• B cell depletion impairs vaccination-induced CD8 T cell responses in a type I interferon-dependent manner.

      Graalmann, Theresa; Borst, Katharina; Manchanda, Himanshu; Vaas, Lea; Bruhn, Matthias; Graalmann, Lukas; Koster, Mario; Verboom, Murielle; Hallensleben, Michael; Guzmán, Carlos Alberto; et al. (BMJ Publishing Group, 2021-07-05)
      Objectives: The monoclonal anti-CD20 antibody rituximab is frequently applied in the treatment of lymphoma as well as autoimmune diseases and confers efficient depletion of recirculating B cells. Correspondingly, B cell-depleted patients barely mount de novo antibody responses during infections or vaccinations. Therefore, efficient immune responses of B cell-depleted patients largely depend on protective T cell responses. Methods: CD8+ T cell expansion was studied in rituximab-treated rheumatoid arthritis (RA) patients and B cell-deficient mice on vaccination/infection with different vaccines/pathogens. Results: Rituximab-treated RA patients vaccinated with Influvac showed reduced expansion of influenza-specific CD8+ T cells when compared with healthy controls. Moreover, B cell-deficient JHT mice infected with mouse-adapted Influenza or modified vaccinia virus Ankara showed less vigorous expansion of virus-specific CD8+ T cells than wild type mice. Of note, JHT mice do not have an intrinsic impairment of CD8+ T cell expansion, since infection with vaccinia virus induced similar T cell expansion in JHT and wild type mice. Direct type I interferon receptor signalling of B cells was necessary to induce several chemokines in B cells and to support T cell help by enhancing the expression of MHC-I. Conclusions: Depending on the stimulus, B cells can modulate CD8+ T cell responses. Thus, B cell depletion causes a deficiency of de novo antibody responses and affects the efficacy of cellular response including cytotoxic T cells. The choice of the appropriate vaccine to vaccinate B cell-depleted patients has to be re-evaluated in order to efficiently induce protective CD8+ T cell responses.
    • The bacterial second messenger cdiGMP exhibits promising activity as a mucosal adjuvant.

      Ebensen, Thomas; Schulze, Kai; Riese, Peggy; Morr, Michael; Guzmán, Carlos A; Department of Vaccinology, Helmholtz Centre for Infection Research, Inhoffenstrasse 7, D-38124 Braunschweig, Germany. (2007-08)
      The development of mucosal adjuvants is still a critical need in vaccinology. In the present work, we show that bis(3',5')-cyclic dimeric GMP (cdiGMP), a second messenger that modulates cell surface properties of several microorganisms, exerts potent activity as a mucosal adjuvant. BALB/c mice were immunized intranasally with the model antigen beta-galactosidase (beta-Gal) coadministered with cdiGMP. Animals receiving cdiGMP as an adjuvant showed significantly higher anti-beta-Gal immunoglobulin G (IgG) titers in sera than controls (i.e., 512-fold [P < 0.05]). Coadministration of cdiGMP also stimulated efficient beta-Gal-specific secretory IgA production in the lung (P < 0.016) and vagina (P < 0.036). Cellular immune responses were observed in response to both the beta-Gal protein and a peptide encompassing its major histocompatibility complex class I-restricted epitope. The IgG1-to-IgG2a ratio of anti-beta-Gal antibodies and the observed profiles of secreted cytokines suggest that a dominant Th1 response pattern is promoted by mucosal coadministration of cdiGMP. Finally, the use of cdiGMP as a mucosal adjuvant also led to the stimulation of in vivo cytotoxic T-lymphocyte responses in C57BL/6 mice intranasally immunized with ovalbumin and cdiGMP (up to 30% of specific lysis). The results obtained indicate that cdiGMP is a promising tool for the development of mucosal vaccines.
    • Bivalent mucosal peptide vaccines administered using the LCP carrier system stimulate protective immune responses against Streptococcus pyogenes infection.

