Single-cell sequencing analysis and multiple machine-learning models revealed the cellular crosstalk of dendritic cells and identified FABP5 and KLRB1 as novel biomarkers for psoriasis.

Background: Psoriasis is an immune-mediated disorder influenced by environmental factors on a genetic basis. Despite advancements, challenges persist, including the diminishing efficacy of biologics and small-molecule targeted agents, alongside managing recurrence and psoriasis-related comorbidities. Unraveling the underlying pathogenesis and identifying valuable biomarkers remain pivotal for diagnosing and treating psoriasis. Methods: We employed a series of bioinformatics (including single-cell sequencing data analysis and machine learning techniques) and statistical methods to integrate and analyze multi-level data. We observed the cellular changes in psoriatic skin tissues, screened the key genes Fatty acid binding protein 5 (FABP5) and The killer cell lectin-like receptor B1 (KLRB1), evaluated the efficacy of six widely prescribed drugs on psoriasis treatment in modulating the dendritic cell-associated pathway, and assessed their overall efficacy. Finally, RT-qPCR, immunohistochemistry, and immunofluorescence assays were used to validate. Results: The regulatory influence of dendritic cells (DCs) on T cells through the CD70/CD27 signaling pathway may emerge as a significant facet of the inflammatory response in psoriasis. Notably, FABP5 and KLRB1 exhibited up-regulation and co-localization in psoriatic skin tissues and M5-induced HaCaT cells, serving as potential biomarkers influencing psoriasis development. Conclusion: Our study analyzed the impact of DC-T cell crosstalk in psoriasis, elucidated the characterization of two biomarkers, FABP5 and KLRB1, in psoriasis, and highlighted the promise and value of tofacitinib in psoriasis therapy targeting DCs.

KLRB1 defines an activated phenotype of CD4+ T cells and shows significant upregulation in patients with primary Sjögren's syndrome.

OBJECTIVE: This study aimed to investigate the role of KLRB1 (CD161) in human CD4+ T cells and elucidate its significance in primary Sjögren's syndrome (pSS). METHODS: Peripheral blood samples from 37 healthy controls and 44 pSS patients were collected. The publicly available single-cell RNA-Seq data from pSS patient PBMCs were utilized to analyse KLRB1 expression in T cells. KLRB1-expressing T lymphocyte subset proportions in pSS patients and healthy controls were determined by flow cytometry. CD25, Ki-67, cytokine secretion, and chemokine receptor expression in CD4+ KLRB1+ T cells were detected and compared with those in CD4+ KLRB1- T cells. Correlation analysis was conducted between KLRB1-related T-cell subsets and clinical indicators. ROC curves were generated to explore the diagnostic potential of KLRB1 for pSS. RESULTS: KLRB1 was significantly upregulated following T-cell activation, and Ki-67 and CD25 expression was significantly greater in CD4+ KLRB1+ T cells than in CD4+ KLRB1- T cells. KLRB1+ CD4+ T cells exhibited greater IL-17A, IL-21, IL-22, and IFN-γ secretion upon stimulation, and there were significantly greater proportions of CCR5+, CCR2+, CX3CR1+, CCR6+, and CXCR3+ cells among CD4+ KLRB1+ T cells than among CD4+ KLRB1- T cells. Compared with that in HCs, KLRB1 expression in CD4+ T cells was markedly elevated in pSS patients and significantly correlated with clinical disease indicators. CONCLUSION: KLRB1 is a characteristic molecule of the CD4+ T-cell activation phenotype. The increased expression of KLRB1 in the CD4+ T cells of pSS patients suggests its potential involvement in the pathogenesis of pSS and its utility as an auxiliary diagnostic marker for pSS.

Inhibition of NK1.1 signaling attenuates pressure overload-induced heart failure, and consequent pulmonary inflammation and remodeling.

