ABSTRACT Objectives To evaluate serum IgG responses against Porphyromonas gingivalis gingipains RgpB and Kgp in patients with stage III and IV periodontitis and examine associations with clinical periodontal parameters. Materials and Methods This exploratory cross‐sectional study included participants with advanced periodontitis (Stage III and IV). Clinical periodontal parameters (number of teeth, bleeding on probing in percent [BoP%], probing pocket depth [PPD], bone loss‐to‐age ratio, periodontal inflamed surface area [PISA] per tooth) were recorded. Blood samples were collected and serum IgG responses against recombinant RgpB and Kgp were analyzed. Serum IgG signals were quantified using enzyme‐linked immunosorbent assay (ELISA). Results All 42 participants (mean age 62 years) exhibited measurable serum IgG responses against P. gingivalis gingipains. IgG signals (optical density) ranged from 0.13 to 1.46 for RgpB and 0.34 to 1.51 for Kgp. RgpB‐specific IgG levels were higher in Stage IV versus Stage III periodontitis (p = 0.023), whereas Kgp‐specific IgG levels showed no significant difference between stages (p = 0.249). Anti‐RgpB IgG levels correlated positively with age (ρ = 0.362, p = 0.019) and inversely with the number of teeth (ρ = −0.372, p = 0.015), whereas anti‐Kgp IgG showed no statistically significant correlations with the assessed clinical parameters. Conclusions Serum IgG binding signals to RgpB and Kgp were measurable by ELISA and showed substantial heterogeneity among patients with advanced periodontitis, with considerable overlap between disease stages. Anti‐RgpB IgG was associated with age and tooth loss, whereas inflammatory measures showed no significant correlations and anti‐Kgp IgG showed only weak trend‐level associations. Overall, total gingipain‐specific IgG appears to reflect cumulative periodontal disease burden and exposure history more clearly than current inflammatory activity in this cohort, with limited value as a standalone marker for differentiating Stage III and Stage IV periodontitis.

Our understanding of the immune response in tuberculosis (TB) remains incomplete. This applies in particular to extrapulmonary TB (EPTB), a highly heterogeneous disease affecting up to 30% of patients in certain regions. Based on data-driven clustering of blood transcriptomes in an EPTB patient cohort, we define three highly distinct immunotypes. Combining bulk with single-cell RNA-sequencing delineates immunological trajectories characterized by dynamic IFN- and IL-1-mediated signalling in monocytes, alongside hyperactivation of T and NK cells, ultimately resulting in extensive immune dysregulation. Integrative analysis of multi-omics data provides deep insights into different layers of the anti-tuberculous immune response and the identification of immunotypes enabling stratification strategies for personalized host-directed treatments. In addition, our comprehensive approach helps to develop an accurate diagnostic gene expression signature for both EPTB and pulmonary TB highlighting the translational potential of our data.

Immune memory plays a critical role in the development of durable antimicrobial immune responses. How precisely mRNA vaccines train innate immune cells to shape protective host defense mechanisms remains unknown. Here we show that SARS-CoV-2 mRNA vaccination significantly establishes histone H3 lysine 27 acetylation (H3K27ac) at promoters of human monocyte-derived macrophages, suggesting epigenetic memory. However, we found that two consecutive vaccinations were required for the persistence of H3K27ac, which matched with pro-inflammatory innate immune-associated transcriptional changes and antigen-mediated cytokine secretion. H3K27ac at promoter regions were preserved for six months and a single mRNA booster vaccine potently restored their levels and release of macrophage-derived cytokines. Interestingly, we found that H3K27ac at promoters is enriched for G-quadruplex DNA secondary structure-forming sequences in macrophage-derived nucleosome-depleted regions, linking epigenetic memory to nucleic acid structure. Collectively, these findings reveal that mRNA vaccines induce a highly dynamic and persistent training of innate immune cells enabling a sustained pro-inflammatory immune response.

Purpose Tuberculosis (TB) remains a leading cause of morbidity and mortality, with 1.3 million deaths in 2022. Extrapulmonary tuberculosis (EPTB) accounts for approximately 20% of all TB cases. We assessed the clinical presentation and challenges during the course of treatment in EPTB patients in a low-incidence setting. Methods We conducted a prospective cohort study involving 44 EPTB patients at the University Hospital of Cologne, Germany. Clinical data were collected before and during treatment. Results The cohort comprised 44 patients originating from 21 countries. Two or more invasive procedures were required for microbiological confirmation in 59% (26/44) of the cases. Sputum culture was positive in 18% (8/44) of patients, with 63% (5/8) showing no radiological signs of pulmonary involvement. The median therapy duration was ten months and increased with disease severity. Paradoxical reactions (PR) occurred in 31% (13/42) of the patients. A previously published clinical scoring system assessing EPTB treatment responses showed a favorable treatment outcome in only 68% (21/31) of the patients in this cohort. Conclusion EPTB exhibits highly variable disease severity and organ involvement. Treatment initiation is often delayed due to diagnostic challenges. Management is complicated by the frequent occurrence of PR, which can lead to treatment durations exceeding standard recommendations. Clinical scores for treatment response assessment may not be reliably applicable, highlighting the need for alternative biomarkers.