      Schulze, Kai; Ebensen, Thomas; Chandrudu, Saranya; Skwarczynski, Mariusz; Toth, Istvan; Olive, Colleen; Guzman, Carlos A; Helmholtz Centre for infection researchGmbH, Inhoffenstr. 7, 38124 Braunschweig, Germany. (2017-09-05)
      Despite the broad knowledge about the pathogenicity of Streptococcus pyogenes there is still a controversy about the correlate of protection in GAS infections. We aimed in further improving the immune responses stimulated against GAS comparing different vaccine formulations including bis-(3',5')-cyclic dimeric adenosine monophosphate (c-di-AMP) and BPPCysMPEG, a derivative of the macrophage-activating lipopeptide (MALP-2), as adjuvants, respectively, to be administered with and without the universal T helper cell epitope P25 along with the optimized B cell epitope J14 of the M protein and B and T cell epitopes of SfbI. Lipopeptide based nano carrier systems (LCP) were used for efficient antigen delivery across the mucosal barrier. The stimulated immune responses were efficient in protecting mice against a respiratory challenge with a lethal dose of a heterologous S. pyogenes strain. Moreover, combination of the LCP based peptide vaccine with c-di-AMP allowed reduction of antigen dose at the same time maintaining vaccine efficacy.
    • Blockade of Neutrophil's Chemokine Receptors CXCR1/2 Abrogate Liver Damage in Acute-on-Chronic Liver Failure.

      Khanam, Arshi; Trehanpati, Nirupma; Riese, Peggy; Rastogi, Archana; Guzman, Carlos A.; Sarin, Shiv Kumar; Helmholtz-Zentrum für Infektionsforschung GmbH, Inhoffenstr. 7, 38124 Braunschweig, Germany. (2017)
      Neutrophils serve as critical players in the pathogenesis of liver diseases. Chemokine receptors CXCR1 and CXCR2 are required for neutrophil chemotaxis to the site of inflammation/injury and are crucial in hepatic inflammatory response. However, key mechanism of neutrophil-mediated liver injury in acute-on-chronic liver failure (ACLF) remains highly elusive; which could be targeted for the development of new therapeutic interventions.
    • Cell aggregation enhances bone formation by human mesenchymal stromal cells.

      Chatterjea, A; LaPointe, V L; Barradas, A; Garritsen, H; Yuan, H; Renard, A; van Blitterswijk, C A; de Beor, J; Hemholtz-Zentrum für Infektionsforschung GmbH, Inhoffenstr. 7, 38124 Vraunschweig, Germany. (2017-02-15)
      The amount of bone generated using current tissue engineering approaches is insufficient for many clinical applications. Previous in vitro studies suggest that culturing cells as 3D aggregates can enhance their osteogenic potential, but the effect on bone formation in vivo is unknown. Here, we use agarose wells to generate uniformly sized mesenchymal stromal cell (MSC) aggregates. When combined with calcium phosphate ceramic particles and a gel prepared from human platelet-rich plasma, we generated a tissue engineered construct which significantly improved in vivo bone forming capacity as compared to the conventional system of using single cells seeded directly on the ceramic surface. Histology demonstrated the reproducibility of this system, which was tested using cells from four different donors. In vitro studies established that MSC aggregation results in an up-regulation of osteogenic transcripts. And finally, the in vivo performance of the constructs was significantly diminished when unaggregated cells were used, indicating that cell aggregation is a potent trigger of in vivo bone formation by MSCs. Cell aggregation could thus be used to improve bone tissue engineering strategies.
    • Characterization of a Novel Intracellularly Activated Gene from Salmonella enterica Serovar Typhi

      Basso, Holger; Rharbaoui, Faiza; Staendner, Lothar H.; Medina, Eva; García-Del Portillo, Francisco; Guzmán, Carlos A. (American Society for Microbiology, 2002-10)
    • Cohort Profile: The LoewenKIDS Study - life-course perspective on infections, the microbiome and the development of the immune system in early childhood.

