Innate and adaptive stimulation of murine diverse NKT cells result in distinct cellular responses.

Natural killer T (NKT) cells recognize glycolipids presented on CD1d. They share features of adaptive T lymphocytes and innate NK cells, and mediate immunoregulatory functions via rapid production of cytokines. Invariant (iNKT) and diverse (dNKT) NKT cell subsets are defined by their TCR. The immunological role of dNKT cells, that do not express the invariant TCRα-chain used by iNKT cells, is less well explored than that of iNKT cells. Here, we investigated signals driving Toll-like receptor (TLR) ligand activation of TCR-transgenic murine dNKT cells. IFN-γ production by dNKT cells required dendritic cells (DC), cell-to-cell contact and presence of TLR ligands. TLR-stimulated DC activated dNKT cells to secrete IFN-γ in a CD1d-, CD80/86- and type I IFN-independent manner. In contrast, a requirement for IL-12p40, and a TLR ligand-selective dependence on IL-18 or IL-15 was observed. TLR ligand/DC stimulation provoked early secretion of pro-inflammatory cytokines by both CD62L+ and CD62L- dNKT cells. However, proliferation was limited. In contrast, TCR/co-receptor-mediated activation resulted in proliferation and delayed production of a broader cytokine spectrum preferentially in CD62L- dNKT cells. Thus, innate (TLR ligand/DC) and adaptive (TCR/co-receptor) stimulation of dNKT cells resulted in distinct cellular responses that may contribute differently to the formation of immune memory.

Defining a novel subset of CD1d-dependent type II natural killer T cells using natural killer cell-associated markers.

Natural killer T (NKT) cells are αß T cell receptor (TCR) expressing innate-like T cells that display natural killer (NK) cell markers. Based on TCR characteristics, they are divided into two groups restricted to the MHC class I-like molecule CD1d. Type I NKT cells, most extensively studied, are identified by a semi-invariant Vα14-Jα18 (mouse, Vα24-Jα18 in humans) TCR reactive to the prototypic ligand α-galactosylceramide presented on CD1d. In contrast, type II NKT cells display diverse TCR reacting to different CD1d-presented ligands. There are no reagents that identify all type II NKT cells, limiting their exploration. Here, we searched for novel type II NKT cells by comparing Jα18-/- MHCII-/- mice that harbour type II but not type I NKT cells, and CD1d-/- MHCII-/- mice, lacking all NKT cells. We identified significantly larger populations of CD4+ and CD4- CD8- (double negative, DN) TCRß+ cells expressing NKG2D or NKG2A/C/E in Jα18-/- MHCII-/- mice compared with CD1d-/- MHCII-/- mice, suggesting that 30%-50% of these cells were type II NKT cells. They expressed CD122, NK1.1, CXCR3 and intermediate/low levels of CD45RB. Further, the CD4+ subset was CD69+ , while the DN cells were CD49b+ and CD62L+ . Both subsets expressed the NKT cell-associated promyelocytic leukaemia zinc finger (PLZF) transcription factor and Tbet, while fewer cells expressed RORγt. NKG2D+ CD4+ and DN populations were producers of IFN-γ, but rarely IL-4 and IL-17. Taken together, we identify a novel subset of primary CD4+ and DN type II NKT cells that expresses NKG2 receptors have typical NKT cell phenotypes and a TH1-like cytokine production.

Sulfatide isoform pattern in cerebrospinal fluid discriminates progressive MS from relapsing-remitting MS.

Multiple sclerosis (MS) is an inflammatory demyelinating disease of the central nervous system (CNS). Several biomarkers including proteins and lipids have been reported in MS cerebrospinal fluid (CSF), reflecting different aspects of the pathophysiology particularly of relapsing-remitting MS (RRMS). Sulfatide, abundant in the myelin sheath and a proposed target for autoimmune attack in MS, has been reported altered in MS CSF. Here, we investigated the potential of CSF sulfatide and its isoforms as biomarkers in MS. A highly sensitive and quantitative mass spectrometry method was employed to determine levels of sulfatide isoforms in CSF from RRMS and progressive MS (PMS) patients, and healthy donors (HD). We demonstrate that levels of total CSF sulfatide and C24:1, C26:1, and C26:1-OH isoforms were significantly increased in PMS compared with RRMS patients and HD, while C23:0-OH was significantly decreased in CSF from PMS patients compared to the other two groups. Multivariate discriminant analysis showed that CSF sulfatide isoform pattern in PMS patients was distinct and non-overlapping with that of RRMS patients and HD. Sulfatide levels did not correlate with tested biomarkers or clinical parameters. The results suggest that CSF sulfatide isoform levels may be used to discriminate the phenotype of MS and might play a role in the progression of the disease.

