BCL11B is a general transcriptional repressor of the HIV-1 long terminal repeat in T lymphocytes through recruitment of the NuRD complex

AbstractIn this study we provide evidence that the transcription factor BCL11B represses expression from the HIV-1 long terminal repeat (LTR) in T lymphocytes through direct association with the HIV-1 LTR. We also demonstrate that the NuRD corepressor complex mediates BCL11B transcriptional repression of the HIV-1 LTR. In addition, BCL11B and the NuRD complex repressed TAT-mediated transactivation of the HIV-1 LTR in T lymphocytes, pointing to a potential role in initiation of silencing. In support of all the above results, we demonstrate that BCL11B affects HIV-1 replication and virus production, most likely by blocking LTR transcriptional activity. BCL11B showed specific repression for the HIV-1 LTR sequences isolated from seven different HIV-1 subtypes, demonstrating that it is a general transcriptional repressor for all LTRs

Inhibition of highly productive HIV-1 infection in T cells, primary human macrophages, microglia, and astrocytes by Sargassum fusiforme

BACKGROUND: The high rate of HIV-1 mutation and increasing resistance to currently available antiretroviral (ART) therapies highlight the need for new antiviral agents. Products derived from natural sources have been shown to inhibit HIV-1 replication during various stages of the virus life cycle, and therefore represent a potential source of novel therapeutic agents. To expand our arsenal of therapeutics against HIV-1 infection, we investigated aqueous extract from Sargassum fusiforme (S. fusiforme) for ability to inhibit HIV-1 infection in the periphery, in T cells and human macrophages, and for ability to inhibit in the central nervous system (CNS), in microglia and astrocytes. RESULTS: S. fusiforme extract blocked HIV-1 infection and replication by over 90% in T cells, human macrophages and microglia, and it also inhibited pseudotyped HIV-1 (VSV/NL4-3) infection in human astrocytes by over 70%. Inhibition was mediated against both CXCR4 (X4) and CCR5 (R5)-tropic HIV-1, was dose dependant and long lasting, did not inhibit cell growth or viability, was not toxic to cells, and was comparable to inhibition by the nucleoside analogue 2', 3'-didoxycytidine (ddC). S. fusiforme treatment blocked direct cell-to-cell infection spread. To investigate at which point of the virus life cycle this inhibition occurs, we infected T cells and CD4-negative primary human astrocytes with HIV-1 pseudotyped with envelope glycoprotein of vesicular stomatitis virus (VSV), which bypasses the HIV receptor requirements. Infection by pseudotyped HIV-1 (VSV/NL4-3) was also inhibited in a dose dependant manner, although up to 57% less, as compared to inhibition of native NL4-3, indicating post-entry interferences. CONCLUSION: This is the first report demonstrating S. fusiforme to be a potent inhibitor of highly productive HIV-1 infection and replication in T cells, in primary human macrophages, microglia, and astrocytes. Results with VSV/NL4-3 infection, suggest inhibition of both entry and post-entry events of the virus life cycle. Absence of cytotoxicity and high viability of treated cells also suggest that S. fusiforme is a potential source of novel naturally occurring antiretroviral compounds that inhibit HIV-1 infection and replication at more than one site of the virus life cycle

Palmitic Acid Analogs Exhibit Nanomolar Binding Affinity for the HIV-1 CD4 Receptor and Nanomolar Inhibition of gp120-to-CD4 Fusion

Background: We recently reported that palmitic acid (PA) is a novel and efficient CD4 fusion inhibitor to HIV-1 entry and infection. In the present report, based on in silico modeling of the novel CD4 pocket that binds PA, we describe discovery of highly potent PA analogs with increased CD4 receptor binding affinities (Kd) and gp120-to-CD4 inhibition constants (Ki). The PA analogs were selected to satisfy Lipinski’s rule of drug-likeness, increased solubility, and to avoid potential cytotoxicity. Principal Findings: PA analog 2-bromopalmitate (2-BP) was most efficacious with Kd,74 nM and Ki,122 nM, ascorbyl palmitate (6-AP) exhibited slightly higher Kd,140 nM and Ki,354 nM, and sucrose palmitate (SP) was least efficacious binding to CD4 with Kd,364 nM and inhibiting gp120-to-CD4 binding with Ki,1486 nM. Importantly, PA and its analogs specifically bound to the CD4 receptor with the one to one stoichiometry. Significance: Considering observed differences between K i and K d values indicates clear and rational direction for improving inhibition efficacy to HIV-1 entry and infection. Taken together this report introduces a novel class of natural small molecules fusion inhibitors with nanomolar efficacy of CD4 receptor binding and inhibition of HIV-1 entry