      Gottschick, Cornelia; Raupach-Rosin, Heike; Langer, Susan; Hassan, Lamiaa; Horn, Johannes; Dorendorf, Evelyn; Caputo, Mahrrouz; Bittner, Martina; Beier, Lea; Rübsamen, Nicole; et al. (Oxford Academic, 2019-02-27)
      [Noabstract available]
    • The Combination Vaccine Adjuvant System Alum/c-di-AMP Results in Quantitative and Qualitative Enhanced Immune Responses Post Immunization.

      Ebensen, Thomas; Delandre, Simon; Prochnow, Blair; Guzmán, Carlos A; Schulze, Kai (2019-01-01)
    • Construction and characterization of a live attenuated vaccine candidate against Shigella dysenteriae type 1.

      Klee, S R; Tzschaschel, B D; Fält, I; Kärnell, A; Lindberg, A A; Timmis, K N; Guzmán, C A (1997-06)
    • Cyanoethylation of the glucans dextran and pullulan: Substitution pattern and formation of nanostructures and entrapment of magnetic nanoparticles.

      Fiege, Kathrin; Lünsdorf, Heinrich; Atarijabarzadeh, Sevil; Mischnick, Petra; Institute for Food Chemistry, Technische Universität Braunschweig, Schleinitzstraße 20, D-38106 Braunschweig, Germany. (2012)
      Cyanoethylglucans with a degree of substitution in the range of 0.74 to 2.40 for dextran and 0.84 to 2.42 for pullulan were obtained by Michael addition of acrylonitrile to the glucans under various conditions. Products were thoroughly characterized, comprising elementary analysis, NMR and ATR-IR spectroscopy, and analysis of the substituent distribution in the glucosyl units by GC-FID and GC-MS of the constituting monosaccharide derivatives. Nanostructuring of the highly substituted cyanoethylpolysaccharides was performed by dialysis against a non-solvent. In the presence of ferromagnetic iron-oxide nanoparticles, multicore cyanoethylglucan-coated ferromagnetic nanoparticles were formed by selective entrapment. The specific interaction between cyano groups and iron could be proven. The size distribution and morphology of the nanoparticles were analyzed by dynamic light scattering (DLS), scanning electron microscopy (SEM) and energy-filtered transmission electron microscopy (EF-TEM) with parallel electron energy loss spectroscopy (PEELS).
    • Cyclic Di-Adenosine Monophosphate: A Promising Adjuvant Candidate for the Development of Neonatal Vaccines.

      Lirussi, Darío; Weissmann, Sebastian Felix; Ebensen, Thomas; Nitsche-Gloy, Ursula; Franz, Heiko B G; Guzmán, Carlos A; HZI,Helmholtz-Zentrum für Infektionsforschung GmbH, Inhoffenstr. 7,38124 Braunschweig, Germany. (MDPI, 2021-02-01)
      Underdeveloped immunity during the neonatal age makes this period one of the most dangerous during the human lifespan, with infection-related mortality being one of the highest of all age groups. It is also discussed that vaccination during this time window may result in tolerance rather than in productive immunity, thus raising concerns about the overall vaccine-mediated protective efficacy. Cyclic di-nucleotides (CDN) are bacterial second messengers that are rapidly sensed by the immune system as a danger signal, allowing the utilization of these molecules as potent activators of the immune response. We have previously shown that cyclic di-adenosine monophosphate (CDA) is a potent and versatile adjuvant capable of promoting humoral and cellular immunity. We characterize here the cytokine profiles elicited by CDA in neonatal cord blood in comparison with other promising neonatal adjuvants, such as the imidazoquinoline resiquimod (R848), which is a synthetic dual TLR7 and TLR8 agonist. We observed superior activity of CDA in eliciting T helper 1 (Th1) and T follicular helper (TfH) cytokines in cells from human cord blood when compared to R848. Additional in vivo studies in mice showed that neonatal priming in a three-dose vaccination schedule is beneficial when CDA is used as a vaccine adjuvant. Humoral antibody titers were significantly higher in mice that received a neonatal prime as compared to those that did not. This effect was absent when using other adjuvants that were reported as suitable for neonatal vaccination. The biological significance of this immune response was assessed by a challenge with a genetically modified influenza H1N1 PR8 virus. The obtained results confirmed that CDA performed better than any other adjuvant tested. Altogether, our results suggest that CDA is a potent adjuvant in vitro on human cord blood, and in vivo in newborn mice, and thus a suitable candidate for the development of neonatal vaccines. Keywords: cyclic di-adenosine monophosphate (CDA); cyclic di-nucleotides (CDN); first dose efficacy; neonatal vaccines; stimulator of interferon genes (STING).
    • Cyclic di-nucleotides: new era for small molecules as adjuvants.

