Impact of species and antibiotic therapy of enterococcal peritonitis on 30-day mortality in critical care - An analysis of the OUTCOMEREA database

Introduction: Enterococcus species are associated with an increased morbidity in intraabdominal infections (IAI). However, their impact on mortality remains uncertain. Moreover, the influence on outcome of the appropriate or inappropriate status of initial antimicrobial therapy (IAT) is subjected to debate, except in septic shock. The aim of our study was to evaluate whether an IAT that did not cover Enterococcus spp. was associated with 30-day mortality in ICU patients presenting with IAI growing with Enterococcus spp. Material and methods: Retrospective analysis of French database OutcomeRea from 1997 to 2016. We included all patients with IAI with a peritoneal sample growing with Enterococcus. Primary endpoint was 30-day mortality. Results: Of the 1017 patients with IAI, 76 (8%) patients were included. Thirty-day mortality in patients with inadequate IAT against Enterococcus was higher (7/18 (39%) vs 10/58 (17%), p = 0.05); however, the incidence of postoperative complications was similar. Presence of Enterococcus spp. other than E. faecalis alone was associated with a significantly higher mortality, even greater when IAT was inadequate. Main risk factors for having an Enterococcus other than E. faecalis alone were as follows: SAPS score on day 0, ICU-acquired IAI, and antimicrobial therapy within 3 months prior to IAI especially with third-generation cephalosporins. Univariate analysis found a higher hazard ratio of death with an Enterococcus other than E. faecalis alone that had an inadequate IAT (HR = 4.4 [1.3-15.3], p = 0.019) versus an adequate IAT (HR = 3.1 [1.0-10.0], p = 0.053). However, after adjusting for confounders (i.e., SAPS II and septic shock at IAI diagnosis, ICU-acquired peritonitis, and adequacy of IAT for other germs), the impact of the adequacy of IAT was no longer significant in multivariate analysis. Septic shock at diagnosis and ICU-acquired IAI were prognostic factors. Conclusion: An IAT which does not cover Enterococcus is associated with an increased 30-day mortality in ICU patients presenting with an IAI growing with Enterococcus, especially when it is not an E. faecalis alone. It seems reasonable to use an IAT active against Enterococcus in severe postoperative ICU-acquired IAI, especially when a third-generation cephalosporin has been used within 3 months. © 2019 The Author(s)

The relationship of mRNA with protein expression in CD8+ T cells associates with gene class and gene characteristics

T cells are key players in our defence against infections and malignancies. When T cells differentiate or become activated, they undergo substantial alterations in gene expression. Even though RNA expression levels are now well documented throughout different stages of T cells, it is not well understood how mRNA expression translates into the protein landscape. By combining paired RNA sequencing and mass spectrometry data of primary human CD8+ T cells, we report that mRNA expression is a poor proxy for the overall protein output, irrespective of the differentiation or activation status. Yet, gene class stratification revealed a function-specific correlation of mRNA with protein expression. This gene class-specific expression pattern associated with differences in gene characteristics such as sequence conservation and untranslated region (UTR) lengths. In addition, the presence of AU-rich elements in the 3’UTR associated with alterations in mRNA and protein abundance T cell activation dependent, gene class-specific manner. In conclusion, our study highlights the role of gene characteristics as a determinant for gene expression in T cells

CD29 identifies IFN-γ-producing human CD8+ T cells with an increased cytotoxic potential

Cytotoxic CD8+ T cells can effectively kill target cells by producing cytokines, chemokines, and granzymes. Expression of these effector molecules is however highly divergent, and tools that identify and preselect CD8+ T cells with a cytotoxic expression profile are lacking. Human CD8+ T cells can be divided into IFN-γ- and IL-2-producing cells. Unbiased transcriptomics and proteomics analysis on cytokine-producing fixed CD8+ T cells revealed that IL-2+ cells produce helper cytokines, and that IFN-γ+ cells produce cytotoxic molecules. IFN-γ+ T cells expressed the surface marker CD29 already prior to stimulation. CD29 also marked T cells with cytotoxic gene expression from different tissues in single-cell RNA-sequencing data. Notably, CD29+ T cells maintained the cytotoxic phenotype during cell culture, suggesting a stable phenotype. Preselecting CD29-expressing MART1 TCR-engineered T cells potentiated the killing of target cells. We therefore propose that CD29 expression can help evaluate and select for potent therapeutic T cell products

