Immunoglobulin superfamily receptor translocation associated 2 protein on lymphoma cell lines and hairy cell leukemia cells detected by novel monoclonal antibodies.
OBJECTIVE
The immunoglobulin superfamily receptor translocation associated 2 (IRTA2) gene encodes a cell surface receptor homologous to the family of Fc receptors. Because of the restricted expression of mRNA in B cell-lineage cells, IRTA2 is a new potential target for the immunotherapy of B cell malignancies. To study the expression of the IRTA2 gene product, we produced monoclonal antibodies (MAbs) specific to IRTA2.


METHODS
A mouse used for cell fusion was DNA-immunized with an expression plasmid encoding the IRTA2 cDNA. The reactivity of MAbs secreted from the hybridomas were characterized with recombinant proteins of IRTA family members in an enzyme immunoassay and a fluorescence-activated cell sorter (FACS). Nineteen human lymphoma cell lines and blood cells from five patients with hairy cell leukemia (HCL) were analyzed with IRTA2 expression using FACS.


RESULTS
Three MAbs (F25, F56, and F119) were selected based on their specific reactivity with recombinant IRTA2 and lack of cross-reactivity with other IRTA family members. In a FACS analysis, MAbs F56 and F119 detected IRTA2 expression in six of seven B cell non-Hodgkin's lymphoma and one of six Burkitt's lymphoma cell lines. Reverse transcriptase-PCR experiments and Western blotting using MAb F25 confirmed the expression profile. We also found that HCL cells from five patients expressed IRTA2.


CONCLUSIONS
Our results provide the first evidence that IRTA2 is expressed on the surface of human lymphoma cell lines and HCL cells. IRTA2 could be useful as a new target for immunotherapy.
Ise
Tomoko
T
Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, Maryland 20892-4264, USA.
Maeda
Hiroshi
H
Santora
Kenneth
K
Xiang
Laiman
L
Kreitman
Robert J
RJ
Pastan
Ira
I
Nagata
Satoshi
S
D000911:Antibodies, Monoclonal / Q000737:chemistry*; D001402:B-Lymphocytes / Q000378:metabolism; D015153:Blotting, Western; D045744:Cell Line, Tumor; D019070:Cell Lineage; D002469:Cell Separation; D003001:Cloning, Molecular; D004247:DNA / Q000737:chemistry / Q000378:metabolism; D017931:DNA Primers / Q000737:chemistry; D018076:DNA, Complementary / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D005434:Flow Cytometry; D006801:Humans; D007136:Immunoglobulins / Q000378:metabolism*; D007167:Immunotherapy / Q000379:methods*; D007700:Kinetics; D007943:Leukemia, Hairy Cell / Q000276:immunology* / Q000378:metabolism; D008223:Lymphoma / Q000276:immunology* / Q000378:metabolism; D016393:Lymphoma, B-Cell; D008856:Microscopy, Fluorescence; D010957:Plasmids / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000096:biosynthesis* / Q000235:genetics*; D011961:Receptors, Fc; D011993:Recombinant Fusion Proteins / Q000737:chemistry; D011994:Recombinant Proteins / Q000737:chemistry; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014162:Transfection
D000911:Antibodies, Monoclonal; D017931:DNA Primers; D018076:DNA, Complementary; C432367:FCRL5 protein, human; D007136:Immunoglobulins; D011956:Receptors, Cell Surface; D011961:Receptors, Fc; D011993:Recombinant Fusion Proteins; D011994:Recombinant Proteins; D004247:DNA