Current Concepts in Natural Killer Cell Biology and Application to Drug Safety Assessments

Mass cytometry reveals atypical immune profile notably impaired maturation of memory CD4 T with Gb3-related CD27 expression in CD4 T cells in Fabry disease

Fabry disease (FD) is an X-linked disease characterized by an accumulation of glycosphingolipids, notably of globotriaosylceramide (Gb3) and globotriaosylsphingosine (lysoGb3) leading to renal failure, cardiomyopathy, and cerebral strokes. Inflammatory processes are involved in the pathophysiology. We investigated the immunological phenotype of peripheral blood mononuclear cells in Fabry patients depending on the clinical phenotype, treatment, Gb3, and lysoGb3 levels and the presence of anti-drug antibodies (ADA). Leucocytes from 41 male patients and 20 controls were analyzed with mass cytometry using both unsupervised and supervised algorithms. FD patients had an increased expression of CD27 and CD28 in memory CD45- and CD45 + CCR7-CD4 T cells (respectively p < 0.014 and p < 0.02). Percentage of CD45RA-CCR7-CD27 + CD28+ cells in CD4 T cells was correlated with plasma lysoGb3 (r = 0.60; p = 0.0036) and phenotype (p < 0.003). The correlation between Gb3 and CD27 in CD4 T cells almost reached significance (r = 0.33; p = 0.058). There was no immune profile associated with the presence of ADA. Treatment with agalsidase beta was associated with an increased proportion of Natural Killer cells. These findings provide valuable insights for understanding FD, linking Gb3 accumulation to inflammation, and proposing new prognostic biomarkers.

Association of Blood NK Cell Phenotype with the Severity of Liver Fibrosis in Patients with Chronic Viral Hepatitis C with Genotype 1 or 3

BACKGROUND

NK cells phenotype and functional state in different genotypes of chronic viral hepatitis C (CVHC), depending on liver fibrosis severity, have not been sufficiently studied, which limits the possibilities for the development of pathology therapy.

METHODS

The CVHC diagnosis was based on the EASL recommendations (2018). Clinical examination with liver elastometry was performed in 297 patients with genotype 1 and in 231 patients with genotype 3 CVHC. The blood NK cells phenotype was determined by flow cytometry in 74 individuals with genotype 1 and in 69 individuals with genotype 3 CVHC.

RESULTS

The frequency of METAVIR liver fibrosis stages F3-F4 was 32.5% in individuals with genotype 3, and 20.5% in individuals with genotype 1 CVHC (p = 0.003). In patients with both genotype 1 and genotype 3 CVHC, a decrease in the total number of blood NK cells, CD56brightCD16+ NK cells and an increase in the proportion of CD56dimCD16+ NK cells, CD94+ and CD38 + CD73+ NK cells were registered in patients with fibrosis stage F3-F4 by METAVIR in comparison with persons with METAVIR fibrosis stage F0-F1.

CONCLUSIONS

In patients with both genotype 1 and genotype 3 CVHC, an imbalance in the ratio between cytokine-producing and cytotoxic NK cells and an increase in the content of NK cells that express inhibitory molecules were determined in patients with severe liver fibrosis.

Acute toxicities of intravenous, intraperitoneal, or intratumoral injection of natural killer cells in human pancreatic adenocarcinoma-bearing mice: Randomized study

AIMS

To investigate the possible acute toxicities and pathological changes associated with intravenous, intraperitoneal, or intratumoral injection of natural killer (NK) cells in mice subcutaneously bearing human pancreatic adenocarcinoma (PaC).

METHODS

100 NPG tumor-bearing mice (50/sex) were engrafted subcutaneously with human PaC BXPC-3 cells 9 days before administration. They were randomly divided into 10 groups with 5 males and 5 females in each group. Mice in Group 1 were given sodium chloride intravenously as vehicle control, and mice in Groups 2-4 human peripheral blood-derived NK cells intravenously at doses of 2 × 107, 1 × 108, and 5 × 108 cells/kg, respectively; mice in Groups 5-7 were injected with NK cells intraperitoneally at doses of 2 × 107, 1 × 108, and 5 × 108 cells/kg, respectively, and mice in Groups 8-10 with NK cells intratumorally at doses of 4 × 103, 2 × 104, and 1 × 105 cells/mm3, respectively. Each group was given a single dose; the mice were observed clinically, and body weight, food intake, blood biochemistry, and tumor volume were measured. On Day 15, the mice were euthanized for gross anatomy and histopathology.

