Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2000-7-19
pubmed:abstractText
In this study, we compared the immunogenicity and tumor-protective activity of anti-idiotypic antibodies mimicking a single tumor-associated epitope and tumor-associated antigen expressing multiple potentially immunogenic epitopes. We focused our study on the colorectal-carcinoma(CRC)-associated antigen GA733 (also known as CO17-1A/KS1-4/KSA/EpCAM). Monoclonal anti-idiotypic antibody (Ab2) BR3E4 was produced against murine anti-CRC mAb CO17-1A (Ab1) in rats. Full-length native GA733 protein was isolated from human tumor cells, and the extracellular domain protein (GA733-2E) was isolated from supernatants of recombinant baculovirus-infected insect cells by immunoaffinity chromatography. The immunomodulatory activity of the Ab2 was compared with that of the antigen, both in rabbits and in mice. Mice, like humans but not rabbits, express a GA733 antigen homologue on some of their normal tissues. Thus, these in vivo models allow the comparison of the immunogenicity of Ab2 and antigen in the presence (mice) and absence (rabbits) of normal tissue expression and immunological tolerance of the GA733 antigen homologue. In rabbits, aluminum-hydroxide(alum)-precipitated native GA733 antigen was superior to alum-precipitated Ab2 in inducing specific humoral immunity. In mice, alum-precipitated recombinant GA733-2E antigen, but not alum-precipitated Ab2, induced specific humoral immunity. However, when the Ab2 was administered to mice in Freund's complete adjuvant, specific humoral immune responses were elicited. Ab2 in complete Freund's adjuvant and GA733-2E in alum were compared for their capacity to induce antigen-specific cellular immunity in mice. Whereas lymphoproliferative responses were obtained with the recombinant antigen only, delayed-type hypersensitivity responses were obtained with both recombinant antigen and Ab2, although these responses were lower than after antigen immunization. The recombinant antigen in alum did not protect mice against challenge with antigen-positive syngeneic murine CRC cells. Similar studies with Ab2 BR3E4 mimicking the CO17-1A epitope were not possible because the tumor cells do not express this epitope after transfection with the human GA733-2 cDNA. However, similar studies with Ab2 mimicking the epitope defined by mAb GA733, which is expressed by the transfected tumor cells, indicated a lack of tumor-protective activity of this Ab2. In contrast, the full-length antigen expressed by recombinant adenovirus inhibited the growth of established tumors in mice. In conclusion, soluble antigen is a more potent modulator of humoral and cellular immune responses than Ab2, both administered in adjuvant. However, for induction of protective immunity, the immunogenicity of the antigen must be further enhanced, e.g., by expression of the antigen in a viral vector.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/Adjuvants, Immunologic, http://linkedlifedata.com/resource/pubmed/chemical/Alum Compounds, http://linkedlifedata.com/resource/pubmed/chemical/Antibodies, Anti-Idiotypic, http://linkedlifedata.com/resource/pubmed/chemical/Antibodies, Monoclonal, http://linkedlifedata.com/resource/pubmed/chemical/Antibodies, Neoplasm, http://linkedlifedata.com/resource/pubmed/chemical/Antigens, Neoplasm, http://linkedlifedata.com/resource/pubmed/chemical/Cancer Vaccines, http://linkedlifedata.com/resource/pubmed/chemical/Cell Adhesion Molecules, http://linkedlifedata.com/resource/pubmed/chemical/Epitopes, http://linkedlifedata.com/resource/pubmed/chemical/Recombinant Fusion Proteins, http://linkedlifedata.com/resource/pubmed/chemical/aluminum sulfate, http://linkedlifedata.com/resource/pubmed/chemical/tumor-associated antigen GA733
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0340-7004
pubmed:author
pubmed:issnType
Print
pubmed:volume
49
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
123-32
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:10881691-Adenocarcinoma, pubmed-meshheading:10881691-Adjuvants, Immunologic, pubmed-meshheading:10881691-Alum Compounds, pubmed-meshheading:10881691-Animals, pubmed-meshheading:10881691-Antibodies, Anti-Idiotypic, pubmed-meshheading:10881691-Antibodies, Monoclonal, pubmed-meshheading:10881691-Antibodies, Neoplasm, pubmed-meshheading:10881691-Antibody Affinity, pubmed-meshheading:10881691-Antigens, Neoplasm, pubmed-meshheading:10881691-Cancer Vaccines, pubmed-meshheading:10881691-Cell Adhesion Molecules, pubmed-meshheading:10881691-Colorectal Neoplasms, pubmed-meshheading:10881691-Epitopes, pubmed-meshheading:10881691-Humans, pubmed-meshheading:10881691-Hypersensitivity, Delayed, pubmed-meshheading:10881691-Immune Tolerance, pubmed-meshheading:10881691-Immunity, Cellular, pubmed-meshheading:10881691-Immunization, pubmed-meshheading:10881691-Lymphocyte Activation, pubmed-meshheading:10881691-Melanoma, Experimental, pubmed-meshheading:10881691-Mice, pubmed-meshheading:10881691-Mice, Inbred BALB C, pubmed-meshheading:10881691-Molecular Mimicry, pubmed-meshheading:10881691-Neoplasm Transplantation, pubmed-meshheading:10881691-Rabbits, pubmed-meshheading:10881691-Rats, pubmed-meshheading:10881691-Recombinant Fusion Proteins, pubmed-meshheading:10881691-Species Specificity, pubmed-meshheading:10881691-Transfection
pubmed:year
2000
pubmed:articleTitle
Cancer vaccines: single-epitope anti-idiotype vaccine versus multiple-epitope antigen vaccine.
pubmed:affiliation
Wistar Institute of Anatomy and Biology, Philadelphia, PA 19104, USA.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't