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The importance of classical CD8+ T cells in tumor eradication is well acknowledged. However, the anti-tumor activity of MHC (major histocompatibility complex) Ib-restricted CD8+ T (Ib-CD8+ T) cells remains obscure. Here, we show that CX3CR1-expressing Ib-CD8+ T cells (Ib-restricted CD8+ T cells) highly express cytotoxic factors, austerely resist exhaustion, and effectively eliminate various tumors. These Ib-CD8+ T cells can be primed by MHC Ia (MHC class Ia molecules) expressed on various cell types for optimal activation in a Tbet-dependent manner. Importantly, MHC Ia does not allogeneically activate Ib-CD8+ T cells, rather, sensitizes these cells for T cell receptor activation. Such effects were observed when MHC Ia+ cells were administered to tumor-bearing Kb−/−Db−/−mice. A similar population of tumoricidal CX3CR1+ CD8+ T cells was identified in wild-type mice and melanoma patients. Adoptive transfer of Ib-CD8+ T cells to wild-type mice inhibited tumor progression without damaging normal tissues. Taken together, we demonstrate that MHC class Ia can prime Ib-CD8+ T cells for robust tumoricidal activities. [ABSTRACT FROM AUTHOR]

A simple imidazo[1,2-a]pyridine-hemicyanine-based near-infrared (NIR) TBET cassette was designed and synthesized. This cassette exhibits ultra large Stokes shifts (400 nm). Furthermore, the cassette has high selectivity and sensitivity toward sulfur dioxide in water. It was practically applied for detecting SO2 derivatives in living cells.

Invariant NKT (iNKT) cells are thymus-generated innate-like T cells, comprised of three distinct subsets with divergent effector functions. The molecular mechanism that drives the lineage trifurcation of immature iNKT cells into the NKT1, NKT2, and NKT17 subsets remains a controversial issue that remains to be resolved. Because cytokine receptor signaling is necessary for iNKT cell generation, cytokines are proposed to contribute to iNKT subset differentiation also. However, the precise roles and requirements of cytokines in these processes are not fully understood. Here, we show that IL-2Rβ, a nonredundant component of the IL-15 receptor complex, plays a critical role in both the development and differentiation of thymic iNKT cells. While the induction of IL-2Rβ expression on postselection thymocytes is necessary to drive the generation of iNKT cells, surprisingly, premature IL-2Rβ expression on immature iNKT cells was detrimental to their development. Moreover, while IL-2Rβ is necessary for NKT1 generation, paradoxically, we found that the increased abundance of IL-2Rβ suppressed NKT1 generation without affecting NKT2 and NKT17 cell differentiation. Thus, the timing and abundance of IL-2Rβ expression control iNKT lineage fate and development, thereby establishing cytokine receptor expression as a critical regulator of thymic iNKT cell differentiation.

Invariant NKT (i NKT) cells are thymus-generated innate-like T cells, comprised of three distinct subsets with divergent effector functions. The molecular mechanism that drives the lineage trifurcation of immature i NKT cells into the NKT1, NKT2, and NKT17 subsets remains a controversial issue that remains to be resolved. Because cytokine receptor signaling is necessary for i NKT cell generation, cytokines are proposed to contribute to i NKT subset differentiation also. However, the precise roles and requirements of cytokines in these processes are not fully understood. Here, we show that IL-2Rβ, a nonredundant component of the IL-15 receptor complex, plays a critical role in both the development and differentiation of thymic i NKT cells. While the induction of IL-2Rβ expression on postselection thymocytes is necessary to drive the generation of i NKT cells, surprisingly, premature IL-2Rβ expression on immature i NKT cells was detrimental to their development. Moreover, while IL-2Rβ is necessary for NKT1 generation, paradoxically, we found that the increased abundance of IL-2Rβ suppressed NKT1 generation without affecting NKT2 and NKT17 cell differentiation. Thus, the timing and abundance of IL-2Rβ expression control i NKT lineage fate and development, thereby establishing cytokine receptor expression as a critical regulator of thymic i NKT cell differentiation. [ABSTRACT FROM AUTHOR]

Summary: Tbet‐deficient mice have reduced natural killer (NK) cells in blood and spleen, but increased NK cells in bone marrow and lymph nodes, a phenotype that is thought to be the result of defective migration. Here, we revisit the role of Tbet in NK cell bone marrow egress. We definitively show that the accumulation of NK cells in the bone marrow of Tbet‐deficient Tbx21−/− animals occurs because of a migration defect and identify a module of genes, co‐ordinated by Tbet, which affects the localization of NK cells in the bone marrow. Cxcr6 is approximately 125‐fold underexpressed in Tbx21−/−, compared with wild‐type, immature NK cells. Immature NK cells accumulate in the bone marrow of CXCR6‐deficient mice, and CXCR6‐deficient progenitors are less able to reconstitute the peripheral NK cell compartment than their wild‐type counterparts. However, the CXCR6 phenotype is largely confined to immature NK cells, whereas the Tbet phenotype is present in both immature and mature NK cells, suggesting that genes identified as being more differentially expressed in mature NK cells, such as S1pr5, Cx3cr1, Sell and Cd69, may be the major drivers of the phenotype. [ABSTRACT FROM AUTHOR]

