Proteome-wide production of monoclonal antibodies and study of intracellular localisation for Varicella-zoster virus (VZV)

Varicella zoster virus (VZV) is a member of the alphaherpesvirus subfamily and with a genome encoding 70 proteins the smallest of all human herpesviruses. Upon primary infection it causes varicella also called chickenpox in children. As a consequence, it reaches sensory nerve ganglia where latency is established. Upon reactivation it causes a secondary disease called Herpes zoster mostly in adults. Todate, VZV is the least studied human herpesvirus due to the lack of cell-free virus in culture, of virus-specific tools and an effective animal model. Therefore, many aspects of the VZV infection cycle, of latency and reactivation are poorly characterized. Moreover, the function of many proteins specific to VZV has not been identified. The goal of this research was to generate hybridoma clones as a permanent source of VZV specific antibodies and to use the antibodies produced to study the localisation of VZV proteins in the viral context on a proteome-wide level. To this end, a VZV ORFeome entry library was constructed using the Gateway® recombinational cloning technology. For VZV protein expression in E. coli, the entry library was subcloned into four different pET derived expression vectors providing either an N-terminal His6, a C-terminal His6, an N-terminal MBP, or an N-terminal GST tag. Following purification of 64 VZV proteins, mice were immunised and subsequently used to generate antibody producing hybridoma clones. So far, our clone collection contains 218 mother clones producing antibodies to 61 (87%) VZV proteins. In this clone collection 190 clones were identified as positive in Western blotting covering 57 VZV ORFs while 123 antibodies were tested positive in immunofluorescence covering 52 VZV ORFs. Using this novel antibody collection, the localisation of 52 (74%) proteins could be determined in the context of VZV infection 22 of which were analysed for the first time. In total, 20 ORFs were localised in the nucleus, 16 ORFs were present in the cytoplasm and 16 ORFs were found in both the nucleus and cytoplasm. Comparison of 41 core proteins present in HSV-1, VZV, CMV, EBV as well as KSHV showed excellent agreement in localisation of conserved glycoproteins, capsid and tegument proteins. Several immunodominant regions on the viral glycoproteins gK, gB, gL, gI, gE and the membrane associated phosphoprotein ORF24 were identified using the pepscan technique. This precious antibody collection gives access to various experimental approaches and will allow to unveil biological secrets in the field of Herpesvirology

Proteome-wide production of monoclonal antibodies and study of intracellular localisation for Varicella-zoster virus (VZV)

Varicella zoster virus (VZV) is a member of the alphaherpesvirus subfamily and with a genome encoding 70 proteins the smallest of all human herpesviruses. Upon primary infection it causes varicella also called chickenpox in children. As a consequence, it reaches sensory nerve ganglia where latency is established. Upon reactivation it causes a secondary disease called Herpes zoster mostly in adults. Todate, VZV is the least studied human herpesvirus due to the lack of cell-free virus in culture, of virus-specific tools and an effective animal model. Therefore, many aspects of the VZV infection cycle, of latency and reactivation are poorly characterized. Moreover, the function of many proteins specific to VZV has not been identified. The goal of this research was to generate hybridoma clones as a permanent source of VZV specific antibodies and to use the antibodies produced to study the localisation of VZV proteins in the viral context on a proteome-wide level. To this end, a VZV ORFeome entry library was constructed using the Gateway® recombinational cloning technology. For VZV protein expression in E. coli, the entry library was subcloned into four different pET derived expression vectors providing either an N-terminal His6, a C-terminal His6, an N-terminal MBP, or an N-terminal GST tag. Following purification of 64 VZV proteins, mice were immunised and subsequently used to generate antibody producing hybridoma clones. So far, our clone collection contains 218 mother clones producing antibodies to 61 (87%) VZV proteins. In this clone collection 190 clones were identified as positive in Western blotting covering 57 VZV ORFs while 123 antibodies were tested positive in immunofluorescence covering 52 VZV ORFs. Using this novel antibody collection, the localisation of 52 (74%) proteins could be determined in the context of VZV infection 22 of which were analysed for the first time. In total, 20 ORFs were localised in the nucleus, 16 ORFs were present in the cytoplasm and 16 ORFs were found in both the nucleus and cytoplasm. Comparison of 41 core proteins present in HSV-1, VZV, CMV, EBV as well as KSHV showed excellent agreement in localisation of conserved glycoproteins, capsid and tegument proteins. Several immunodominant regions on the viral glycoproteins gK, gB, gL, gI, gE and the membrane associated phosphoprotein ORF24 were identified using the pepscan technique. This precious antibody collection gives access to various experimental approaches and will allow to unveil biological secrets in the field of Herpesvirology

Azlocillin can be the potential drug candidate against drug-tolerant Borrelia burgdorferi sensu stricto JLB31.

