Enriched CD45RA−CD62L+ central memory T and decreased CD3+CD56+ natural killer T lymphocyte subsets in the rectum of ulcerative colitis patients

Objectives To investigate the distinctive features of lymphocytes promoting inflammation in ulcerative colitis. Methods We performed flow cytometric analysis of peripheral blood mononuclear cells (PBMCs) and colorectal mucosa lymphocytes in ulcerative colitis patients ( n = 13) and control patients ( n = 5). Results CD62L+/CD3+CD4+ (35.7 ± 14.0% vs. 19.9 ± 6.4%) and CD62L+/CD3+CD4− cells (17.1 ± 17.4% vs. 2.4 ± 3.9%) were higher in the rectum of ulcerative colitis patients than in control patients. Subpopulation analysis revealed that CD45RA−CD62L+/CD3+CD4+, that is, central memory T cell fraction in CD4+ T cells, was significantly increased in the rectum of ulcerative colitis, compared to that in control patients (23.3 ± 10.5% vs. 8.2 ± 4.0%). Comparison of rectum and colon samples in ulcerative colitis patients indicated that CD56+/CD3+ was decreased in the rectum compared to that in the colon (11.3 ± 12.5% vs. 21.3 ± 16.5%). The ratio of CD56+/CD3+ was also decreased in the rectum of active ulcerative colitis patients compared to that in ulcerative colitis patients at the endoscopic remission stages (2.8 ± 1.7% vs. 18.5 ± 13.3%). Conclusion We demonstrated that CD62L+ T lymphocytes, particularly the CD45RA−CD62L+ T cell subset that represents central memory T cells, were increased in the rectum of patients with ulcerative colitis. In addition, the CD56+/CD3+ subset (natural killer T cells) was decreased in the rectum compared to that of less inflamed colonic mucosa. These results suggest that the enrichment of central memory T lymphocytes and the reduction of natural killer T cells in the gut mucosa are involved in the pathogenesis of ulcerative colitis.

Expansion of invariant natural killer T cells from systemic lupus erythematosus patients by alpha-Galactosylceramide and IL-15

CD1d-restricted invariant natural killer T cells (iNKT cells) may play an important role in the pathogenesis of systemic lupus erythematosus (SLE). Interleukin (IL)-15 is a pro-inflammatory cytokine which is over-expressed in SLE patients. In the present study, we investigated the iNKT cell expansion of mononuclear cells (MNCs) from SLE patients following 10 days’ culture with α-galactosylceramide (α-Galcer) and /or IL-15. We sought to determine the phenotypic and functional characteristics of the expanded iNKT cells compared to healthy controls and correlated with disease activity. We observed that 1. The percentages of Vα24+/Vβ11+ iNKT cells following 10-day incubation was lower in SLE groups compared to controls; 2. The percentages and absolute numbers of Vα24+/Vβ11+ iNKT cells were expanded by α-galactosylceramide (α-Galcer), and further enhanced with IL-15 in SLE patient, but the effect of IL-15 was much lower than controls; 3.IL-15 +α-Galcer expanded CD3+/CD56+ NKT-like cells from SLE patients, especially with active disease 4. The CD161+ Vα24+/Vβ11+ iNKT cells in SLE were more responsive to α-Galcer stimulation than the CD161- counterpart; 5. IL-15 decreased apoptosis of α-Galcer activated SLE iNKT cells; 6. IL-15 enhanced CD69, CD1d and CD11a expression on α-Galcer treated iNKT cells; 7. The IL-4 production of iNKT cells was decreased in SLE patients compared to controls; 8. IL-15 increased IFN-γ and IL-4 production of SLE iNKT cells; 8. IL-15 failed to augment the ability of iNKT cells to aid NK-mediated K562 cytolysis in SLE patients; 9. CD161 positivity, granzyme B and perforin expression of α-Galcer+IL-15 expanded iNKT cells correlated with C3 levels in SLE patients. Taken together, our results demonstrated numeric and functional deficiency of iNKT cells and their response to IL-15 in SLE patients. Our finding may provide insight for using adoptive iNKT cell therapy in autoimmune diseases.

Primary infection by E. multilocularis induces distinct patterns of crosstalk between hepatic regulatory T and natural killer T cells in mice

The larval stage of the helminthic cestode Echinococcus multilocularis can inflict tumor-like hepatic lesions that cause the parasitic disease alveolar echinococcosis in humans, with high mortality in untreated patients. Recently, opportunistic properties of the disease have been proposed based on the increased incidence in immunocompromised patients and mouse models, indicating that an appropriate adaptive immune response is required for the control of the disease. However, little is known about how the local hepatic immune responses modulate the infection with E. multilocularis. In a mouse model of oral infection that mimics the normal infection route in human patients, the adaptive immune response in the liver was assessed using single-cell RNA sequencing of isolated hepatic CD3+ T cells at different infection stages. We observed an early significant increase in regulatory T and natural killer T cells in parallel with an active downregulation of CD4+ and CD8+ T cells. Early interactions between regulatory T cells and natural killer T cells indicate a promotion of the formation of hepatic lesions and later contribute to suppression of the resolution of parasite-induced pathology. The obtained data provides a fresh insight on the adaptive immune responses and local regulatory pathways at different infection stages of E. multilocularis in mice.

