Epitope mapping and biological function analysis of antibodies produced by immunization of mice with an inactivated Chinese isolate of severe acute respiratory syndrome-associated coronavirus (SARS-CoV).
Inactivated severe acute respiratory syndrome-associated coronavirus (SARS-CoV) has been tested as a candidate vaccine against the re-emergence of SARS. In order to understand the efficacy and safety of this approach, it is important to know the antibody specificities generated with inactivated SARS-CoV. In the current study, a panel of twelve monoclonal antibodies (mAbs) was established by immunizing Balb/c mice with the inactivated BJ01 strain of SARS-CoV isolated from the lung tissue of a SARS-infected Chinese patient. These mAbs could recognize SARS-CoV-infected cells by immunofluorescence analysis (IFA). Seven of them were mapped to the specific segments of recombinant spike (S) protein: six on S1 subunit (aa 12-798) and one on S2 subunit (aa 797-1192). High neutralizing titers against SARS-CoV were detected with two mAbs (1A5 and 2C5) targeting at a subdomain of S protein (aa 310-535), consistent with the previous report that this segment of S protein contains the major neutralizing domain. Some of these S-specific mAbs were able to recognize cleaved products of S protein in SARS-CoV-infected Vero E6 cells. None of the remaining five mAbs could recognize either of the recombinant S, N, M, or E antigens by ELISA. This study demonstrated that the inactivated SARS-CoV was able to preserve the immunogenicity of S protein including its major neutralizing domain. The relative ease with which these mAbs were generated against SARS-CoV virions further supports that subunit vaccination with S constructs may also be able to protect animals and perhaps humans. It is somewhat unexpected that no N-specific mAbs were identified albeit anti-N IgG was easily identified in SARS-CoV-infected patients. The availability of this panel of mAbs also provided potentially useful agents with applications in therapy, diagnosis, and basic research of SARS-CoV.
Chou
Te-hui W
TH
Laboratory of Nucleic Acid Vaccines, Department of Medicine, University of Massachusetts Medical School, 364 Plantation Street, Lazare Research Building, Worcester, MA 01605-2397, USA.
Wang
Shixia
S
Sakhatskyy
Pavlo V
PV
Mboudjeka
Innocent
I
Mboudoudjeck
Innocent
I
Lawrence
John M
JM
Huang
Song
S
Coley
Scott
S
Yang
Baoan
B
Li
Jiaming
J
Zhu
Qingyu
Q
Lu
Shan
S
D000818:Animals; D000911:Antibodies, Monoclonal / Q000096:biosynthesis; D000914:Antibodies, Viral / Q000096:biosynthesis; D000956:Antigens, Viral / Q000235:genetics; D002681:China; D002522:Chlorocebus aethiops; D018604:Epitope Mapping; D006801:Humans; D007114:Immunization; D008562:Membrane Glycoproteins / Q000235:genetics / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D009500:Neutralization Tests; D011817:Rabbits; D045473:Severe acute respiratory syndrome-related coronavirus / Q000235:genetics / Q000276:immunology* / Q000302:isolation & purification; D064370:Spike Glycoprotein, Coronavirus; D015164:Vaccines, Inactivated / Q000276:immunology; D014709:Vero Cells; D014759:Viral Envelope Proteins / Q000235:genetics / Q000276:immunology; D014765:Viral Vaccines / Q000276:immunology*
D000911:Antibodies, Monoclonal; D000914:Antibodies, Viral; D000956:Antigens, Viral; D008562:Membrane Glycoproteins; D064370:Spike Glycoprotein, Coronavirus; D015164:Vaccines, Inactivated; D014759:Viral Envelope Proteins; D014765:Viral Vaccines; C578557:spike glycoprotein, SARS-CoV; C578553:spike protein, mouse hepatitis virus