Background: Inflammation contributes to heart failure (HF) development, the progression from left ventricular failure to pulmonary remodeling, and the consequent right ventricular hypertrophy and failure. NK1.1 plays a critical role in Natural killer (NK) and NK T (NKT) cells, but the role of NK1.1 in HF development and progression is unknown. Methods: We studied the effects of NK1.1 inhibition on transverse aortic constriction (TAC)-induced cardiopulmonary inflammation, HF development, and HF progression in immunocompetent male mice of C57BL/6J background. Results: We found that NK1.1+ cell-derived interferon gamma+ (IFN-γ+) was significantly increased in pulmonary tissues after HF. In addition, anti-NK1.1 antibodies simultaneously abolished both NK1.1+ cells, including the NK1.1+NK and NK1.1+NKT cells in peripheral blood, spleen, and lung tissues, but had no effect on cardiopulmonary structure and function under control conditions. However, systemic inhibition of NK1.1 signaling by anti-NK1.1 antibodies significantly rescued mice from TAC-induced left ventricular inflammation, fibrosis, and failure. Inhibition of NK1.1 signaling also significantly attenuated TAC-induced pulmonary leukocyte infiltration, fibrosis, vessel remodeling, and consequent right ventricular hypertrophy. Moreover, inhibition of NK1.1 signaling significantly reduced TAC-induced pulmonary macrophage and dendritic cell infiltration and activation. Conclusions: Our data suggest that inhibition of NK1.1 signaling is effective in attenuating systolic overload-induced cardiac fibrosis, dysfunction, and consequent pulmonary remodeling in immunocompetent mice through modulating the cardiopulmonary inflammatory response.

Expansion of mixed immune cells using CD3/CD161 co-stimulation for the treatment of cancer.

Adoptive cell transfer (ACT) is a type of personalized immunotherapy in which expanded immune cells are administered to patients with cancer. However, single-cell populations, such as killer T cells, dendritic cells, natural killer (NK) cells, and NKT (NKT) cells, have been generally used, and their effectiveness remains limited. Here, we established a novel culture method via CD3/CD161 co-stimulation and successfully expanded CD3+/CD4+ helper T cells, CD3+/CD8+ cytotoxic T cells (CTLs), CD3-/CD56+ NK cells, CD3+/CD1d+ NKT cells, CD3+/CD56+ NKT cells, CD3+/TCRγδ+ T cells, and CD3-/CD11c+/HLA-DR+ dendritic cells in peripheral blood mononuclear cells from healthy donors; their respective numbers were 155.5, 1132.5, 5.7, 117.0, 659.2, 325.6, and 6.8 times higher than those before expansion. These mixed immune cells showed strong cytotoxicity against cancer cell lines Capan-1 and SW480. Moreover, both CD3+/CD8+ CTLs and CD3+/CD56+ NKT cells killed tumor cells in cell contact-dependent and -independent manners via granzyme B and interferon-γ/TNF-α, respectively. Furthermore, the cytotoxicity of the mixed cells was significantly superior to that of CTLs or NKTs alone. A bet-hedging CTL-NKT circuitry is one potential mechanism underlying this cooperative cytotoxicity. Collectively, CD3/CD161 co-stimulation may be a promising culture method to expand multiple, distinct immune cell populations for the treatment of cancer.

Clr-f expression regulates kidney immune and metabolic homeostasis.

The C-type lectin-related protein, Clr-f, encoded by Clec2h in the mouse NK gene complex (NKC), is a member of a family of immune regulatory lectins that guide immune responses at distinct tissues of the body. Clr-f is highly expressed in the kidney; however, its activity in this organ is unknown. To assess the requirement for Clr-f in kidney health and function, we generated a Clr-f-deficient mouse (Clr-f-/-) by targeted deletions in the Clec2h gene. Mice lacking Clr-f exhibited glomerular and tubular lesions, immunoglobulin and C3 complement protein renal deposits, and significant abdominal and ectopic lipid accumulation. Whole kidney transcriptional profile analysis of Clr-f-/- mice at 7, 13, and 24 weeks of age revealed a dynamic dysregulation in lipid metabolic processes, stress responses, and inflammatory mediators. Examination of the immune contribution to the pathologies of Clr-f-/- mouse kidneys identified elevated IL-12 and IFNγ in cells of the tubulointerstitium, and an infiltrating population of neutrophils and T and B lymphocytes. The presence of these insults in a Rag1-/-Clr-f-/- background reveals that Clr-f-/- mice are susceptible to a T and B lymphocyte-independent renal pathogenesis. Our data reveal a role for Clr-f in the maintenance of kidney immune and metabolic homeostasis.