3D micro-organisation printing of mammalian cells to generate biological tissues.

Significant strides have been made in the development of in vitro systems for disease modelling. However, the requirement of microenvironment control has placed limitations on the generation of relevant models. Herein, we present a biological tissue printing approach that employs open-volume microfluidics to position individual cells in complex 2D and 3D patterns, as well as in single cell arrays. The variety of bioprinted cell types employed, including skin epithelial (HaCaT), skin cancer (A431), liver cancer (Hep G2), and fibroblast (3T3-J2) cells, all of which exhibited excellent viability and survivability, allowing printed structures to rapidly develop into confluent tissues. To demonstrate a simple 2D oncology model, A431 and HaCaT cells were printed and grown into tissues. Furthermore, a basic skin model was established to probe drug response. 3D tissue formation was demonstrated by co-printing Hep G2 and 3T3-J2 cells onto an established fibroblast layer, the functionality of which was probed by measuring albumin production, and was found to be higher in comparison to both 2D and monoculture approaches. Bioprinting of primary cells was tested using acutely isolated primary rat dorsal root ganglia neurons, which survived and established processes. The presented technique offers a novel open-volume microfluidics approach to bioprint cells for the generation of biological tissues.

Type II NKT Cells: An Elusive Population With Immunoregulatory Properties.

Natural killer T (NKT) cells are unique unconventional T cells that are reactive to lipid antigens presented on the non-polymorphic major histocompatibility class (MHC) I-like molecule CD1d. They have characteristics of both innate and adaptive immune cells, and have potent immunoregulatory roles in tumor immunity, autoimmunity, and infectious diseases. Based on their T cell receptor (TCR) expression, NKT cells are divided into two subsets, type I NKT cells with an invariant TCRα-chain (Vα24 in humans, Vα14 in mice) and type II NKT cells with diverse TCRs. While type I NKT cells are well-studied, knowledge about type II NKT cells is still limited, and it is to date only possible to identify subsets of this population. However, recent advances have shown that both type I and type II NKT cells play important roles in many inflammatory situations, and can sometimes regulate the functions of each other. Type II NKT cells can be both protective and pathogenic. Here, we review current knowledge on type II NKT cells and their functions in different disease settings and how these cells can influence immunological outcomes.

High Interferon-γ Uniquely in Vδ1 T Cells Correlates with Markers of Inflammation and Axonal Damage in Early Multiple Sclerosis.

We have identified a population of T lymphocytes in peripheral blood, Vδ1 TCRγδ T lymphocytes, which unexpectedly was uniquely expressing high production of interferon-γ in newly diagnosed, untreated multiple sclerosis (MS) patients. IFN-γ production in this population distinctly correlated to parameters of clinical disease activity, inflammation, and neuronal damage. These Vδ1 T lymphocytes belong to a population of innate T lymphocytes that recognize antigen in the context of CD1d/CD1c and which include reactivity to the myelin glycosphingolipid sulfatide. Importantly, patients treated with natalizumab, blocking leukocyte transmigration to central nervous system, had completely normalized levels of interferon-γ-producing Vδ1 T lymphocytes. A biomarker and early sign of demyelinating disease in MS is much warranted and would help identify immunopathogenesis and prognosis of disease as well as monitor success with adequate treatment. The present study identifies the Vδ1 T lymphocytes as an early marker of MS and a possible link to understanding the disease etiology.

Natural killer T cell anergy, co-stimulatory molecules and immunotherapeutic interventions.

Natural killer T (NKT) cells are a unique subset of glycolipid-reactive T lymphocytes that share properties with natural killer (NK) cells. These lymphocytes can produce array of cytokines and chemokines that modulate the immune response, and play a pivotal role in cancer, autoimmunity, infection and inflammation. Owing to these properties, NKT cells have gained attentions for its potential use in antitumor immunotherapies. To date several NKT cell-based clinical trials have been performed in patients with cancer using its potent ligand α-galactosylceramide (α-GalCer). However, inconsistent therapeutic benefit, and inevitable health risks associated with drug dose and NKT cell activation have been observed. α-GalCer-activated NKT cells become anergic and produce both Th1 and Th2 cytokines that may function antagonistically, limiting the desired effector functions. Besides, various co-stimulatory and signaling molecules such as programmed death-1 (PD-1; CD279), casitas B-cell lymphoma-b (Cbl-b) and CARMA1 have been shown to be implicated in the induction of NKT cell anergy. In this review, we discuss the role of such key regulators and their functional mechanisms that may facilitate the development of improved approaches to overcome NKT cell anergy. In addition, we describe the evidences indicating that tailored-ligands can optimally activate NKT cells to obtain desired immune responses.

