Search

Mucopolysaccharidoses (MPSs) are rare inherited lysosomal storage diseases (LSDs) caused by deficient activity in one of the enzymes responsible for glycosaminoglycans lysosomal degradation. MPS II is caused by pathogenic mutations in the IDS gene, leading to deficient activity of the enzyme iduronate-2-sulfatase, which causes dermatan and heparan sulfate storage in the lysosomes. In MPS VI, there is dermatan sulfate lysosomal accumulation due to pathogenic mutations in the ARSB gene, leading to arylsulfatase B deficiency. Alterations in the immune system of MPS mouse models have already been described, but data concerning MPSs patients is still scarce. Herein, we study different leukocyte populations in MPS II and VI disease patients. MPS VI, but not MPS II patients, have a decrease percentage of natural killer (NK) cells and monocytes when compared with controls. No alterations were identified in the percentage of T, invariant NKT, and B cells in both groups of MPS disease patients. However, we discovered alterations in the naïve versus memory status of both helper and cytotoxic T cells in MPS VI disease patients compared to control group. Indeed, MPS VI disease patients have a higher frequency of naïve T cells and, consequently, lower memory T cell frequency than control subjects. Altogether, these results reveal MPS VI disease-specific alterations in some leukocyte populations, suggesting that the type of substrate accumulated and/or enzyme deficiency in the lysosome may have a particular effect on the normal cellular composition of the immune system. [ABSTRACT FROM AUTHOR]

Background: Influenza A virus (IAV) infection leads to significant morbidity and mortality. Biological sex influences the immune responses to IAV infection, resulting in higher mortality in women of reproductive age. Previous studies revealed increased activation of T and B cells in female mice after IAV infection, but extensive analysis of sex differences in both innate and adaptive immune cells over time is lacking. Invariant natural killer T (iNKT) cells are fast‐reacting forces and modulators of immune responses that are important to IAV immunity, but it is not known if the presence and function of iNKT cells differ between females and males. The aim of this study was to determine immunological mechanisms that contribute to the increased disease severity in female mice during IAV infection. Methods: Female and male mice were infected with mouse‐adapted IAV and monitored for weight loss and survival. Immune cell populations and cytokine expression in bronchoalveolar lavage fluid, lung, and mediastinal lymph node were determined at three time points after infection using flow cytometry and ELISA. Results: The results reveal increased severity and mortality in adult female mice compared to age‐matched males. Female mice show larger increases in innate and adaptive immune cell populations and cytokine production in lung compared to mock on Day 6 postinfection. On Day 9 postinfection, female mice express higher numbers of iNKT cells in lung and liver compared to males. Conclusions: This comprehensive analysis of immune cells and cytokines over time following IAV infection reveals increased leukocyte expansion and stronger proinflammatory cytokine responses in female mice during disease initiation. Furthermore, this is the first study to report a sex bias in iNKT cell populations after IAV infection. The data suggests that the process of recovery from IAV‐induced airway inflammation is associated with increased expansion of several different iNKT cell subpopulations in female mice. Highlights: Infection with influenza A virus (IAV) leads to increased weight loss and mortality in female mice.IAV infection induces increased leukocyte expansion and stronger proinflammatory cytokine responses in the lung of female mice compared to mock on Day 6 postinfection.IAV infection leads to a sex‐specific increase of invariant natural killer T (iNKT) cell populations in lung and liver of female mice on Day 9 postinfection.The association between weight gain and the sex‐specific increase in iNKT cells on Day 9 postinfection implicate a role for iNKT cells in the resolution of inflammation in female mice. [ABSTRACT FROM AUTHOR]

