Nicotinamide activates latent HIV-1 ex vivo in ART suppressed individuals, revealing higher potency than the association of two methyltransferase inhibitors, chaetocin and BIX01294

ABSTRACT Background: Latent HIV-1 is a major hurdle in obtaining HIV-1 sustained virological remission (SVR). Here we explored histone deacetylation inhibition property of nicotinamide (NAM; n = 17) for the first time in comparison to a combination of methyltransferase inhibitors (MTIs; Chaetocin and BIX01294; n = 25) to reactivate latent HIV ex vivo in CD8-depleted PBMCs from antiretroviral treated aviremic individuals. Results: NAM reactivated HIV-1 from 13/17 (76.4%) samples compared to 20/25 (80.0%) using MTIs with mean viral load (VLs) of 4.32 and 3.22 log10 RNA copies/mL, respectively (p = 0.004). Mean purging time after NAM and MTIs stimulation was 5.1 and 6.75 days, respectively (p = 0.73). Viral purging in autologous cultures exhibited blunted HIV recovery with fluctuating VLs followed by a complete viral extinction when expanded in allogenic system. Electron microscopy from five supernatants revealed anomalous viral particles, with lack of complete viral genomes when characterized by ultradeep sequencing through metagenomics approach (n = 4). Conclusion: NAM alone was more potent HIV-1 activator than combination of MTIs, with potential of clinical use.

Challenging management of hepatitis B infection in ankylosing spondylitis patients in an endemic area during immunosuppressive therapy

Abstract Hepatitis B infection is a global health issue. When considering patients with rheumatic diseases, this is no different. By using immunosuppressant drugs, such as DMARDs and biologics, viral reactivation is possible, leading to serious consequences on the patient. We report 3 cases of association between ankylosing spondylitis and hepatitis B with the use of immunosuppressant drugs. Case 1 was a patient with previous HBV infection using DMARD. Cases 2 and 3 were patients chronically infected by HBV during immunosuppressant therapy. The management of HBV infection during immunosuppressant therapy is challenging and needs multidisciplinary support.

Alemtuzumab as graft-versus-host disease (GVHD) prophylaxis strategy in a developing country: lower rate of acute GVHD, increased risk of cytomegalovirus reactivation

Acute graft-versus-host disease (aGVHD) and cytomegalovirus reactivation are important complications after allogeneic stem cell transplantation (alloHSCT). Here, we evaluated the impact of treatment with alemtuzumab on the occurrence of aGVHD, cytomegalovirus reactivation and survival after alloHSCT. This was a prospective cohort study conducted at the allo-HSCT unit of Hospital das Clínicas, Universidade Federal de Minas Gerais, Brazil, from January 2009 to December 2011. Fifty-seven patients who underwent alloHSCT were included. Forty-five (79%) patients had a malignant disease. Alemtuzumab was administered before the conditioning regimen at a dose of 1 mg/kg in children and 30 mg/day for 2 days in adults or children weighing more than 40 kg (a total dose of 60 mg) with a non-malignant disease or patients with a malignant disease and high-risk for GVHD mortality. Alemtuzumab was used in 23 (40%) patients, of whom 17 received a reduced-intensity conditioning. Eleven patients presented aGVHD (grade 2–4) and only 1 of them received alemtuzumab. Cumulative incidence of aGVHD (grade 2–4) at day 100 after transplantation (D+100) was 4 for patients receiving alemtuzumab and 29% for patients not receiving alemtuzumab. Cumulative incidence of cytomegalovirus reactivation for patients receiving or not alemtuzumab was 62 and 38%, respectively. Sixteen patients died in the first 100 days after alloHSCT, most of them due to bacterial sepsis. Only 2 patients died of aGVHD until D+100. Overall survival was 50% without any impact of alemtuzumab. Alemtuzumab effectively controlled aGVHD but increased the risk of cytomegalovirus reactivation without improving survival.

The use of ustekinumab in a patient with severe psoriasis and positive HBV serology

Psoriasis is a chronic inflammatory, immune-mediated disease that affects 1% to 2% of the world's population. Immunobiological medications are prescribed for certain patients with severe forms of psoriasis, however, these drugs increase the risk of reactivation of viral diseases such as hepatitis B. We report the case of a patient with severe psoriasis with positive serology for the Hepatitis B virus, who received ustekinumab (a human monoclonal antibody against interleukin 12 and 23). In this patient, the use of ustekinumab did not reactivate the Hepatitis B virus. Given the high prevalence of chronic viral infections in patients who are candidates for biologic therapy, as well as the potential for reactivate chronic viral illness, randomized controlled studies are needed to assess the risks and benefits of such therapy in these populations.

A bovine herpesvirus 5 recombinant defective in the thymidine kinase (TK) gene and a double mutant lacking TK and the glycoprotein E gene are fully attenuated for rabbits