• Roles for IRF8, IRF4, NOTCH, ZEB2, KLF4 and TBet in cDC1 and cDC2 fate specification. • Switch from +41 kb to +32 kb enhancer in IRF8 is required for cDC1 development. • NFIL3 functions to inhibit ZEB2 enabling ID2 expression in cDC1s. • cDC2 heterogeneity across tissues remains incompletely understood. • Role of tissue microenvironment in cDC2 heterogeneity remains to be studied. Dendritic cells function in the immune system to instruct adaptive immune cells to respond accordingly to different threats. While conventional dendritic cells can be subdivided into two main subtypes, termed cDC1s and cDC2s, it is clear that further heterogeneity exists within these subtypes, particularly for cDC2s. Understanding the signals involved in specifying each of these lineages and subtypes thereof is crucial to (i) enable us to determine their specific functions and (ii) put us in a position to be able to target these cells to promote or prevent a specific function in any given disease setting. Although we still have much to learn regarding the specification of these cells, here we review the most recent advances in our understanding of this and highlight some of the next questions for the future. [ABSTRACT FROM AUTHOR]

Summary: Chronic lymphocytic leukaemia (CLL) is associated with alterations in T cell number, subset distribution and function. Among these changes, an increase in CD4+ T cells was reported. CD4+ T cells are a heterogeneous population and distinct subsets have been described to exert pro‐ and anti‐tumour functions. In CLL, controversial reports describing the dominance of IFNγ‐expressing Th1 T cells or of IL‐4‐producing Th2 T cells exist. Our study shows that blood of CLL patients is enriched in Th1 T cells producing high amounts of IFNγ. Moreover, we observed that their frequency remains relatively stable in CLL patients over a time course of five years. Furthermore, we provide evidence for an accumulation of Th1 T cells in the Eµ‐TCL1 mouse model of CLL. As TBET (encoded by Tbx21) is a crucial transcription factor for Th1 polarization, we generated Tbx21−/− bone marrow chimaeric mice which showed a lower number of IFNγ‐producing Th1 T cells, and used them for adoptive transfer of Eµ‐TCL1 leukaemia. Disease development in these mice was, however, comparable to that in wild‐type controls, excluding a major role for TBET‐expressing Th1 cells in Eµ‐TCL1 leukaemia. Collectively, our data highlight that Th1 T cells accumulate in CLL but reducing their number has no impact on disease development. [ABSTRACT FROM AUTHOR]

In normal conditions gut homeostasis is maintained by the suppressive activity of regulatory T cells (Tregs), characterized by the expression of the transcription factor FoxP3. In human inflammatory bowel disease, which is believed to be the consequence of the loss of tolerance toward antigens normally contained in the gut lumen, Tregs have been found to be increased and functionally active, thus pointing against their possible role in the pathogenesis of this immune-mediated disease. Though, in inflammatory conditions, Tregs have been shown to upregulate the T helper (Th) type 1-related transcription factor Tbet and to express the pro-inflammatory cytokine IFNγ, thus suggesting that at a certain point of the inflammatory process, Tregs might contribute to inflammation rather than suppress it. Starting from the observation that Tregs isolated from the lamina propria of active but not inactive IBD patients or uninflamed controls express Tbet and IFNγ, we investigated the functional role of Th1-like Tregs in the dextran sulfate model of colitis. As observed in human IBD, Th1-like Tregs were upregulated in the inflamed lamina propria of treated mice and the expression of Tbet and IFNγ in Tregs preceded the accumulation of conventional Th1 cells. By using a Treg-specific Tbet conditional knockout, we demonstrated that Tbet expression in Tregs is required for the development of colitis. Indeed, Tbet knockout mice developed milder colitis and showed an impaired Th1 immune response. In these mice not only the Tbet deficient Tregs but also the Tbet proficient conventional T cells showed reduced IFNγ expression. However, Tbet deficiency did not affect the Tregs suppressive capacity in vitro and in vivo in the adoptive transfer model of colitis. In conclusion here we show that Tbet expression by Tregs sustains the early phase of the Th1-mediated inflammatory response in the gut.

