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Epoxidation of linseed oil fatty acid ethyl esters promoted by a series of functionalized imidazolium ionic liquids was studied. In this reaction acidic imidazolium ILs behave not only as an acid catalysts but also play an additional role as a specific activator for the reaction of epoxidation of unsaturated fatty derivatives in H2O2/formic acid oxidation system. The obtained results indicate that the hydrogen‐bonding interaction of imidazolium cation with epoxide group influences the selectivity of the epoxidation reaction. In particular, the presence of unprotected weak "acid" C2‐H proton significantly lowers the selectivity to hydroxyl derivatives. The obtained results also point to another example of specific polyfunctionality of ILs, especially imidazolium one, used as surfactants and process activators. [ABSTRACT FROM AUTHOR]

SARS‐CoV‐2 specific T‐cell response has been associated with disease severity, immune memory and heterologous response to endemic coronaviruses. However, an integrative approach combining a comprehensive analysis of the quality of SARS‐CoV‐2 specific T‐cell response with antibody levels in these three scenarios is needed. In the present study, we found that, in acute infection, while mild disease was associated with high T‐cell polyfunctionality biased to IL‐2 production and inversely correlated with anti‐S IgG levels, combinations only including IFN‐γ with the absence of perforin production predominated in severe disease. Seven months after infection, both non‐hospitalised and previously hospitalised patients presented robust anti‐S IgG levels and SARS‐CoV‐2 specific T‐cell response. In addition, only previously hospitalised patients showed a T‐cell exhaustion profile. Finally, combinations including IL‐2 in response to S protein of endemic coronaviruses were the ones associated with SARS‐CoV‐2 S‐specific T‐cell response in pre‐COVID‐19 healthy donors' samples. These results could have implications for protective immunity against SARS‐CoV‐2 and recurrent COVID‐19 and may help for the design of new prototypes and boosting vaccine strategies. [ABSTRACT FROM AUTHOR]

Long‐lived T‐memory stem cells (TSCM) are key to both naturally occurring and vaccine‐conferred protection against infection. These cells are characterized by the CD45RA+CCR7+CD95+ phenotype. Significant heterogeneity within the TSCM population is recognized, but distinguishing surface markers and functional characterization of potential subsets are lacking. Human CD8 TSCM subsets were identified in healthy subjects who had been previously exposed to CMV or Influenza (Flu) virus in flow cytometry by expression of CD122 or CXCR3, and then characterized in proliferation, multipotency, self‐renewal, and intracellular cytokine production (TNF‐α, IL‐2, IFN‐γ), together with transcriptomic profiles. The TSCMCD122hi‐expressing subset (versus CD122lo) demonstrated greater proliferation, greater multipotency, and enhanced polyfunctionality with higher frequencies of triple positive (TNF‐α, IL‐2, IFN‐γ) cytokine‐producing cells upon exposure to recall antigen. The TSCMCXCR3lo subpopulation also had increased proliferation and polyfunctional cytokine production. Transcriptomic analysis further showed that the TSCMCD122hi population had increased expression of activation and homing molecules, such as Ccr6, Cxcr6, Il12rb, and Il18rap, and downregulated cell proliferation inhibitors, S100A8 and S100A9. These data reveal that the TSCMCD122hi phenotype is associated with increased proliferation, enhanced multipotency and polyfunctionality with an activated memory‐cell like transcriptional profile, and hence, may be favored for induction by immunization and for adoptive immunotherapy. [ABSTRACT FROM AUTHOR]