Bovine herpesvirus 5 (BoHV-5), the agent of herpetic meningoencephalitis in cattle, is an important pathogen of cattle in South America and several efforts have been made to produce safer and more effective vaccines. In the present study, we investigated in rabbits the virulence of three recombinant viruses constructed from a neurovirulent Brazilian BoHV-5 strain (SV507/99). The recombinants are defective in glycoprotein E (BoHV-5gEÄ), thymidine kinase (BoHV-5TKÄ) and both proteins (BoHV-5gEÄTKÄ). Rabbits inoculated with the parental virus (N = 8) developed neurological disease and died or were euthanized in extremis between days 7 and 13 post-infection (pi). Infectivity was detected in several areas of their brains. Three of 8 rabbits inoculated with the recombinant BoHV-5gEÄ developed neurological signs between days 10 and 15 pi and were also euthanized. A more restricted virus distribution was detected in the brain of these animals. Rabbits inoculated with the recombinants BoHV-5TKÄ (N = 8) or BoHV-5gEÄTKÄ (N = 8) remained healthy throughout the experiment in spite of variable levels of virus replication in the nose. Dexamethasone (Dx) administration to rabbits inoculated with the three recombinants at day 42 pi did not result in viral reactivation, as demonstrated by absence of virus shedding and/or increase in virus neutralizing titers. Nevertheless, viral DNA was detected in the trigeminal ganglia or olfactory bulbs of all animals at day 28 post-Dx, demonstrating they were latently infected. These results show that recombinants BoHV-5TKÄ and BoHV-5gEÄTKÄ are attenuated for rabbits and constitute potential vaccine candidates upon the confirmation of this phenotype in cattle.

Dexamethasone-induced reactivation of bovine herpesvirus type 5 latent infection in experimentally infected rabbits results in a broader distribution of latent viral DNA in the brain

Bovine herpesvirus type 5 (BHV-5) is a major agent of meningoencephalitis in cattle and establishes latent infections mainly in sensory nerve ganglia. The distribution of latent BHV-5 DNA in the brain of rabbits prior to and after virus reactivation was studied using a nested PCR. Fifteen rabbits inoculated intranasally with BHV-5 were euthanized 60 days post-inoculation (group A, N = 8) or submitted to dexamethasone treatment (2.6 mg kg-1 day-1, im, for 5 days) and euthanized 60 days later (group B, N = 7) for tissue examination. Two groups of BHV-1-infected rabbits (C, N = 3 and D, N = 3) submitted to each treatment were used as controls. Viral DNA of group A rabbits was consistently detected in trigeminal ganglia (8/8), frequently in cerebellum (5/8), anterior cerebral cortex and pons-medulla (3/8) and occasionally in dorsolateral (2/8), ventrolateral and posterior cerebral cortices, midbrain and thalamus (1/8). Viral DNA of group B rabbits showed a broader distribution, being detected at higher frequency in ventrolateral (6/7) and posterior cerebral cortices (5/7), pons-medulla (6/7), thalamus (4/7), and midbrain (3/7). In contrast, rabbits inoculated with BHV-1 harbored viral DNA almost completely restricted to trigeminal ganglia and the distribution did not change post-reactivation. These results demonstrate that latency by BHV-5 is established in several areas of the rabbit's brain and that virus reactivation leads to a broader distribution of latent viral DNA. Spread of virus from trigeminal ganglia and other areas of the brain likely contributes to this dissemination and may contribute to the recrudescence of neurological disease frequently observed upon BHV-5 reactivation.

The effects of exogenous interleukin-12 on the induction of immune response to Porphyromonas gingivalis in vivo in mice.

The effects of treatment with exogenous interleukin-12 (IL-12) on the induction of immune response to Porphyromonas gingivalis, a black pigmented periodontopathic oral bacterium in mice, were determined in the present study. An increased footpad swelling representing a delayed type hypersensitivity (DTH) response to P. gingivalis in IL-12-treated mice could be observed, although increasing doses of IL-12 did not produce cumulative effects on this cellular Immune response. Multiple injections with IL-12 also resulted in elevated serum IFN-gamma levels. Treatment with this cytokine the day before, on and after immunization with heat-killed P. gingivalis augmented the levels of serum antigen-specific IgG2a and IgG3 antibodies, but had obviously little or no effects on those of serum antigen-specific IgG1 and IgG2b antibodies. The results of this study suggest that treatment with exogenous IL-12 In P. gingivalis-immunized mice may enhance DTH response and Th1 cell-associated antibody production.

Induction of prophage lambda by nitrofurantoin and its modulation by butylated hydroxytoluene, sodium arsenite and alpha tocopherol.

Nitrofurantoin induced prophage-lambda in E. coli K12 strain GY5027(lambda) in a dose dependent manner, the maximum induction being 10-fold the spontaneous induction level and the maximum efficiency of induction 74%. The lever extract used as a metabolizing mixture enhanced the induction level significantly. Chloramphenicol at a concentration of 20 micrograms/ml inhibited the prophage induction by nitrofurantoin, indicating that the induction required concomitant protein synthesis. Butylated hydroxytoluene(BHT) and sodium arsenite enhanced the nitrofurantoin induced prophage-lambda induction in E. coli GY 5027(lambda) cells in a dose dependent manner. The maximum modulations in induction level (I/Io) were achieved with 100 micrograms/ml BHT and 250 micrograms/ml sodium arsenite corresponding to a nitrofurantoin concentration of 15 micrograms/ml and were found significant on statistical analysis. alpha-tocopherol, however, did not produce any effect on the prophage-lambda induction by nitrofurantoin.

Genotoxicity of plant extracts

Aqueous extracts of seven species used in Brazilian popular medicine (Achyrocline satureoides, Iodina rhombifolia, Desmodium incanum, Baccharis anomala, Tibouchina asperior, Luehea divaricata, Maytenus ilicifolia) were screened to the presence of mutagenic activity in the Ames test (Salmonella/microsome). Positive results were obtained for A. satureoides, B anomala and L. divaricata with microsomal activation. As shown elsewhere (Vargas et al., 1990) the metabolites of A. satureoides extract also show the capacity to induce prophage and/or SOS response in microscreen phage induction assay and SOS spot chromotest.