Genome-wide scan for analysis of simple and imperfect microsatellites in diverse carlaviruses.

An exhaustive compilation and analysis of incidence, distribution and variation of simple sequence repeats (SSRs) in viruses are required to understand the evolution and functional aspects of repetitive sequences. Present study focuses on the analysis of SSRs in 32 species of carlaviruses. The full length genome sequences were assessed from NCBI (http://www.ncbi.nlm.nih.-gov/) and analyzed using IMEx software. Variance in incidence of SSRs was observed, independent of genome size. Though the conversion of SSRs to imperfect microsatellite or compound SSR is low; compound microsatellites constituted by variant motifs accounted for up to 12.5% of the SSRs. Mononucleotide A/T is most prevalent followed by dinucleotide GT/TG and trinucleotide AAG/GAA in these genomes. The SSR and cSSR are predominantly localized to the coding region RDRP (RNA dependent RNA polymerase) and ORF-6 (open reading frame). The relative frequency of different classes of simple and compound microsatellites has been highlighted in accordance with the biology of carlavirus. Characterization of such variations would be pivotal for deciphering the enigma of these widely used, but incompletely understood sequences.

Frequency and distribution of simple and compound microsatellites in forty-eight Human papillomavirus (HPV) genomes.

Simple sequence repeats (SSRs) are tandem-repeated sequences ubiquitously present but differentially distributed across genomes. Present study is a systematic analysis for incidence, composition and complexity of different microsatellites in 48 representative Human papillomavirus (HPV) genomes. The analysis revealed a total of 1868 SSRs and 120 cSSRs. However, four genomes (HPV-60, HPV-92, HPV-112 and HPV-136) lacked any cSSR content; while HPV-31 accounted for a maximum of 10 cSSRs. An overall increase in cSSR% with higher dMAX was observed. The SSRs and cSSRs were prevalent in coding regions. Poly(A/T) repeats were significantly more abundant than poly(G/C) repeats possibly due to high (A/T) content of the HPV genomes. Further, higher prevalence of di-nucleotide repeats over tri-nucleotide repeats may be attributed to instability of former because of higher slippage rate. An in-depth study of the satellite sequences would provide an insight into the imperfections and evolution of microsatellites.

Incidence, complexity and diversity of simple sequence repeats across potexvirus genomes.

An in-silico analysis of simple sequence repeats (SSRs) in genomes of 32 species of potexviruses was performed wherein a total of 691 SSRs and 33 cSSRs were observed. Though SSRs were present in all the studied genomes their incident frequency ranged from 11 to 30 per genome. Further, 10 potexvirus genomes possessed no cSSRs when extracted at a dMAX of 10 and wherein present, the highest frequency was 3. SSR and cSSR incidence, relative density and relative abundance were non-significantly correlated with genome size and GC content suggesting an ongoing evolutionary and adaptive phase of the virus species. SSRs present primarily ranged from mono- to tri-nucleotide repeat motifs with a greatly skewed distribution across the coding and non-coding regions. Present work is an effort for the undergoing compilation and analysis of incidence, distribution and variation of the viral repeat sequences to understand their evolutionary and functional relevance.

Inter-relation of Th1, Th2, Th17 and Treg cytokines in oral cancer patients and their clinical significance.

