Publications by authors named "Ayelet Alpert"

8 Publications

  • Page 1 of 1

TIM-3 Genetic Variants Are Associated with Altered Clinical Outcome and Susceptibility to Gram-Positive Infections in Patients with Sepsis.

Int J Mol Sci 2020 Nov 6;21(21). Epub 2020 Nov 6.

Department of Anesthesiology, University Medical Center, Georg August University, D-37075 Goettingen, Germany.

: Previous studies have reported the fundamental role of immunoregulatory proteins in the clinical phenotype and outcome of sepsis. This study investigated two functional single nucleotide polymorphisms (SNPs) of T cell immunoglobulin and mucin domain-containing protein 3 (TIM-3), which has a negative stimulatory function in the T cell immune response. : Patients with sepsis ( = 712) were prospectively enrolled from three intensive care units (ICUs) at the University Medical Center Goettingen since 2012. All patients were genotyped for the TIM-3 SNPs rs1036199 and rs10515746. The primary outcome was 28-day mortality. Disease severity and microbiological findings were secondary endpoints. : Kaplan-Meier survival analysis demonstrated a significantly lower 28-day mortality for TIM-3 rs1036199 AA homozygous patients compared to C-allele carriers (18% vs. 27%, = 0.0099) and TIM-3 rs10515746 CC homozygous patients compared to A-allele carriers (18% vs. 26%, = 0.0202). The TIM-3 rs1036199 AA genotype and rs10515746 CC genotype remained significant predictors for 28-day mortality in the multivariate Cox regression analysis after adjustment for relevant confounders (adjusted hazard ratios: 0.67 and 0.70). Additionally, patients carrying the rs1036199 AA genotype presented more Gram-positive and infections, and rs10515746 CC homozygotes presented more infections. : The studied TIM-3 genetic variants are associated with altered 28-day mortality and susceptibility to Gram-positive infections in sepsis.
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http://dx.doi.org/10.3390/ijms21218318DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7664272PMC
November 2020

Response to: 'Tofacitinib for the treatment of polyarteritis nodosa: a literature review' by Akiyama .

Ann Rheum Dis 2020 Sep 9. Epub 2020 Sep 9.

Department of Immunology, Ruth and Bruce Rappaport Faculty of Medicine, Technion Israel Institute of Technology, Haifa, Israel.

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http://dx.doi.org/10.1136/annrheumdis-2020-218790DOI Listing
September 2020

A clinically meaningful metric of immune age derived from high-dimensional longitudinal monitoring.

Nat Med 2019 03 6;25(3):487-495. Epub 2019 Mar 6.

Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel.

Immune responses generally decline with age. However, the dynamics of this process at the individual level have not been characterized, hindering quantification of an individual's immune age. Here, we use multiple 'omics' technologies to capture population- and individual-level changes in the human immune system of 135 healthy adult individuals of different ages sampled longitudinally over a nine-year period. We observed high inter-individual variability in the rates of change of cellular frequencies that was dictated by their baseline values, allowing identification of steady-state levels toward which a cell subset converged and the ordered convergence of multiple cell subsets toward an older adult homeostasis. These data form a high-dimensional trajectory of immune aging (IMM-AGE) that describes a person's immune status better than chronological age. We show that the IMM-AGE score predicted all-cause mortality beyond well-established risk factors in the Framingham Heart Study, establishing its potential use in clinics for identification of patients at risk.
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http://dx.doi.org/10.1038/s41591-019-0381-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6686855PMC
March 2019

CTLA-4 Genetic Variants Predict Survival in Patients with Sepsis.

J Clin Med 2019 Jan 10;8(1). Epub 2019 Jan 10.

Department of Anesthesiology, University Medical Center, Georg August University, D-37075 Goettingen, Germany.

Cytotoxic T lymphocyte-associated protein 4 (CTLA-4) is a coinhibitory checkpoint protein expressed on the surface of T cells. A recent study by our working group revealed that the rs231775 single nucleotide polymorphism (SNP) in the CTLA-4 gene was associated with the survival of patients with sepsis and served as an independent prognostic variable. To further investigate the impact of CTLA-4 genetic variants on sepsis survival, we examined the effect of two functional SNPs, CTLA-4 rs733618 and CTLA-4 rs3087243, and inferred haplotypes, on the survival of 644 prospectively enrolled septic patients. Kaplan⁻Meier survival analysis revealed significantly lower 90-day mortality for rs3087243 G allele carriers ( = 502) than for AA-homozygous ( = 142) patients (27.3% vs. 40.8%, = 0.0024). Likewise, lower 90-day mortality was observed for TAA haplotype-negative patients ( = 197; compound rs733618 T/rs231775 A/rs3087243 A) than for patients carrying the TAA haplotype ( = 447; 24.4% vs. 32.9%, = 0.0265). Carrying the rs3087243 G allele hazard ratio (HR): 0.667; 95% confidence interval (CI): 0.489⁻0.909; = 0.0103) or not carrying the TAA haplotype (HR: 0.685; 95% CI: 0.491⁻0.956; = 0.0262) remained significant covariates for 90-day survival in the multivariate Cox regression analysis and thus served as independent prognostic variables. In conclusion, our findings underscore the significance of CTLA-4 genetic variants as predictors of survival of patients with sepsis.
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http://dx.doi.org/10.3390/jcm8010070DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6352177PMC
January 2019

