Investigation of immune responses against Staphylococcus aureus * analysis of antibodies and antibody producing cells in patients with Staphylococcus aureus infections and patients whose wounds are colonised by Staphylococcus aureus

Staphylococcus aureus is a Gram-positive bacterium that colonizes the skin and
anterior nares of about 25-30% of the healthy human population. Although mainly
a harmless coloniser, S. aureus can cause severe infection. Its
methicillin-resistant form (MRSA) is the most important cause of
antibiotic-resistant health care-associated infections worldwide.
Glycopeptides, especially vancomycin, are currently used as first-line
treatment of MRSA infections. Unfortunately, this has led to the emergence of
vancomycin-intermediate and vancomycin-resistant MRSA (VISA and VRSA). This
raises concern that the current first-line treatment for MRSA infection will
become increasingly ineffective. New classes of antimicrobials are thus
urgently needed to treat infections with multi-drug resistant S. aureus.
The aim of the research and development in question is to generate human
monoclonal antibodies recognizing S. aureus - associated antigens and to
develop these antibodies into therapeutics for the prophylactic and/or
therapeutic treatment of infectious diseases. Using the technology to generate
and develop fully human human monoclonal antibodies from the blood of infected
patients, we in collaboration with IQ Corporation, want to develop a number of
human monoclonal antibodies against pathogenic S. aureus strains and their
toxins. After a whole blood donation, the peripheral blood mononuclear cells
(PBMC) will be isolated from the donated blood. The subsequent in vitro
procedure for processing of the donated blood includes sorting single human B
lymphocytes, and isolating RNA for the expression of the antibody-encoding
genes in an antibody production platform. The resulting fusion products will be
screened for relevant specificities against S. aureus. A selection of the most
promising antibodies will, after in vitro efficacy studies, be subjected to
pre-clinical and clinical research for the purpose of developing an
antibody-based drug for the treatment of certain infectious diseases mediated
by S. aureus. In addition, the sera isolated from the blood will be tested for
the presence of antibodies against S. aureus cell-wall, exoproteins and toxins.
This will be done by immunoproteomics (collaboration with Dr. B. Bröker,
University of Greifswald) and by protein chip technology (collaboration with
PepScan).
To develop the human monoclonal antibodies, whole blood is necessary from
patients with an invasive S. aureus infection, from patients who suffer from
detectable toxins produced by S. aureus and from patients whose wounds are
colonised by S. aureus (Epidemolysis bullosa). The study will include both
adult patients and minors.
Risks for patients who donate 12 ml of whole blood are deemed to be minimal.
After blood donation the identity of the volunteers will be anonimised to
safeguard their privacy. The patients will not have any personal therapeutic
benefits from participating in this study but developing human monoclonal
antibodies may be beneficial to patient populations in general.

The objective of this study is to obtain whole blood from patients with S.
aureus infections and/or patients whose wounds are colonized by S. aureus for
in vitro development of human monoclonal antibodies against S. aureus.

The protocol concerns a mono-center, cohort study. It will take 4 years to
include 120 patients from which 40 are diagnosed with invasive S. aureus
infection and 20 who are infected with S. aureus strains producing one of the
major staphylococcal toxins (PVL, ETA, TSST). Patients with S. aureus
infections and patients whose wounds are colonized with S. aureus will be
recruited to donate 12 milliliters blood during regular blood sampling. Most of
the patients will donate blood only once, and perhaps a few patients will be
ask for an additional blood donation. Adults will donate blood maximally 3
times and minors maximally 2 times over a period of one year with minimal
intervals of 3 days.
The study will take place at the University Medical Center Groningen (UMCG).
Whole blood will be taken during regular blood sampling.

Risks for patients donating 12 ml of whole blood are deemed to be minimal. The
blood will be taken during regular blood sampling. The patients will not have
any personal therapeutic benefits in participating in this study, but the
development of human monoclonal antibodies may be beneficial to patient
populations in general.