The Immune System in Duchenne Muscular Dystrophy Pathogenesis

Growing evidence demonstrates the crosstalk between the immune system and the skeletal muscle in inflammatory muscle diseases and dystrophic conditions such as Duchenne Muscular Dystrophy (DMD), as well as during normal muscle regeneration. The rising of inflammation and the consequent activation of the immune system are hallmarks of DMD: several efforts identified the immune cells that invade skeletal muscle as CD4+ and CD8+ T cells, Tregs, macrophages, eosinophils and natural killer T cells. The severity of muscle injury and inflammation dictates the impairment of muscle regeneration and the successive replacement of myofibers with connective and adipose tissue. Since immune system activation was traditionally considered as a consequence of muscular wasting, we recently demonstrated a defect in central tolerance caused by thymus alteration and the presence of autoreactive T-lymphocytes in DMD. Although the study of innate and adaptive immune responses and their complex relationship in DMD attracted the interest of many researchers in the last years, the results are so far barely exhaustive and sometimes contradictory. In this review, we describe the most recent improvements in the knowledge of immune system involvement in DMD pathogenesis, leading to new opportunities from a clinical point-of-view.

The Total Synthesis of Proposed Immunoactive Glycolipids from S. Pneumoniae and a Re-evaluation of Their Immunological Activity

Invariant natural killer T cells (iNKT) are responsible for the production of pro-inflammatory cytokines which induce a systemic immune response. They are distinctive in possessing an invariant T-cell receptor that recognizes glycolipid antigens presented by the class I major histocompatibility complex-related protein CD1d, conserved across multiple mammalian species in a class of proteins well-renowned for their high degree of polymorphism. This receptor’s first identified antigen is the potent α-galactose ceramide, KRN7000, a glycosphingolipid isolated from bacteria that were found on a Japanese marine sponge. The corresponding terrestrial antigen remained unidentified until quite recently, when diacylglycerol-containing glycolipids, reported to activate iNKT cells, were isolated from Streptococcus pneumoniae. We report the total synthesis and immunological re-evaluation of these two glycolipids. The compounds are unable to meaningfully activate iNKT cells. Computational modelling shows that these ligands, while being capable of interacting with the CD1d receptor, create a different surface for the binary complex that makes formation of the ternary complex with the iNKT T-cell receptor difficult. Together these results suggest that the reported activity might have been due to an impurity in the original isolated sample and highlights the importance of taking care when reporting biological activity from isolated natural products.

Favorable function of Ectonucleoside triphosphate diphosphohydrolase 1 high expression in thyroid carcinoma

Background Ectonucleoside triphosphate diphosphohydrolase 1 (ENTPD1) has been proved to play a vital role in human cancers. Nevertheless, the exact role of ENTPD1 in thyroid carcinoma (THCA) remained unclear. This study aimed to evaluate its prognostic value and reveal the potential regulatory mechanism in THCA. Results (1) Higher expression of ENTPD1 was found in THCA tissue compared with normal tissue (all P < 0.05). ENTPD1 expression was associated with age, sub-type and clinical stage of THCA patients (all P < 0.05). Immunohistochemistry showed its higher expression in patients with early stage. (2) ENTPD1 high expression was associated with favorable overall survival of THCA patients (all P < 0.05), especially for male patients and those with advanced stage, B-cells and Natural killer T-cells decreased (all P < 0.05). (3) Pathway analysis indicated that ENTPD1 mainly participated in metabolic process and negatively regulated metabolism-related pathway such as butanoate metabolism, pyruvate metabolism and fatty acid metabolism ((all P < 0.05). (4) ENTPD1 appeared genetic alteration in THCA, and the main mutation type of ENTPD1 was missense substitution (15.89%). (5) A weak correlation between ENTPD1 expression and methylation was found (P < 0.001). Methylation of ENTPD1 in THCA was lower than in normal group (P < 0.001), but it did not correlate with any clinical phenotypes of THCA patients. Conclusions ENTPD1 was highly expressed in THCA, and ENTPD1 high expression contributed to the prognosis of THCA patients. The present study inferred that ENTPD1 might serve as a metabolism-related gene and play a critical role in THCA through regulating metabolic pathways.