CD69+NK cells contribute to the murine hepatitis virus strain 3-induced murine hepatitis

Extraction of Innate Immune Genes in Dairy Cattle and the Regulation of Their Expression in Early Embryos

As more and more of the available genomic data have been published, several databases have been developed for deciphering early mammalian embryogenesis; however, less research has been conducted on the regulation of the expression of natural immunity genes during early embryonic development in dairy cows. To this end, we explored the regulatory mechanism of innate immunity genes at the whole-genome level. Based on comparative genomics, 1473 innate immunity genes in cattle were obtained by collecting the latest reports on human innate immunity genes and updated bovine genome data for comparison, and a preliminary database of bovine innate immunity genes was constructed. In order to determine the regulatory mechanism of innate immune genes in dairy cattle early embryos, we conducted weighted co-expression network analysis of the innate immune genes at different developmental stages of dairy cattle early embryos. The results showed that specific module-related genes were significantly enriched in the MAPK signaling pathway. Protein-protein interaction (PPI) analysis showed gene interactions in each specific module, and 10 of the highest connectivity genes were chosen as potential hub genes. Finally, combined with the results for differential expressed genes (DEGs), ATF3, IL6, CD8A, CD69, CD86, HCK, ERBB3, LCK, ITGB2, LYN, and ERBB2 were identified as the key genes of innate immunity in dairy cattle early embryos. In conclusion, the bovine innate immunity gene set was determined and the co-expression network of innate immunity genes in the early embryonic stage of dairy cattle was constructed by comparing and analyzing the whole genome of bovines and humans. The findings in this study provide the basis for exploring the involvement and regulation of innate immune genes in the early embryonic development of dairy cattle.

C-C chemokine receptor 5 is essential for conventional NK cell trafficking and liver injury in a murine hepatitis virus-induced fulminant hepatic failure model

BACKGROUND

Previous studies have demonstrated that natural killer (NK) cells migrated into the liver from peripheral organs and exerted cytotoxic effects on hepatocytes in virus-induced liver failure.

AIM

This study aimed to investigate the potential therapeutic role of chemokine receptors in the migration of NK cells in a murine hepatitis  virus strain 3 (MHV-3)-induced fulminant hepatic failure (MHV-3-FHF) model and its mechanism.

RESULTS

By gene array analysis, chemokine (C-C motif) receptor 5 (CCR5) was found to have remarkably elevated expression levels in hepatic NK cells after MHV-3 infection. The number of hepatic CCR5+ conventional NK (cNK) cells increased and peaked at 48 h after MHV-3 infection, while the number of hepatic resident NK (rNK) cells steadily declined. Moreover, the expression of CCR5-related chemokines, including macrophage inflammatory protein (MIP)-1α, MIP-1β and regulated on activation, normal T-cell expressed and secreted (RANTES) was significantly upregulated in MHV-3-infected hepatocytes. In an in vitro Transwell migration assay, CCR5-blocked splenic cNK cells showed decreased migration towards MHV-3-infected hepatocytes, and inhibition of MIP-1β or RANTES but not MIP-1α decreased cNK cell migration. Moreover, CCR5 knockout (KO) mice displayed reduced infiltration of hepatic cNK cells after MHV-3 infection, accompanied by attenuated liver injury and improved mouse survival time. Adoptive transfer of cNK cells from wild-type mice into CCR5 KO mice resulted in the abundant accumulation of hepatic cNK cells and aggravated liver injury. Moreover, pharmacological inhibition of CCR5 by maraviroc reduced cNK cell infiltration in the liver and liver injury in the MHV-3-FHF model.

CONCLUSION

The CCR5-MIP-1β/RANTES axis played a critical role in the recruitment of cNK cells to the liver during MHV-3-induced liver injury. Targeted inhibition of CCR5 provides a therapeutic approach to ameliorate liver damage during virus-induced acute liver injury.

