Histidine-Rich Glycoprotein Inhibits HIV-1 Infection in a pH-Dependent Manner

Histidine-rich glycoprotein (HRG) is an abundant plasma protein with a multidomain structure, allowing its interaction with many ligands, including phospholipids, plasminogen, fibrinogen, IgG antibodies, and heparan sulfate. HRG has been shown to regulate different biological responses, such as angiogenesis, coagulation, and fibrinolysis. Here, we found that HRG almost completely abrogated the infection of Ghost cells, Jurkat cells, CD4+ T cells, and macrophages by HIV-1 at a low pH (range, 6.5 to 5.5) but not at a neutral pH. HRG was shown to interact with the heparan sulfate expressed by target cells, inhibiting an early postbinding step associated with HIV-1 infection. More importantly, by acting on the viral particle itself, HRG induced a deleterious effect, which reduces viral infectivity. Because cervicovaginal secretions in healthy women show low pH values, even after semen deposition, our observations suggest that HRG might represent a constitutive defense mechanism in the vaginal mucosa. Of note, low pH also enabled HRG to inhibit the infection of HEp-2 cells and Vero cells by respiratory syncytial virus (RSV) and herpes simplex virus 2 (HSV-2), respectively, suggesting that HRG might display broad antiviral activity under acidic conditions.Fil: Dantas, Ezequiel Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas en Retrovirus y Sida. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas en Retrovirus y Sida; ArgentinaFil: Díaz, Fernando Erra. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas en Retrovirus y Sida. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas en Retrovirus y Sida; ArgentinaFil: Pereyra Gerber, Federico Pehuén. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas en Retrovirus y Sida. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas en Retrovirus y Sida; ArgentinaFil: Varese, Augusto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas en Retrovirus y Sida. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas en Retrovirus y Sida; ArgentinaFil: Jerusalinsky, Diana Alicia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Biología Celular y Neurociencia "Prof. Eduardo de Robertis". Universidad de Buenos Aires. Facultad de Medicina. Instituto de Biología Celular y Neurociencia; ArgentinaFil: Epstein, Alberto Luis. Université de Versailles Saint-quentin-en-yvelines.; Francia. Inserm; FranciaFil: García Rivello, Hernán J.. Hospital Italiano. Instituto Universitario. Escuela de Medicina; ArgentinaFil: del Valle Jaén, Ana. Hospital Italiano. Instituto Universitario. Escuela de Medicina; ArgentinaFil: Pandolfi, Julieta Belen. Hospital Italiano. Instituto Universitario. Escuela de Medicina; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Ceballos, Ana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas en Retrovirus y Sida. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas en Retrovirus y Sida; ArgentinaFil: Ostrowski, Matias. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas en Retrovirus y Sida. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas en Retrovirus y Sida; ArgentinaFil: Sabatté, Juan. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas en Retrovirus y Sida. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas en Retrovirus y Sida; ArgentinaFil: Geffner, Jorge Raúl. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas en Retrovirus y Sida. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas en Retrovirus y Sida; Argentin

Altered mRNA Expression of Telomere-Associated Genes in Monoclonal Gammopathy of Undetermined Significance and Multiple Myeloma

In this study, we explored changes in the expression of the telomere maintenance genes, TRF1, TRF2 and TANK1 in patients with monoclonal gammopathy of undetermined significance (MGUS) and multiple myeloma (MM). Results were correlated with human telomerase reverse transcriptase (hTERT ) expression, telomere length (TL) and clinicopathological characteristics. Bone marrow (BM) samples from 132 patients, 64 with MGUS and 68 with MM, were studied. Real-time quantitative reverse transcription–polymerase chain reaction was used to quantify gene expression. TL was evaluated by terminal restriction fragment length analysis. MGUS patients showed increased TRF1 levels (P = 0.006) and lower expression of TRF2 (P = 0.005) and TANK1 (P = 0.003) compared with MM patients. For hTERT analysis, patients were divided into three groups by use of receiver operating characteristics: low (group I [GI]), intermediate (group II [GII]) and high (group III [GIII]) expression. We observed increasing expression of TRF2 and TANK1 from GI to GIII in MGUS and MM, with differences for both genes in MM (P < 0.01) and for TRF2 in MGUS (P < 0.01). GIII patients with the highest telomerase expression had the shortest TL. In both entities, a positive association between TRF2-TANK1, TRF2-hTERT and TANK1-hTERT (P ≤ 0.01) was observed. In MM, the percentage of BM infiltration and Ki-67 index were positively associated with TRF2, TANK1 and hTERT expression (P ≤ 0.03) and negatively with TL (P = 0.02), whereas lactate dehydrogenase was significantly correlated with TRF2 mRNA (P = 0.008). Our findings provide the first evidence of a modification in the expression of telomeric proteins in plasma cell disorders, and suggest that mechanisms other than telomerase activation are involved in TL maintenance in these pathologies