BACKGROUND: Altered cytokine production can lead to immune dysfunction in cancer patients. Hence, we investigated the cytokine balance in oral squamous cell carcinoma (OSCC) patients and their significance in providing new therapeutic insights. METHODS: We quantified Th17 (IL17A), Treg (TGFß1), Th1 (IL2, IFNγ) and Th2 (IL4, IL10) like cytokines in the sera of 78 cases and 39 controls by ELISA. The intracellular expression of these cytokines was analyzed in 10 subjects from each group by flow cytometry. RESULTS: Serum levels of IL17A, TGFß1, IL4 and IL10 were significantly higher while IL2 and IFNγ were relatively lower in patients as compared to controls. TGFß1 (r=0.55), IL4 (r=0.75) and IL10 (r=0.80) significantly (P<0.0001) correlated with disease progression and their elevated levels showed increased odd ratios of approximately 18, 14 and 37, respectively. IL17A appeared as a risk factor (OR=2.21, 95% CI=0.89-5.42) although statistically insignificant. The levels neither correlated with disease progression nor with TGFß1, IL4 and IL10 but showed positive association with IL2 (r=0.51, P<0.0001) and IFNγ (r=0.24). Flow cytometry data also showed similar trend. CONCLUSIONS: We reported a distinct TGFß1 and Th2 (IL4, IL10) polarization with a borderline elevation of IL17A while, a suppression of Th1 (IL2, IFNγ) cytokines in OSCC patients.

In- silico exploration of thirty alphavirus genomes for analysis of the simple sequence repeats.

The compilation of simple sequence repeats (SSRs) in viruses and its analysis with reference to incidence, distribution and variation would be instrumental in understanding the functional and evolutionary aspects of repeat sequences. Present study encompasses the analysis of SSRs across 30 species of alphaviruses. The full length genome sequences, assessed from NCBI were used for extraction and analysis of repeat sequences using IMEx software. The repeats of different motif sizes (mono- to penta-nucleotide) observed therein exhibited variable incidence across the species. Expectedly, mononucleotide A/T was the most prevalent followed by dinucleotide AG/GA and trinucleotide AAG/GAA in these genomes. The conversion of SSRs to imperfect microsatellite or compound microsatellite (cSSR) is low. cSSR, primarily constituted by variant motifs accounted for up to 12.5% of the SSRs. Interestingly, seven species lacked cSSR in their genomes. However, the SSR and cSSR are predominantly localized to the coding region ORFs for non structural protein and structural proteins. The relative frequencies of different classes of simple and compound microsatellites within and across genomes have been highlighted.

In-silico analysis of simple and imperfect microsatellites in diverse tobamovirus genomes.

An in-silico analysis of simple sequence repeats (SSRs) in 30 species of tobamoviruses was done. SSRs (mono to hexa) were present with variant frequency across species. Compound microsatellites, primarily of variant motifs accounted for up to 11.43% of the SSRs. Motif duplications were observed for A, T, AT, and ACA repeats. (AG)-(TC) was the most prevalent SSR-couple. SSRs were differentially localized in the coding region with ~54% on the 128 kDa protein while 20.37% was exclusive to 186 kDa protein. Characterization of such variations is important for elucidating the origin, sequence variations, and structure of these widely used, but incompletely understood sequences.

Skewed immunological balance between Th17 (CD4(+)IL17A (+)) and Treg (CD4 (+)CD25 (+)FOXP3 (+)) cells in human oral squamous cell carcinoma.

BACKGROUND: Several studies have documented modulation of Th17 and T regulatory (Treg) cells in various human malignancies which may vary with the type and extent of the disease. However, such data in patients with oral cancer is scarce and hence the current study was designed to elaborate the immunological balance between these two T cell subsets in oral cancer. METHODS AND RESULTS: We analyzed various T cell subsets in the peripheral blood of 45 oral squamous cell carcinoma (OSCC) patients and 40 healthy volunteers. We found that, compared with the healthy controls, patients had a significantly (p < 0.0001) higher proportion of both Th17 (CD4(+)IL17A(+)) and Treg (CD4(+)CD25(+)FOXP3(+)) cells, which further showed a reciprocal balance in relation to clinico-pathological parameters in patients. We also detected a circulating CD8(+) subset of these cells in both patients and healthy controls, although the difference between the two groups was statistically insignificant. Higher frequencies of Th17 cells were found in patients with early stages and without lymph node involvement, while an increased prevalence of Tregs was associated with higher clinical stages and lymph node involvement. Moreover, Th17 cells were quantitatively and positively correlated to CD4(+)T and CD8(+)T cells and inversely correlated with Tregs. Contrarily, Tregs showed a negative association with CD4(+)T and CD8(+)T cells. CONCLUSIONS: Our results suggest an increase in Th17/Tregs ratio in early stages and a decrease in this ratio in higher stages of oral cancer. Such counter regulation of Th17 and Tregs may be a significant prognostic factor in oral cancer patients.