Lyme disease is one of most common vector-borne diseases, reporting more than 300,000 cases annually in the United States. Treating Lyme disease during its initial stages with traditional tetracycline antibiotics is effective. However, 10-20% of patients treated with antibiotic therapy still shows prolonged symptoms of fatigue, musculoskeletal pain, and perceived cognitive impairment. When these symptoms persists for more than 6 months to years after completing conventional antibiotics treatment are called post-treatment Lyme disease syndrome (PTLDS). Though the exact reason for the prolongation of post treatment symptoms are not known, the growing evidence from recent studies suggests it might be due to the existence of drug-tolerant persisters. In order to identify effective drug molecules that kill drug-tolerant borrelia we have tested two antibiotics, azlocillin and cefotaxime that were identified by us earlier. The in vitro efficacy studies of azlocillin and cefotaxime on drug-tolerant persisters were done by semisolid plating method. The results obtained were compared with one of the currently prescribed antibiotic doxycycline. We found that azlocillin completely kills late log phase and 7-10 days old stationary phase B. burgdorferi. Our results also demonstrate that azlocillin and cefotaxime can effectively kill in vitro doxycycline-tolerant B. burgdorferi. Moreover, the combination drug treatment of azlocillin and cefotaxime effectively killed doxycycline-tolerant B. burgdorferi. Furthermore, when tested in vivo, azlocillin has shown good efficacy against B. burgdorferi in mice model. These seminal findings strongly suggests that azlocillin can be effective in treating B. burgdorferi sensu stricto JLB31 infection and furthermore in depth research is necessary to evaluate its potential use for Lyme disease therapy

Identification of New Drug Candidates Against \u3cem\u3eBorrelia burgdorferi\u3c/em\u3e Using High-Throughput Screening

Lyme disease is the most common zoonotic bacterial disease in North America. It is estimated that .300,000 cases per annum are reported in USA alone. A total of 10%–20% of patients who have been treated with antibiotic therapy report the recrudescence of symptoms, such as muscle and joint pain, psychosocial and cognitive difficulties, and generalized fatigue. This condition is referred to as posttreatment Lyme disease syndrome. While there is no evidence for the presence of viable infectious organisms in individuals with posttreatment Lyme disease syndrome, some researchers found surviving Borrelia burgdorferi population in rodents and primates even after antibiotic treatment. Although such observations need more ratification, there is unmet need for developing the therapeutic agents that focus on removing the persisting bacterial form of B. burgdorferi in rodent and nonhuman primates. For this purpose, high-throughput screening was done using BacTiter-Glo assay for four compound libraries to identify candidates that stop the growth of B. burgdorferi in vitro. The four chemical libraries containing 4,366 compounds (80% Food and Drug Administration [FDA] approved) that were screened are Library of Pharmacologically Active Compounds (LOPAC1280), the National Institutes of Health Clinical Collection, the Microsource Spectrum, and the Biomol FDA. We subsequently identified 150 unique compounds, which inhibited .90% of B. burgdorferi growth at a concentration of ,25 µM. These 150 unique compounds comprise many safe antibiotics, chemical compounds, and also small molecules from plant sources. Of the 150 unique compounds, 101 compounds are FDA approved. We selected the top 20 FDA-approved molecules based on safety and potency and studied their minimum inhibitory concentration and minimum bactericidal concentration. The promising safe FDA-approved candidates that show low minimum inhibitory concentration and minimum bactericidal concentration values can be chosen as lead molecules for further advanced studies

In vitro and in vivo evaluation of cephalosporins for the treatment of Lyme disease.