Extrapulmonary tuberculosis (EPTB) presents significant challenges in diagnosis and treatment and generally receives less attention than pulmonary tuberculosis (PTB). We conducted a retrospective analysis of tuberculosis (TB) patients reported to the public health department of Cologne from 2012 to 2022 focussing on EPTB, its epidemiology, diagnostic methods, and treatment protocols, within a major German city. A subgroup analysis of EPTB patients (2012–2019, n = 254) examined diagnostic accuracy, treatment regimens, and adherence. Of 1,003 notified TB diagnoses, 33

The novel coronavirus pandemic, whose first outbreak was reported in December 2019 in Wuhan, China (COVID-19), is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Tissue damage caused by the virus leads to a strong immune response and activation of antigen-presenting cells, which can elicit acute respiratory distress syndrome (ARDS) characterized by the rapid onset of widespread inflammation, the so-called cytokine storm. In many viral infections the recruitment of monocytes into the lung and their differentiation to dendritic cells (DCs) are seen as a response to the viral infection. DCs are critical players in the development of the acute lung inflammation that causes ARDS. Here we focus on the interaction of the ORF8 protein, a specific SARS-CoV-2 open reading frame protein, with dendritic cells (DCs). We show that ORF8 binds to dendritic cells, causes a pre-maturation of differentiating DCs, and induces the secretion of multiple pro-inflammatory cytokines by these cells. In addition, we identified dendritic cell-specific intercellular adhesion molecule-3-grabbing non-integrin (DC-SIGN) as a possible interaction partner of ORF8 on dendritic cells. Blockade of ORF8 signaling leads to reduced production of IL-1β, IL-6, IL-12p70, TNF-α, MCP-1 (CCL2), and IL-10 by dendritic cells. Analysis of patient sera with high anti-ORF8 antibody titers showed that there was nearly no neutralization of the ORF8 protein and its function. Therefore, a neutralizing antibody that has the capacity of blocking the cytokine and chemokine response mediated by ORF8 protein might be an essential and novel additional step in the therapy of severe SARS-CoV-2 cases.

Monoclonal antibodies (mAbs) targeting bacterial virulence factors may represent promising therapeutics in the fight against severe bacterial infections. Here, we present an approach for developing human-derived antibodies targeting the type III secretion system (T3SS) of Pseudomonas aeruginosa (PA) by neutralizing the function of the T3SS-tip protein PcrV. The protocol involves identifying individuals with protective antibodies, isolating PcrV-specific B cells from these individuals, and producing and testing anti-PcrV mAbs derived from single B cells.For complete details on the use and execution of this protocol, please refer to Simonis et al.1

Dengue is an increasing threat to individuals living in or visiting endemic countries. Effective vaccines have become available, but their use in travelers is typically only recommended to individuals with documented prior infection. We present a fatal case of severe dengue in an unvaccinated traveler without known prior dengue virus infection but longitudinal serologic and molecular evidence for secondary infection. In the context of this case and vaccination guidance for travelers, we discuss pre-vaccination screening, potential implications for travelers to regions with ongoing outbreaks, and emphasize the importance of serostatus-independent vaccines.

Background:Symptoms lasting longer than 12  weeks after severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) infection are called post-coronavirus disease (COVID) syndrome (PCS). The identification of new biomarkers that predict the occurrence or course of PCS in terms of a post-viral syndrome is vital. T-cell dysfunction, cytokine imbalance, and impaired autoimmunity have been reported in PCS. Nevertheless, there is still a lack of conclusive information on the underlying mechanisms due to, among other things, a lack of controlled study designs.Methods:Here, we conducted a prospective, controlled study to characterize the humoral and cellular immune response in unvaccinated patients with and without PCS following SARS-CoV-2 infection over 7 months and unexposed donors.Results:Patients with PCS showed as early as 6 weeks and 7 months after symptom onset significantly increased frequencies of SARS-CoV-2-specific CD4+ and CD8+ T-cells secreting IFNγ, TNF, and expressing CD40L, as well as plasmacytoid dendritic cells (pDC) with an activated phenotype. Remarkably, the immunosuppressive counterparts type 1 regulatory T-cells (TR1: CD49b/LAG-3+) and IL-4 were more abundant in PCS+.Conclusion:This work describes immunological alterations between inflammation and immunosuppression in COVID-19 convalescents with and without PCS, which may provide potential directions for future epidemiological investigations and targeted treatments.