The adult human liver hosts a complex repertoire of liver resident and transient natural killer (NK) cell populations with diverse phenotypes and functions. Liver resident NK cells are CD56bright NK cells defined by a unique expression profile of transcription factors and cell surface markers (EomeshiTbetloTIGIT+CD69+CXCR6+CD49e−). Despite extensive characterization of the phenotype of liver resident NK cells, it remains unclear how factors within the liver microenvironment induce and maintain this unique phenotype. In this study, we have explored the factors regulating the phenotype of liver resident NK cells. Isolation of healthy liver resident NK cells from donor liver perfusate and in vitro culture results in the gradual loss of the characteristic Tbetlo phenotype, with the cells increasing Tbet expression significantly at day 7. This phenotypic loss could be halted through the dose-dependent addition of liver conditioned media (LCM), generated from the ex vivo culture of liver biopsies from healthy organ donors. TGF-β, but not IL-10, replicated the Tbet suppressive effects of LCM in both liver resident and peripheral blood NK cells. Furthermore, blocking TGF-β receptor signaling using the inhibitor SB431542, reversed the effect of LCM treatment on liver resident NK cells, causing the loss of tissue resident Eomeshi Tbetlo phenotype. Our findings identify liver-derived TGF-β as an important component of the liver microenvironment, which acts to regulate and maintain the phenotype of liver resident NK cells.

Purpose: The recent success of anti-PD1 antibody in metastatic colorectal cancer (CRC) patients with microsatellite instability (MSI), known to be associated with an upregulated Th1/Tc1 gene signature, provides new promising therapeutic strategies. However, the partial objective response highlights a crucial need for relevant, easily evaluable, predictive biomarkers. Here we explore whether in situ assessment of Tbet+ tumor infiltrating lymphocytes (TILs) reflects a pre-existing functional antitumor Th1/Tc1/IFNγ response, in relation with clinicopathological features, microsatellite status and expression of immunoregulatory molecules (PD1, PDL1, IDO-1). Methodology: In two independent cohorts of CRC (retrospective n = 80; prospective n = 27) we assessed TILs density (CD3, Tbet, PD1) and expression profile of PDL1 and IDO-1 by immunohistochemistry/image analysis. Furthermore, the prospective cohort allowed to perform ex vivo CRC explant cultures and measure by Elisa the IFNγ response, at baseline and upon anti-PD1 treatment. Results: The density of Tbet+ TILs was significantly higher in MSI CRC, especially in the medullary subtype but also in a subgroup of MSS (microsatellite stable), and positively correlated with PD1 and PDL1 expression, but not with IDO-1. Finally, a high number of Tbet+ TILs was associated with a favorable overall survival. These Tbet+ TILs were functional as their density positively correlated with basal IFNγ levels. In addition, the combined score of Tbet+ PD1+ TILs coupled with IDO-1 expression predicted the magnitude of the IFNγ response upon anti-PD1. Conclusion: Altogether, immunohistochemical quantification of Tbet+ TILs is a reliable and accurate tool to recapitulate a preexisting Th1/Tc1/IFNγ antitumor response that can be reinvigorated by anti-PD1 treatment.

We investigated the ability of a novel triazatruxene–rhodamine-based (TAT-ROD) chemosensor to detect the trivalent metal ions aluminium (Al3+), iron (Fe3+) and chromium (Cr3+). Operating via the through-bond energy transfer (TBET) pathway, the chemosensor exhibited low detection limits of 23.0, 25.0 and 170.0 nM for Al3+, Fe3+ and Cr3+, respectively, along with high sensitivity and selectivity during a brief period (<15 s). The binding ratio of the chemosensor and trivalent metal ions achieved by Job's method was 3:1, and when we added ethylenediaminetetraacetic acid (EDTA), the sensing process reversed. Altogether, our TAT-ROD chemosensor marks the first triazatruxene-based colorimetric and fluorometric metal ion sensor reported in the literature. [ABSTRACT FROM AUTHOR]

In normal conditions gut homeostasis is maintained by the suppressive activity of regulatory T cells (Tregs), characterized by the expression of the transcription factor FoxP3. In human inflammatory bowel disease, which is believed to be the consequence of the loss of tolerance toward antigens normally contained in the gut lumen, Tregs have been found to be increased and functionally active, thus pointing against their possible role in the pathogenesis of this immune-mediated disease. Though, in inflammatory conditions, Tregs have been shown to upregulate the T helper (Th) type 1-related transcription factor Tbet and to express the pro-inflammatory cytokine IFNγ, thus suggesting that at a certain point of the inflammatory process, Tregs might contribute to inflammation rather than suppress it. Starting from the observation that Tregs isolated from the lamina propria of active but not inactive IBD patients or uninflamed controls express Tbet and IFNγ, we investigated the functional role of Th1-like Tregs in the dextran sulfate model of colitis. As observed in human IBD, Th1-like Tregs were upregulated in the inflamed lamina propria of treated mice and the expression of Tbet and IFNγ in Tregs preceded the accumulation of conventional Th1 cells. By using a Treg-specific Tbet conditional knockout, we demonstrated that Tbet expression in Tregs is required for the development of colitis. Indeed, Tbet knockout mice developed milder colitis and showed an impaired Th1 immune response. In these mice not only the Tbet deficient Tregs but also the Tbet proficient conventional T cells showed reduced IFNγ expression. However, Tbet deficiency did not affect the Tregs suppressive capacity in vitro and in vivo in the adoptive transfer model of colitis. In conclusion here we show that Tbet expression by Tregs sustains the early phase of the Th1-mediated inflammatory response in the gut. [ABSTRACT FROM AUTHOR]