LLT1-CD161 Interaction in Cancer: Promises and Challenges.

The success of immune checkpoint therapy in cancer has changed our way of thinking, promoting the design of future cancer treatments that places the immune system at the center stage. The knowledge gained on immune regulation and tolerance helped the identification of promising new clinical immune targets. Among them, the lectin-like transcript 1 (LLT1) is the ligand of CD161 (NKR-P1A) receptor expressed on natural killer cells and T cells. LLT1/CD161 interaction modulates immune responses but the exact nature of the signals delivered is still partially resolved. Investigation on the role of LLT1/CD161 interaction has been hampered by the lack of functional homologues in animal models. Also, some studies have been misled by the use of non-specific reagents. Recent studies and meta-analyses of single cell data are bringing new insights into the function of LLT1 and CD161 in human pathology and notably in cancer. The advances made on the characterization of the tumor microenvironment prompt us to integrate LLT1/CD161 interaction into the equation. This review recapitulates the key findings on the expression profile of LLT1 and CD161, their regulation, the role of their interaction in cancer development, and the relevance of targeting LLT1/CD161 interaction.

CD161 expression and regulation defines rapidly responding effector CD4+ T cells associated with improved survival in HPV16-associated tumors.

BACKGROUND: Expression of killer cell lectin-like receptor B1 (KLRB1), the gene encoding the cell surface molecule CD161, is associated with favorable prognosis in many cancers. CD161 is expressed by several lymphocyte populations, but its role and regulation on tumor-specific CD4+ T cells is unknown. METHODS: We examined the clinical impact of CD4+CD161+ T cells in human papillomavirus (HPV)16+ oropharyngeal squamous cell carcinoma (OPSCC), analyzed their contribution in a cohort of therapeutically vaccinated patients and used HPV16-specific CD4+CD161+ tumor-infiltrating lymphocytes and T cell clones for in-depth mechanistic studies. RESULTS: Central and effector memory CD4+ T cells express CD161, but only CD4+CD161+ effector memory T cells (Tem) are associated with improved survival in OPSCC. Therapeutic vaccination activates and expands type 1 cytokine-producing CD4+CD161+ effector T cells. The expression of CD161 is dynamic and follows a pattern opposite of the checkpoint molecules PD1 and CD39. CD161 did not function as an immune checkpoint molecule as demonstrated using multiple experimental approaches using antibodies to block CD161 and gene editing to knockout CD161 expression. Single-cell transcriptomics revealed KLRB1 expression in many T cell clusters suggesting differences in their activation. Indeed, CD4+CD161+ effector cells specifically expressed the transcriptional transactivator SOX4, known to enhance T cell receptor (TCR) signaling via CD3ε. Consistent with this observation, CD4+CD161+ cells respond more vigorously to limiting amounts of cognate antigen in presence of interleukin (IL)-12 and IL-18 compared to their CD161- counterparts. The expression of CD161/KLRB1 and SOX4 was downregulated upon TCR stimulation and this effect was boosted by transforming growth factor (TGF)ß1. CONCLUSION: High levels of CD4+CD161+ Tem are associated with improved survival and our data show that CD161 is dynamically regulated by cell intrinsic and extrinsic factors. CD161 expressing CD4+ T cells rapidly respond to suboptimal antigen stimulation suggesting that CD161, similar to SOX4, is involved in the amplification of TCR signals in CD4+ T cells.

Reevaluation of NOD/SCID Mice as NK Cell-Deficient Models.