Drug-resistant Pseudomonas aeruginosa (PA) poses an emerging threat to human health with urgent need for alternative therapeutic approaches. Here, we deciphered the B cell and antibody response to the virulence-associated type III secretion system (T3SS) in a cohort of patients chronically infected with PA. Single-cell analytics revealed a diverse B cell receptor repertoire directed against the T3SS needle-tip protein PcrV, enabling the production of monoclonal antibodies (mAbs) abrogating T3SS-mediated cytotoxicity. Mechanistic studies involving cryoelectron microscopy identified a surface-exposed C-terminal PcrV epitope as the target of highly neutralizing mAbs with broad activity against drug-resistant PA isolates. These anti-PcrV mAbs were as effective as treatment with conventional antibiotics in vivo. Our study reveals that chronically infected patients represent a source of neutralizing antibodies, which can be exploited as therapeutics against PA.

Durable cell‐mediated immune responses require efficient innate immune signaling and the release of pro‐inflammatory cytokines. How precisely mRNA vaccines trigger innate immune cells for shaping antigen specific adaptive immunity remains unknown. Here, we show that SARS‐CoV‐2 mRNA vaccination primes human monocyte‐derived macrophages for activation of the NLRP3 inflammasome. Spike protein exposed macrophages undergo NLRP3‐driven pyroptotic cell death and subsequently secrete mature interleukin‐1β. These effects depend on activation of spleen tyrosine kinase (SYK) coupled to C‐type lectin receptors. Using autologous cocultures, we show that SYK and NLRP3 orchestrate macrophage‐driven activation of effector memory T cells. Furthermore, vaccination‐induced macrophage priming can be enhanced with repetitive antigen exposure providing a rationale for prime‐boost concepts to augment innate immune signaling in SARS‐CoV‐2 vaccination. Collectively, these findings identify SYK as a regulatory node capable of differentiating between primed and unprimed macrophages, which modulate spike protein‐specific T cell responses. Innate immune signalling in monocytes following SARS‐CoV‐2 mRNA vaccination is not well understood. This study reports that macrophages isolated from vaccinated individuals participating in a longitudinal study undergo NLRP3 inflammasome activation upon re‐exposure to the SARS‐CoV‐2 spike protein (S‐protein). Innate immune signalling in monocytes following SARS‐CoV‐2 mRNA vaccination is not well understood. This study reports that macrophages isolated from vaccinated individuals participating in a longitudinal study undergo NLRP3 inflammasome activation upon re‐exposure to the SARS‐CoV‐2 spike protein (S‐protein).

Metastatic small cell lung cancer (SCLC) is not curable. While SCLC is initially sensitive to chemotherapy, remissions are short-lived. The relapse is induced by chemotherapy-selected tumor stem cells, which express the AC133 epitope of the CD133 stem cell marker. We studied the effectiveness of AC133-specific CART cells post-chemotherapy using human primary SCLC and an orthotopic xenograft mouse model. AC133-specific CAR T cells migrated to SCLC tumor lesions, reduced the tumor burden, and prolonged survival in a humanized orthotopic SCLC model, but were not able to entirely eliminate tumors. We identified CD73 and PD-L1 as immune-escape mechanisms and combined PD-1-inhibition and CD73-inhibition with CAR T cell treatment. This triple-immunotherapy induced cures in 25% of the mice, without signs of graft-versus-host disease or bone marrow failure. AC133(+) cancer stem cells and PD-L1(+)CD73(+) myeloid cells were detectable in primary human SCLC tissues, suggesting that patients may benefit from the triple-immunotherapy. We conclude that the combination of AC133-specific CAR T cells, anti-PD-1-antibody and CD73-inhibitor specifically eliminates chemo-resistant tumor stem cells, overcomes SCLC-mediated T cell inhibition, and might induce long-term complete remission in an otherwise incurable disease.

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of the Editor-in-Chief. Following the publication of the above article, the Editor was notified that an error occurred in which all images were published with incorrect versions. The Editor has taken the decision that the manuscript is no longer acceptable in its current form, nor with a corrigendum, as the extensive changes to the figures and publication would lead to ambiguity for our readers. We have therefore made the decision to retract this manuscript from Cancer Letters with the possibility of resubmission and republication of the manuscript in its corrected form after peer review.