The adult human liver hosts a complex repertoire of liver resident and transient natural killer (NK) cell populations with diverse phenotypes and functions. Liver resident NK cells are CD56bright NK cells defined by a unique expression profile of transcription factors and cell surface markers (EomeshiTbetloTIGIT+CD69+CXCR6+CD49e−). Despite extensive characterization of the phenotype of liver resident NK cells, it remains unclear how factors within the liver microenvironment induce and maintain this unique phenotype. In this study, we have explored the factors regulating the phenotype of liver resident NK cells. Isolation of healthy liver resident NK cells from donor liver perfusate and in vitro culture results in the gradual loss of the characteristic Tbetlo phenotype, with the cells increasing Tbet expression significantly at day 7. This phenotypic loss could be halted through the dose-dependent addition of liver conditioned media (LCM), generated from the ex vivo culture of liver biopsies from healthy organ donors. TGF-β, but not IL-10, replicated the Tbet suppressive effects of LCM in both liver resident and peripheral blood NK cells. Furthermore, blocking TGF-β receptor signaling using the inhibitor SB431542, reversed the effect of LCM treatment on liver resident NK cells, causing the loss of tissue resident Eomeshi Tbetlo phenotype. Our findings identify liver-derived TGF-β as an important component of the liver microenvironment, which acts to regulate and maintain the phenotype of liver resident NK cells. [ABSTRACT FROM AUTHOR]

Despite the opposite roles of Tbet and Foxp3 in the immune system as well as in tumour biology, recent studies have demonstrated the presence of of CD4+ T cells, expressing both, Tbet and Foxp3. Although Tbet+Foxp3+ T cells are currently a subject of intense research, less is known about their biological function especially in cancer. Here we found a considerable accumulation of Tbet+Foxp3+CD4+ T cells, mediated by the immunosuppressive cytokine TGFβ in the lungs of tumour bearing mice. This is in line with previous studies, demonstrating the important role of TGFβ for the immunopathogenesis of cancer. By gathering results both in murine model and in human disease, we demonstrate that, the conversion of IFNγ producing anti-tumoral T-bet+Th1 CD4+ T cells into immunosuppressive Tbet and Foxp3-PD1 co-expressing regulatory cells could represent an additional important mechanism of TGFβ-mediated blockade of anti-tumour immunity.

Graphical abstract In this article, a naphthalimide-rhodamine fluorescent turn-on probe RHSNO with red emission for hypochlorous acid based on dual reaction linkage induce through-bond energy transfer (TBET) system was designed and synthesized, and had been applied to the detection of endogenous and exogenous ClO−. Highlights • A naphthalimide-rhodamine probe RHSNO with red emission for ClO− based on dual reaction linkage induce TBET. • ClO− triggered intramolecular desulfurization cyclization and the fluorescence of rhodamine enhanced up to 260-fold. • The efficiency of energy transfer was calculated to be 86%, and the quantum yield of rhodamine moiety is 0.64. • The probe RHSNO had been employed for endogenous and exogenous imaging in MCF-7 cell for ClO−. Abstract A naphthalimide-rhodamine fluorescent turn-on probe RHSNO with red emission for hypochlorous acid based on dual reaction linkage induce through-bond energy transfer (TBET) system was designed and synthesized. Rhodamine B thiohydrazide and naphthalimide -N,N- dimethylthiocarbamate (DMTC) were linked to form a structure of monothio-bishydrazide. In addition, introduce dimethylthiocarbamoyl chloride as another reaction site of ClO−, and it acts to quench the fluorescence of naphthalimide. In the presence of ClO−, RHSNO exhibits high selectivity toward ClO− at trace levels over other anions/ROS based on ClO−-triggered intramolecular desulfurization cyclization of rhodamine-thiohydrazide, the spiro ring of rhodamine was opened and meanwhile desulfurization hydrogenation happened at DMTC of naphthalimide moiety. These dual linkage reaction happened simultaneously made a typical TBET process took place from naphthalimide donor to rhodamine acceptor, an obvious increase of rhodamine emission at 590 nm and enhanced up to 260-fold gradually after adding ClO− with the increase of the concentrations. The efficiency of energy transfer was calculated to be 86%. And the quantum yield of rhodamine moiety is 0.64. Besides, the chemodosimeter RHSNO for ClO− with high sensitivity, a dramatic color change from colorless to brightly pink among 2 s after the addtion of ClO−. The detection limit was determined to be 22.1 nM and works excellently within a wide pH range of 5–10. Moreover, RHSNO had been employed for endogenous imaging in MCF-7 cell for ClO−. The results indicated that the probe could permeated into the cells and reacted with the intracellular ClO−. It is excellent to design fluorescence sensor RHSNO as a quick and effective method for detecting excess ClO− in living cell, for maintaining the balance of hypochlorite in the body and ensure normal life activities. [ABSTRACT FROM AUTHOR]

