Biochemical and structural comparisons of non-nucleoside reverse transcriptase inhibitors against feline and human immunodeficiency viruses

Background@#Feline immunodeficiency virus (FIV) causes an acquired immunodeficiencylike syndrome in cats. FIV is latent. No effective treatment has been developed for treatment the infected cats. The first and second generations non-nucleoside reverse transcriptase inhibitors (NNRTIs) for HIV treatment, nevirapine (NVP) and efavirenz (EFV), and rilpivirine (RPV), were used to investigate the potential of NNRTIs for treatment of FIV infection. @*Objective@#This study aims to use experimental and in silico approaches to investigate the potential of NNRTIs, NVP, EFV, and RPV, for inhibition of FIV reverse transcriptase (FIV-RT). @*Methods@#The FIV-RT and human immunodeficiency virus reverse transcriptase (HIV-RT) were expressed and purified using chromatography approaches. The purified proteins were used to determine the IC50 values with NVP, EFV, and RPV. Surface plasmon resonance (SPR) analysis was used to calculate the binding affinities of NNRTIs to HIV-RT and FIV-RT.The molecular docking and molecular dynamic simulations were used to demonstrate the mechanism of FIV-RT and HIV-RT with first and second generation NNRTI complexes. @*Results@#The IC50 values of NNRTIs NVP, EFV, and RPV against FIV-RT were in comparable ranges to HIV-RT. The SPR analysis showed that NVP, EFV, and RPV could bind to both enzymes. Computational calculation also supports that these NNRTIs can bind with both FIV-RT and HIV-RT. @*Conclusions@#Our results suggest the first and second generation NNRTIs (NVP, EFV, and RPV) could inhibit both FIV-RT and HIV-RT.

Development of a biosensor from aptamers for detection of the porcine reproductive and respiratory syndrome virus

Background@#Recently, the pork industry of Thailand faced an epidemic of highly virulent strains of porcine reproductive and respiratory syndrome virus (PRRSV), which spread throughout Southeast Asia, including the Lao People's Democratic Republic and Cambodia.Hence, the rapid and on-site screening of infected pigs on a farm is essential. @*Objectives@#To develop the new aptamer as a biosensor for detection PRRSV which are rapid and on-site screening of infected pig. @*Methods@#New aptamers against PRSSV were identified using the combined techniques of capillary electrophoresis, colorimetric assay by gold nanoparticles, and quartz crystal microbalance (QCM). @*Results@#Thirty-six candidate aptamers of the PRRSV were identified from the systematic evolution of ligands by exponential enrichment (SELEX) by capillary electrophoresis. Only 8 out of 36 aptamers could bind to the PRSSV, as shown in a colorimetric assay. Of the 8 aptamers tested, only the 1F aptamer could bind specifically to the PRSSV when presented with the classical swine fever virus and a pseudo rabies virus. The QCM was used to confirm the specificity and sensitivity of the 1F aptamer with a detection limit of 1.87 × 10 10 particles. @*Conclusions@#SELEX screening of the aptamer equipped with capillary electrophoresis potentially revealed promising candidates for detecting the PRRSV. The 1F aptamer exhibited the highest specificity and selectivity against the PRRSV. These findings suggest that 1F is a promising aptamer for further developing a novel PRRSV rapid detection kit.

Acquisition of naturally acquired antibody response to Plasmodium falciparum erythrocyte membrane protein 1-DBLα and differential regulation of IgG subclasses in severe and uncomplicated malaria

Objectives To explore whether individuals infected with Plasmodium falciparum (P. falciparum) develop antibodies directed against PfEMP1-DBLα and to assess their IgG subclass distribution in severe and uncomplicated malaria. Methods The anti-PfDBLα IgG and their IgG subclass distributions in plasma of severe (SM) and uncomplicated malaria (UCM) were assessed by enzyme-linked immunoabsorbent assay. The antibody profiles to P. falciparum blood stage antigens were evaluated. CD36 binding ability was determined by static receptor-binding assays. Rosette formation was performed by staining with acridine orange. Results Significantly higher number of UCM (86.48%) than SM (57.78%) plasma contained total acquisition of specific IgG to P. falciparum antigens (P = 0.000). Similar manners were seen in response to P. falciparum DBLα with significant difference (UCM, 59.46% vs SM, 40.00%; P = 0.014). Anti-PfDBLα-IgG1 and -IgG3 were the predominant subclasses. Similar percentage of UCM (31.82%) and SM (33.33%) plasma contained only IgG1, while 13.64% of UCM and 27.78% of SM plasma contained only IgG3. Anti-PfDBLα-IgG1 coexpressed with more than one subclass was noted (UCM, 27.27%; SM, 16.67%). Obviously, IgG1 coexpressed with IgG3 (9.09%) was observed in only UCM plasma. IgG1 was coexpressed with IgG2 in UCM (9.09%) and SM (11.11%) plasma, while IgG1 was coexpressed with IgG4 only in UCM plasma (4.55%). IgG subclasses to P. falciparum antigens were distributed in a similar manner. Only the levels of IgG1, but not IgG3 were significantly higher in UCM than in SM. Conclusions These data suggest that individuals infected with P. falciparum can develop the anti-PfEMP1 antibodies with the major contribution of specific IgG subclasses. The balance and the levels of anti-PfDBLα IgG subclasses play a crucial role in antibody mediated protection against severe malaria.