Monoclonal antibodies targeting different cell wall antigens of group B streptococcus mediate protection in both Fc-dependent and independent manner.

Group B streptococcus remains an important neonatal pathogen in spite of widely adopted intrapartum antibiotic administration; therefore immune prophylaxis for GBS infections is highly warranted. In passive immunization and lethal challenge studies with multiple GBS strains, we characterized the protective effect of rabbit polyclonal and murine monoclonal antibodies specific for four multi-functional cell wall anchored proteins, FbsA, BibA, PilA and PilB. Single specificity rabbit sera or mAbs induced high level, but strain dependent protection, while their combinations resulted in superior and broad efficacy against all GBS strains tested.

Immunological fingerprinting of group B streptococci: from circulating human antibodies to protective antigens.

Group B streptococcus is one of the most important pathogens in neonates, and causes invasive infections in non-pregnant adults with underlying diseases. Applying a genomic approach that relies on human antibodies we identified antigenic GBS proteins, among them most of the previously published protective antigens. In vitro analyses allowed the selection of conserved candidate antigens that were further evaluated in murine lethal sepsis models using several GBS strains.

Novel conserved group A streptococcal proteins identified by the antigenome technology as vaccine candidates for a non-M protein-based vaccine.

Group A streptococci (GAS) can cause a wide variety of human infections ranging from asymptomatic colonization to life-threatening invasive diseases. Although antibiotic treatment is very effective, when left untreated, Streptococcus pyogenes infections can lead to poststreptococcal sequelae and severe disease causing significant morbidity and mortality worldwide. To aid the development of a non-M protein-based prophylactic vaccine for the prevention of group A streptococcal infections, we identified novel immunogenic proteins using genomic surface display libraries and human serum antibodies from donors exposed to or infected by S.

The pneumococcal eukaryotic-type serine/threonine protein kinase StkP co-localizes with the cell division apparatus and interacts with FtsZ in vitro.

The importance of serine/threonine phosphorylation in signalling and regulation of gene expression in prokaryotes has been widely recognized. Driven by our interest in StkP (the pneumococcal serine/threonine kinase homologue) for vaccine development, we studied its cellular localization. We found that the C-terminally located PASTA (penicillin-binding protein and serine/threonine kinase associated) domains, but not the N-terminal kinase domain of StkP, were located on the surface of live pneumococcal cells grown in vitro and were also accessible to antibodies during pneumococcal infection in mice and man.

Composition of the ANTIGENome of Helicobacter pylori defined by human serum antibodies.

Helicobacter pylori is the most prevalent human pathogen and although, it remains silent in most individuals for lifetime, colonization may develop into severe gastric and duodenal conditions. Rapidly developing resistance to antibiotic treatment urgently calls for the development of effective vaccines. We determined the ANTIGENome of two clinical isolates of H.

Discovery of a novel class of highly conserved vaccine antigens using genomic scale antigenic fingerprinting of pneumococcus with human antibodies.

Pneumococcus is one of the most important human pathogens that causes life-threatening invasive diseases, especially at the extremities of age. Capsular polysaccharides (CPSs) are known to induce protective antibodies; however, it is not feasible to develop CPS-based vaccines that cover all of the 90 disease-causing serotypes. We applied a genomic approach and described the antibody repertoire for pneumococcal proteins using display libraries expressing 15-150 amino acid fragments of the pathogen's proteome.

High-affinity binding of the staphylococcal HarA protein to haptoglobin and hemoglobin involves a domain with an antiparallel eight-stranded beta-barrel fold.

Iron scavenging from the host is essential for the growth of pathogenic bacteria. In this study, we further characterized two staphylococcal cell wall proteins previously shown to bind hemoproteins. HarA and IsdB harbor homologous ligand binding domains, the so called NEAT domain (for "near transporter") present in several surface proteins of gram-positive pathogens.

Comparison of antibody repertoires against Staphylococcus aureus in healthy individuals and in acutely infected patients.

The management of staphylococcal diseases is increasingly difficult with present medical approaches. Preventive and therapeutic vaccination is considered to be a promising alternative; however, little is known about immune correlates of protection and disease susceptibility. To better understand the immune recognition of Staphylococcus aureus by the human host, we studied the antistaphylococcal humoral responses in healthy people in comparison to those of patients with invasive diseases.

PIBF (progesterone induced blocking factor) is overexpressed in highly proliferating cells and associated with the centrosome.

PIBF was previously identified as a 34 kDa immunomodulatory molecule secreted by pregnancy lymphocytes and is thought to play a crucial role in preventing rejection of the embryo by the maternal immune response. Recent data suggested that PIBF protein was also expressed by the progesterone receptor (PR) positive MCF-7 breast tumor cell line. Therefore our study was designed to analyze the expression of PIBF in malignant cell lines and primary tumors both at the mRNA and protein levels.

Identification of a novel iron regulated staphylococcal surface protein with haptoglobin-haemoglobin binding activity.

Staphylococcus aureus is an extremely adaptable pathogen causing a wide variety of infections. Staphylococcal surface proteins that directly interact with host extracellular proteins greatly contribute to virulence and are involved in adhesion, immune escape and nutrient acquisition. In our extensive search for highly immunogenic, in vivo-expressed, staphylococcal proteins, previously, we identified a novel member of the family of Gram-positive anchor motif proteins with a predicted 895 amino acid long sequence.

Concomitant determination of absolute values of cellular protein amounts, synthesis rates, and turnover rates by quantitative proteome profiling.

Two-dimensional gel electrophoresis of protein fractions isolated from (35)S-radiolabeled cells provides qualitative information on intracellular amounts, (35)S incorporation rates, protein modifications, and subcellular localizations of up to thousands of individual proteins. In this study we extended proteome profiling to provide quantitative data on synthesis rates of individual proteins. We combined fluorescence detection of radiolabeled proteins with SYPRO ruby(TM) staining and subsequent autoradiography of the same gels, thereby quantifying protein amounts and (35)S incorporation.

Plasma from cancer patients featuring a characteristic protein composition mediates protection against apoptosis.

By comparative proteome analysis we searched for characteristic alterations of human plasma accompanying neoplastic disease. We identified protein alterations in plasma of prostate-, lung-, and breast-cancer patients in comparison to controls, comprising elevated levels of fibrinogen gamma-chain dimer, degradation products of antiplasmin and laminin gamma-chain, and elevated levels of acute phase proteins. The latter proteins and laminin fragments have been described as anti-apoptotic factors.