      Libanova, Rimma; Becker, Pablo D; Guzmán, Carlos A; Helmholtz Centre for infection research, Inhoffenstr. 7, 38124 Braunschweig, Germany. (2012-03)
      The implementation of vaccination as an empiric strategy to protect against infectious diseases was introduced even before the advent of hygiene and antimicrobials in the medical practice. Nevertheless, it was not until a few decades ago that we really started understanding the underlying mechanisms of protection triggered by vaccination. Vaccines were initially based on attenuated or inactivated organisms. Subunit vaccines were then introduced as more refined formulations, exhibiting improved safety profiles. However, purified antigens tend to be poorly immunogenic and often require the use of adjuvants to achieve adequate stimulation of the immune system. Vaccination strategies, such as mucosal administration, also require potent adjuvants to improve performance. In the 1990s, immunologists found that pathogens could be sensed as 'danger signals' by receptors recognizing conserved motifs. Although our knowledge is still limited, tremendous advances were made in the understanding of host defence mechanisms regulated by these evolutionary conserved receptors, and the molecular structures which are recognized by them. This opened a new era in adjuvant development. Some of the latest players arrived to this field are the cyclic di-nucleotides, which are ubiquitous prokaryotic intracellular signalling molecules. This review is focused on their potential for the development of vaccines and immunotherapies.
    • Cyclic GMP-AMP Displays Mucosal Adjuvant Activity in Mice.

      Skrnjug, Ivana; Guzmán, Carlos Alberto; Ruecker, Christine; Helmholtz Cente for infection research,Inhoffenstr. 7, D38124 Braunschweig, Germany. (2014)
      The recently discovered mammalian enzyme cyclic GMP-AMP synthase produces cyclic GMP-AMP (cGAMP) after being activated by pathogen-derived cytosolic double stranded DNA. The product can stimulate STING-dependent interferon type I signaling. Here, we explore the efficacy of cGAMP as a mucosal adjuvant in mice. We show that cGAMP can enhance the adaptive immune response to the model antigen ovalbumin. It promotes antigen specific IgG and a balanced Th1/Th2 lymphocyte response in immunized mice. A characteristic of the cGAMP-induced immune response is the slightly reduced induction of interleukin-17 as a hallmark of Th17 activity - a distinct feature that is not observed with other cyclic di-nucleotide adjuvants. We further characterize the innate immune stimulation activity in vitro on murine bone marrow-derived dendritic cells and human dendritic cells. The observed results suggest the consideration of cGAMP as a candidate mucosal adjuvant for human vaccines.
    • Deletion of Irf3 and Irf7 Genes in Mice Results in Altered Interferon Pathway Activation and Granulocyte-Dominated Inflammatory Responses to Influenza A Infection.

