A peptide mimetic of the mycobacterial mannosylated lipoarabinomannan: characterization and potential applications.
Mannosylated lipoarabinomannan (ManLAM), a complex lipoglycan, is a major component of Mycobacterium tuberculosis, the agent of tuberculosis (TB), and is an antigen used for serological diagnosis of TB. Screening random phage-display peptide libraries with anti-ManLAM mAb CS40 for peptide epitope mimics (mimotopes) led to the isolation of a panel of peptides. One of these peptides (B11) was characterized as a ManLAM mimotope: it bound the anti-ManLAM CS40 mAb and competed with ManLAM for antibody binding. Mice immunized with keyhole limpet haemocyanin-conjugated B11 peptide in a proper adjuvant developed antibodies that recognized ManLAM. Competition experiments demonstrated that the B11 peptide inhibited binding of mAb CS40 to ManLAM in a concentration-dependent manner. The data indicated that the affinity of CS40 mAb to B11 (K(D) 1.33 x 10(-8)) is higher than its affinity to ManLAM (K(D) 3.00 x 10(-7)). The sera of TB patients, as well as the sera of mice experimentally infected with M. tuberculosis, contained significant levels of antibodies that recognized both the B11 peptide and ManLAM. The specificity and sensitivity of the ELISA B11-based test were similar to those of the ELISA ManLAM-based test, indicating that the B11 antigen could be a good substitute for ManLAM serology for the diagnosis of TB.
Barenholz
Ayelet
A
Department of Clinical Microbiology, The Faculty of Medicine of the Hebrew University of Jerusalem, Jerusalem, Israel.
Hovav
Avi-Hai
AH
Department of Clinical Microbiology, The Faculty of Medicine of the Hebrew University of Jerusalem, Jerusalem, Israel.
Fishman
Yolanta
Y
Department of Clinical Microbiology, The Faculty of Medicine of the Hebrew University of Jerusalem, Jerusalem, Israel.
Rahav
Galia
G
Unit of Infectious Diseases, Sheba Medical Center, Ramat Gan, Israel.
Gershoni
Jonathan M
JM
Department of Cell Research and Immunology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel.
Bercovier
Hervé
H
Department of Clinical Microbiology, The Faculty of Medicine of the Hebrew University of Jerusalem, Jerusalem, Israel.
D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D005260:Female; D008070:Lipopolysaccharides / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D018716:Molecular Mimicry; D009169:Mycobacterium tuberculosis / Q000276:immunology*; D019151:Peptide Library; D010455:Peptides / Q000235:genetics / Q000276:immunology* / Q000302:isolation & purification; D014376:Tuberculosis / Q000175:diagnosis* / Q000276:immunology
D000907:Antibodies, Bacterial; D008070:Lipopolysaccharides; D019151:Peptide Library; D010455:Peptides; C050016:lipoarabinomannan