HPV test by Hybrid Capture II for the diagnosis of HR-HPV persistent infection.

INTRODUCTION: Persistent high-risk HPV (HR-HPV) infection is associated with a greater risk of cervical cancer. PATIENTS AND METHODS: Statistical data on the prevalence of HR-HPV infections in the Algerian population is lacking. We conducted a prospective study of 300 women aged between 25 and 50 years, screened for cervical cancer from 2012 to 2015 in Sidi Bel Abbès, a western region of Algeria. We aimed to assess the reliability of the repeated use of the HC II test (three longitudinal HPV tests 9 months apart from each other) in diagnosing the persistence of HR-HPV infection. RESULTS: The prevalence of HR-HPV infection was 7.33% and infected women were aged 37.9±3years. For 90.9% of HR-HPV-positive patients, the infection persisted for a mean of 18.5months [95% CI: 16.9-22.1months]. Among these patients, 55.55% developed CIN1 and 11.11% developed CIN2. The sensitivity of the HC II test was 81.74% [95% CI: 71.3-89.6] and its positive predictive value associated with abnormal cervical biopsy was 27.49% [95% CI: 16.0-33.33]. CONCLUSION: Repeating the HC II test is a good predictor for identifying women at high risk of cervical cancer.

Retinoic acid receptor alpha1 variants, RARalpha1DeltaB and RARalpha1DeltaBC, define a new class of nuclear receptor isoforms.

Retinoic acid (RA) binds and activates retinoid X receptor (RXR)/retinoic acid receptor (RAR) heterodimers, which regulate the transcription of genes that have retinoic acid response elements (RARE). The RAR isotypes (alpha, beta and gamma) are comprised of six regions designated A-F. Two isoforms of RARalpha, 1 and 2, have been identified in humans, which have different A regions generated by differential promoter usage and alternative splicing. We have isolated two new splice variants of RARalpha1 from human B lymphocytes. In one of these variants, exon 2 is juxtaposed to exon 5, resulting in an altered reading frame and a stop codon. This variant, designated RARalpha1DeltaB, does not code for a functional receptor. In the second variant, exon 2 is juxtaposed to exon 6, maintaining the reading frame. This isoform, designated RARalpha1DeltaBC, retains most of the functional domains of RARalpha1, but omits the transactivation domain AF-1 and the DNA-binding domain. Consequently, it does not bind nor transactivate RARE on its own. Nevertheless, RARalpha1DeltaBC interacts with RXRalpha and, as an RXRalpha/RARalpha1DeltaBC heterodimer, transactivates the DR5 RARE upon all-trans-RA binding. The use of RAR- and RXR-specific ligands shows that, whereas transactivation of the DR5 RARE through the RXRalpha/RARalpha1 heterodimer is mediated only by RAR ligands, transactivation through the RXRalpha/RARalpha1DeltaBC heterodimer is mediated by RAR and RXR ligands. Whilst RARalpha1 has a broad tissue distribution, RARalpha1DeltaBC has a more heterogeneous distribution, but with significant expression in myeloid cells. RARalpha1DeltaBC is an infrequent example of a functional nuclear receptor which deletes the DNA-binding domain.

Physical and functional interactions between cellular retinoic acid binding protein II and the retinoic acid-dependent nuclear complex.

Two sorts of proteins bind to, and mediate the developmental and homeostatic effects of, retinoic acid (RA): the RAR and RXR nuclear receptors, which act as ligand-dependent transcriptional regulators, and the cellular RA binding proteins (CRABPI and CRABPII). CRABPs are generally known to be implicated in the synthesis, degradation, and control of steady-state levels of RA, yet previous and recent data have indicated that they could play a role in the control of gene expression. Here we show for the first time that, both in vitro and in vivo, CRABPII is associated with RARalpha and RXRalpha in a ligand-independent manner in mammalian cells (HL-60, NB-4, and MCF-7). In the nucleus, this protein complex binds the RXR-RAR-specific response element of an RA target gene (RARE-DR5). Moreover, in the presence of retinoids that bind both the nuclear receptors and CRABPII, enhancement of transactivation by RXRalpha-RARalpha heterodimers is observed in the presence of CRABPII. Thus, CRABPII appears to be a novel transcriptional regulator involved in RA signaling.

HLA-DR and DQ antigens in chronic lymphocytic leukemia: dissociation of expression revealed by cell surface, protein, and mRNA studies.

We studied peripheral blood lymphocytes (PBL) of eight B chronic lymphocytic leukemia (CLL) patients for the expression of the human leucocyte antigens, HLA-DR and HLA-DQ. Cell surface expression of HLA class II epitopes was analyzed by fluorescent activated cell sorter (FACS) using three monomorphic anti-HLA class II monoclonal antibodies (mAb) specific for DR (D1.12) and DQ (TU22, L2) and a polymorphic anti-DQ (G2A5). The DR and DQ molecules were characterized by two-dimensional gel electrophoresis (2D-PAGE) of the specific immunoprecipitates from biosynthetically labeled cells. DR, DQ specific probes were used to characterize the class II transcripts of the corresponding genes. The data obtained with immunofluorescence disclosed two distinct patterns of HLA class II expression leading to two cell surface phenotypes: (DR+DQ+) and (DR+DQ-). In all cases the cells expressed normal amounts of HLA-DR gene products in terms of mRNA. DR cell surface determinants were present in more than 80% of cells in every sample. By 2-D gel analysis DR proteins disclosed the normal classical pattern associating the alpha, beta, and invariant chain gamma with normal level of biosynthesis for alpha and gamma but decreased biosynthesis for one of the beta gene products. Moreover, the three chains demonstrated defect in glycosylation process. In half of the cases studied the cells lacked DQ molecules at the cell surface. DQ alpha and DQ beta transcripts were detected in all cases, although the amount was extremely low in one case. DQ proteins were variable in the DQ+ phenotype and absent in the DQ- one. Interestingly, TPA and rIFN gamma treatment could restore normal glycosylation process of the DR isotype and increase biosynthesis of DQ alpha and beta chains. Those combined results support the view that transcriptional, post-transcriptional, and posttranslational mechanisms underlie the heterogeneity of class II expression observed in CLL. Moreover, 2-D gel analysis may be an invaluable tool for the analysis of the biosynthetic process of class II molecules.