cargo protein-synthesizing plasma cells. These cells produce long-lasting, therapeutic levels of serum antibody against HIV-1 or malaria and an anti-influenza virus bNAb that mediated universal protection from heterologous lethal challenge. Our data provide a paradigm for cell therapy approaches to prevent or treat disease using self-amplifying B cell protein factories.

immunology↗

bioRxiv2025

Multi-parameter spectral flow cytometry panel for immune phenotyping of murine B and T cell responses

Graphical abstractTo enable the analysis of B cell and T cell immune responses in mouse lymph nodes, spleen, and bone marrow, including different B cell and T cell subsets and their activation status, as well as the antigen-reactivity and isotype of B cells and level of T cell exhaustion, a novel 31-parameter spectral flow cytometry panel was developed. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=199 SRC="FIGDIR/small/665522v1_ufig1.gif" ALT="Figure 1"> View larger version (52K): org.highwire.dtl.DTLVardef@1efbad2org.highwire.dtl.DTLVardef@1d23e4borg.highwire.dtl.DTLVardef@1f7d3caorg.highwire.dtl.DTLVardef@17177e2_HPS_FORMAT_FIGEXP M_FIG C_FIG Created in https://BioRender.com

immunology↗

bioRxiv2025

Clonality, specificity, and HLA restriction of human T cell receptors against Plasmodium falciparum CSP

Plasmodium falciparum malaria remains a significant global health challenge. Current vaccines elicit antibody responses against circumsporozoite protein (PfCSP) that prevent the infection of hepatocytes but offer only moderate protection. Cellular immunity has emerged as a critical component of pre-erythrocytic protection that might be leveraged to develop improved PfCSP vaccines. Here, we characterized the clonality, molecular features, epitope specificity, and HLA-restrictions of the human PfCSP-specific CD4+ and CD8+ T cell response to vaccination with an adjuvanted PfCSP vaccine, FMP013/ALFQ. Using TCR expression cloning, we identified novel conserved CD4+ T cell epitopes in the PfCSP N terminus and show that the C-terminal CS.T3 epitope was targeted by CD4+ and rare CD8+ T cells, which recognized this epitope co-receptor-independently presented on a class II HLA. Our findings provide insights into the utility of these epitopes as targets for strain-transcending immunity compared to the immunodominant but highly polymorphic epitopes in the PfCSP C terminus, offering guidance for the design of improved malaria vaccines.

immunology↗

bioRxiv2024

Somatic hypermutation-mediated paratope flexibility improves the cross-reactivity of human malaria antibodies

The protective capacity of antibodies targeting circumsporozoite protein on sporozoites of the malaria parasite Plasmodium falciparum (PfCSP) is linked to high affinity and cross-reactivity with the PfCSP central repeat domain and N-terminal junction. However, the role of somatic hypermutation (SHM) in the development of such antibodies remains unclear. Here we define the contributions of SHM to the high affinity and strong repeat and N-junction cross-reactivity of the potent anti-PfCSP monoclonal antibody (mAb) 4493 and of similar antibodies with shared SHM and affinity maturation trajectories. Molecular dynamics simulations reveal that SHM reduces the flexibility of the unbound mAb 4493 but increases the flexibility of the antigen-bound complex, thereby lowering the entropic cost for antigen binding. Furthermore, we identify an inverse relation between antibody affinity and serum stability, which limits the protective capacity of these antibodies. Our study provides molecular level evidence for the different roles that the SHM process plays in increasing VH3-49+V{kappa}3-20 antibody affinity and cross-reactivity and demonstrates how antibody affinity maturation can negatively impact antibody stability and thereby function.

immunology↗

bioRxiv2023

Memory B cells dominate the early antibody-secreting cell response to SARS-CoV-2 mRNA vaccination in naive individuals independently of their antibody affinity