The rescue of exhausted CD8+ cytolytic T-cells (CTLs) by anti-Programmed Cell Death-1 (anti-PD-1) blockade has been found to require CD28 expression. At the same time, we have shown that the inactivation of the serine/threonine kinase glycogen synthase kinase (GSK)-3α/β with small-interfering RNAs (siRNAs) and small molecule inhibitors (SMIs) specifically down-regulates PD-1 expression for enhanced CD8+ CTL function and clearance of tumors and viral infections. Despite this, it has been unclear whether the GSK-3α/β pathway accounts for CD28 costimulation of CD8+ CTL function. In this article, we show that inactivation of GSK-3α/β through siRNA or by SMIs during priming can substitute CD28 co-stimulation in the potentiation of cytotoxic CD8+ CTL function against the EL-4 lymphoma cells expressing OVA peptide. The effect was seen using several structurally distinct GSK-3 SMIs and was accompanied by an increase in Lamp-1 and GZMB expression. Conversely, CD28 crosslinking obviated the need for GSK-3α/β inhibition in its enhancement of CTL function. Our findings support a model where GSK-3 is the central cosignal for CD28 priming of CD8+ CTLs in anti-PD-1 immunotherapy.

We have previously reported that direct injection of dendritic cells (DC) engineered to express the Type-1 transactivator Tbet (i.e., DC.Tbet) into murine tumors results in antitumor efficacy in association with the development of structures resembling tertiary lymphoid organs (TLO) in the tumor microenvironment (TME). These TLO contained robust infiltrates of B cells, DC, NK cells, and T cells in proximity to PNAd+ blood vessels; however, they were considered incomplete, since the recruited B cells failed to organize into classic germinal center-like structures. We now report that antitumor efficacy and TLO-inducing capacity of DC.Tbet-based i.t. therapy is operational in peripheral lymph node-deficient LTA−/− mice, and that it is highly dependent upon a direct Tbet target gene product, IL-36γ/IL-1F9. Intratumoral DC.Tbet fails to provide protection to tumor-bearing IL-36R−/− hosts, or to tumor-bearing wild-type recipient mice co-administered rmIL-1F5/IL-36RN, a natural IL-36R antagonist. Remarkably, the injection of tumors with DC engineered to secrete a bioactive form of mIL-36γ (DC.IL36γ) also initiated therapeutic TLO and slowed tumor progression in vivo. Furthermore, DC.IL36γ cells strongly upregulated their expression of Tbet, suggesting that Tbet and IL-36γ cooperate to reinforce each other's expression in DC, rendering them competent to promote TLO formation in an “immunologically normalized,” therapeutic TME.

A new ratiometric fluorescent probe ( RPM ) was developed based on through-bond energy transfer (TBET) mechanism for detecting hypochlorous acid. The probe was constructed from imidazo[1,5- a ]pyridine as the energy donor and the rhodamine as the energy acceptor. The probe could be used to determine the concentration of HOCl with high selectivity and sensitivity (the detection limit = 2.08 × 10 −6 M). In addition, RPM had a good time resolution for measuring HOCl with the response time of less than 30 s. Upon addition of HOCl, the fluorescence colors of probe RPM solution changed from green to red. Moreover, the probe has been successfully utilized for sensing HOCl in living cells. [ABSTRACT FROM AUTHOR]

Background There is now increasing evidence that asthma and atopy originate in part in utero, with disease risk being associated with the altered epigenetic regulation of genes. Objective and Methods To determine the relationship between variations in DNA methylation at birth and the development of allergic disease, we examined the methylation status of CpG loci within the promoter regions of Th1/2 lineage commitment genes ( GATA3, IL-4, IL-4R, STAT4 and TBET) in umbilical cord DNA at birth in a cohort of infants from the Southampton Women's Survey (n = 696) who were later assessed for asthma, atopic eczema and atopy. Results We found that higher methylation of GATA3 CpGs −2211/−2209 at birth was associated with a reduced risk of asthma at ages 3 (median ratio [median methylation in asthma group/median methylation in non-asthma group] = 0.74, P = .006) and 6-7 (median ratio 0.90, P = .048) years. Furthermore, we demonstrated that the GATA3 CpG loci associated with later risk of asthma lie within a NF-κB binding site and that methylation here blocks transcription factor binding to the GATA3 promoter in the human Jurkat T-cell line. Associations between umbilical cord methylation of CpG loci within IL-4R with atopic eczema at 12 months (median ratio 1.02, P = .028), and TBET with atopy (median ratio 0.98, P = .017) at 6-7 years of age were also observed. Conclusions and Clinical Relevance Our findings provide further evidence of a developmental contribution to the risk of later allergic disorders and suggest that involvement of epigenetic mechanisms in childhood asthma is already demonstrable at birth. [ABSTRACT FROM AUTHOR]