CD29 identifies IFN-γ-producing human CD8+ T cells with an increased cytotoxic potential

Cytotoxic CD8+ T cells can effectively kill target cells by producing cytokines, chemokines, and granzymes. Expression of these effector molecules is however highly divergent, and tools that identify and preselect CD8+ T cells with a cytotoxic expression profile are lacking. Human CD8+ T cells can be divided into IFN-γ- and IL-2-producing cells. Unbiased transcriptomics and proteomics analysis on cytokine-producing fixed CD8+ T cells revealed that IL-2+ cells produce helper cytokines, and that IFN-γ+ cells produce cytotoxic molecules. IFN-γ+ T cells expressed the surface marker CD29 already prior to stimulation. CD29 also marked T cells with cytotoxic gene expression from different tissues in single-cell RNA-sequencing data. Notably, CD29+ T cells maintained the cytotoxic phenotype during cell culture, suggesting a stable phenotype. Preselecting CD29-expressing MART1 TCR-engineered T cells potentiated the killing of target cells. We therefore propose that CD29 expression can help evaluate and select for potent therapeutic T cell products

The two enantiomers of 2-hydroxyglutarate differentially regulate cytotoxic T cell function

2-Hydroxyglutarate (2HG) is a byproduct of the tricarboxylic acid (TCA) cycle and is readily detected in the tissues of healthy individuals. 2HG is found in two enantiomeric forms: S-2HG and R-2HG. Here, we investigate the differential roles of these two enantiomers in cluster of differentiation (CD)8+ T cell biology, where we find they have highly divergent effects on proliferation, differentiation, and T cell function. We show here an analysis of structural determinants that likely underlie these differential effects on specific a-ketoglutarate (aKG)-dependent enzymes. Treatment of CD8+ T cells with exogenous S-2HG, but not R-2HG, increased CD8+ T cell fitness in vivo and enhanced anti-tumor activity. These data show that S-2HG and R-2HG should be considered as two distinct and important actors in the regulation of T cell function

Polyfunctional tumor-reactive T cells are effectively expanded from non-small cell lung cancers, and correlate with an immune-engaged T cell profile

Non-small cell lung cancer (NSCLC) is the second most prevalent type of cancer. With the current treatment regimens, the mortality rate remains high. Therefore, better therapeutic approaches are necessary. NSCLCs generally possess many genetic mutations and are well infiltrated by T cells (TIL), making TIL therapy an attractive option. Here we show that T cells from treatment naive, stage I-IVa NSCLC tumors can effectively be isolated and expanded, with similar efficiency as from normal lung tissue. Importantly, 76% (13/17) of tested TIL products isolated from NSCLC lesions exhibited clear reactivity against primary tumor digests, with 0.5%-30% of T cells producing the inflammatory cytokine Interferon (IFN)-γ. Both CD4+ and CD8+ T cells displayed tumor reactivity. The cytokine production correlated well with CD137 and CD40L expression. Furthermore, almost half (7/17) of the TIL products contained polyfunctional T cells that produced Tumor Necrosis Factor (TNF)-α and/or IL-2 in addition to IFN-γ, a hallmark of effective immune responses. Tumor-reactivity in the TIL products correlated with high percentages of CD103+CD69+CD8+ T cell infiltrates in the tumor lesions, with PD-1hiCD4+ T cells, and with FoxP3+CD25+CD4+ regulatory T cell infiltrates, suggesting that the composition of T cell infiltrates may predict the level of tumor reactivity. In conclusion, the effective generation of tumor-reactive and polyfunctional TIL products implies that TIL therapy will be a successful treatment regimen for NSCLC patients