Leupaxin Expression Is Dispensable for B Cell Immune Responses

PD1+CD4+ T cells promote receptor editing and suppress autoreactivity of CD19+CD21low B cells within the lower respiratory airways in adenovirus pneumonia

Human adenovirus (HAdV) pneumonia poses a major health burden for young children, however, factors that contribute to disease severity remain elusive. We analyzed immune cells from bronchoalveolar lavage (BAL) of children with HAdV pneumonia and found that CD19+CD21low B cells were significantly enriched in the BAL and were associated with increased autoantibody concentrations and disease severity. Myeloid cells, PD-1+CD4+ T helper cells and CD21low B cells formed tertiary lymphoid structures within the respiratory tracts. Myeloid cells promoted autoantibody production by expressing high amounts of B cell activating factor (BAFF). In contrast, PD-1+CD4+ T helper cells induced production of IgG1 and IgG3 antibodies but suppressed autoreactive IgGs by initiating B cell receptor editing. In summary, this study reveals cellular components involved in protective versus autoreactive immune pathways in the respiratory tract, and these findings provide potential therapeutic targets for severe HAdV lower respiratory tract infections.

Comparative Profiling of Milk Somatic Cells Proteomes Revealed Key Players in Mammary Immune Mechanisms During Mastitis in Tropical Sahiwal (Bos indicus) Cows

PURPOSE

Bovine mastitis poses a significant economic burden on the dairy industry worldwide. This pioneering proteomic study conducted a comparative profiling of milk somatic cell (SC) proteins contributing to mammary immune defense during subclinical and clinical mastitis (CM) in Sahiwal (Bos indicus) cows.

EXPERIMENTAL DESIGN

Based on California mastitis test (CMT) scores, milk SC counts, differential leukocyte counts (DLCs), and bacteriological culture results, quarter milk SC samples were categorized into healthy (H), subclinical mastitis (SCM), and CM groups. Comparative proteome profiling of milk SCs was done using a label-free liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) proteomic approach.

RESULTS

The identified upregulated proteins in mastitis groups such as Vanin 2, Thioredoxin reductase-like selenoprotein T, Ceramidase, Lymphocyte antigen 75, Misshapen-like kinase 1 (MINK1), Thrombospondin 1, Macrophage scavenger receptor 1, Leupaxin, and Lipoamide acyltransferase, involved in immune responses. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed immune functions and pathways like antigen processing, complement cascades, extracellular matrix receptor interaction, efferocytosis, leukocyte migration, chemokine, peroxisome proliferator-activated receptors (PPARs), and transforming growth factor (TGF)-beta signaling.

CONCLUSIONS AND CLINICAL RELEVANCE

These findings provide essential information on proteomic profiling in milk SCs and contribute valuable insights into immune-related proteins regulated during mastitis in dairy cows. Further, validated proteins (Vanin 2, MINK1, and Thrombospondin 1) offer potential inflammatory biomarkers for early mastitis detection in dairy cows.

Multiple reaction monitoring assays for large-scale quantitation of proteins from 20 mouse organs and tissues

Mouse is the mammalian model of choice to study human health and disease due to its size, ease of breeding and the natural occurrence of conditions mimicking human pathology. Here we design and validate multiple reaction monitoring mass spectrometry (MRM-MS) assays for quantitation of 2118 unique proteins in 20 murine tissues and organs. We provide open access to technical aspects of these assays to enable their implementation in other laboratories, and demonstrate their suitability for proteomic profiling in mice by measuring normal protein abundances in tissues from three mouse strains: C57BL/6NCrl, NOD/SCID, and BALB/cAnNCrl. Sex- and strain-specific differences in protein abundances are identified and described, and the measured values are freely accessible via our MouseQuaPro database: http://mousequapro.proteincentre.com . Together, this large library of quantitative MRM-MS assays established in mice and the measured baseline protein abundances represent an important resource for research involving mouse models.

Sec22b is a critical and nonredundant regulator of plasma cell maintenance

Despite the essential role of plasma cells in health and disease, the cellular mechanisms controlling their survival and secretory capacity are still poorly understood. Here, we identified the soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) Sec22b as a unique and critical regulator of plasma cell maintenance and function. In the absence of Sec22b, plasma cells were hardly detectable and serum antibody titers were dramatically reduced. Accordingly, Sec22b-deficient mice fail to mount a protective immune response. At the mechanistic level, we demonstrated that Sec22b contributes to efficient antibody secretion and is a central regulator of plasma cell maintenance through the regulation of their transcriptional identity and of the morphology of the endoplasmic reticulum and mitochondria. Altogether, our results unveil an essential and nonredundant role for Sec22b as a regulator of plasma cell fitness and of the humoral immune response.

A genome-wide screen for resilient responses in growing pigs

Background

There is a growing interest to decipher the genetic background of resilience and its possible improvement through selective breeding. The objective of the present study was to provide new insights into the genetic make-up of resilience in growing pigs by identifying genomic regions and candidate genes associated with resilience indicators. Commercial Duroc pigs were challenged with an attenuated Aujeszky vaccine at 12 weeks of age. Two resilience indicators were used: deviation from the expected body weight at 16 weeks of age given the growth curve of non-vaccinated pigs (∆BW) and the increase in acute-phase protein haptoglobin at four days post-vaccination (∆HP). Genome-wide association analyses were carried out on 445 pigs, using genotypes at 41,165 single nucleotide polymorphisms (SNPs) and single-marker and Bayesian multiple-marker regression approaches.

Results

Genomic regions on pig chromosomes 2, 8, 9, 11 (∆BW) and 8, 9, 13 (∆HP) were found to be associated with the resilience indicators and explained high proportions of their genetic variance. The genomic regions that were associated explained 27 and 5% of the genetic variance of ∆BW and ∆HP, respectively. These genomic regions harbour promising candidate genes that are involved in pathways related to immune response, response to stress, or signal transduction (CD6, PTGDR2, IKZF1, RNASEL and MYD88), and growth (GRB10 and LCORL).

Conclusions

Our study identified novel genomic regions that are associated with two resilience indicators (∆BW and ∆HP) in pigs. These associated genomic regions harbour potential candidate genes involved in immune response and growth pathways, which emphasise the strong relationship between resilience and immune response.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12711-022-00739-1.