Ex vivo purification and characterization of human invariant Natural Killer T cells

Characterization and function of circulating mucosal-associated invariant T cells and γδT cells in oral lichen planus

BACKGROUND

Oral lichen planus (OLP) is a T-cell-mediated chronic inflammatory disease with uncertain aetiology. Mucosal-associated invariant T (MAIT) cells and γδT cells are unconventional, innate-like T cells with immunoregulatory capacity. This study aimed to investigate the potential effects of MAIT and γδT cells on the pathogenesis of OLP.

METHODS

Circulating MAIT cells and γδT cells were identified using flow cytometry. Surface proteins including CD4, CD8, CD69, CD103, CD49d, programmed death-1 (PD-1) and its ligand PD-L1 were assessed. Cytokines containing interleukin (IL)-4, IL-17, interferon (IFN)-γ, granzyme B and tumour necrosis factor (TNF)-α released by MAIT and γδT cells were measured following PMA and ionomycin stimulation.

RESULTS

Circulating MAIT and γδT cells were deficient in OLP. The percentage of CD4⁺ , CD69⁺ , CD103⁺ and PD-1⁺ MAIT cells was increased in OLP, while that of CD8⁺ and CD49d⁺ MAIT cells was decreased. The percentage of CD103⁺ , PD-1⁺ and PD-L1⁺ γδT cells was upregulated in OLP. Both the MAIT and γδT cells in OLP produced less IL-4 than controls. The granzyme B-producing MAIT cells were increased, while γδT cells secreting granzyme B and TNF-α were reduced in OLP. IL-17 and IFN-γ in OLP MAIT and γδT cells were not significantly different from that in controls. The frequency of OLP MAIT cells and the MAIT/γδT rate were positively associated with the disease severity.

CONCLUSION

The deficient MAIT and γδT cells expressing functional proteins and releasing cytokines may play an immunoregulatory role in the pathogenesis of OLP.

Hepatocellular cancer-derived alpha fetoprotein uptake reduces CD1 molecules on monocyte-derived dendritic cells

Alpha fetoprotein (AFP) is produced by over 50% of hepatocellular carcinomas (HCC). Uptake of tumor-derived AFP (tAFP) can impair activity of human dendritic cells (DC). The expression pattern of the lipid antigen presenting genes from the CD1 family is reduced in AFP-treated monocyte-derived DC. Surface CD1 family proteins, particularly CD1d, were reduced in AFP-exposed DC (by both normal cord blood-derived AFP (nAFP) and tAFP). NKT cells recognize lipid antigens presented by CD1d molecules. They play an important role in connecting the innate and adaptive immune systems, and in anti-tumor immunity. We hypothesized that AFP might impair the ability of DC to stimulate natural killer T (NKT) cells. No significant impact of AFP was observed on NKT cell stimulation. By examining secreted cytokines, we observed non-significant AFP-induced changes in several secreted proteins. These data indicate that AFP downregulates CD1 molecules on DC, but the impact on NKT cell activations is minimal.

Subpopulations of natural killer-T-like cells before and after surgical treatment of laryngeal cancer

Introduction

Tumours connected with head and neck comprise about 5% of all tumours. The most frequent histological type of laryngeal carcinoma is squamous cell carcinoma. Different research projects suggest that the role of T lymphocytes might be significant in tumour development. iNKT cells are a new subpopulation of T cells and show cytotoxic activity against tumours. iNKT cells participate in modulating the function of other cells which have anti-tumour properties and secrete cytokines, which have pro-inflammatory and anti-inflammatory effects. In animal models the significance of iNKT cells in various diseases including cancer was shown.

Aim of the study

The aim of this study was to determine the percentages of iNKT cells, CD161+ cells, CD161– cells, iNKT CD4+ cells, and iNKT CD8+ cells, NK cells, NKT-like cells, and T cells subsets present in peripheral blood of patients with laryngeal cancer before and two months after the tumour resection, in comparison to healthy volunteers.

Materials and methods

This study included material from laryngeal patients who were treated at the Department of Otolaryngology and Laryngological Oncology (Medical University of Lublin) between 2012 and 2013. A total of 50 patients (40 men and 10 women) aged between 45 and 77 years (median age: 60 years) were enrolled. Based on the TNM classification, the patients were classified as having stage I-IV laryngeal cancer. The control group was composed of 15 healthy volunteers (12 men and three women) aged between 43 and 82 years (median age: 61 years). The protocol of the study was approved by the Local Bioethical Committee at the Medical University of Lublin.