RESULTS

On planned euthanasia, in Groups 2-4 no gross or microscopic pathological changes related to cells injection were found; in Groups 5-7 mice of both sexes showed a decrease in extramedullary hematopoiesis of spleen, and at the dose of 5 × 108 cells/kg, mice of both sexes showed an increase in the composition of spleen white pulp cells. In Groups 8-10, mice of both sexes at doses of 4 × 103 and 1 × 105 cells/mm3 and female mice at the dose of 2 × 104 cells/mm3 showed a decrease in extramedullary hematopoiesis of spleen, and female mice at a dose of 4 × 103 cells/mm3 and mice of both sexes at doses of ≥ 2 × 104 cells/mm3 showed an increase in the composition of spleen white pulp cells; perivascular/peribronchiolar inflammatory cell infiltration in lung and bronchus was observed in mice of both sexes at doses of ≥ 2 × 104 cells/mm3, and inflammatory cell infiltration in liver was observed in mice of both sexes at a dose of 1 × 105 cells/mm3. No other abnormal changes with toxicological significance in clinical observation, body weight, food intake, or blood biochemistry were observed in each group.

CONCLUSIONS

In our study intravenous injection appears the safest way to give NK cells to human PaC-bearing mice. Using intraperitoneal or intratumoral administration, spleen, liver, and lung were the most often affected organs, albeit with mostly mild pathological changes.

Consensus on the Key Characteristics of Immunotoxic Agents as a Basis for Hazard Identification

BACKGROUND

Key characteristics (KCs), properties of agents or exposures that confer potential hazard, have been developed for carcinogens and other toxicant classes. KCs have been used in the systematic assessment of hazards and to identify assay and data gaps that limit screening and risk assessment. Many of the mechanisms through which pharmaceuticals and occupational or environmental agents modulate immune function are well recognized. Thus KCs could be identified for immunoactive substances and applied to improve hazard assessment of immunodulatory agents.

OBJECTIVES

The goal was to generate a consensus-based synthesis of scientific evidence describing the KCs of agents known to cause immunotoxicity and potential applications, such as assays to measure the KCs.

METHODS

A committee of 18 experts with diverse specialties identified 10 KCs of immunotoxic agents, namely, 1) covalently binds to proteins to form novel antigens, 2) affects antigen processing and presentation, 3) alters immune cell signaling, 4) alters immune cell proliferation, 5) modifies cellular differentiation, 6) alters immune cell-cell communication, 7) alters effector function of specific cell types, 8) alters immune cell trafficking, 9) alters cell death processes, and 10) breaks down immune tolerance. The group considered how these KCs could influence immune processes and contribute to hypersensitivity, inappropriate enhancement, immunosuppression, or autoimmunity.

DISCUSSION

KCs can be used to improve efforts to identify agents that cause immunotoxicity via one or more mechanisms, to develop better testing and biomarker approaches to evaluate immunotoxicity, and to enable a more comprehensive and mechanistic understanding of adverse effects of exposures on the immune system. https://doi.org/10.1289/EHP10800.

How I Manage Natural Killer Cell Deficiency

Natural killer (NK) cell deficiency (NKD) is a subset of primary immunodeficiency disorders (PID) in which an abnormality of NK cells represents a major immunological defect resulting in the patient’s clinical immunodeficiency. This is distinct from a much larger group of PIDs that include an NK cell abnormality as a minor component of the immunodeficiency. Patients with NKD most frequently have atypical consequences of herpesviral infections. There are now 6 genes that have been ascribed to causing NKD, some exclusively and others that also cause other known immunodeficiencies. This list has grown in recent years and as such the mechanistic and molecular clarity around what defines an NKD is an emerging and important field of research. Continued increased clarity will allow for more rational approaches to the patients themselves from a therapeutic standpoint. Having evaluated numerous individuals for NKD, I share my perspective on approaching the diagnosis and managing these patients.