Engagement of Na,K-ATPase beta3 subunit by a specific mAb suppresses T and B lymphocyte activation.
In order to identify new molecules involved in regulation of T cell proliferation, we generated various mAb by immunization of mice with the T cell line Molt4. We found one mAb (termed P-3E10) that down-regulated the in vitro T cell proliferation induced by CD3-specific OKT3 mAb. The P-3E10 mAb was also able to inhibit IFN-gamma, IL-2, IL-4 and IL-10 production of OKT3-activated T cells. The antigen recognized by P-3E10 mAb is broadly expressed on all hematopoietic as well as on all non-hematopoietic cell lines tested so far. Within peripheral blood leukocytes, the P-3E10 antigen was detected on lymphocytes, monocytes and granulocytes. Human umbilical vein endothelial cells (HUVEC) also scored positively. By evaluating the effect of P-3E10 mAb on these cell types we found that it also inhibited anti-IgM-induced B cell proliferation. However, it did not block growth factor-mediated proliferation of HUVEC, and spontaneous proliferation of SupT-1, Jurkat, Molt4 and U937 cell lines. Moreover, it did not influence phagocytosis of human blood monocytes and granulocytes. Biochemical analysis revealed that the P-3E10 antigen is a protein with a mol. wt of 45-50 kDa under non-reducing and 50-55 kDa under reducing conditions. By using a retroviral cloning system, the P-3E10 antigen was cloned. Sequence analysis revealed the P-3E10 antigen to be identical to the beta3 subunit of the Na,K-ATPase.
Chiampanichayakul
Sawitree
S
Department of Clinical Immunology, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai 50200, Thailand.
Szekeres
Andreas
A
Khunkaewla
Panida
P
Moonsom
Seangduen
S
Leksa
Vladimir
V
Drbal
Karel
K
Zlabinger
Gerhard J
GJ
Hofer-Warbinek
Renate
R
Stockinger
Hannes
H
Kasinrerk
Watchara
W
D000595:Amino Acid Sequence; D000911:Antibodies, Monoclonal / Q000276:immunology*; D000941:Antigens / Q000737:chemistry / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D001402:B-Lymphocytes / Q000166:cytology / Q000276:immunology*; D001483:Base Sequence; D002455:Cell Division; D002460:Cell Line; D003001:Cloning, Molecular; D016207:Cytokines / Q000096:biosynthesis; D006801:Humans; D008213:Lymphocyte Activation; D008969:Molecular Sequence Data; D008970:Molecular Weight; D021122:Protein Subunits / Q000737:chemistry / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D000254:Sodium-Potassium-Exchanging ATPase / Q000276:immunology / Q000378:metabolism*; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology* / Q000378:metabolism
D000911:Antibodies, Monoclonal; D000941:Antigens; D016207:Cytokines; D021122:Protein Subunits; D000254:Sodium-Potassium-Exchanging ATPase