Polyfunctionality/multifunctionality of effector T cells at the single cell level has been shown as an important parameter to predict the quality of T cell response and immunological control of infectious disease and malignancy. However, the fate of polyfunctional CD8+ CTLs and the factors that control the polyfunctionality of T cells remain largely unknown. Here we show that the acquisition of polyfunctionality on the initial stimulation is a sensitive immune correlate of CTL survival and memory formation. CD8+ T cells with high polyfunctionality, assessed with γ‐interferon and tumor necrosis factor‐α production and surface mobilization of the degranulation marker CD107a, showed enhanced Bcl‐2 expression, low apoptosis, and increased CD127highKLRG1low memory precursor phenotype. Consistent with these observations, CD8+ T cells were found to acquire high frequency of cells with polyfunctionality when stimulated in conditions known to enhance memory formation, such as the presence of CD4+ T cells, interleukin (IL)‐2, or IL‐21. Utilizing T‐cell receptor (TCR) transgenic mouse‐derived CD8+ T cells that express a TCR specific for a tumor‐derived neoantigen, we showed that polyfunctional tumor‐specific CTLs generated in the presence of CD4+ T cells showed long persistence in vivo and induced enhanced tumor regression when adoptively transferred into mice with progressing tumor. Acquisition of polyfunctionality thus impacts CTL survival and memory formation associated with immunological control of tumor. [ABSTRACT FROM AUTHOR]

Summary: Primary and chronic human immunodeficiency virus (HIV) infection alters γδ T‐cell features. However, there is no evidence about early combined antiretroviral therapy (cART) and γδ T‐cell dynamics. In the present study, HIV‐positive individuals were divided into those with early primary infection (EPI) and those with late primary infection (LPI). The analysis of γδ T cells was performed by flow cytometry before and after therapy. Polyfunctional profile was assessed after in vitro peripheral blood mononuclear cell (PBMC) exposure to specific antigens. The results show that primary infection induced an expansion of Vδ1 T cells in LPI. Before treatment, a massive activation of γδ T‐cell subsets was observed in both groups of patients, that correlated with disease progression and was significantly reduced after cART introduction. Despite this, CD107A‐expressing Vδ1 T cells in both groups were significantly fewer than in healthy donors, but were restored by therapy introduction. Polyfunctional analysis of Vδ1 T cells from HIV‐positive individuals revealed a lower frequency of CD107A+ CCL‐4+ Vδ1 T‐cell subsets than healthy donors that persists after therapy. Functional profile of Vδ2 was similar to that in healthy donors before therapy but, at 6 months, a lower frequency of CD107A, interferon‐γ‐ or tumor necrosis factor‐α‐producing Vδ2 T cells was observed in the EPI group. Finally, individuals with LPI showed a lower frequency of quadruple‐functional Vδ2 T‐cell subset. In conclusion, during primary HIV infection, the baseline Vδ1 T‐cell activation is correlated with immune reconstitution potential. Moreover, an altered γδ polyfunctional profile occurred, persisting after cART. Further studies are needed to understand whether a longer treatment of primary infection may increase γδ T‐cell functionality. [ABSTRACT FROM AUTHOR]

An important aspect of immune monitoring for vaccine development, clinical trials, and research is the detection, measurement, and comparison of antigen-specific T-cells from subject samples under different conditions. Antigen-specific T-cells compose a very small fraction of total T-cells. Developments in cytometry technology over the past five years have enabled the measurement of single-cells in a multivariate and high-throughput manner. This growth in both dimensionality and quantity of data continues to pose a challenge for effective identification and visualization of rare cell subsets, such as antigen-specific T-cells. Dimension reduction and feature extraction play pivotal role in both identifying and visualizing cell populations of interest in large, multi-dimensional cytometry datasets. However, the automated identification and visualization of rare, high-dimensional cell subsets remains challenging. Here we demonstrate how a systematic and integrated approach combining targeted feature extraction with dimension reduction can be used to identify and visualize biological differences in rare, antigen-specific cell populations. By using OpenCyto to perform semi-automated gating and features extraction of flow cytometry data, followed by dimensionality reduction with t-SNE we are able to identify polyfunctional subpopulations of antigen-specific T-cells and visualize treatment-specific differences between them. © 2015 International Society for Advancement of Cytometry [ABSTRACT FROM AUTHOR]