Marie Ravoet

CD4+ follicular helper T cell infiltration predicts breast cancer survival

CD4⁺ T cells are critical regulators of immune responses, but their functional role in human breast cancer is relatively unknown. The goal of this study was to produce an image of CD4⁺ T cells infiltrating breast tumors using limited ex vivo manipulation to better understand the in vivo differences associated with patient prognosis. We performed comprehensive molecular profiling of infiltrating CD4⁺ T cells isolated from untreated invasive primary tumors and found that the infiltrating T cell subpopulations included follicular helper T (Tfh) cells, which have not previously been found in solid tumors, as well as Th1, Th2, and Th17 effector memory cells and Tregs. T cell signaling pathway alterations included a mixture of activation and suppression characterized by restricted cytokine/chemokine production, which inversely paralleled lymphoid infiltration levels and could be reproduced in activated donor CD4⁺ T cells treated with primary tumor supernatant. A comparison of extensively versus minimally infiltrated tumors showed that CXCL13-producing CD4⁺ Tfh cells distinguish extensive immune infiltrates, principally located in tertiary lymphoid structure germinal centers. An 8-gene Tfh signature, signifying organized antitumor immunity, robustly predicted survival or preoperative response to chemotherapy. Our identification of CD4⁺ Tfh cells in breast cancer suggests that they are an important immune element whose presence in the tumor is a prognostic factor.

Implementation of genomic arrays in prenatal diagnosis: The Belgian approach to meet the challenges

After their successful introduction in postnatal testing, genome-wide arrays are now rapidly replacing conventional karyotyping in prenatal diagnostics. While previous studies have demonstrated the advantages of this method, we are confronted with difficulties regarding the technology and the ethical dilemmas inherent to genomic arrays. These include indication for testing, array design, interpretation of variants and how to deal with variants of unknown significance and incidental findings. The experiences with these issues reported in the literature are most often from single centres. Here, we report on a national consensus approach how microarray is implemented in all genetic centres in Belgium. These recommendations are subjected to constant re-evaluation based on our growing experience and can serve as a useful tool for those involved in prenatal diagnosis.

Molecular profiling of CD3−CD4+ T cells from patients with the lymphocytic variant of hypereosinophilic syndrome reveals targeting of growth control pathways

The clonal CD3(-)CD4(+) T-cell population characterizing lymphocytic variant hypereosinophilic syndrome (L-HES) persists for years, with a subgroup of patients ultimately progressing to T lymphoma. The molecular changes associated with the premalignant clone and the emergence of malignant subclones are unknown, precluding the development of targeted therapy for this HES variant. In this study, we used whole genome arrays to examine gene expression in the CD3(-)CD4(+) T cells and found that 850 genes were differentially regulated during chronic disease compared with CD3(+)CD4(+) T cells from healthy donors. Changes in the expression of 349 genes were altered in association with the clinical progression from chronic L-HES to T lymphoma in 1 patient, with 87 of 349 genes representing further changes in genes whose expression was altered in all chronic disease patients (87 of 850). Array analysis after CD2/CD28-mediated activation revealed that the major gene expression changes observed in the CD3(-)CD4(+) T cells do not reflect activation induced alterations but rather pathways involved in T-cell homeostasis, including transforming growth factor-beta signaling, apoptosis, and T-cell maturation, signaling, and migration. Examination of microRNA expression in the CD3(-)CD4(+) T cells from patients with chronic disease identified 23 microRNAs that changed significantly, among which miR-125a further decreased in association with one patients evolution to T lymphoma.

A new case of syndromic craniosynostosis with cryptic 19p13.2-p13.13 deletion.

A New Case of Syndromic Craniosynostosis With Cryptic 19p13.2–p13.13 Deletion Philippe A. Lysy,* Marie Ravoet, Sandrine Wustefeld, Pierre Bernard, Marie-C ecile Nassogne, Elisabeth Wyns, and Catherine Sibille HPED Department, PEDI Unit, Cliniques Universitaires Saint Luc, Universit e Catholique de Louvain, Brussels, Belgium GMED Department, Center of Medical Genetics, Cliniques Universitaires Saint Luc, Universit e Catholique de Louvain, Brussels, Belgium Obstetrics Service, GYNE Department, Cliniques Universitaires Saint Luc, Universit e Catholique de Louvain, Brussels, Belgium Neuropediatrics Service, NEPE Department, Cliniques Universitaires Saint Luc, Universit e Catholique de Louvain, Brussels, Belgium

Severe growth retardation, delayed bone age, and facial dysmorphism in two patients with microduplications in 2p16 → p22

Interstitial duplications of the short arm of chromosome 2 have been rarely described. Here, we report on two unrelated patients with overlapping chromosome 2p16 → p22 de novo microduplications found by SNP‐array analysis. The affected individuals were an 8‐year‐3‐month‐old boy with a direct duplication of approximately 14.6 Mb harboring 63 genes, and a 12‐year‐old girl with a direct duplication of around 9.6 Mb harboring 48 genes. Both patients have severe growth retardation, delayed bone age, prominent veins on trunk and extremities, total IGF1 level in the low range, mild developmental delay, and facial dysmorphism such as relative macrocephaly, a broad and prominent forehead, and a large anterior fontanelle. Comparison with patients previously reported in the literature and in the DECIPHER 5.1 and ECARUCA databases indicates a common region of interest of around 1.9 Mb responsible for most of the features. Two candidate genes (EPAS and RHOQ), may be particularly relevant for the marked growth retardation and developmental delay.

Five int22h homologous copies at the Xq28 locus identified in intron22 inversion type 3 of the Factor VIII gene

Five int22h homologous copies at the Xq28 locus identified in intron22 inversion type 3 of the Factor VIII gene.

The human CD3 g gene promoter is controlled by an RNA element that binds P-TEFb and is negatively regulated by HIV-1 Tat

Our studies show that HIV-1 infection provokes a progressive defect in surface TCR/CD3 receptors due to the specific and escalating loss of CD3 g mRNA. The human CD3 g gene is transcribed from a weak, lymphoid-specific promoter with significant transcription initiation site heterogeneity in normal T cells. However, early after HIV-1 infection CD3 g transcripts preferentially initiate at the +1 and +13 with further focusing over time as +1 transcripts are lost first. Mutant and deletion analysis delimited a 43 bp sequence from the +1 as critical for positive gene expression. DNA probes covering this sequence do not bind nuclear proteins. RNA probes from the +1 or +13 specifically bind the cellular proteins Cyclin T1 and cdk9 (P-TEFb) as well as HIV-1 Tat. The +1 to +43 sequence, defined as the CD3 g RCE (RNA control element), forms a secondary structure containing a uridine bulge, a side loop and a double apical loop with sequence similarity to HIV-1 TAR. Five GGCU repeats present from +18 to +37 form a similar double apical loop structure for +13 transcripts that lack the bulge and side loop. Deletion or mutation in the CD3 g RCE dramatically affects function with a 4 nt apical loop mutation abrogating both promoter activity and nuclear protein binding. Co-transfection of Tat with CD3 g promoter constructs suppresses promoter activity. In infected cells, knocking down tat gene expression restores surface TCR/CD3 whereas treatment with Tat protein accelerates TCR/CD3 downmodulation. Thus, P-TEFb binding to the CD3 g RCE in the presence of Tat is associated with negative transcriptional regulation.