Screening and characterization of monoclonal antibodies to the surface antigens of Listeria monocytogenes serotype 4b.
OBJECTIVE
This study aims to develop and characterize monoclonal antibodies (Mabs) with high specificity and affinity for surface antigens of an epidemiologically important serotype 4b of Listeria monocytogenes.


RESULTS
Hybridoma clones were derived from B lymphocytes of mice immunized with L. monocytogenes serotype 4b and screened against this strain by an enzyme-linked immunosorbent assay. Twenty-nine clones secreting Mabs reactive with formalin-killed bacteria were obtained; 15, 8, 5 and 1 Mabs were immunoglobulin subclasses IgG2a, IgG2b, IgM and IgG1, respectively. Immunofluorescence or immunogold labelling demonstrated all except five IgM and one IgG2a Mabs bound to the surface of a live L. monocytogenes serotype 4b. The majority of the 23 surface-binding Mabs recognized linear epitopes on a 77-kDa protein. These surface-binding Mabs exhibited little or no cross-reactivity with non-4b serotypes (1/2a, 1/2b, 3a, etc.) of L. monocytogenes, five other Listeria species, Escherichia coli O157:H7 and Salmonella enterica serovar Typhimurium.


CONCLUSIONS
The Mabs recognizing a 77-kDa surface protein are novel antibodies with specificity and affinity for L. monocytogenes serotype 4b.


CONCLUSIONS
These anti-77 kDa surface protein Mabs may be explored as reagents for the development of Mabs-based diagnostic immunoassays for L. monocytogenes serotype 4b strains.
Lin
M
M
Canadian Food Inspection Agency, Ottawa Laboratory Fallowfield, 3851 Fallowfield Road, Ottawa, Ontario, Canada. linm@inspection.gc.ca
Armstrong
S
S
Ronholm
J
J
Dan
H
H
Auclair
M-E
ME
Zhang
Z
Z
Cao
X
X
D000818:Animals; D000911:Antibodies, Monoclonal / Q000096:biosynthesis* / Q000276:immunology; D000915:Antibody Affinity; D000918:Antibody Specificity; D000942:Antigens, Bacterial / Q000276:immunology*; D000954:Antigens, Surface / Q000276:immunology; D015153:Blotting, Western; D003429:Cross Reactions; D004797:Enzyme-Linked Immunosorbent Assay; D005455:Fluorescent Antibody Technique; D006825:Hybridomas; D007074:Immunoglobulin G / Q000145:classification / Q000276:immunology; D007075:Immunoglobulin M / Q000145:classification / Q000276:immunology; D007150:Immunohistochemistry; D008089:Listeria monocytogenes / Q000145:classification / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C
D000911:Antibodies, Monoclonal; D000942:Antigens, Bacterial; D000954:Antigens, Surface; D007074:Immunoglobulin G; D007075:Immunoglobulin M