Peripheral blood samples (15 ml) from the basilic vein were collected by venipuncture using sterile, sodium heparin-treated tubes (20 units per ml of blood) and used for cytometric analyses.

Results

iNKT cells were analysed among T CD3+ cells. The percentage of CD3+ and CD3+CD4+ T cells before tumour resection was higher than in the control group, but the increase of CD3+ T cells was not significant. The T CD3+CD4+ / T CD3+CD8+ cell ratio was significantly higher than in healthy donors. After tumour resection a decreased percentage of CD3+CD4+ T cells but an increased percentage of CD8+CD3+T cells was noted. The T CD3+CD4+ / T CD3+CD8+ cell ratio was significantly higher in patients before and after the surgery than in the control group. The amount of NKT-like cells increased after resection and was significantly higher than in the control group.

Conclusions

Our study exhibited the change in percentage of iNKT, NK, NKT-like cells, and T lymphocytes after tumour resection in patients with laryngeal cancer. The research explains the contribution of those cells in immunological response against tumour.

An Immunological Perspective on Neonatal Sepsis

Despite concerted international efforts, mortality from neonatal infections remains unacceptably high in some areas of the world, particularly for premature infants. Recent developments in flow cytometry and next-generation sequencing technologies have led to major discoveries over the past few years, providing a more integrated understanding of the developing human immune system in the context of its microbial environment. We review these recent findings, focusing on how in human newborns incomplete maturation of the immune system before a full term of gestation impacts on their vulnerability to infection. We also discuss some of the clinical implications of this research in guiding the design of more-accurate age-adapted diagnostic and preventive strategies for neonatal sepsis.

Severely depressed interleukin-17 production by human neonatal mononuclear cells

BACKGROUND

The role of T-helper 17 cells (Th17) in neonatal host defense remains to be fully elucidated. Interleukin (IL)-17 plays an important role in the immune response to bacterial and fungal pathogens by promoting inflammation.

METHODS

We examined neonatal production of IL-17 in mixed mononuclear cells (MMCs) isolated from umbilical cord blood for comparison with adult peripheral blood mononuclear cell controls.

RESULTS

IL-17 production was profoundly diminished in MMCs isolated from cord blood when compared with MMCs from adult blood. This was associated with a marked reduction in the population of CCR6+ IL-17(+) T-cells in the neonatal cord blood. We also found diminished intracellular formation of IL-17, and diminished IL-17 responses to both group B streptococci (GBS) and Escherichia coli. Neonatal mononuclear cells were found to adequately phosphorylate signal transducer and activator of transcription 3, pY705, and pS727. We and others have reported markedly reduced interferon-γ production by neonate mononuclear cells exposed to GBS. Here, we correct that profound abnormality with added IL-17.

CONCLUSION

Our results suggest that profound deficiency of IL-17 production associated with a marked decrease in Th17 cells likely contributes significantly to the increased susceptibility of human neonates to invasive bacterial and fungal infections.

The role of type 2 innate lymphoid cells in asthma

Asthma is a complex and heterogeneous disease with several phenotypes, including an allergic asthma phenotype, characterized by Th2 cytokine production and associated with allergen sensitization and adaptive immunity. Asthma also includes nonallergic asthma phenotypes that require innate rather than adaptive immunity. These innate pathways to asthma involve macrophages, neutrophils, as well as ILCs, newly described cell types that produce a variety of cytokines, including IL-5 and IL-13. We review the recent data regarding ILCs and their role in asthma.

Type 2 innate lymphoid cells: friends or foes-role in airway allergic inflammation and asthma

Innate-like lymphocytes (ILLs) and innate lymphoid cells (ILCs) are two newly characterized families of lymphocytes with limited and no rearranged antigen receptors, respectively. These soldiers provide a first line of defense against foreign insults by triggering a prompt innate immune response and bridging the gap of innate and adaptive immunity. Type 2 innate lymphoid cells (ILCs2) are newly identified members of the ILC family that play a key role in type 2 immune responses by prompt production of type 2 cytokines (especially IL-5 and IL-13) in response to antigen-induced IL-25/33 and by recruiting type 2 “immune franchise.” Regarding the two different roles of type 2 cytokines, helminth expulsion and type 2-related diseases, here we review the latest advances in ILC2 biology and examine the pivotal role of resident ILCs2 in allergen-specific airway inflammation and asthma.