Memory B cells (MBCs) formed over the individuals lifetime constitute nearly half of the adult peripheral blood B cell repertoire in humans. To assess their response to novel antigens, we tracked the origin and followed the differentiation paths of MBCs in the early anti-S response to mRNA vaccination in SARS-CoV-2-naive individuals on single-cell and monoclonal antibody level. Newly generated and pre-existing MBCs differed in their differentiation paths despite similar levels of SARS-CoV-2 and common corona virus S-reactivity. Pre-existing highly mutated MBCs showed no signs of germinal center re-entry and rapidly developed into mature antibody secreting cells (ASCs). In contrast, newly generated MBCs derived from naive precursors showed strong signs of antibody affinity maturation before differentiating into ASCs. Thus, although pre-existing human MBCs have an intrinsic propensity to differentiate into ASCs, the quality of the anti-S antibody and MBC response improved through the clonal selection and affinity maturation of naive precursors. HighlightsO_LImRNA vaccination of SARS-CoV-2 naive individuals recruits naive and pre-existing MBCs with similar levels of S-reactivity into the response C_LIO_LIS-reactive naive but not pre-existing MBCs undergo affinity maturation C_LIO_LIS-reactive pre-existing MBCs dominate the early ASC response independent of their antigen affinity C_LIO_LIHigh-affinity S-reactive MBCs and ASCs develop over time and originate from affinity matured naive precursors C_LI

immunology↗

bioRxiv2023

Molecular and functional properties of human Plasmodium falciparum CSP C-terminus antibodies

Human monoclonal antibodies (mAbs) against the central repeat and junction domain of Plasmodium falciparum circumsporozoite protein (PfCSP) have been studied extensively to guide malaria vaccine design compared to antibodies against the PfCSP C terminus. Here, we describe the molecular characteristics and protective potential of a panel of 73 germline and mutated human mAbs against the highly immunogenic PfCSP C-terminal domain. Two mAbs recognized linear epitopes in the C-terminal linker with sequence similarity to repeat and junction motifs, whereas all others targeted conformational epitopes in the -thrombospondin repeat (-TSR) domain. Specificity for the polymorphic Th2R/Th3R but not the conserved RII+ region in the -TSR was associated with IGHV3-21/IGVL3-21 or IGLV3-1 gene usage. Although the C terminus specific mAbs showed signs of more efficient affinity maturation and class-switching compared to anti-repeat mAbs, parasite inhibitory activity was limited to a single C-linker reactive mAb with cross-reactivity to the central repeat and junction. The data provide novel insights in the human anti-C-linker and anti--TSR antibody response that support exclusion of the PfCSP C terminus from malaria vaccine designs.

immunology↗

bioRxiv2021

MDA-LDL vaccination induces athero-protective germinal center-derived antibody responses

Atherosclerosis is a chronic inflammatory disease of the arteries that can lead to thrombosis, infarction and stroke and is the leading cause of mortality worldwide. Immunization of pro-atherogenic mice with malondialdehyde-modified low-density lipoprotein (MDA-LDL) neo-antigen is athero-protective. However, the immune response to MDA-LDL and the mechanisms responsible for this athero-protection are not completely understood. Here, we find that immunization of mice with MDA-LDL elicits memory B cells, plasma cells, and switched anti-MDA-LDL antibodies as well as clonal expansion and affinity maturation, indicating that MDA-LDL triggers a bona fide germinal center antibody response. Further, Prdm1fl/fl Aicda-Cre+/ki Ldlr-/- pro-atherogenic chimeras, which lack germinal center-derived plasma cells, show accelerated atherosclerosis. Finally, we show that MDA-LDL immunization is not athero-protective in mice lacking germinal-center derived plasma cells. Our findings give further support to the development of MDA-LDL-based vaccines for the prevention or treatment of atherosclerosis.

immunology↗

bioRxiv2021

Clonal evolution and specificity of the human T follicular helper cell response to Plasmodium falciparum circumsporozoite protein