GUIDELINES FOR GENETIC COUNSELLING AND TESTING FOR HEREDITARY BREAST AND OVARIAN CANCER

Tijekom posljednjih desetljeća svjedoci smo velikog napretka u izvedivosti i kliničkoj iskoristivosti genetičkog testiranja kod nasljednih karcinoma. Nasljedni karcinomi dojke i jajnika najčešće su posljedica mutacija u genima BRCA1 i BRCA2. Ovim smjernicama obuhvatili smo kriterije za upućivanje pacijenata na genetičko savjetovanje i testiranje; kriterije za upućivanje zdravih pojedinaca na prediktivno testiranje ako nije moguće testiranje oboljelog člana obitelji; postupak genetičkog savjetovanja prije i nakon testiranja; nalaz testiranja, kategorije nalaza i razine rizika; preporuke za daljnje praćenje osoba s povišenim rizikom; kemoprevenciju i profilaktičku kirurgiju kod nositelja/-ica patogenih mutacija gena BRCA 1 i BRCA 2; očuvanje reproduktivne funkcije u žena oboljelih od raka dojke i nositeljica mutacija BRCA i pristanak informiranog bolesnika na genetičko testiranje. Smjernice su namijenjene svim specijalistima koji su na bilo koji način uključeni u zbrinjavanje oboljelih od nasljednih karcinoma dojke i jajnika, a sastavila ih je radna skupina prema podacima iz relevantne medicinske literature te kliničkim iskustvima članova radne skupine.The last few decades have witnessed a great progress in feasibility and clinical utilization of genetic testing for hereditary cancers. Hereditary breast and ovarian cancers are most often the result of BRCA1 and BRCA2 gene mutations. In these guidelines we have covered: the criteria for referral of patients to genetic counselling and testing; the criteria for referral of healthy family members to predictive testing in the event when there is no possibility of testing the patient; the process of genetic counselling before and after testing; test results, their categories and risk levels; recommendations for monitoring of individuals with an increased risk; chemoprevention and prophylactic surgery for carriers of BRCA1 and BRCA2 gene mutations; preservation of reproductive function in women with breast cancer and in carriers of BRCA mutations; and informed consent for genetic testing. The guidelines are intended for all specialists who are in any way involved in the care of patients with hereditary breast and ovarian cancer, and are compiled by the working group according to the data from the relevant medical literature and from clinical experience of the members of the working group

Smjernice za genetičko savjetovanje i testiranje na nasljedni rak dojke i jajnika [Guidelines for genetic counselling and testing for hereditary breast and ovarian cancer]

The last few decades have witnessed a great progress in feasibility and clinical utilization of genetic testing for hereditary cancers. Hereditary breast and ovarian cancers are most often the result of BRCA1 and BRCA2 gene mutations. In these guidelines we have covered: the criteria for referral of patients to genetic counselling and testing; the criteria for referral of healthy family members to predictive testing in the event when there is no possibility of testing the patient; the process of genetic counselling before and after testing; test results, their categories and risk levels; recommendations for monitoring of individuals with an increased risk; chemoprevention and prophylactic surgery for carriers of BRCA1 and BRCA2 gene mutations; preservation of reproductive function in women with breast cancer and in carriers of BRCA mutations; and informed consent for genetic testing. The guidelines are intended for all specialists who are in any way involved in the care of patients with hereditary breast and ovarian cancer, and are compiled by the working group according to the data from the relevant medical literature and from clinical experience of the members of the working group

Inhibition of HIV-1 infection in ex vivo cervical tissue model of human vagina by palmitic acid; implications for a microbicide development.

Approximately 80% of all new HIV-1 infections are acquired through sexual contact. Currently, there is no clinically approved microbicide, indicating a clear and urgent therapeutic need. We recently reported that palmitic acid (PA) is a novel and specific inhibitor of HIV-1 fusion and entry. Mechanistically, PA inhibits HIV-1 infection by binding to a novel pocket on the CD4 receptor and blocks efficient gp120-to-CD4 attachment. Here, we wanted to assess the ability of PA to inhibit HIV-1 infection in cervical tissue ex vivo model of human vagina, and determine its effect on Lactobacillus (L) species of probiotic vaginal flora.Our results show that treatment with 100-200 µM PA inhibited HIV-1 infection in cervical tissue by up to 50%, and this treatment was not toxic to the tissue or to L. crispatus and jensenii species of vaginal flora. In vitro, in a cell free system that is independent of in vivo cell associated CD4 receptor; we determined inhibition constant (Ki) to be ∼2.53 µM.These results demonstrate utility of PA as a model molecule for further preclinical development of a safe and potent HIV-1 entry microbicide inhibitor

Inhibition of HIV-1 infection in human cervix model of vaginal mucosa.

<p>3 mm³ biopsy punches of the ectocervix tissue samples from premenopausal women with conditions not involving the cervix were processed within 1–3 hours after surgery and directly cultured in 48 well plates in 300 µl/well DMEM/F12 media. (A) Paraffin embedded, and hematoxylin and eosin (H&E) stained sections of the uninfected ectocervix tissue were identified to be composed of (a) stratified squamous epithelial cell layer, (b) basal epithelial layer, and (c) submocosa, which was visualized on an Olympus BX41 Altra 20 Soft Image System, 100× magnification. (B) Replicates (n = 6) of tissue were treated for 24 h with 0, 100, or 200 µM PA, and then infected with 2×10⁵ p24/ml cell-free HIV-1 BaL in 300 µl for 16 h. Tissues was washed 3 times to remove the virus, and returned to culture with each respective treatment for the duration of the experiment. At the indicated time points, HIV-1 replication was tested by p24 ELISA, and repeated measures ANOVA was used to calculate statistical significance (*) between groups. (C) At day 10 after infection, tissue was collected and viability determined by the MTT assay. Representative of three experiments, all data are mean ± SD.</p