Mucopolysaccharidoses (MPSs) are rare inherited lysosomal storage diseases (LSDs) caused by deficient activity in one of the enzymes responsible for glycosaminoglycans lysosomal degradation. MPS II is caused by pathogenic mutations in the IDS gene, leading to deficient activity of the enzyme iduronate-2-sulfatase, which causes dermatan and heparan sulfate storage in the lysosomes. In MPS VI, there is dermatan sulfate lysosomal accumulation due to pathogenic mutations in the ARSB gene, leading to arylsulfatase B deficiency. Alterations in the immune system of MPS mouse models have already been described, but data concerning MPSs patients is still scarce. Herein, we study different leukocyte populations in MPS II and VI disease patients. MPS VI, but not MPS II patients, have a decrease percentage of natural killer (NK) cells and monocytes when compared with controls. No alterations were identified in the percentage of T, invariant NKT, and B cells in both groups of MPS disease patients. However, we discovered alterations in the naïve versus memory status of both helper and cytotoxic T cells in MPS VI disease patients compared to control group. Indeed, MPS VI disease patients have a higher frequency of naïve T cells and, consequently, lower memory T cell frequency than control subjects. Altogether, these results reveal MPS VI disease-specific alterations in some leukocyte populations, suggesting that the type of substrate accumulated and/or enzyme deficiency in the lysosome may have a particular effect on the normal cellular composition of the immune system.

Chimeric antigen receptor (CAR) T cell is a T lymphocyte-based immunotherapy, which achieves great successes in treating blood malignancies and provides new hope to cue advanced cancer patients. Invariant natural killer T (iNKT) cells are a kind of special T lymphocytes characterized by expressing invariant TCR of Vα24Vβ11 to recognize CD1d-presented glycolipid antigens, which bridge innate and adaptive immune responses. iNKT cells themselves show strong anti-tumor effect in tumor models via CD1d-mediated killing of CD1d-positive tumor cells and immunosuppressive TAMs and MDSCs, and are closely related to the prognosis of cancer patients. iNKT cells are not restricted to polymorphic human leukocyte antigen (HLA) and can prevent Graft versus Host Disease (GvHD), which makes it to be an ideal CAR vector for allogeneic therapy. Although CAR-iNKT was developed and verified by several different teams and attracts more and more attentions, many obstacles are still needed to be resolved before obtaining CAR-iNKT therapeutics. In this review, we summarized the current status of clinical application of iNKT cells and the latest achievements of CAR-iNKT cells, which provides new insight in CAR-iNKT development and usages.

Invariant natural killer T (iNKT) cells are integral components of immune responses during many chronic diseases, yet their surface phenotypes, subset distribution, and polyfunctional capacity in this environment are largely unknown. Therefore, using flow cytometry, we determined iNKT cell phenotypic and functional characteristics in subjects with chronic inflammatory disease sarcoidosis and matched controls. We found that sarcoidosis subjects displayed lower iNKT-cell frequencies, which correlated with lung fibrosis, C-reactive protein levels, and other measures of clinical disease. The CD4(-) CD8(-) (double negative, DN) iNKT-cell population was selectively lower in diseased individuals and the remaining DN iNKT cells exhibited higher frequencies of the activation markers CD69 and CD56. Functionally, both total IFN-γ(+) and the dual-functional IFN-γ(+) TNF-α(+) iNKT cells were decreased in sarcoidosis subjects and these functional defects correlated with total iNKT-cell circulating frequencies. As the loss of polyfunctionality can reflect functional exhaustion, we measured the surface antigens programmed death-1 receptor and CD57 and found that levels inversely correlated with dual-functional iNKT-cell percentages. These findings reveal that, similar to traditional T cells, iNKT cells may also undergo functional exhaustion, and that circulating iNKT-cell frequencies reflect these defects. Programmed death-1 receptor antagonists may therefore be attractive therapeutic candidates for sarcoidosis and other iNKT-cell-mediated chronic diseases.

Aspergillus fumigatus is the most common cause for invasive fungal infections, a disease associated with high mortality in immune-compromised patients. CD1d-restricted invariant natural killer T (iNKT) cells compose a small subset of T cells known to impact the immune response toward various infectious pathogens. To investigate the role of human iNKT cells during A. fumigatus infection, we studied their activation as determined by CD69 expression and cytokine production in response to distinct fungal morphotypes in the presence of different CD1d+ antigen presenting cells using flow cytometry and multiplex enzyme-linked immunosorbent assay (ELISA). Among CD1d+ subpopulations, CD1d+CD1c+ mDCs showed the highest potential to activate iNKT cells on a per cell basis. The presence of A. fumigatus decreased this effect of CD1d+CD1c+ mDCs on iNKT cells and led to reduced secretion of TNF-α, G-CSF and RANTES. Production of other Th1 and Th2 cytokines was not affected by the fungus, suggesting an immune-modulating function for human iNKT cells during A. fumigatus infection. [ABSTRACT FROM AUTHOR]