BackgroundLyme disease accounts for >90% of all vector-borne disease cases in the United States and affect ~300,000 persons annually in North America. Though traditional tetracycline antibiotic therapy is generally prescribed for Lyme disease, still 10%-20% of patients treated with current antibiotic therapy still show lingering symptoms.MethodsIn order to identify new drugs, we have evaluated four cephalosporins as a therapeutic alternative to commonly used antibiotics for the treatment of Lyme disease by using microdilution techniques like minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC). We have determined the MIC and MBC of four drugs for three Borrelia burgdorferi s.s strains namely CA8, JLB31 and NP40. The binding studies were performed using in silico analysis.ResultsThe MIC order of the four drugs tested is cefoxitin (1.25 µM/mL) > cefamandole (2.5 µM/mL), > cefuroxime (5 µM/mL) > cefapirin (10 µM/mL). Among the drugs that are tested in this study using in vivo C3H/HeN mouse model, cefoxitin effectively kills B. burgdorferi. The in silico analysis revealed that all four cephalosporins studied binds effectively to B. burgdorferi proteins, SecA subunit penicillin-binding protein (PBP) and Outer surface protein E (OspE).ConclusionBased on the data obtained, cefoxitin has shown high efficacy killing B. burgdorferi at concentration of 1.25 µM/mL. In addition to it, cefoxitin cleared B. burgdorferi infection in C3H/HeN mice model at 20 mg/kg

Screening of NCI-DTP Library to Identify New Drug Candidates for \u3cem\u3eBorrelia burgdorferi\u3c/em\u3e

Lyme disease is the most rapidly growing tick borne zoonotic disease of the Northern Hemisphere and is among the 10 most commonly reported nationally notifiable diseases in the United States.1 Clinical presentations include erythema migrans, fever, chills, muscle and joint pain.2, 3 Though these symptoms tend to fade away even without therapeutic intervention, a significant number of untreated patients develop arthritis and persistent myalgia following exposure to Borrelia burgdorferi.4 Furthermore, 10–20% of patients treated for Lyme disease develop symptoms considered typical, or even exaggerated, including muscle, joint pain and generalized fatigue5, 6. This condition is referred as post-treatment lyme disease syndrome (PTLDS)

From Solvent-Free Microspheres to Bioactive Gradient Scaffolds

A solvent-free microsphere sintering technique was developed to fabricate scaffolds with pore size gradient for tissue engineering applications. Poly(D,L-Lactide) microspheres were fabricated through an emulsification method where TiO2 nanoparticles were employed both as particulate emulsifier in the preparation procedure and as surface modification agent to improve bioactivity of the scaffolds. A fine-tunable pore size gradient was achieved with a pore volume of 30±2.6%. SEM, EDX, XRD and FTIR analyses all confirmed the formation of bone-like apatite at the 14th day of immersion in Simulated Body Fluid (SBF) implying the ability of our scaffolds to bond to living bone tissue. In vitro examination of the scaffolds showed progressive activity of the osteoblasts on the scaffold with evidence of increase in its mineral content. The bioactive scaffold developed in this study has the potential to be used as a suitable biomaterial for bone tissue engineering and hard tissue regeneration

In vitro and in vivo evaluation of cephalosporins for the treatment of Lyme disease.

BackgroundLyme disease accounts for >90% of all vector-borne disease cases in the United States and affect ~300,000 persons annually in North America. Though traditional tetracycline antibiotic therapy is generally prescribed for Lyme disease, still 10%-20% of patients treated with current antibiotic therapy still show lingering symptoms.MethodsIn order to identify new drugs, we have evaluated four cephalosporins as a therapeutic alternative to commonly used antibiotics for the treatment of Lyme disease by using microdilution techniques like minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC). We have determined the MIC and MBC of four drugs for three Borrelia burgdorferi s.s strains namely CA8, JLB31 and NP40. The binding studies were performed using in silico analysis.ResultsThe MIC order of the four drugs tested is cefoxitin (1.25 µM/mL) > cefamandole (2.5 µM/mL), > cefuroxime (5 µM/mL) > cefapirin (10 µM/mL). Among the drugs that are tested in this study using in vivo C3H/HeN mouse model, cefoxitin effectively kills B. burgdorferi. The in silico analysis revealed that all four cephalosporins studied binds effectively to B. burgdorferi proteins, SecA subunit penicillin-binding protein (PBP) and Outer surface protein E (OspE).ConclusionBased on the data obtained, cefoxitin has shown high efficacy killing B. burgdorferi at concentration of 1.25 µM/mL. In addition to it, cefoxitin cleared B. burgdorferi infection in C3H/HeN mice model at 20 mg/kg