Two novel through-bond energy transfer (TBET) based naphthoquinone derivatives, R1 and R2, have been designed and synthesized with characteristics of a dyad (rhodamine-quinone) and a triad (rhodamine-quinone-rhodamine), respectively. Probes R1 and R2 selectively sense Hg 2+ ions over other common interference metal ions in aqueous-methanol medium with a broad pH range (6.0–8.0). By the combination of dual functions, (i.e., fluorescence off-on (rhodamine) and TBET off-on (through a conjugation linker) processes), the proposed TBET-probes exhibit very large pseudo-Stokes shifts, with a wavelength difference ≈210 nm, and high energy transfer efficiency for the detection of Hg 2+ with a detection limit of 41 nM. The fluorescence intensity of the triad ( R2 ) is nearly 2 orders of magnitude greater than that of the dyad R1 due to the existence of two rhodamine fragments. The OFF-ON fluorescence effect of the TBET cassettes regains the ON-OFF mode by subsequent addition of the I − ion. The optical restoring behavior of the R1 / R2 -Hg 2+ complex with I − could be potentially be applied as an INHIBIT molecular logic gate with the combination of YES and NOT functions. Finally, the Hg 2+ ion sensing ability of TBET probes R1 and R2 was utilized in a HeLa cell imaging application, and the probe R1 was used to monitor the Hg 2+ ion in live zebrafish. [ABSTRACT FROM AUTHOR]

The importance of classical CD8 + T cells in tumor eradication is well acknowledged. However, the anti-tumor activity of MHC (major histocompatibility complex) Ib-restricted CD8 + T (Ib-CD8 + T) cells remains obscure. Here, we show that CX3CR1-expressing Ib-CD8 + T cells (Ib-restricted CD8 + T cells) highly express cytotoxic factors, austerely resist exhaustion, and effectively eliminate various tumors. These Ib-CD8 + T cells can be primed by MHC Ia (MHC class Ia molecules) expressed on various cell types for optimal activation in a Tbet-dependent manner. Importantly, MHC Ia does not allogeneically activate Ib-CD8 + T cells, rather, sensitizes these cells for T cell receptor activation. Such effects were observed when MHC Ia + cells were administered to tumor-bearing K b-/- D b-/- mice. A similar population of tumoricidal CX3CR1 + CD8 + T cells was identified in wild-type mice and melanoma patients. Adoptive transfer of Ib-CD8 + T cells to wild-type mice inhibited tumor progression without damaging normal tissues. Taken together, we demonstrate that MHC class Ia can prime Ib-CD8 + T cells for robust tumoricidal activities.

Background: The ability to identify clinically isolated syndrome (CIS) patients at high risk of progression to clinically definite multiple sclerosis (CDMS) would be clinically beneficial. The initiation of T cell mediated autoimmune diseases such as multiple sclerosis (MS) requires the initial inappropriate activation and differentiation of auto-reactive CD4 T cells. The quiescence of naive T cells is actively maintained by molecules such as TOB1, which control the threshold of activation. Upon activation, CD4 T cells can differentiate into various subsets depending on the milieu present. Th1 and Th17 cells are strongly implicated in MS, while regulatory T (Treg) cells constrain autoimmune inflammation and prevent autoimmunity. Findings: We therefore investigated the expression of TOB1, CD44 and Treg, Th1 and Th17 transcription factors in relation to CIS progression. The expression of TOB1, CD44, FOXP3, TBX21 and RORC genes were measured in CD4 T cells from 10 healthy controls, 20 CIS patients within 3 months of initial clinical presentation and 10 relapsing remitting MS patients sampled within 2 months of relapse. CIS patients were subsequently grouped into those who converted to CDMS within 1 year and those who remained CIS. No differences in the expression of TOB1, CD44, FOXP3 and RORC were observed. There was a significant increase in the expression of the Th1 transcription factor Tbet, encoded by TBX21, in CIS patients that converted within 1 year compared with those who did not. Conclusion: This pilot data suggests a role for Th1 cells in CIS progression and warrants further evaluation in a larger cohort. [ABSTRACT FROM AUTHOR]