      Hatesuer, Bastian; Hoang, Hang Thi Thu; Riese, Peggy; Trittel, Stephanie; Gerhauser, Ingo; Elbahesh, Husni; Geffers, Robert; Wilk, Esther; Schughart, Klaus; Helmholtz-Zentrum für Infektionsforschung GmbH, Inhoffenstr.7, 38124 Braunschweig, Germany. (2017)
      The interferon (IFN) pathway plays an essential role in the innate immune response following viral infections and subsequent shaping of adaptive immunity. Infections with influenza A viruses (IAV) activate the IFN pathway after the recognition of pathogen-specific molecular patterns by respective pattern recognition receptors. The IFN regulatory factors IRF3 and IRF7 are key players in the regulation of type I and III IFN genes. In this study, we analyzed the role of IRF3 and IRF7 for the host response to IAV infections in Irf3-/-, Irf7-/-, and Irf3-/-Irf7-/- knockout mice. While the absence of IRF3 had only a moderate impact on IFN expression, deletion of IRF7 completely abolished IFNα production after infection. In contrast, lack of both IRF3 and IRF7 resulted in the absence of both IFNα and IFNβ after IAV infection. In addition, IAV infection of double knockout mice resulted in a strong increase of mortality associated with a massive influx of granulocytes in the lung and reduced activation of the adaptive immune response.
    • Development and characterization of attenuated metabolic mutants of Bordetella bronchiseptica for applications in vaccinology.

      Yevsa, Tetyana; Ebensen, Thomas; Fuchs, Barbara; Zygmunt, Beata; Libanova, Rimma; Gross, Roy; Schulze, Kai; Guzmán, Carlos A; Department of Vaccinology and Applied Microbiology, Helmholtz Centre for Infection Research, D-38124 Braunschweig, Germany. (2013-01)
      Bordetella bronchiseptica is an important pathogen causing a number of veterinary respiratory syndromes in agriculturally important and food-producing confinement-reared animals, resulting in great economic losses annually amounting to billions of euros worldwide. Currently available live vaccines are incompletely satisfactory in terms of efficacy and safety. An efficient vaccine for livestock animals would allow reducing the application of antibiotics, thereby preventing the massive release of pharmaceuticals into the environment. Here, we describe two new potential vaccine strains based on the BB7865 strain. Two independent attenuating mutations were incorporated by homologous recombination in order to make negligible the risk of recombination and subsequent reversion to the virulent phenotype. The mutations are critical for bacterial metabolism, resistance to oxidative stress, intracellular survival and in vivo persistence. The resulting double mutants BB7865 risA aroA and BB7865 risA dapE were characterized as promising vaccine candidates, which are able to confer protection against colonization of the lower respiratory tract after sublethal challenge with the wild-type strain.
    • Dynamic changes in viral population structure and compartmentalization during chronic hepatitis C virus infection in children.

      Gismondi, María Inés; Díaz Carrasco, Juan María; Valva, Pamela; Becker, Pablo Daniel; Guzmán, Carlos Alberto; Campos, Rodolfo Héctor; Preciado, María Victoria; Helmholtz Centre for infection research, D-38124 Braunschweig, Germany (2013-12)
      Classic phylogenetic and modern population-based clustering methods were used to analyze hepatitis C virus (HCV) evolution in plasma and to assess viral compartmentalization within peripheral blood mononuclear cells (PBMCs) in 6 children during 3.2-9.6yr of follow-up. Population structure analysis of cloned amplicons encompassing hypervariable region 1 led to the distinction of two evolutionary patterns, one highly divergent and another one genetically homogeneous. Viral adaptability was reflected by co-evolution of viral communities switching rapidly from one to another in the context of divergence and stability associated with highly homogeneous communities which were replaced by new ones after long periods. Additionally, viral compartmentalization of HCV in PBMCs was statistically demonstrated, suggesting their role as a pool of genetic variability. Our results support the idea of a community-based structure of HCV viral populations during chronic infection and highlight a role of the PBMC compartment in the persistence of such structure.
    • Efficient nanoparticle-mediated needle-free transcutaneous vaccination via hair follicles requires adjuvantation.

