We have developed a real-time quantitative polymerase chain reaction (PCR) assay using TaqMan technology (Applied Biosystems, Foster City, CA) for monitoring donor cell engraftment in allogenic hematopoietic stem cell transplant recipients. For this purpose, we selected 19 specific sequence polymorphisms belonging to 11 human biallelic loci located on 9 different chromosomes. Using a set of specially designed primers and fluorogenic probes, we evaluated the 19 markers' informativity on a panel of 126 DNA samples from 63 recipient/donor pairs. In more than 90% of these pairs, discrimination between recipient and donor genetic profile was possible. By using serial dilutions of mixed DNAs, we evaluated the linearity and sensitivity of the method. A linear correlation with r higher than 0.98 and a sensitivity of 0.1% proved reproducible.

The dosage of soluble programmed cell death ligand 1 (sPD-L1) protein in the blood of adults with cancer has never been performed in a prospective patient cohort. We evaluated the clinical impact of sPD-L1 level measured at the time of diagnosis for newly diagnosed diffuse large B-cell lymphoma (DLBCL). Soluble PD-L1 was measured in the plasma of 288 patients enrolled in a multicenter, randomized phase III trial that compared R-high-dose chemotherapy with R-CHOP. The median follow-up was 41.4 months. A cutoff of 1.52 ng/ml of PD-L1 level was determined and related to overall survival (OS). Patients with elevated sPD-L1 experienced a poorer prognosis with a 3-year OS of 76% versus 89% (P<0.001). Considering clinical characteristics, the multivariate analysis retained this biomarker besides bone marrow involvement and abnormal lymphocyte-monocyte score as independently related to poor outcome. sPD-L1 was detectable in the plasma and not in the serum, found elevated in patients at diagnosis compared with healthy subjects and its level dropped back to normal value after CR. The intention-to-treat analysis showed that elevated sPD-L1 was associated with a poorer prognosis for patients randomized within the R-CHOP arm (P<0.001). Plasma PD-L1 protein is a potent predicting biomarker in DLBCL and may indicate usefulness of alternative therapeutic strategies using PD-1 axis inhibitors.

Multiple sclerosis is a common disease with proven heritability, but, despite large-scale attempts, no underlying risk genes have been identified. Traditional linkage scans have so far identified only one risk haplotype for multiple sclerosis (at HLA on chromosome 6), which explains only a fraction of the increased risk to siblings. Association scans such as admixture mapping have much more power, in principle, to find the weak factors that must explain most of the disease risk. We describe here the first high-powered admixture scan, focusing on 605 African American cases and 1,043 African American controls, and report a locus on chromosome 1 that is significantly associated with multiple sclerosis.

Accumulating evidences indicate that the cellular and molecular microenvironment of follicular lymphoma (FL) has a key role in both lymphomagenesis and patient outcome. Malignant FL B cells are found admixed to specific stromal and immune cell subsets, in particular CD4 pos T cells displaying phenotypic features of follicular helper T cells (T FH ). The goal of our study was to functionally characterize intratumoral CD4 pos T cells. We showed that CXCR5 hi ICOS hi CD4 pos T cells sorted from FL biopsies comprise at least two separate cell populations with distinct genetic and functional features: (i) CD25 pos follicular regulatory T cells (T FR ), and (ii) CD25 neg T FH displaying a FL-B cell supportive activity without regulatory functions. Furthermore, despite their strong similarities with tonsil-derived T FH , purified FL-derived T FH displayed a specific gene expression profile including an overexpression of several genes potentially involved directly or indirectly in lymphomagenesis, in particular TNF, LTA, IL4 or CD40LG. Interestingly, we further demonstrated that these two last signals efficiently rescued malignant B cells from spontaneous and rituximab-induced apoptosis. Altogether, our study demonstrates that tumor-infiltrating CD4 pos T cells are more heterogeneous than previously presumed, and underlines for the first time the crucial role of T FH in the complex set of cellular interactions within FL microenvironment.

SummaryRheumatoid arthritis is a multistep disorder associated with autoimmune features of yet unknown etiology. Implication of viruses such as Epstein-Barr virus (EBV) in rheumatoid arthritis pathogenesis has been suspected on the basis of several indirect observations, but thus far, a direct link between EBV and rheumatoid arthritis has not been provided. Here we show that a large fraction of T cells infiltrating affected joints from a patient with chronic rheumatoid arthritis recognizes two EBV transactivators (BZLF1 and BMLF1) in a major histocompatibility complex-restricted fashion. Responses to these EBV antigens by synovial lymphocytes from several other chronic rheumatoid arthritis panents were readily detectable. Thus these results suggest a direct contribution of EBV to chronic rheumatoid arthritis pathogenesis. They also demonstrate for the first time the occurrence of T cell responses against EBV transactivating factors, which might be central in the control of virus reactivation.

It has been demonstrated that T cells with regulatory properties are present within the peripheral blood CD4

A nonisotopic oligotyping method using reverse dot blot hybridization was developed for HLA class II DQA1, DQB1, DPB1, DRB1, DRB3, DRB4, DRB5 alleles. The polymorphic second exon of the different genes was amplified by the polymerase chain reaction (PCR). For each gene the amplified DNA was hybridized at stringent conditions to membrane-bound sequence-specific oligonucleotides (SSOs) and visualization of positive signals was done by chemiluminescence. A combination of 11, 18, 23 and 31 SSOs was designed to identify 9/13 DQA1, 16/17 DQB1, 23/24 DPB1 and 50/55 DRB1, 4 DRB3, 1 DRB4, 3/4 DRB5 alleles respectively. For the DRB1 locus, an additional DRB1*04 group-specific PCR was developed to make discrimination between the DR4 alleles possible in different heterozygous combinations. The procedure described here provides rapid and nonisotopic genotyping of heterozygous samples from a variety of sources and can be applied for tissue typing, disease susceptibility studies and forensic medicine.

Multiple sclerosis (MS) is the most common chronic inflammatory neurologic disorder diagnosed in young adults and, due to its chronic course, is responsible for a substantial economic burden. MS is considered to be a multifactorial disease in which both genetic and environmental factors intervene. The well-established human leukocyte antigen (HLA) association does not completely explain the genetic impact on disease susceptibility. However, identification and validation of non-HLA-genes conferring susceptibility to MS has proven to be difficult probably because of the small individual contribution of each of these genes. Recently, associations with two single nucleotide polymorphisms (SNPs) in the IL2RA gene (rs12722489, rs2104286) and one SNP in the IL7RA gene (rs6897932) have been reported by several groups. These three SNPs were genotyped in a French and a German population of MS patients using the hME assay by the matrix-assisted laser desorption/ionization time of flight technology (Sequenom, San Diego, CA, USA). We show that these SNPs do contribute to the risk of MS in these two unrelated European MS patient populations with odds ratios varying from 1.1 to 1.5. The discovery and validation of new genetic risk factors in independent populations may help toward the understanding of MS pathogenesis by providing valuable information on biological pathways to be investigated.