Search results for "Neutralization"

Activation of gp 130 by IL-6/soluble IL-6 receptor induces neuronal differentiation

1998

Interleukin-6 (IL-6) on target cells binds to the specific IL-6 receptor (IL-6R) and subsequently induces homodimerization of the signal-transducing protein gp130. Cells which express gp130 but no IL-6R and which therefore do not respond to IL-6 can be stimulated by the complex of IL-6 and soluble IL-6R (slL-6R). Here we show that on rat pheochromocytoma cells (PC12), the combination of IL-6 and slL-6R but not IL-6 alone induces expression of c-fos, GAP-43 and neuron-specific enolase followed by neuron-specific differentiation and formation of a neuronal network. The differentiation was dose-and time-dependent and followed the same kinetics as nerve-growth factor (NGF)-induced differentiati…

2019

Abstract Type B Coxsackieviruses (CVBs) belong to the enterovirus genus, and they cause both acute and chronic diseases in humans. CVB infections usually lead to flu-like symptoms but can also result in more serious diseases such as myocarditis, aseptic meningitis and life-threatening multi-organ infections in young infants. Thus, CVBs have long been considered as important targets of future vaccines. We have previously observed CVB1 capsid disintegration and virus concentration decrease with 12-day long formalin inactivation protocol. Here a scalable ion exchange chromatography purification method was developed, and purified CVB1 was inactivated with UV-C or formalin. Virus morphology and …

N-terminal myristoylation-dependent masking of neutralizing epitopes in the preS1 attachment site of hepatitis B virus

2011

The N-terminally myristoylated preS1 domain of the large hepatitis B surface protein (LHBs) mediates specific attachment of hepatitis B virus (HBV) to hepatocytes. Its B-cell epitopes leading to neutralization of infectivity are not yet characterized.We inserted C- and N-terminal preS1 peptides into the most immunogenic region of HBV core particles, therewith immunized Balb/c mice and determined binding properties and neutralization potential of resulting antibodies in vitro.The particles with preS1 inserts were highly immunogenic and the corresponding anti-preS antibodies strongly bound to HBV particles from chronic carriers infected with different HBV genotypes A-F. However, antibodies bi…

Development of novel vaccine strategies against human cytomegalovirus infection based on subviral particles.

2002

Abstract Background: Pre- and perinatal human cytomegalovirus (HCMV) infection remains one of the major causes of mental defects and sensineural hearing loss in children. In addition, it is a prominent infectious complication in immunosuppressed individuals such as AIDS patients or transplant recipients. Therefore, the development of an HCMV vaccine has been given top priority by health care institutions. Study design: Defective subviral particles of HCMV, termed Dense Bodies (DB) contain the dominant target antigens for humoral and cellular immune responses elicited during natural infection. These enveloped particles are released from infected culture cells and can be purified by gradient …

An antigen fragment encompassing the AD2 domains of glycoprotein B from two different strains is sufficient for differentiation of primary vs. recurr…

2001

Primary human cytomegalovirus (HCMV) infection during pregnancy is a frequent cause of fatal damage in populations with low prevalence of HCMV. Differentiation of primary vs. recurrent HCMV infection is an important issue in prenatal counseling. Antibodies specific for viral glycoproteins become detectable only with considerable delay with relation to HCMV infection or IgG seroconversion. Thus, lack of glycoprotein specific (gp-specific) antibodies can serve as a convenient indicator to identify those pregnant women that bear an elevated risk for HCMV transplacental transmission and fetal sequelae. In the opposite case, presence of gp-specific antibodies virtually excludes HCMV primary infe…

Allergen-specific immune deviation from a T H2 to a T H1 response induced by dendritic cells and collagen type I

1999

Background: Atopy and IgE production are associated with enhanced allergen-specific TH2 responses. Therefore a causative treatment may result from the deviation of this T H2dominated immune response toward a TH1 response. Objective: This study was carried out to analyze whether dendritic cells, the most potent antigen-presenting cells that are also known to induce antigen-specific T H1 responses, are suitable for therapy of atopic diseases by shifting the allergen-specific TH2 response toward a TH1 response. Methods: Monocyte-derived dendritic cells were used to present allergens in vitro to autologous CD4 + T cells of allergic persons. Because collagen type I activates dendritic cells and …

Untersuchungen zur Bedeutung der Frühsommer-Meningoenzephalitis in Rheinland-Pfalz

2002

Within the scope of a prospective clinical study during 2001 in Rhineland-Palatinate specimen from sera and cerebrospinal fluids of 163 patients with suspected meningitis were controlled in an enzyme immunoassay concerning a TBE infection. Questionable results were checked via a neutralisation test. In no case such an infection was confirmed. No virus specific nucleic acids could be detected in 998 nymphs and adults of Ixodes ricinus in an additional investigation in 2000. Therefore Rhineland-Palatinate has to be considered as a region with low virus prevalence. A general recommendation for vaccination is not necessary.

Colon Cancer Stem Cells Dictate Tumor Growth and Resist Cell Death by Production of Interleukin-4

2007

A novel paradigm in tumor biology suggests that cancer growth is driven by stem-like cells within a tumor. Here, we describe the identification and characterization of such cells from colon carcinomas using the stem cell marker CD133 that accounts around 2% of the cells in human colon cancer. The CD133(+) cells grow in vitro as undifferentiated tumor spheroids, and they are both necessary and sufficient to initiate tumor growth in immunodeficient mice. Xenografts resemble the original human tumor maintaining the rare subpopulation of tumorigenic CD133(+) cells. Further analysis revealed that the CD133(+) cells produce and utilize IL-4 to protect themselves from apoptosis. Consistently, trea…

Modulation of epitope-specific anti-hepatitis C virus E2 (anti-HCV/E2) antibodies by antiviral treatment

2006

The dynamic features of three specific anti-hepatitis C virus (HCV) antibody subpopulations directed against different conformational epitopes of the viral E2 protein (HCV/E2) have been evaluated in patients with primary and persistent HCV infection; the three subpopulations are present in patients infected with different HCV genotypes and have shown a different activity using a pseudovirus neutralization assay (antibodies e301 and e137 exhibiting high neutralizing activity, while antibody e509 enhancement of HCV infectivity). In sequential samples from five patients with primary HCV infection and different virological outcome, all samples tested negative with the single exception of the e5…

MRI activity and neutralising antibody as predictors of response to interferon beta treatment in multiple sclerosis

2008

Objective: To prospectively validate MRI activity and neutralising anti-interferon antibody (NAb) during the first 6 months of interferon β treatment as response indicators in multiple sclerosis (MS). Methods: Patients with relapsing–remitting MS were followed during the first 2 years of treatment. Neurological assessments were performed every 3 months or when a relapse was suspected. MRI scans performed at baseline and at 3, 4, 5 and 6 months after the start of treatment were assessed centrally for disease activity: new T2 or gadolinium enhancing T1 lesions. NAb were assessed using the MxA protein assay; positivity was defined as two consecutive titres ⩾20 NU/ml. We evaluated the predictiv…