Dendritic cells (DCs) and invariant natural killer T (iNKT) cells play important roles in linking innate immunity and adaptive immunity. Mature DCs activated by Toll-like receptor (TLR) agonists directly activate iNKT cells and the iNKT ligand a-galactosylceramide (α-Galcer) can induce DC maturation, resulting in enhanced protective immune responses. In the present study, we aimed to boost anti-tumour immunity in a murine colon cancer model by synergizing DCs and iNKT cells using α-Galcerloaded tumour cells (tumour-Gal) and the TLR9 agonist cytosinephosphorothioate- guanine (CpG1826). The vaccine strategy was sufficient to inhibit growth of established tumours and prolonged survival of tumour-bearing mice. Importantly, the immunization induced an adaptive memory immune response as the survivors from primary tumour inoculations were resistant to a tumour rechallenge. Furthermore, injection of tumour-Gal with CpG1826 resulted in iNKT cell activation and DC maturation as defined by interferon (IFN)-γ secretion by iNKT, natural killer (NK) cells and interleukin (IL)-12 by DCs. Immunohistochemistry analysis revealed that cluster of differentiation (CD)4+ T-cells and CD8+ T-cells played important roles in anti-tumour immunity. Additionally, the vaccine redirected Th2 (T-helper cell type 2) responses toward Th1 (T-helper cell type 1) responses with increases in IL-2, IFN-γ expression and decreases in IL-4 and IL-5 expression after immunization with tumour-Gal with CpG1826. Taken together, our results demonstrated a novel vaccination by synergizing tumour-Gal and CpG1826 against murine colon cancer, which can be further developed as tumourspecific immunotherapy against human cancer. [ABSTRACT FROM AUTHOR]

Sarcoidosis is a multisystem granulomatous disorder characterized by marked T-cell expansion of T helper 1 (Th1) cells. The cause of T-cell overactivity is unknown. We hypothesized that interleukin-10 (IL-10) production by a yet undefined cell type might be defective, resulting in loss of regulation of T-cell activity. Focusing on IL-10-producing monocytes, we first showed that monocytes isolated from the peripheral blood of corticosteroid-naïve sarcoidosis patients ( n = 51) produced less IL-10 compared to controls, and were less able to suppress T-cell proliferation. In addition, monocytic IL-10 production correlated negatively with disease activity score. As invariant natural killer T (iNKT) cells are known to both interact with monocytes and be reduced in sarcoidosis patients, we then asked whether iNKT-specific defects might be responsible for this reduced IL-10 production. We found that greater numbers of circulating iNKT cells was associated with higher IL-10 production. Moreover, iNKT cells enhanced monocytic IL-10 production in vitro. Defective IL-10 production and T-cell suppression by sarcoidosis monocytes could be restored following their coculture with iNKT cells, in a CD1d- and cell contact-dependent process. We suggest that reduced iNKT-cell numbers in sarcoidosis may lead to impaired monocytic IL-10 production and unchecked T-cell expansion in sarcoidosis. These findings provide fresh insight into the mechanism of sarcoidosis disease, and interaction between iNKT cells and monocytes. [ABSTRACT FROM AUTHOR]