OBJECTIVE: Natural killer (NK) cell-deficient mice are useful models in biomedical research. NOD/SCID mice have been used as a model of this type in research. However, the actual status of NK cells in NOD/SCID mice and CB17/SCID mice in comparison with that in BALB/c mice has not been sufficiently evaluated. METHODS: Splenocytes from naïve or poly(I:C)-treated mice were isolated for phenotyping and analysis of cytotoxicity-related molecules and inhibitory receptors; for cytotoxicity assay, purified NK cells were also used. RESULTS: The proportion of splenic NK cells did not differ significantly between NOD/SCID and CB17/SCID mice. The perforin levels in NK cells were similar between the poly(I:C)-treated CB17/SCID and NOD/SCID mice, while the granzyme B and NKG2A/C/E levels in NK cells from NOD/SCID mice were significantly lower than those from CB17/SCID mice. Moreover, the NKG2D and Ly49A levels in NK cells from NOD/SCID mice were higher than those from CB17/SCID. The splenocytes from CB17/SCID mice showed higher cytotoxicity than those from NOD/SCID mice, while the cytotoxicity of purified NK cells basically did not differ between the two strains. After in vitro stimulation with cytokines, the splenocytes from CB17/SCID mice showed higher IFN-γ production than those from NOD/SCID mice; however, NK cells did not. CONCLUSION: There was no significant difference in the proportion of splenic NK cells between CB17/SCID and NOD/SCID mice, and the function of NK cells was only partially compromised in NOD/SCID mice. Caution should be taken when considering the use of NOD/SCID mice as an NK-deficient model.

A Pan-Cancer Analysis of CD161, a Potential New Immune Checkpoint.

Background: CD161, encoded by killer cell lectin-like receptor B1 gene, is a newly reported candidate inhibitor of tumour-infiltrating T cells. Antibody-mediated CD161 blockade enhances T cell-mediated killing of cancer cells in vitro and in vivo in several tumour types. We evaluated the role of CD161 using The Cancer Genome Atlas (TCGA) Pan-Cancer Data. Methods: CD161 expression was analysed using RNAseq data from TCGA and the Genotype-Tissue Expression (GTEx) database. HPA, GeneCards, and String database were used to explore the protein information of CD161. The prognostic value of CD161 was analysed using clinical survival data from the TCGA. Enrichment analysis of CD161 was conducted using the R package "clusterProfiler". We downloaded the immune cell infiltration score of TCGA samples from published articles and online databases and performed a correlation analysis between immune cell infiltration levels and CD161 expression. We further assessed the association between CD161 and immune checkpoints, immune activating genes, immunosuppressive genes, chemokines, and chemokine receptors. Findings: CD161 was differentially expressed and predicted better survival status in most tumour types in TCGA. In addition, CD161 expression was significantly associated with immunoregulatory interactions between lymphoid and non-lymphoid cells. CD161 expression was closely correlated with T cell infiltration, immune checkpoints, immune activating genes, immunosuppressive genes, chemokines, and chemokine receptors. Interpretation: Our results suggest that CD161 is a potential cancer biomarker. CD161 might synergize with other immune checkpoints to regulate the immune microenvironment, which could be applied in the development of new-targeted drugs for immunotherapy. Funding: This work was supported by the National Nature Science Foundation of China (grant numbers 81773008, 81672756, 81872399, 81972897), the Guangdong Province Universities and Colleges Pearl River Scholar Funded Scheme (2015), the Natural Science Foundation of Guangdong Province (grant number 2017A030311023), the Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program: 2017BT01S131 and the Guangzhou Technology Project (grant number 201804010044), National Key R&D Program of China (Grant Nos. 2020YFC2006400), Key-Area Research and Development Program of Guangdong Province (2019B020227004).

NK cells associate with ALS in a sex- and age-dependent manner.