NK cells contribute to reovirus-induced IFN responses and loss of tolerance to dietary antigen

Celiac disease is an immune-mediated intestinal disorder that results from loss of oral tolerance (LOT) to dietary gluten. Reovirus elicits inflammatory Th1 cells and suppresses Treg responses to dietary antigen in a strain-dependent manner. Strain type 1 Lang (T1L) breaks oral tolerance, while strain type 3 Dearing reassortant virus (T3D-RV) does not. We discovered that intestinal infection by T1L in mice leads to the recruitment and activation of NK cells in mesenteric lymph nodes (MLNs) in a type I IFN-dependent manner. Once activated following infection, NK cells produce type II IFN and contribute to IFN-stimulated gene expression in the MLNs, which in turn induces inflammatory DC and T cell responses. Immune depletion of NK cells impairs T1L-induced LOT to newly introduced food antigen. These studies indicate that NK cells modulate the response to dietary antigen in the presence of a viral infection.

KIR- Ligand Interactions in Hypertensive Disorders in Pregnancy

Hypothesis

The activity of natural killer (NK) cells is considered an important factor for the tolerance of the fetus during pregnancy. The complications of pregnancy, such as hypertensive disorders (HDP), may be therefore associated with this immune compartment.

Methods

The current study included 41 pregnant women diagnosed with HDPs (Gestational Hypertension; GH or Preeclampsia; PE) and 21 healthy women. All the patients were under continuous obstetric care during the pregnancy and labour. The number of mother-child mismatches within killer immunoglobulin-like receptors (KIRs), their ligands [MM], and missing KIR ligands [MSLs] was assessed. KIRs and their ligands were assessed with Next Generation Sequencing (NGS) and Polymerase Chain Reaction Sequence-Specific Oligonucleotide (PCR-SSO) typing. The subsets of NK cells were assessed with multicolor flow cytometry and correlated to the number of MSLs.

Results

The number of MSLs was significantly higher in HDP patients when compared to healthy non-complicated pregnancy patients. Some MSLs, such as those with 2DS2 activating KIR, were present only in HDP patients. The percentage of CD56+CD16-CD94+ NK cells and CD56+CD16-CD279+ NK cells correlated with the number of MSLs with inhibiting KIRs only in healthy patients. In HDP patients, there was a correlation between the percentage of CD56-CD16+CD69+ NK cells and the number of MSLs with inhibiting and activating KIRs. As compared to the healthy group, the percentage of CD56+CD16-CD279+ NK cells and CD56-CD16+CD279+ NK cells were lower in HDP patients. HDP patients were also characterized by a higher percentage of CD56+CD16+perforin+ NK cells than their healthy counterparts.

Conclusions

Patients with HDP were characterized by a higher number of MSLs within the KIRs receptors. It seemed that the number of MSLs in the healthy group was balanced by various receptors, such as CD94 or inhibitory CD279, expressed on NK cells. Conversely, in HDP patients the number of MSLs was associated with the activation detected as the increased level of CD69+ NK cells.

Study of surface activation markers on CD3- CD16+ NK cells and their correlation with clinical manifestations in children with infectious mononucleosis

This study aimed to investigate the proportion of surface activation markers on natural killer (NK) cells in children with infectious mononucleosis (IM) and to explore its clinical relevance. A total of 17 children hospitalized with IM were included in this study as the experimental group. Meanwhile, healthy children matched for age and gender served as controls. First, we isolated peripheral blood mononuclear cells from children with IM and healthy children. Then, NK cell surface markers were stained with monoclonal antibodies and analyzed by flow cytometry. The results showed that the percentage of CD3^- CD16⁺ NK cells was higher in peripheral blood lymphocytes from children with IM than that from healthy children (t = -4.52, P < 0.05). And the expression of the surface activation markers CD69 and CD25 on CD3^- CD16⁺ NK cells was also higher in children with IM (t = -7.729, P < 0.05; t = -5.068, P < 0.05). There was a positive correlation between the percentage of CD3^- CD16⁺ NK cells in peripheral blood and the duration of fever in children with IM (r = 0.530, P < 0.05). Therefore, the proportion of NK cell subsets in children's peripheral blood changes in the acute phase of IM, suggesting that NK cells enhance their cytotoxicity and play a role in the control of infection in children with IM. Higher levels of CD3^- CD16⁺ NK cells and the association with disease progression suggest that these cells might be a useful index to help evaluate the disease course.