      Mittal, Ankit; Schulze, Kai; Ebensen, Thomas; Weißmann, Sebastian; Hansen, Steffi; Lehr, Claus-Michael; Guzmán, Carlos A; Helmholtz Centre for Infection Research (HZI), Braunschweig, Germany. (2015-01)
      Trans-follicular (TF) vaccination has recently been studied as a unique route for non-invasive transcutaneous vaccination. The present study aims to extensively characterize the immune responses triggered by TF vaccination using ovalbumin loaded chitosan-PLGA (poly lactic-co-glycolic acid) nanoparticles without skin pre-treatment to preserve skin integrity. The impact of formulation composition i.e. antigenic solution or antigen-loaded nanoparticles with or without adjuvant [bis-(3',5')-cyclic dimeric adenosine monophosphate] on immune response quality following TF immunization was analyzed and compared with immune responses obtained after tape stripping the skin. The results presented in this study confirm the ability of nanoparticle based vaccine formulations to deliver antigen across the intact skin via the follicular route, but at the same time demonstrate the necessity to include adjuvants to generate efficient antigen-specific humoral and cellular immune responses.
    • Engineered dendritic cells from cord blood and adult blood accelerate effector T cell immune reconstitution against HCMV.

      Daenthanasanmak, Anusara; Salguero, Gustavo; Sundarasetty, Bala Sai; Waskow, Claudia; Cosgun, Kadriye Nehir; Guzman, Carlos A; Riese, Peggy; Gerasch, Laura; Schneider, Andreas; Ingendoh, Alexandra; et al. (2015)
      Human cytomegalovirus (HCMV) harmfully impacts survival after peripheral blood hematopoietic stem cell transplantation (PB-HSCT). Delayed immune reconstitution after cord blood (CB)-HSCT leads to even higher HCMV-related morbidity and mortality. Towards a feasible dendritic cell therapy to accelerate de novo immunity against HCMV, we validated a tricistronic integrase-defective lentiviral vector (coexpressing GM-CSF, IFN-α, and HCMV pp65 antigen) capable to directly induce self-differentiation of PB and CB monocytes into dendritic cells processing pp65 ("SmyleDCpp65"). In vitro, SmyleDCpp65 resisted HCMV infection, activated CD4(+) and CD8(+) T cells and expanded functional pp65-specific memory cytotoxic T lymphocytes (CTLs). CD34(+) cells obtained from PB and CB were transplanted into irradiated NOD.Rag1(-/-).IL2γc(-/-) mice. Donor-derived SmyleDCpp65 administration after PB-HSCT stimulated peripheral immune effects: lymph node remodeling, expansion of polyclonal effector memory CD8(+) T cells in blood, spleen and bone marrow, and pp65-reactive CTL and IgG responses. SmyleDCpp65 administration after CB-HSCT significantly stimulated thymopoiesis. Expanded frequencies of CD4(+)/CD8(+) T cell precursors containing increased levels of T-cell receptor excision circles in thymus correlated with peripheral expansion of effector memory CTL responses against pp65. The comparative in vivo modeling for PB and CB-HSCT provided dynamic and spatial information regarding human T and B cell reconstitution. In vivo potency supports future clinical development of SmyleDCpp65.
    • Engineered trivalent immunogen adjuvanted with a STING agonist confers protection against Trypanosoma cruzi infection.

      Sanchez Alberti, Andrés; Bivona, Augusto E; Cerny, Natacha; Schulze, Kai; Weißmann, Sebastian; Ebensen, Thomas; Morales, Celina; Padilla, Angel M; Cazorla, Silvia I; Tarleton, Rick L; et al. (2017)
      The parasite Trypanosoma cruzi is the causative agent of Chagas disease, a potentially life-threatening infection that represents a major health problem in Latin America. Several characteristics of this protozoan contribute to the lack of an effective vaccine, among them: its silent invasion mechanism, T. cruzi antigen redundancy and immunodominance without protection. Taking into account these issues, we engineered Traspain, a chimeric antigen tailored to present a multivalent display of domains from key parasitic molecules, combined with stimulation of the STING pathway by c-di-AMP as a novel prophylactic strategy. This formulation proved to be effective for the priming of functional humoral responses and pathogen-specific CD8+ and CD4+ T cells, compatible with a Th1/Th17 bias. Interestingly, vaccine effectiveness assessed across the course of infection, showed a reduction in parasite load and chronic inflammation in different proof of concept assays. In conclusion, this approach represents a promising tool against parasitic chronic infections.