NK cells are innate immune cells implicated in ALS; whether NK cells impact ALS in a sex- and age-specific manner was investigated. Herein, NK cells were depleted in male and female SOD1G93A ALS mice, survival and neuroinflammation were assessed, and data were stratified by sex. NK cell depletion extended survival in female but not male ALS mice with sex-specific effects on spinal cord microglia. In humans, NK cell numbers, NK cell subpopulations, and NK cell surface markers were examined in prospectively blood collected from subjects with ALS and control subjects; longitudinal changes in these metrics were correlated to revised ALS functional rating scale (ALSFRS-R) slope and stratified by sex and age. Expression of NK cell trafficking and cytotoxicity markers was elevated in subjects with ALS, and changes in CXCR3+ NK cells and 7 trafficking and cytotoxicity markers (CD11a, CD11b, CD38, CX3CR1, NKG2D, NKp30, NKp46) correlated with disease progression. Age affected the associations between ALSFRS-R and markers NKG2D and NKp46, whereas sex impacted the NKp30 association. Collectively, these findings suggest that NK cells contribute to ALS progression in a sex- and age-specific manner and demonstrate that age and sex are critical variables when designing and assessing ALS immunotherapy.

A CD4+CD161+ T-Cell Subset Present in Unexposed Humans, Not Tb Patients, Are Fast Acting Cells That Inhibit the Growth of Intracellular Mycobacteria Involving CD161 Pathway, Perforin, and IFN-γ/Autophagy.

It remains undefined whether a subset of CD4+ T cells can function as fast-acting cells to control Mycobacterium tuberculosis (Mtb) infection. Here we show that the primary CD4+CD161+ T-cell subset, not CD4+CD161-, in unexposed healthy humans fast acted as unconventional T cells capable of inhibiting intracellular Mtb and BCG growth upon exposure to infected autologous and allogeneic macrophages or lung epithelial A549 cells. Such inhibition coincided with the ability of primary CD4+CD161+ T cells to rapidly express/secrete anti-TB cytokines including IFN-γ, TNF-α, IL-17, and perforin upon exposure to Mtb. Mechanistically, blockades of CD161 pathway, perforin or IFN-γ by blocking mAbs abrogated the ability of CD4+CD161+ T cells to inhibit intracellular mycobacterial growth. Pre-treatment of infected macrophages with inhibitors of autophagy also blocked the CD4+CD161+ T cell-mediated growth inhibition of mycobacteria. Furthermore, adoptive transfer of human CD4+CD161+ T cells conferred protective immunity against mycobacterial infection in SCID mice. Surprisingly, CD4+CD161+ T cells in TB patients exhibited a loss or reduction of their capabilities to produce perforin/IFN-γ and to inhibit intracellular growth of mycobacteria in infected macrophages. These immune dysfunctions were consistent with PD1/Tim3 up-regulation on CD4+CD161+ T cells in active tuberculosis patients, and the blockade of PD1/Tim3 on this subset cells enhanced the inhibition of intracellular mycobacteria survival. Thus, these findings suggest that a fast-acting primary CD4+CD161+T-cell subset in unexposed humans employs the CD161 pathway, perforin, and IFN-γ/autophagy to inhibit the growth of intracellular mycobacteria, thereby distinguishing them from the slow adaptive responses of conventional CD4+ T cells. The presence of fast-acting CD4+CD161+ T-cell that inhibit mycobacterial growth in unexposed humans but not TB patients also implicates the role of these cells in protective immunity against initial Mtb infection.

CD161a-positive natural killer (NK) cells and α-smooth muscle actin-positive myofibroblasts were upregulated by extrarenal DPP4 in a rat model of acute renal rejection.

AIMS: Systemic inhibition of dipeptidyl peptidase 4 (DPP4) showed a protective effect in several transplant models. Here we assessed the specific role of extrarenal DPP4 in renal transplant rejection. METHODS: Kidneys from wildtype (wt) F344 rats were either transplanted in wt Dark Agouti or congenic rats not expressing DPP4. The remaining, not transplanted donor kidney served as healthy controls. To investigate early inflammatory events rats were sacrificed 3 days after transplantation and kidneys were evaluated for inflammatory cells, capillary rarefaction, proliferation, apoptosis and myofibroblasts by immunohistochemistry. RESULTS: Capillary ERG-1-positive endothelial cells were significantly more abundant in renal cortex when transplanted into DPP4 deficient compared to wt recipients. In contrast, TGF-ß and myofibroblasts were reduced by more than 25% in kidneys transplanted into DPP4 deficient compared to wt recipients. Numbers of CD161a-positive NK-cells were significantly lower in allografts in DPP4 deficient compared to wt recipients. Numbers of all other investigated immune cells were not affected by the lack of extrarenal DPP4. CONCLUSION: In early transplant rejection extrarenal DPP4 is involved in the recruitment of NK-cells and early fibrosis. Beneficial effects were less pronounced than reported for systemic DPP4 inhibition, indicating that renal DPP4 is an important player in transplantation-mediated injury.