UV-Protection Timer Controls Linkage between Stress and Pigmentation Skin Protection Systems.

Mol Cell 2018 11 25;72(3):444-456.e7. Epub 2018 Oct 25.

Department of Human Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel. Electronic address:

Skin sun exposure induces two protection programs: stress responses and pigmentation, the former within minutes and the latter only hours afterward. Although serving the same physiological purpose, it is not known whether and how these programs are coordinated. Here, we report that UVB exposure every other day induces significantly more skin pigmentation than the higher frequency of daily exposure, without an associated increase in stress responses. Using mathematical modeling and empirical studies, we show that the melanocyte master regulator, MITF, serves to synchronize stress responses and pigmentation and, furthermore, functions as a UV-protection timer via damped oscillatory dynamics, thereby conferring a trade-off between the two programs. MITF oscillations are controlled by multiple negative regulatory loops, one at the transcriptional level involving HIF1α and another post-transcriptional loop involving microRNA-148a. These findings support trait linkage between the two skin protection programs, which, we speculate, arose during furless skin evolution to minimize skin damage.
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http://dx.doi.org/10.1016/j.molcel.2018.09.022DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6224604PMC
November 2018

The CTLA-4 rs231775 GG genotype is associated with favorable 90-day survival in Caucasian patients with sepsis.

Sci Rep 2018 10 11;8(1):15140. Epub 2018 Oct 11.

Department of Anesthesiology, University Medical Center, Georg August University, Robert-Koch-Str. 40, D-37075, Goettingen, Germany.

Cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) is a surface protein on T cells, that has an inhibitory effect on the host immune reaction and prevents overreaction of the immune system. Because the functional single-nucleotide polymorphism (SNP) rs231775 of the CTLA-4 gene is associated with autoimmune diseases and because of the critical role of the immune reaction in sepsis, we intended to examine the effect of this polymorphism on survival in patients with sepsis. 644 septic adult Caucasian patients were prospectively enrolled in this study. Patients were followed up for 90 days. Mortality risk within this period was defined as primary outcome parameter. Kaplan-Meier survival analysis revealed a significantly lower 90-day mortality risk among GG homozygous patients (n = 101) than among A allele carriers (n = 543; 22% and 32%, respectively; p = 0.03565). Furthermore, the CTLA-4 rs231775 GG genotype remained a significant covariate for 90-day mortality risk after controlling for confounders in the multivariate Cox regression analysis (hazard ratio: 0.624; 95% CI: 0.399-0.975; p = 0.03858). In conclusion, our study provides the first evidence for CTLA-4 rs231775 as a prognostic variable for the survival of patients with sepsis and emphasizes the need for further research to reveal potential functional associations between CTLA-4 and the immune pathophysiology of sepsis.
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http://dx.doi.org/10.1038/s41598-018-33246-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6181961PMC
October 2018

Alignment of single-cell trajectories to compare cellular expression dynamics.

Nat Methods 2018 04 12;15(4):267-270. Epub 2018 Mar 12.

Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel.

Single-cell RNA sequencing and high-dimensional cytometry can be used to generate detailed trajectories of dynamic biological processes such as differentiation or development. Here we present cellAlign, a quantitative framework for comparing expression dynamics within and between single-cell trajectories. By applying cellAlign to mouse and human embryonic developmental trajectories, we systematically delineate differences in the temporal regulation of gene expression programs that would otherwise be masked.
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http://dx.doi.org/10.1038/nmeth.4628DOI Listing
April 2018

Tofacitinib for polyarteritis nodosa: a tailored therapy.

Ann Rheum Dis 2016 12 24;75(12):2214-2216. Epub 2016 Aug 24.

Department of Immunology, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel.

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http://dx.doi.org/10.1136/annrheumdis-2016-209330DOI Listing
December 2016