Interleukin-17 expression in the human placenta

Interleukin (IL)-17 is a proinflammatory cytokine with pleiotropic activities including inducing neovascularization and production of proangiogenic molecules. As pregnancy outcome depends on the balance of Th1-like/Th2-like cytokines and an increased blood supply to the fetoplacental unit, the expression of IL-17 mRNA and protein in human placental tissues was investigated. IL-17 mRNA was expressed by purified cytokeratin-positive term placental trophoblast cells, HLA-G+ extravillous trophoblast cells and placental macrophages (Hofbauer cells). IL-17 localized in both cyto- and syncytiotrophoblasts of normal term pregnancy, spontaneous miscarriage and in molar pregnancy. In spontaneous miscarriage and molar pregnancy extravillous trophoblast cells were consistently immunoreactive for IL-17. IL-17 expression in human placenta may play a key role in angiogenesis and/or immunoregulation in the establishment of pregnancy.

The effect of interleukin-17 on the proliferation and invasion of JEG-3 human choriocarcinoma cells

PROBLEM

As there has been a study in mice showing the expression of IL-17 by decidual cells and the status of IL-17 receptor expression in human pregnancy is not known, we hypothesized that IL-17 may regulate human trophoblast proliferation and invasion.

METHOD OF STUDY

JEG-3 cell line was used as a model for human trophoblast. Immunohistochemitry and reverse transcriptase polymerase chain reaction techniques were used to identify IL-17 receptor protein and mRNA, respectively. The effects of IL-17 on JEG-3 cell proliferation and invasion were tested using the BrdU incorporation and the Matrigel invasion assays, respectively.

RESULTS

IL-17 increased the invasive capacity of JEG-3 cells but had no effect on the proliferation and multinucleated formation of JEG-3 cells.

CONCLUSION

In this JEG-3 cell model of human trophoblast, the IL-17R and IL-17 may have a regulatory role in trophoblast invasion.

Placental Fas and Fas ligand expression in normal early, term and molar pregnancy

To clarify the Fas and Fas-ligand status of normal and molar trophoblast, the expression of Fas and FasL by placental trophoblast populations in partial and complete hydatidiform moles was compared with that in normal first trimester and term pregnancies using an avidin-biotin peroxidase technique on frozen and formalin-fixed paraffin-embedded placental tissues with both monoclonal and polyclonal antibodies. The TUNEL technique was used to detect apoptotic cells in the same tissues. The immunoreactivity for Fas and Fas-ligand was comparable with both monoclonal and polyclonal antibodies on frozen as well as paraffin-embedded sections. In normal early and molar pregnancy there was strong FasL expression by villous cytotrophoblast and syncytiotrophoblast. However, there were significant differences in FasL expression by trophoblast subpopulations in both early and term normal pregnancy and between the same trophoblast subpopulation at different gestations, with FasL staining generally being weaker at term. Strong FasL staining by cytotrophoblast cells in the distal parts of cell columns contrasted with unstained cytotrophoblast in the proximal part of columns. Distinct trophoblast subpopulations in partial hydatidiform mole also differentially expressed FasL with reduced FasL expression in proliferating syncytiotrophoblast. In contrast there was no differential FasL expression in complete hydatidiform mole, all trophoblast subpopulations strongly expressing FasL. Unlike the differential expression of FasL there were no differences in Fas expression by trophoblast populations in normal early or term placental tissues. Fas expression was reduced in villous cytotrophoblast at term. Differential expression of Fas by different trophoblast subpopulations was noted in partial and complete hydatidiform mole. In complete mole villous cytotrophoblast and syncytiotrophoblast stained strongly compared with proliferating trophoblast. Using TUNEL labelling apoptosis was rarely detected in placental trophoblast. Differential Fas and FasL expression by trophoblast subpopulations in normal and pathological pregnancy does not appear to be related to apoptosis of trophoblast.

Interleukin-17 increased progesterone secretion by JEG-3 human choriocarcinoma cells

PROBLEM

JEG-3 choriocarcinoma cell line has previously been reported to express a receptor for interleukin (IL)-17. The involvement of IL-17 in the production of progesterone and human chorionic gonadotropin by placental trophoblast has not been investigated.