T follicular helper (TFH) cells play a crucial role in the development of long-lived, quality-improved B cell responses after infection and vaccination. However, little is known about their clonal evolution. Here we assessed the cell phenotype, clonal dynamics, and TCR specificity of human circulating TFH (cTFH) cells at monoclonal level during successive malaria immunizations with radiation-attenuated Plasmodium falciparum (Pf) sporozoites. Repeated parasite exposures induced a dynamic, polyclonal cTFH response with high frequency of cells specific to the Pf circumsporozoite protein (PfCSP), the main surface protein of sporozoites and a validated vaccine target. Repeated immunizations were required to induce detectable PfCSP-reactive cTFH cell responses to a small number of epitopes. HLA-restrictions and differences in TCR generation probability explain the high targeting frequency of the polymorphic Th2R/T* region over the conserved T1 epitope. The vast majority of anti-Th2R/T* TCRs failed to tolerate natural polymorphisms in their target peptide sequence suggesting that parasite diversity limits natural boosting of the cTFH cell response in endemic areas and protection from non-vaccine strains. Among convergent anti-Th2R/T* TCRs with high sequence similarity, subtle differences in CDR3 composition discriminated cross-reactive from non-cross-reactive cTFH cells. Thus, our study provides deep molecular and cellular insights into the kinetics, fine specificity and HLA-restrictions of the anti-cTFH cell response that are of direct relevance for the design of PfCSP-based malaria vaccines by guiding the selection of PfCSP peptides that induce optimal B cell help.

immunology↗

bioRxiv2020

A high-affinity antibody against the CSP N-terminal domain lacks Plasmodium falciparum inhibitory activity

Malaria is a global health concern and research efforts are ongoing to develop a superior vaccine to RTS,S/AS01. To guide immunogen design, we seek a comprehensive understanding of the protective humoral response against Plasmodium falciparum circumsporozoite protein (PfCSP). In contrast to the well-studied responses to the repeat region and the C-terminus, the antibody response against the N-terminal domain of PfCSP (N-CSP) remains obscure. Here, we characterized the molecular recognition and functional efficacy of the N-CSP-specific monoclonal antibody 5D5. The crystal structure at 1.85 [A] resolution revealed that 5D5 binds an -helical epitope in N-CSP with high affinity through extensive shape and charge complementarity, and the unusual utilization of an N-linked glycan. Nevertheless, functional studies indicated low 5D5 binding to live Pf sporozoites, and lack of sporozoite inhibition in vitro and in mosquitoes. Overall, our data on low recognition and inhibition of sporozoites do not support the inclusion of the 5D5 epitope into the next generation of CSP-based vaccines. Summary StatementThe Plasmodium falciparum sporozoite surface protein, PfCSP, is an attractive vaccine target, but the antibody response against the CSP N-terminal domain has remained understudied. Here, to guide immunogen design, Thai et al. provide insights into the binding motif and functional efficacy of the N-terminal domain-specific monoclonal antibody, 5D5.

immunology↗

bioRxiv2019

Evolution of protective human antibodies against Plasmodium falciparum circumsporozoite protein repeat motifs

Circumsporozoite protein of the human malaria parasite Plasmodium falciparum (PfCSP) is the main target of antibodies that prevent the infection and disease. Protective antibodies recognize the central PfCSP domain, but our understanding of how parasite inhibition is associated with recognition of this domain and with the evolution of potent antibodies remains scattered. Here, we characterized the epitope specificity of 200 human monoclonal PfCSP antibodies. We show that the majority of PfCSP antibodies bind to NANP and NANP-like motifs with different preferences and define the molecular basis for recognition. Epitope cross-reactivity evolved with increasing antibody affinity around a conserved (N/D)P-NANP-N(V/A) core. High affinity to this motif, but not binding to NANP-like motifs, was associated with parasite inhibition and protection. Thus, NANP drives the development of potent PfCSP antibodies independently of their cross-reactivity profile, a finding with direct implications for the design of a second-generation PfCSP-based malaria vaccine.\n\nHIGHLIGHTSO_LIThe majority of human PfCSP antibodies recognize multiple epitopes\nC_LIO_LINANP affinity maturation drives the evolution of cross-reactive PfCSP antibodies\nC_LIO_LIPreferential PfCSP antibody binding to a conserved core motif\nC_LIO_LIHigh affinity not epitope specificity is associated with PfCSP antibody potency\nC_LI

immunology↗