Interleukin-12 (IL-12) is a key cytokine involved in regulating the balance between TH1 and TH2 cells by promoting TH1 response. A reduced capacity to produce this cytokine could lead to aberrant TH2 development. On the same aspect significant impact of IL-12 on invariant natural killer T (iNKT) cells was reported. Therefore, we examined the serum levels of IL-12 and the absolute number of peripheral blood iNKT cells from 37 children with controlled asthma and 11 normal controls (age-matched) and correlating these two parameters with clinical asthma severity and Pulmonary function tests (PFTs). A significant decrease of serum levels of IL-12 and peripheral iNKT cells was found in total asthmatic cases compared with normal controls. This significant decrease of IL-12 levels was observed in severe asthmatic patients compared with mild and moderate cases. Serum levels of IL-12 and the numbers of peripheral iNKT cells were positively correlated with PFTs in both total asthmatic groups and in children with severe persistent asthma. Inverse correlation was found between serum level of IL-12 and different degrees of asthma. Whereas the numbers of peripheral blood iNKT cells showed no significant difference between clinical asthma severities. Impaired IL-12 production in asthmatic children beside decreasing the number of peripheral blood iNKT cells could be considered as a key component in asthma pathogenesis and hence their therapeutic manipulation may be of help in asthma management.

Invariant natural killer T (i NKT) cells are integral components of immune responses during many chronic diseases, yet their surface phenotypes, subset distribution, and polyfunctional capacity in this environment are largely unknown. Therefore, using flow cytometry, we determined i NKT cell phenotypic and functional characteristics in subjects with chronic inflammatory disease sarcoidosis and matched controls. We found that sarcoidosis subjects displayed lower i NKT-cell frequencies, which correlated with lung fibrosis, C-reactive protein levels, and other measures of clinical disease. The CD4− CD8− (double negative, DN) i NKT-cell population was selectively lower in diseased individuals and the remaining DN i NKT cells exhibited higher frequencies of the activation markers CD69 and CD56. Functionally, both total IFN-γ+ and the dual-functional IFN-γ+ TNF-α+ i NKT cells were decreased in sarcoidosis subjects and these functional defects correlated with total i NKT-cell circulating frequencies. As the loss of polyfunctionality can reflect functional exhaustion, we measured the surface antigens programmed death-1 receptor and CD57 and found that levels inversely correlated with dual-functional i NKT-cell percentages. These findings reveal that, similar to traditional T cells, i NKT cells may also undergo functional exhaustion, and that circulating i NKT-cell frequencies reflect these defects. Programmed death-1 receptor antagonists may therefore be attractive therapeutic candidates for sarcoidosis and other i NKT-cell-mediated chronic diseases. [ABSTRACT FROM AUTHOR]

Melioidosis is an infectious disease caused by Burkholderia pseudomallei. High interferon gamma (IFN-γ) levels in naive mice were reported to mediate protection against B. pseudomallei infection. Invariant natural killer T (iNKT) cells can produce and secrete several cytokines, including IFN-γ. When iNKT cell-knockout (KO) BALB/c mice were infected with B. pseudomallei, their survival time was significantly shorter than wild-type mice. Naive BALB/c mice pretreated intraperitoneally with α-galactosylceramide (α-GalCer), an iNKT cell activator, 24 h before infection demonstrated 62.5% survival at the early stage, with prolonged survival time compared to nonpretreated infected control mice (14 ± 1 days versus 6 ± 1 days, respectively). At 4 h after injection with α-GalCer, treated mice showed significantly higher levels of serum IFN-γ, interleukin-4 (IL-4), IL-10, and IL-12 than control mice. Interestingly, the IFN-γ levels in the α-GalCer-pretreated group were decreased at 4, 24, and 48 h after infection, while they were highly increased in the control group. At 24 h postinfection in the α-GalCer group, bacterial loads were significantly lower in blood (no growth and 1,780.00 ± 51.21, P  < 0.0001), spleens (no growth and 34,300 ± 1,106.04, P < 0.0001), and livers (1,550 ± 68.72 and 13,400 ± 1,066.67, P < 0.0001) than in the control group, but not in the lungs (15,300 ± 761.10 and 1,320 ± 41.63, P < 0.0001), and almost all were negative at 48 h postinfection. This study for the first time shows that early activation of iNKT cells by α-GalCer helps clearance of B. pseudomallei and prolongs mouse survival.

