Single‐cell transcriptomics reveals distinct cell response between acute and chronic pulmonary infection of Pseudomonas aeruginosa

Abstract

Knowledge of the changes in the immune microenvironment during pulmonary bacterial acute and chronic infections is limited. The dissection of immune system may provide a basis for effective therapeutic strategies against bacterial infection. Here, we describe a single immune cell atlas of mouse lungs after acute and chronic Pseudomonas aeruginosa infection using single‐cell transcriptomics, multiplex immunohistochemistry, and flow cytometry. Our single‐cell transcriptomic analysis revealed large‐scale comprehensive changes in immune cell composition and high variation in cell–cell interactions after acute and chronic P. aeruginosa infection. Bacterial infection reprograms the genetic architecture of immune cell populations. We identified specific immune cell types, including Cxcl2+ B cells and interstitial macrophages, in response to acute and chronic infection, such as their proportions, distribution, and functional status. Importantly, the patterns of immune cell response are drastically different between acute and chronic infection models. The distinct molecular signatures highlight the importance of the highly dynamic cell–cell interaction process in different pathological conditions, which has not been completely revealed previously. These findings provide a comprehensive and unbiased immune cellular landscape for respiratory pathogenesis in mice, enabling further understanding of immunologic mechanisms in infection and inflammatory diseases.

Nanobody-targeted conditional antimicrobial therapeutics

“…Given the rapid influx of neutrophils at the site of infection, 18 we first evaluated VHH16, a nanobody that recognizes Ly6G/C, present primarily on monocytes and neutrophils. 21,22 The schematic of our POL-based targeted antimicrobial conjugate VHH16-(ABD) 2 -(EEG) 6 -S17-POL is shown in Figure 2A.…”

“…Ly6G/C, CD11b, ADAM10, and ADAM17) are enriched at the site of infection. [18][19][20] As model, we used Pseudomonas aeruginosa strain O1 (PAO1) to establish a pulmonary infection in mice. We hypothesized that active targeting via VHHs might enhance interaction between infectionlocalized proteases and the cleavable linker by a proximity effect and so increase activation of the conditional antimicrobial therapeutics (Figure 1C).…”

“…The conjugate with the TENtide linker S26 was activated as efficiently as the one with the S17 linker, suggesting a contribution of ADAM10 in the infected lungs (Figure 3B). Even though NE is abundant in the infected microenvironment 18 and the linker S17 can be cleaved by NE in vitro (Figure S6), the conjugate with a different NE-cleavable linker (S27), 27 which is insensitive to ADAM10 cleavage (Figure S4 and S6), was not efficiently activated in the infected lungs. This points to a modest contribution, if any, of NE to in vivo activation of the VHH16-based conditional therapeutics (Figure 3B).…”

Holding glycolysis in check though Alox15 activity is required for macrophage M2 commitment and function in tissue repair and anti-helminth immunity

“…Default parameters were utilized, except for employing 40 dimensions of input features and proceeding with a resolution of 2 for cluster analysis. Manual annotations were conducted by referencing markers from various published sources [70][71][72][73][74][75][76].…”

Applications of nanomaterials as treatments and diagnostic biosensors in microbial infections

“…However, there are still significant obstacles to overcome before nanomaterials can be fully developed for clinical use. 219 Nanomaterials may be cytotoxic to some extent. Some metals (Ag, CuO, etc.)…”