Background : COVID-19 is known to disrupt immune response and induce hyperinflammation that could potentially induce fatal outcome of the disease. Until now, it is known that interplay among cytokines is rather important for clinical presentation and outcome of COVID-19. The aim of this study was to determine transcriptional activity and functional phenotype of T cells and the relationship between pro- and anti-inflammatory cytokines and clinical parameters of COVID-19 severity. Methods : All recruited patients met criteria for COVID-19 are were divided in four groups according to disease severity. Serum levels of IL-12, IFN-γ, IL-17 and IL-23 were measured, and flow cytometry analysis of T cells from peripheral blood was performed. Results : Significant elevation of IL-12, IFN-γ, IL-17 and IL-23 in stage IV of the disease has been revealed. Further, strong intercorrelation between IL-12, IFN-γ, IL-17 and IL-23 was also found in stage IV of the disease, marking augmented Th1 and Th17 response. Analyses of T cells subsets indicate a noticeable phenotype change. CD4 + , but not CD8 + T cells expressed increased transcriptional activity through increased expression of Tbet and RORγT, accompanied with increased percentage of IFN-γ and IL-17 producing T cells. Conclusion : Our results pose a novel hypothesis of the underlying mechanism behind deteriorating immune response in severe cases of COVID-19., Competing Interests: Competing Interests: The authors have declared that no competing interest exists., (© The author(s).)

We have designed and synthesized known coumarin-rhodamine (CR1) derivative for sensing the Al3+ion in the presence of aprotic (CH3CN/H2O) medium via TBET mechanism. The results of the photo physical studies revealed that the sensing mechanism involves Al3+induced change from non-fluoroscent (spirolactam form) to fluorescent (ring opening form) inCR1leading to the visible color change. The Job's plot indicated the formation of 2:1 complex betweenCR1and Al3+with limit of detection is 1.78 × 10−8M. Various spectroscopy techniques and theoretical calculation have been employed to investigate the mechanism of the sensing property ofCR1with Al3+. [ABSTRACT FROM AUTHOR]

Fluorescent labelling of specific proteins in complex biological systems remains an important challenge in chemical biology. One promising approach comprises the use of small molecules designed to react specifically with a targeted protein of interest and to increase in fluorescent intensity following this reaction. This kind of fluorogenic reaction generally derives from fluorescence quenching in the unreacted probe that is abrogated over the course of the reaction. Herein, we review the mechanistic principles of three major photophysical quenching mechanisms involving Förster resonance energy transfer (FRET), through-bond energy transfer (TBET), and photoinduced electron transfer (PeT). We then present design principles for novel fluorogenic probes based on an understanding of these quench mechanisms, with emphasis on the emerging utility of density functional theory (DFT) calculations in the design process. [ABSTRACT FROM AUTHOR]

Just over a decade ago, it was established that NK cells in the thymus do not follow precisely the same developmental pathway as conventional NK cells that develop in the bone marrow. Subsequently, it has emerged that NK cells are one branch of a family of innate lymphoid cells (ILCs). ILC1s and thymic NK cells have, however, sufficient similarities such that questions have been raised about how distinctive each cell type is from the other. In this issue of European Journal of Immunology, Gabrielli et al. [Eur. J. Immunol. 2017. 47: 800-805] make a detailed study of the transcription factor requirements of murine thymic NK cells. They provide a valuable insight into the distinctive identity of thymic NK cells with regard to Tbet, Nfil3, Id2, and Ets1. In addition, they clarify the nature of DX5 expression on NK cells and ILC-like cells in the murine thymus. [ABSTRACT FROM AUTHOR]

• ARG1 was the only studied gene significantly elevated in CML patients at diagnosis. • ARG1 normalized to control levels at 3 months only in optimal responder patients. • TBET expression reached normal level after 12 months in both groups of patients. • CIITA expression continued downregulated during the first year of treatment. • IL10 and TGFB1 expression achieved normal levels early at 3 months in both groups. The use of tyrosine kinase inhibitors seems to restore the broadly compromised immune system described in chronic myeloid leukaemia (CML) patients at diagnosis leading to a re-activation of the effector-mediated immune surveillance. Here, we describe the expression dynamics of immune factors during the first year on imatinib therapy. Gene expression was evaluated in 132 peripheral blood samples from 79 CML patients, including 34 who were serially followed. An aliquot of the stored sample used to monitor BCR-ABL1 levels was retro -transcribed to cDNA and gene expression was quantified by real-time PCR. An elevated expression of ARG1 was observed at diagnosis, while TBET , CIITA , IL10 and TGFB1 were significantly decreased. Once on therapy, each gene displayed a particular behaviour. ARG1 normalized to control levels at 3 months only in optimal molecular responders and was identified as the major contributor to the difference among patients. TBET reached normal levels after 12 months in optimal responders and non-responders, regardless the Th1-response previously associated, and CIITA continued downregulated. IL10 and TGFB1 achieved normal levels early at 3 months in both groups, afterwards IL10 was sustained while TGFB1 was slightly increased after 1 year in responders. Our findings are in agreement with an immune re-activation after imatinib initiation; however, some immune mediators may require a longer exposition. The follow-up of novel and reliable biomarkers, such as ARG1 , one of the principal mechanisms of myeloid-derived-suppressor cells to inhibit immune system, may be useful to deepen the characterization of early responder patients. [ABSTRACT FROM AUTHOR]