Immunobiology and conflicting roles of the human CD161 receptor in T cells.

Human C-type lectin-like CD161 is a type-II transmembrane protein expressed on the surface of various lymphocytes across innate and adaptive immune systems. CD161+ T cells displayed enhanced ability to produce cytokines and were shown to be enriched in the gut. Independently of function, CD161 was used as marker of innate-like T cells and marker of IL-17-producing cells. The function of CD161 is still not fully understood. In T cells, CD161 was proposed to act as co-signalling receptor that influence T-cell receptor-dependent responses. However, conflicting studies were published demonstrating lack of agreement over the role of CD161 during T-cell activation. In this review, we outline phenotypical and functional consequences of CD161 expression in T cells. We provide critical discussion over the most pressing issues including in depth evaluation of the literature concerning CD161 putative co-signalling properties.

C-type lectin-like CD161 is not a co-signalling receptor in gluten-reactive CD4 + T cells.

C-type lectin-like CD161, a class II transmembrane protein, is a surface receptor expressed by NK cells and T cells. In coeliac disease, CD161 was expressed more frequently on gluten-reactive CD4 + T cells compared to other memory CD4 + T cells isolated from the same tissue compartment. CD161 is a putative co-signalling molecule that was proposed to act as co-stimulatory receptor in the context of signalling through TCR, but contradicting results were published. In order to understand the role of CD161 in gluten-reactive CD4 + T cells, we combined T cell stimulation assays or T cell proliferation assays with ligation of CD161 and intracellular cytokine staining. We found that CD161 ligation provided neither co-stimulatory nor co-inhibitory signals to modulate proliferation and IFN-γ or IL-21 production by gluten-reactive CD4 + T cell clones. Thus, we suggest that CD161 does not function as a co-signalling receptor in the context of gluten-reactive CD4 + T cells.

Longitudinal Analysis of Peripheral and Colonic CD161+ CD4+ T Cell Dysfunction in Acute HIV-1 Infection and Effects of Early Treatment Initiation.

CD161 expression on CD4+ T cells is associated with a Th17 functional phenotype, as well as with an innate capacity to respond to interleukin (IL)-12 and IL-18 without T cell receptor (TCR) stimulation. Chronic HIV-1 infection is associated with loss of the CD161+ CD4 T cell population, and non-human primate studies suggest that their depletion is associated with disease progression. However, the dynamics of the CD161+ CD4+ T cell population during acute HIV-1 infection remains unknown. In this study, we characterize peripheral blood CD161+ CD4+ T cells in detail, and examine how they are affected during the earliest stages of HIV-1 infection. Unbiased surface proteome screening and principal component analysis indicated that CD161+ CD4+ T cells are relatively phenotypically homogeneous between donors, and are intermediates between conventional CD4 T cells and innate-like T cells. In acute untreated HIV-1 infection, the circulating CD161+ CD4+ T cell population decreased in frequency, as did absolute cell counts starting from peak viral load, with elevated levels of activation and exhaustion markers expressed throughout acute HIV-1 infection. The capacity of these cells to respond to stimulation with IL-12 and IL-18 was also reduced. Early initiation of anti-retroviral treatment (ART) during acute HIV-1 infection restored the functionality of peripheral blood CD161+ CD4+ T cells, but not their frequency. In contrast, early ART initiation prevented the decline of colonic CD161+ CD4+ T cells that otherwise started during acute infection. Furthermore, loss of peripheral and colonic CD161+ CD4+ T cells in untreated infection was associated with levels of viral load. These results suggest that acute HIV-1 infection has profound effects on the CD161+ CD4+ T cell population that could not be completely prevented by the initiation of ART.