Abstract: Chronic mucocutaneous candidiasis (CMC) is a group of heterogeneous disorders characterised by primary selective susceptibility to chronic, recurrent Candida infections. The genetic defect of one subgroup of CMC patients have been identified as mutations of the autoimmune regulator (AIRE) gene. Recent data implicated the AIRE gene in iNKT cell development, raising the possibility that iNKT cells may be important in defending against Candida infections. In this study, we enumerated the circulating iNKT frequency in 22 CMC patients (9 with AIRE gene mutations) and 25 healthy controls. We also examined the effect of Candida stimulation on iNKT cells in vitro. Our data demonstrated that peripheral iNKT cell frequency is significantly reduced in CMC patients compared to healthy controls, regardless of their AIRE gene mutation status. Direct stimulation with heat-inactivated whole Candida did not induce iNKT cell proliferation. Furthermore, circulating iNKT cell frequencies in some healthy controls were comparable to CMC patients. These observations suggest that iNKT cell deficiency is part of the CMC disease phenotype irrespective of the presence of AIRE gene mutations but does not appear to confer susceptibility to chronic Candida infections. We postulate that the reduced circulating iNKT cell frequency in CMC is a consequence rather than a cause of chronic Candida infections. [ABSTRACT FROM AUTHOR]

Abstract: Invariant natural killer T (iNKT) cells have evolved to recognize CD1d-presented lipid antigens and are known to play important roles during infection with bacterial, viral, protozoan, and fungal pathogens. The limited antigen specificity and reactivity to self- and foreign antigens distinguish iNKT cells from MHC-restricted T cells and bear similarity to innate-like lymphocytes, such as NK cells, γδ T cells, MZB and B1-B cells. This review summarizes how direct recognition of microbial lipids or synergistic stimulation by self-lipids and pro-inflammatory cytokines results in activation of these innate-like iNKT cell during infection. iNKT cell activation in the absence of foreign antigen recognition is unique for cells bearing TCRs and underscores that not only the function but also the activation mechanism of iNKT cells is innate-like, and distinct from adaptive T cells. The different pathways of activation endow iNKT cells with the ability to respond rapidly to a wide variety of infectious agents and to contribute effectively to the early immune response during infection. [Copyright &y& Elsevier]

Interleukin-12 (IL-12) is a key cytokine involved in regulating the balance between TH1 and TH2 cells by promoting TH1 response. A reduced capacity to produce this cytokine could lead to aberrant TH2 development. On the same aspect significant impact of IL-12 on invariant natural killer T (iNKT) cells was reported. Therefore, we examined the serum levels of IL-12 and the absolute number of peripheral blood iNKT cells from 37 children with controlled asthma and 11 normal controls (age-matched) and correlating these two parameters with clinical asthma severity and Pulmonary function tests (PFTs). A significant decrease of serum levels of IL-12 and peripheral iNKT cells was found in total asthmatic cases compared with normal controls. This significant decrease of IL-12 levels was observed in severe asthmatic patients compared with mild and moderate cases. Serum levels of IL-12 and the numbers of peripheral iNKT cells were positively correlated with PFTs in both total asthmatic groups and in children with severe persistent asthma. Inverse correlation was found between serum level of IL-12 and different degrees of asthma. Whereas the numbers of peripheral blood iNKT cells showed no significant difference between clinical asthma severities. Impaired IL-12 production in asthmatic children beside decreasing the number of peripheral blood iNKT cells could be considered as a key component in asthma pathogenesis and hence their therapeutic manipulation may be of help in asthma management. [ABSTRACT FROM AUTHOR]

To track recent thymic emigrants (RTEs) or study T cell development in the thymus, intra-thymic injection of a cellular tag or precursor cells for various T cell lineages is often desired. However, the traditional surgical approach to expose the thymus for intra-thymic injection is time-consuming and can cause a high level of pain and stress to animals, which might disrupt immune homeostasis, potentially confounding the results. Here, we introduce an ultrasound guided intra-thymic injection procedure, which is non-surgical and minimally invasive to animals. This technique is relatively easy to learn and offers an efficient and accurate tool to track RTEs or perform intra-thymic transfer of various cell types to investigate their differentiation., Competing Interests: Competing interestsThe authors declare no competing financial interests., (Copyright © The Authors; exclusive licensee Bio-protocol LLC.)