Helicobacter pylori (H. pylori) manipulates the host immune system to establish a persistent colonization, posing a serious threat to human health, but the mechanisms remain poorly understood. Here we integrate single-cell RNA sequencing and TCR profiling for analyzing 187,192 cells from 11 H. pylori-negative and 12 H. pylori-positive individuals to describe the human gastric ecosystem reprogrammed by H. pylori infection, as manifested by impaired antigen presentation and phagocytosis function. We further delineate a monocyte-to-C1QC+ macrophage differentiation trajectory driven by H. pylori infection, while T cell responses exhibit broad functional impairment and hyporesponsiveness with restricted clonal expansion capacity. We also identify an HLA-DRs- and CTLA4-expressing T cell population residing in H. pylori-inhabited stomach that potentially contribute to immune evasion. Together, our findings provide single-cell resolution information into the immunosuppressive microenvironment shaped by H. pylori infection, offering critical insights for developing novel therapeutic approaches to eliminate this globally prevalent pathogen.
© 2025. The Author(s).

Anti-sense oligonucleotides (ASOs) are modified synthetic single-stranded molecules with enhanced stability, activity, and bioavailability. They associate with RNA through sequence complementarity and can reduce or alter mRNA expression upon binding of splice site positions. To target RNA in the nucleus or cytoplasm, ASOs must cross membranes, a poorly understood process. We have performed an unbiased CRISPR/Cas9 knockout screen with a genetic splice reporter to identify genes that can increase or decrease ASOs activity, resulting in the most comprehensive catalog of ASOs-activity modifier genes. Distinct targets were uncovered, including AP1M1 and TBC1D23, linking ASOs activity to transport of cargo between the Golgi and endosomes. AP1M1 absence strongly increased ASO activity by delaying endosome-to-lysosome transport in vitro and in vivo . Prolonged ASOs residence time in the endosomal system may increase the likelihood of ASOs escape from this organelle before they reach lysosomes. This insight into AP1M1 role in ASOs trafficking suggests a way for enhancing the therapeutic efficacy of ASOs by manipulating the endolysosomal pathways.

The Bacillus Calmette-Guérin (BCG) vaccine, currently the sole authorized vaccine against tuberculosis (TB), demonstrates limited effectiveness in safeguarding adolescents and adults from active TB, even when administered as a booster with either BCG itself or heterologous vaccine candidates. To effectively control the persistent epidemic of adult TB, it is imperative to investigate the mechanisms responsible for the suboptimal efficacy of the BCG prime-boosting strategy against primary Mycobacterium tuberculosis (M.tb) infection.
C57BL/6J mice were immunized with the BCG vaccine either once or twice, followed by analysis of lung tissue to assess changes in cytokine levels. Additionally, varying intervals between vaccinations and detection times were examined to study IL-10 expression across different organs. IL-10-expressing cells in the lungs, spleen, and lymph nodes were analyzed through FACS and intracellular cytokine staining (ICS). BCG-revaccinated IL-10-/- mutant mice were compared with wild-type mice to evaluate antigen-specific IgG antibody and T cell responses. Protection against M.tb aerosol challenge was evaluated in BCG-revaccinated mice, either untreated or treated with anti-IL-10R monoclonal antibody.
IL-10 was significantly upregulated in the lungs of BCG-revaccinated mice shortly after the booster immunization. IL-10 expression peaked in the lungs 3-6 weeks post-revaccination and was also detected in lymph nodes and spleen as early as 2 weeks following the booster dose, regardless of the intervals between the prime and booster vaccinations. The primary sources of IL-10 in these tissues were identified as macrophages and dendritic cells. Blocking IL-10 signaling in BCG-revaccinated mice-either by using IL-10-/- mutant mice or administering anti-IL-10R monoclonal antibody increased levels of antigen-specific IFN-γ+ or IL-2+ CD4+ T cells, enhanced central and effector memory CD4+ T cell responses, and provided better protection against aerosol infection with 300 CFUs of M.tb.
Our findings are crucial for formulating effective immunization strategies related to the BCG vaccine and for developing efficacious adult TB vaccines.
© 2024. The Author(s).

Diverse post-translational modifications have been shown to play important roles in regulating protein function in eukaryotes. By contrast, the roles of post-translational modifications in bacteria are not so well understood, particularly as they relate to pathogenesis. Here, we demonstrate post-translational protein modification by covalent addition of lactate to lysine residues (lactylation) in the human pathogen Staphylococcus aureus. Lactylation is dependent on lactate concentration and specifically affects alpha-toxin, in which a single lactylated lysine is required for full activity and virulence in infection models. Given that lactate levels typically increase during infection, our results suggest that the pathogen can use protein lactylation as a mechanism to increase toxin-mediated virulence during infection.
© 2024. This is a U.S. Government work and not under copyright protection in the US; foreign copyright protection may apply.

Current therapies against pancreatic ductal adenocarcinoma (PDAC) have limited clinical benefits owing to tumor heterogeneity and their unique immunosuppressive microenvironments. The eukaryotic initiation factor (eIF) 4F complex is involved in regulating translation and various downstream carcinogenic signaling pathways. We report that eIF4G1, one of the subunits of eIF4F, is overexpressed in cancer cells and cancer-associated fibroblasts, and this correlates with poor prognosis in patients with PDAC. In PDAC mice, eIF4G1 inhibition limits tumor progression and prolongs overall survival, especially when combined with PD1/PDL1 antagonists and gemcitabine. Mechanistically, eIF4G1 inhibition hinders the production of cytokines and chemokines that promote fibrosis and inhibit cytotoxic T cell chemotaxis. Moreover, eIF4G1 inhibition impairs integrinβ1 protein translation and exerts tumor suppression effects through the FAK-ERK/AKT signaling pathway. These findings highlight the effects of eIF4G1 on tumor immune dependence and independence and identify eIF4G1 as a promising therapeutic target for PDAC.
Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.