An association of iNKT+/CD3+/CD161+ lymphocytes in ovarian cancer tissue with CA125 serum concentration.

The purpose of this study was to investigate the association of iNKT (human invariant natural killer T) cells with the key marker of ovarian cancer (OC) - CA125 (cancer antigen125) in serum. The study reports the assessment of iNKT cells in peripheral blood and tissue of benign and borderline ovarian tumors (BOTs) and in the advanced-stage ovarian cancer. The study groups were as follows: 25 women with benign ovarian tumors, 11 women with BOTs, and 24 women with primary advanced-stage ovarian cancers. The control group consisted of 20 patients without the ovarian pathology. The rates of iNKT lymphocytes in the peripheral blood and tissue specimens were evaluated by a flow cytometry. Significant differences in the percentage of iNKT+/CD3+ of CD3+ lymphocytes, iNKT+/CD3+/CD161+ among CD3+ and iNKT+/CD3+/CD161+ among CD3+/iNKT+ between the control group and patients with ovarian tumors in the peripheral blood and tumor tissue were identified. Significant correlations were noticed between the proportion of lymphocytes iNKT+/CD3+/CD161+ among CD3+/iNKT cells in blood and in cancer tissue of both benign and malignant tumors. In the OC group, neither the ratio of iNKT cells in the blood (P = 0.07), nor the intra-tumor NKT-cell infiltration (P = 0.5) were independent prognostic factors for the follow-up. An increased rate of iNKT cells was detected in benign ovarian tumors compared to OCs. In patients with ovarian cancer, a higher rate of iNKT cells in tumor tissue was present related to that noted in the patient's blood. In addition, a correlation was discovered between the CA125 serum marker and NKT cells from the ovarian cancer tissue. This article has for the first time demonstrated a negative relationship between serum levels and NKT lymphocyte count from ovarian tissue. The inflammatory process in ovarian cancer tissue and the potential infiltration of endothelial immune cells, may result in a reduced number of NKT cells in the tumor microenvironment and increased circulation of the CA125 marker. Presented findings underscore new aspects of the iNKT cells involvement in the ovarian cancer development.

Depletion of NK Cells Improves Cognitive Function in the Alzheimer Disease Mouse Model.

Despite mounting evidence suggesting the involvement of the immune system in regulating brain function, the specific role of immune and inflammatory cells in neurodegenerative diseases remain poorly understood. In this study, we report that depletion of NK cells, a type of innate lymphocytes, alleviates neuroinflammation, stimulates neurogenesis, and improves cognitive function in a triple-transgenic Alzheimer disease (AD) mouse model. NK cells in the brains of triple-transgenic AD mouse model (3xTg-AD) mice exhibited an enhanced proinflammatory profile. Depletion of NK cells by anti-NK1.1 Abs drastically improved cognitive function of 3xTg-AD mice. NK cell depletion did not affect amyloid ß concentrations but enhanced neurogenesis and reduced neuroinflammation. Notably, in 3xTg-AD mice depleted of NK cells, microglia demonstrated a homeostatic-like morphology, decreased proliferative response and reduced expression of neurodestructive proinflammatory cytokines. Together, our results suggest a proinflammatory role for NK cells in 3xTg-AD mice and indicate that targeting NK cells might unlock novel strategies to combat AD.

Transcription/Expression of KLRB1 Gene as A Prognostic Indicator in Human Esophageal Squamous Cell Carcinoma.

