Asashima, H. | bioRxiv Science

bioRxiv2022

Neutrophils regulate ITPR2 levels in epithelia by direct injection of elastase

The destructive role of neutrophils in inflammation is well known1 but they also have less damaging effects such as tissue remodeling and modulation of metabolism2, 3. Usually, neutrophils in tissues release toxic or digestive compounds into the extracellular region4-8. Here we report that neutrophils can inject their granule contents directly into hepatocytes. Neutrophil elastase within the hepatocytes selectively degrades the inositol trisphosphate receptor (ITPR), especially the type 2 isoform which is the predominant intracellular calcium release channel in these cells9. This action reduces calcium signals and cell proliferation without cellular damage. In response, the hepatocytes increase expression of serpins E2 and A3, which block the effect of elastase. This phenomenon is also observed in liver biopsies from patients with alcoholic hepatitis, a condition characterized by infiltration of neutrophils10, 11. This non-destructive and reversible effect on hepatocytes defines a previously unappreciated role of neutrophils in transiently regulating signaling mechanisms in epithelia.

cell biology↗

bioRxiv2022

Microfluidic immuno-serology assay revealed a limited diversity of protection against COVID-19 in patients with altered immunity

The immune response to SARS-CoV-2 for patients with altered immunity such as hematologic malignancies and autoimmune disease may differ substantially from that in general population. These patients remain at high risk despite wide-spread adoption of vaccination. It is critical to examine the differences at the systems level between the general population and the patients with altered immunity in terms of immunologic and serological responses to COVID-19 infection and vaccination. Here, we developed a novel microfluidic chip for high-plex immuno-serological assay to simultaneously measure up to 50 plasma or serum samples for up to 50 soluble markers including 35 plasma proteins, 11 anti-spike/RBD IgG antibodies spanning all major variants, and controls. Our assay demonstrated the quintuplicate test in a single run with high throughput, low sample volume input, high reproducibility and high accuracy. It was applied to the measurement of 1,012 blood samples including in-depth analysis of sera from 127 patients and 21 healthy donors over multiple time points, either with acute COVID infection or vaccination. The protein association matrix analysis revealed distinct immune mediator protein modules that exhibited a reduced degree of diversity in protein-protein cooperation in patients with hematologic malignancies and patients with autoimmune disorders receiving B cell depletion therapy. Serological analysis identified that COVID infected patients with hematologic malignancies display impaired anti-RBD antibody response despite high level of anti-spike IgG, which could be associated with limited clonotype diversity and functional deficiency in B cells and was further confirmed by single-cell BCR and transcriptome sequencing. These findings underscore the importance to individualize immunization strategy for these high-risk patients and provide an informative tool to monitor their responses at the systems level.

bioengineering↗

bioRxiv2022

Spatial-CITE-seq: spatially resolved high-plex protein and whole transcriptome co-mapping

We present spatial-CITE-seq for high-plex protein and whole transcriptome co-mapping, which was firstly demonstrated for profiling 189 proteins and transcriptome in multiple mouse tissue types. It was then applied to human tissues to measure 273 proteins and transcriptome that revealed spatially distinct germinal center reaction in tonsil and early immune activation in skin at the COVID-19 mRNA vaccine injection site. Spatial-CITE-seq may find a range of applications in biomedical research.

genomics↗