METHOD OF STUDY

The present study investigated the in vitro effect of IL-17 on progesterone and human chorionic gonadotropin (hCG) secretion by JEG-3 cells. Both hormones were quantified using enzyme-linked immunosorbent assays.

RESULTS

The results showed that IL-17 significantly increased progesterone secretion at 6 (P < 0.001) and 24 (P < 0.01) hr, while this cytokine had no effect on hCG secretion.

CONCLUSION

Interleukin-17 may regulate the function of JEG-3 cells through increased progesterone secretion.

No evidence for apoptosis of decidual leucocytes in normal and molar pregnancy: implications for immune privilege

Complete hydatidiform moles are totally paternally derived and represent complete allografts that might be expected to provoke maternal immune rejection. Our previous and other studies have shown expression of Fas by increased numbers of activated decidual CD4(+) T cells in both complete and partial molar pregnancy as well as increased FasL(+) expression by molar trophoblasts compared with trophoblasts in normal pregnancies. As the Fas/FasL system represents a major apoptotic pathway that can play a role in immune privilege, the aim of this study was to investigate whether apoptosis of decidual immune cells, particularly T cells, could be responsible for maternal immune tolerance in molar pregnancy. Using terminal deoxynucleotidyl transferase (TdT)-mediated nick end-labelling (TUNEL), a significant increase in TUNEL(+) cells was demonstrated in decidua associated with partial (P = 0.0052) and complete (P = 0.0096) hydatidiform mole compared with normal early pregnancy. Co-labelling immunoperoxidase studies showed that the TUNEL(+) cells in both normal and molar pregnancies were not activated CD45RO(+) immune cells, CD3(+) T cells, CD56(+) uterine natural killer (NK) cells or CD14(+) CD68(+) macrophages. Double immunohistochemical labelling with antiactive caspase-3 and leucocyte markers confirmed the lack of leucocyte apoptosis. Double immunostaining with anticytokeratin to detect trophoblast and M30 CytoDeath, which detects a neoepitope of cytokeratin 18 revealed after caspase-mediated cleavage, revealed apoptotic extravillous trophoblast cells within decidual tissue. We conclude that there is no evidence that apoptosis of decidual leucocytes plays a role in maintaining maternal tolerance in either normal or molar pregnancy.

Protective effect of silk lutein on ultraviolet B-irradiated human keratinocytes

Carotenoids are efficient antioxidants that are of great importance for human health. Lutein and zeaxanthin are carotinoids present in high concentrations in the human retina which are involved in the photoprotection of the human eye. Lutein may also protect the skin from ultraviolet (UV)-induced damage. The present study investigated the protective effect of lutein extracted from yellow silk cocoons of Bombyx mori on human keratinocytes against UVB irradiation. A human keratinocyte cell line and primary human keratinocytes were used to investigate the UVB protection effects of silk lutein and plant lutein. Silk lutein showed no cytotoxicity to keratinocytes. Treatment with silk lutein prior to UVB irradiation enhanced cell viability and cell proliferation, and reduced cell apoptosis. The protective effects of silk lutein may be superior to those of plant lutein. Silk lutein may have a benefit for protection of keratinocytes against UVB-irradiation.

JEG-3 cell culture supernatants cause reduced interferon-gamma and interleukin-17 production in mixed-lymphocyte reactions

PROBLEM

Immunoregulatory effects of choriocarcinoma-derived factors on leukocytes have been documented. The present study was designed to investigate the effect of JEG-3 culture supernatants on interferon-gamma (IFN-gamma), interleukin-17 (IL-17) and IL-1beta production in the mixed lymphocyte reactions (MLRs).

METHOD OF STUDY

A human choriocarcinoma cell line JEG-3 was used to test the effects of its culture supernatants on the proliferation and cytokine production in the MLRs. The cell proliferation was assessed using the BrdU incorporation and the amounts of cytokines were measured using enzyme-linked immunosorbent assays.

RESULTS

The JEG-3 culture supernatants caused significantly reduced IFN-gamma and IL-17 production in the MLRs. However, the supernatants did not influence MLR production of IL-1beta.