AIM AND OBJECTIVE: Esophageal squamous cell carcinoma (ESCC) is the most prevalent type of cancer with worldwide distribution and dismal prognosis despite ongoing efforts to improve treatment options. Therefore, it is essential to determine the prognostic factors for ESCC. METHODS AND RESULTS: We determined KLRB1 to be a prognostic indicator of human ESCC. KLRB1 was expressed at low levels in ESCC patients. Based on the risk score, patients were divided into high and low-risk groups. High-risk patients showed a poor survival rate. The prediction model based on the N stage, sex, and KLRB1 was significantly better than that based on the N stage and sex. The modified prediction model showed a robust ROC curve with an AUC value of 0.973. The knockdown of KLRB1 inhibited the growth of human ESCC cells. KLRB1 regulated Akt, mTOR, p27, p38, NF-κB, Cyclin D1, and JNK signaling, which was consistent with the result of GSEA. CONCLUSION: KLRB1 is a potential prognostic marker for human ESCC patients.

Changes of frequency and expression level of CD161 in CD8+ T cells and natural killer T cells in peripheral blood of patients with systemic lupus erythematosus.

Immunologic abnormalities of natural killer (NK) cells and T cells play a role in the pathogenesis of systemic lupus erythematosus (SLE). CD161 is expressed on most of the NK cells and on some T cells. The quantities of CD161-expressing cells and expression levels of CD161 were analyzed in T cells and NK cells from patients with SLE compared with normal controls. The expression of CD161 on NK cells, NKT cells, CD4+ T cells, and CD8+ T cells in peripheral blood from patients with inactive SLE and active SLE, and from the normal controls group were determined using flow cytometry. The frequency and expression level of CD161 in the lymphocyte subsets and its relationship with the quantity of regulatory T cells, anti-double stranded DNA antibody, and the titer of antinuclear antibody were evaluated. Both the percentages of the CD161+ subpopulation and the mean fluorescence intensities (MFIs) of CD161 in CD8+ T cells and NKT cells decreased significantly in SLE patients compared with normal controls (P < .001). The CD161 expression in CD8+ T cells and NKT cells also decreased in the anti-dsDNA (+) group (P < .05). The counts of Treg cells were lower in SLE patients and were weakly correlated with the percentage of the CD161 subpopulation (r = 0.229, P = .016) and the MFIs of CD161 expression in CD8+ T cells (r = .232, P = .014). The frequencies and levels of CD161 expression on CD8+ T cells and NKT cells were reduced in SLE patients, suggesting that an abnormality of these cells was related to the pathogenesis of SLE.

Changes in the Vα7.2+ CD161++ MAIT cell compartment in early pregnancy are associated with preterm birth in HIV-positive women.

PROBLEM: Human immunodeficiency virus (HIV) infection is associated with an increased risk of adverse pregnancy outcomes, including preterm birth (PTB), despite viral suppression with antiretroviral therapy. Mucosal-associated invariant T (MAIT) cells are an immune cell subset involved in antimicrobial immunity at mucosal surfaces. MAIT cells have been found at the maternal-foetal interface, and MAIT cells are typically depleted early in HIV infection. We aimed to investigate changes in MAIT cells in relation to maternal HIV/ART status and PTB. METHOD OF STUDY: We conducted flow cytometric analysis of peripheral blood samples from 47 HIV-positive (HIV+) and 45 HIV-negative (HIV-) pregnant women enrolled in a prospective pregnancy cohort study in Soweto, South Africa. Frequencies of Vα7.2+ CD161++ MAIT cells and proportions of CD4+ , CD8+ and double-negative MAIT cells were compared between women with and without HIV infection, and between women with and without PTB or spontaneous preterm labour (Sp-PTL). RESULTS: Although overall MAIT cell frequencies were the same between HIV+ and HIV- patients, HIV+ patients had a higher proportion of CD8+ MAIT cells in the first two trimesters. Women with PTB and Sp-PTL also had a higher proportion of CD8+ MAIT cells in the first trimester compared to women without these outcomes. The association between changes in MAIT cell subsets and PTB/Sp-PTL was present in both HIV+ and HIV- women, and an additive effect on MAIT cell subsets was seen in women with both HIV infection and PTB. CONCLUSIONS: Interactions between HIV-related and pregnancy-related changes in MAIT cell subsets and distribution may lead to imbalances in peripheral MAIT cell subsets in early pregnancy. This may contribute to the increased risk of PTB in HIV+ patients by altering the overall functionality of the peripheral MAIT cell compartment.