Open Access Research article

Novel human recombinant antibodies against Mycobacterium tuberculosis antigen 85B

Manon Fuchs1, Susanne Kämpfer2, Saskia Helmsing1, Ralf Spallek2, Wulf Oehlmann2, Wiebke Prilop2, Ronald Frank34, Stefan Dübel1, Mahavir Singh2 and Michael Hust1*

Author Affiliations

1 Technische Universität Braunschweig, Institut für Biochemie und Biotechnologie, Spielmannstr.7, 38106 Braunschweig, Germany

2 Lionex GmbH, Salzdahlumer Str. 196, 38126 Braunschweig, Germany

3 Helmholtz Zentrum für Infektionsforschung, Abteilung Chemische Biologie, Inhoffenstr. 7, 38124 Braunschweig, Germany

4 Leibniz-Institut für Molekulare Pharmakologie, Robert-Roessle-Str. 10, 13125 Berlin, Germany

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BMC Biotechnology 2014, 14:68  doi:10.1186/1472-6750-14-68

Published: 17 July 2014

Abstract

Background

Tuberculosis is the leading cause of death due to bacterial infections worldwide, mainly caused by Mycobacterium tuberculosis. The antigen 85 complex comprises a set of major secreted proteins of M. tuberculosis, which are potential biomarkers for diagnostic.

Results

In this work, the first human single chain fragment variable (scFv) antibodies specific for the tuberculosis biomarker 85 B were selected by phage display from naïve antibody gene libraries (HAL7/8). Produced as scFv-Fc in mammalian cells, these antibodies were further characterized and analysed for specificity and applicability in different tuberculosis antigen detection assays. Sandwich detection of recombinant 85 B was successful in enzyme linked immunosorbent assay (ELISA), lateral flow immunoassay and immunoblot. Whereas detection of M. tuberculosis cell extracts and culture filtrates was only possible in direct ELISA and immunoblot assays. It was found that the conformation of 85 B, depending on sample treatment, influenced antigen detection.

Conclusions

Recombinant antibodies, selected by phage display, may be applicable for 85 B detection in various assays. These antibodies are candidates for the development of future point of care tuberculosis diagnostic kits. Using 85 B as a biomarker, the antigen conformation influenced by sample treatment is important.