Remdesivir, a drug with provisional approval for the treatment of COVID-19, is not recommended in patients with an estimated glomerular filtration rate ≤ 30 mL/min. Here we provide a first detailed pharmacokinetic assessment of remdesivir and its major metabolites in a patient with end stage renal disease on hemodialysis.

Innate immunity triggers responsible for viral control or hyperinflammation in COVID-19 are largely unknown. Here we show that the SARS-CoV-2 spike protein (S-protein) primes inflammasome formation and release of mature interleukin-1β (IL-1β) in macrophages derived from COVID-19 patients but not in macrophages from healthy SARS-CoV-2 naïve individuals. Furthermore, longitudinal analyses reveal robust S-protein-driven inflammasome activation in macrophages isolated from convalescent COVID-19 patients, which correlates with distinct epigenetic and gene expression signatures suggesting innate immune memory after recovery from COVID-19. Importantly, we show that S-protein-driven IL-1β secretion from patient-derived macrophages requires non-specific monocyte pre-activation in vivo to trigger NLRP3-inflammasome signaling. Our findings reveal that SARS-CoV-2 infection causes profound and long-lived reprogramming of macrophages resulting in augmented immunogenicity of the SARS-CoV-2 S-protein, a major vaccine antigen and potent driver of adaptive and innate immune signaling.

Key Points Human inv(16) AML cells express CSF-1R and are exposed to CSF-1 in vivo. Inhibition of CSF-1R signaling reduces viability of inv(16) AML cells in vitro and in therapeutic settings in humanized mice in vivo.

Infections with viral pathogens are widespread and can cause a variety of different diseases. In-depth knowledge about viral triggers initiating an immune response is necessary to decipher viral pathogenesis. Inflammasomes, as part of the innate immune system, can be activated by viral pathogens. However, viral structural components responsible for inflammasome activation remain largely unknown. Here we analyzed glycoproteins derived from SARS-CoV-1/2, HCMV and HCV, required for viral entry and fusion, as potential triggers of NLRP3 inflammasome activation and pyroptosis in THP-1 macrophages. All tested glycoproteins were able to potently induce NLRP3 inflammasome activation, indicated by ASC-SPECK formation and secretion of cleaved IL-1β. Lytic cell death via gasdermin D (GSDMD), pore formation, and pyroptosis are required for IL-1β release. As a hallmark of pyroptosis, we were able to detect cleavage of GSDMD and, correspondingly, cell death in THP-1 macrophages. CRISPR-Cas9 knockout of NLRP3 and GSDMD in THP-1 macrophages confirmed and strongly support the evidence that viral glycoproteins can act as innate immunity triggers. With our study, we decipher key mechanisms of viral pathogenesis by showing that viral glycoproteins potently induce innate immune responses. These insights could be beneficial in vaccine development and provide new impulses for the investigation of vaccine-induced innate immunity.

Acute myeloid leukemia (AML) initiating and sustaining cells maintain high cell-surface similarity with their cells-of-origin, i.e., hematopoietic stem and progenitor cells (HSPCs), and identification of truly distinguishing leukemia-private antigens has remained elusive to date. To nonetheless utilize surface antigen-directed immunotherapy in AML, we here propose targeting both, healthy and malignant human HSPC, by chimeric antigen receptor (CAR) T-cells with specificity against CD117, the cognate receptor for stem cell factor. This approach should spare most mature hematopoietic cells and would require CAR T termination followed by subsequent transplantation of healthy HSPCs to rescue hematopoiesis. We successfully generated anti-CD117 CAR T-cells from healthy donors and AML patients. Anti-CD117 CAR T-cells efficiently targeted healthy and leukemic CD117-positive cells in vitro. In mice xenografted with healthy human hematopoiesis, they eliminated CD117-expressing, but not CD117-negative human cells. Importantly, in mice xenografted with primary human CD117-positive AML, they eradicated disease in a therapeutic setting. Administration of ATG in combination with rituximab, which binds to the co-expressed CAR T-cell transduction/selection marker RQR8, led to CAR T-cell depletion. Thus, we here provide the first proof of concept for the generation and preclinical efficacy of CAR T-cells directed against CD117-expressing human hematopoietic cells.

Innate immunity triggers responsible for viral control or hyperinflammation in COVID- 19 are largely unknown. Here we show that the SARS-CoV-2 spike protein primes inflammasome activation and interleukin 1-beta (IL-1β) secretion in macrophages derived from COVID-19 patients but not in macrophages from healthy SARS-CoV-2 naïve controls. Chemical NLRP3 inhibition blocks spike protein-induced IL-1β secretion ex vivo . These findings can accelerate research on COVID-19 vaccine design and drug treatment.