Classical hairy cell leukaemia (HCLc), its variant form (HCLv), and splenic diffuse red pulp lymphoma (SDRPL) constitute a subset of relatively indolent B cell tumours, with low incidence rates of high-grade transformations, which primarily involve the spleen and bone marrow and are usually associated with circulating tumour cells characterised by villous or irregular cytoplasmic borders. The primary aim of this review is to summarise their cytogenetic, genomic, immunogenetic, and epigenetic features, with a particular focus on the clonal BRAFV600E mutation, present in most cases currently diagnosed with HCLc. We then reflect on their cell of origin and pathogenesis as well as present the clinical implications of improved biological understanding, extending from diagnosis to prognosis assessment and therapy response.

• T cells are critical for protective immunity but can also induce graft rejection. • T cell differentiation is primarily regulated by intrinsic transcriptional pathways. • New reports suggest that context-dependent T cell differentiation programs exist. • Recent advances and implications for transplantation will be discussed. • Specifically, IRF4, Tbet/Eomes and regulation of tissue-resident memory cells (Trm). • Understanding these pathways may aid the development of novel anti-rejection therapies. While T cells play a critical role in protective immunity against infection, they are also responsible for graft rejection in the setting of transplantation. T cell differentiation is regulated by both intrinsic transcriptional pathways as well as extrinsic factors such as antigen encounter and the cytokine milieu. Herein, we review recent discoveries in the transcriptional regulation of T cell differentiation and their impact on the field of transplantation. Recent studies uncovering context-dependent differentiation programs that differ in the setting of infection or transplantation will also be discussed. Understanding the key transcriptional pathways that underlie T cell responses in transplantation has important clinical implications, including development of novel therapeutic agents to mitigate graft rejection. [ABSTRACT FROM AUTHOR]

Vaccine-induced memory B cell responses to evolving viruses like influenza A involve activation of pre-existing immunity and generation of new responses. To define the contribution of these two types of responses, we analyzed the response to H7N9 vaccination in H7N9-naive adults. We performed comprehensive comparisons at the single-cell level of the kinetics, Ig repertoire, and activation phenotype of established pre-existing memory B cells recognizing conserved epitopes and the newly generated memory B cells directed toward H7 strain-specific epitopes. The recall response to conserved epitopes on H7 HA involved a transient expansion of memory B cells with little observed adaptation. However, the B cell response to newly encountered epitopes was phenotypically distinct and generated a sustained memory population that evolved and affinity matured months after vaccination. These findings establish clear differences between newly generated and pre-existing memory B cells, highlighting the challenges in achieving long-lasting, broad protection against an ever-evolving virus. • Newly generated memory B cells evolve and affinity mature over several months • Long-term pre-existing memory B cells evolve little upon re-vaccination • Newly generated memory B cells transiently become atypical, T-bethi CD21lo CD27− • T-betlo CD21hi CD27−, but not CD27+, resting memory B cells are maintained long-term Influenza vaccination occurs in the context of pre-existing immunity. Andrews et al. compare the pre-existing memory IgG B cell response recognizing conserved epitopes on influenza hemagglutinin with the newly generated response to strain-specific epitopes upon H7N9 vaccination. The differences in magnitude, phenotype, and affinity maturation between the two responses highlight the challenges in achieving long-lasting, broad protection against an ever-evolving virus. [ABSTRACT FROM AUTHOR]

Iron is an essential nutrient needed for physiological functions, particularly during the developmental period of the early childhood of at-risk populations. The purpose of this study was to investigate, in an experimental colitis, the consequences of daily oral iron ingestion in the early period on the inflammatory response, the spleen T helper (Th) profiles and the associated molecular mechanisms. Juvenile mice orally received microencapsulated ferric iron or water for 6 weeks. On adult mice, we induced a sham or experimental trinitrobenzene sulfonic acid (TNBS) moderate colitis during the last week of the experiment before sacrificing the animals 7 days later. The severity of the gut inflammation was assessed by macroscopic damage scores (MDS) and the myeloperoxidase activity (MPO). Th profiles were evaluated by the examination of the splenic gene expression of key transcription factors of the Th differentiation (Tbet, Gata3, Foxp3 and RORγ) and the methylation of their respective promoter. While TNBS-induced colitis was associated with a change of the Th profile (notably an increase in the Tbet/Gata3 ratio in the spleen), the colitis-inhibition induced by ferric iron was associated with a limitation of the splenic Th profiles perturbation. The inhibition of the splenic Tbet gene overexpression was associated with an inhibition of promoter hypomethylation. In summary, mice treated by long-term oral ferric iron in the early period of life exhibited an inhibition of colitis associated with the inhibition of the splenic Tbet promoter hypomethylation and gene overexpression. [ABSTRACT FROM AUTHOR]