CONCLUSION

IFN-gamma and IL-17 are mainly produced by activated T cells but IL-1beta is primarily produced by monocytes, thus suggesting that immunoregulatory factors of JEG-3 cells selectively inhibit cytokine production by activated T cells rather than that of the monocytes.

Comparative study of interleukin-1beta expression by peripheral blood mononuclear cells and purified monocytes experimentally infected with Burkholderia pseudomallei and Burkholderia thailandensis

Burkholderia pseudomallei is a causative agent of melioidosis. The present study investigated IL-1beta mRNA and protein expression by peripheral blood mononuclear cells and purified monocytes (n = 10) in response to infection with B. pseudomallei and B. thailandensis. Similarly increased IL-1beta mRNA and protein expression was found in both PBMC and purified monocytes stimulated with B. pseudomallei and B. thailandensis. Thus, this study suggests that IL-1beta response does not differ between infections with B. pseudomallei and its non-virulent counterpart and other mechanisms may be involved in their distinct virulence in causing the disease.

Reduced interleukin-17 expression of Burkholderia pseudomallei-infected peripheral blood mononuclear cells of diabetic patients

Burkholderia pseudomallei is the causative agent of melioidosis. One of the main risk factors for B. pseudomallei infection in endemic areas is diabetes mellitus. The present study investigated IL-17 mRNA and protein expression by peripheral blood mononuclear cells in response to B. pseudomallei infection in 10 diabetic patients in comparison to 10 healthy blood donors. The IL-17 expression in diabetic patients was significantly lower (p < 0.05) than in the controls. However, IL-23 mRNA expression of the 2 groups was comparable. The present findings suggest that melioidosis affects T cell IL-17 production and that patients with diabetes mellitus have a defective IL-17 production in response to this type of infection.

Immunopeptidomics in the cancer immunotherapy era

Cancer is the primary cause of death worldwide, and conventional treatments are painful, complicated, and have negative effects on healthy cells. However, cancer immunotherapy has emerged as a promising alternative. Principle of cancer immunotherapy is the re-activation of T-cell to combat the tumor that presents the peptide antigen on major histocompatibility complex (MHC). Those peptide antigens are identified with the set of omics technology, proteomics, genomics, and bioinformatics, which referred to immunopeptidomics. Indeed, immunopeptidomics can identify the neoantigens that are very useful for cancer immunotherapies. This review explored the use of immunopeptidomics for various immunotherapies, i.e., peptide-based vaccines, immune checkpoint inhibitors, oncolytic viruses, and chimeric antigen receptor T-cell. We also discussed how the diversity of neoantigens allows for the discovery of novel antigenic peptides while post-translationally modified peptides diversify the overall peptides binding to MHC or so-called MHC ligandome. The development of immunopeptidomics is keeping up-to-date and very active, particularly for clinical application. Immunopeptidomics is expected to be fast, accurate and reliable for the application for cancer immunotherapies.

Impaired interleukin-1beta expression by monocytes stimulated with Staphylococcus aureus in diabetes

Diabetic patients with poorly controlled blood glucose have frequent and persistent bacterial infections particularly those infecting the skin, such as Staphylococcus aureus and S. epidermidis. The function of phagocytes of diabetic patients is believed to be impaired due to hyperglycemia, leading to suboptimal immune response to clear acute infection. The present study investigated interleukin (IL)-1beta expression by diabetic patients' monocytes (n = 22) experimentally infected with S. aureus compared with that from healthy subjects (n = 30). In addition, the in vitro effect of hyperglycemia on IL-1beta expression by monocytes from normal subjects (n = 18) stimulated with S. aureus and S. epidermidis was investigated. Monocytes from diabetic patients, stimulated or not with S. aureus, express significantly lower levels of IL-1beta than those from healthy subjects. In vitro hyperglycemia did not affect IL-1beta expression by unstimulated monocytes. However, at the same levels of glucose normal monocytes stimulated with S. aureus produce significantly higher IL-1beta than those stimulated with S. epidermidis. These findings suggest that diabetic patients have abnormally lower IL-1beta expression and hyperglycemia is related to abnormal expression of IL-1beta by monocytes, which could lead to enhanced susceptibility to infection by the more virulent bacteria.