High-dimensional single cell mass cytometry analysis of the murine hematopoietic system reveals signatures induced by ageing and physiological pathogen challenges

BACKGROUND

Immune ageing is a result of repetitive microbial challenges along with cell intrinsic or systemic changes occurring during ageing. Mice under 'specific-pathogen-free' (SPF) conditions are frequently used to assess immune ageing in long-term experiments. However, physiological pathogenic challenges are reduced in SPF mice. The question arises to what extent murine experiments performed under SPF conditions are suited to analyze immune ageing in mice and serve as models for human immune ageing. Our previous comparisons of same aged mice with different microbial exposures, unambiguously identified distinct clusters of immune cells characteristic for numerous previous pathogen encounters in particular in pet shop mice.

RESULTS

We here performed single cell mass cytometry assessing splenic as secondary and bone marrow as primary lymphoid organ-derived leukocytes isolated from young versus aged SPF mice in order to delineate alterations of the murine hematopoietic system induced during ageing. We then compared immune clusters from young and aged SPF mice to pet shop mice in order to delineate alterations of the murine hematopoietic system induced by physiological pathogenic challenges and those caused by cell intrinsic or systemic changes during ageing. Notably, distinct immune signatures were similarly altered in both pet shop and aged SPF mice in comparison to young SPF mice, including increased frequencies of memory T lymphocytes, effector-cytokine producing T cells, plasma cells and mature NK cells. However, elevated frequencies of CD4⁺ T cells, total NK cells, granulocytes, pDCs, cDCs and decreased frequencies of naïve B cells were specifically identified only in pet shop mice. In aged SPF mice specifically the frequencies of splenic IgM⁺ plasma cells, CD8⁺ T cells and CD4⁺ CD25⁺ Treg were increased as compared to pet shop mice and young mice.

CONCLUSIONS

Our study dissects firstly how ageing impacts both innate and adaptive immune cells in primary and secondary lymphoid organs. Secondly, it partly distinguishes murine intrinsic immune ageing alterations from those induced by physiological pathogen challenges highlighting the importance of designing mouse models for their use in preclinical research including vaccines and immunotherapies.

Changes in cellular proliferation and plasma products are associated with liver failure

AIM

To study the differences in immune response and cytokine profile between acute liver failure and self-limited acute hepatitis.

METHODS

Forty-six patients with self-limited acute hepatitis (AH), sixteen patients with acute liver failure (ALF), and twenty-two healthy subjects were involved in this study. The inflammatory and anti-inflammatory products in plasma samples were quantified using commercial enzyme-linked immunoassays and quantitative real-time PCR. The cellular immune responses were measured by proliferation assay using flow cytometry. The groups were divided into viral- and non-viral-induced self-limited AH and ALF. Thus, we worked with five groups: Hepatitis A virus (HAV)-induced self-limited acute hepatitis (HAV-AH), HAV-induced ALF (HAV-ALF), non-viral-induced self-limited acute hepatitis (non-viral AH), non-viral-induced acute liver failure (non-viral ALF), and healthy subjects (HC). Comparisons among HAV and non-viral-induced AH and ALF were performed.

RESULTS

The levels of mitochondrial DNA (mtDNA) and the cytokines investigated [interleukin (IL)-6, IL-8, IL-10, interferon gamma, and tumor necrosis factor] were significantly increased in ALF patients, independently of etiology (P < 0.05). High plasma mtDNA and IL-10 were the best markers associated with ALF [mtDNA: OR = 320.5 (95%CI: 14.42-7123.33), P < 0.0001; and IL-10: OR = 18.8 (95%CI: 1.38-257.94), P = 0.028] and death [mtDNA: OR = 12.1 (95%CI: 2.57-57.07), P = 0.002; and IL-10: OR = 8.01 (95%CI: 1.26-50.97), P = 0.027]. In the cellular proliferation assay, NK^bright, NKT and regulatory T cells (TReg) predominated in virus-specific stimulation in HAV-induced ALF patients with an anergic behavior in the cellular response to mitotic stimulation. Therefore, in non-viral-induced ALF, anergic behavior of activated T cells was not observed after mitotic stimulation, as expected and as described by the literature.

CONCLUSION

mtDNA and IL-10 may be predictors of ALF and death. TReg cells are involved in immunological disturbance in HAV-induced ALF.