Generation and characterization of an antagonistic monoclonal antibody against an extracellular domain of mouse DP2 (CRTH2/GPR44) receptors for prostaglandin D2

• Published in: PloS one Vol. 12; no. 4; p. e0175452
• Main Authors: Nagata, Nanae, Iwanari, Hiroko, Kumagai, Hidetoshi, Kusano-Arai, Osamu, Ikeda, Yuichi, Aritake, Kosuke, Hamakubo, Takao, Urade, Yoshihiro
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 01.04.2017; Public Library of Science (PLoS)
• Subjects: Animals; Antibodies, Monoclonal - biosynthesis; Antibodies, Monoclonal - chemistry; Antibodies, Monoclonal - immunology; Antibody Specificity; Antigens; beta-Arrestins - metabolism; Binding; Biological effects; Biology and Life Sciences; CD4-Positive T-Lymphocytes - metabolism; CHO Cells; COS Cells; Cricetulus; Cyclic AMP - metabolism; Cytokines; Disease Models, Animal; Epitope Mapping; HEK293 Cells; Homology; Humans; Hybridomas - metabolism; Immunization; Immunoglobulins; Immunohistochemistry; Immunology; In vivo methods and tests; Inflammation; Interleukins; Kidney - metabolism; Kidney - pathology; Lipids; Lymphocytes; Lymphocytes T; Medicine and Health Sciences; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Mice, Knockout; Monoclonal antibodies; Precursor Cells, B-Lymphoid - immunology; Prostaglandin D2 - analogs & derivatives; Prostaglandin D2 - antagonists & inhibitors; Proteins; Receptors; Receptors, Immunologic - genetics; Receptors, Immunologic - immunology; Receptors, Prostaglandin - genetics; Receptors, Prostaglandin - immunology; Research and Analysis Methods; Rodents; Ureteral Obstruction - immunology; Ureteral Obstruction - metabolism; Ureteral Obstruction - pathology; Japan
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0175452

Prostaglandin D2 (PGD2) is a lipid mediator involved in sleep regulation and inflammation. PGD2 interacts with 2 types of G protein-coupled receptors, DP1 and DP2/CRTH2 (chemoattractant receptor homologous molecule expressed on T helper type 2 cells)/GPR44 to show a variety of biological effects. DP1 activation leads to Gs-mediated elevation of the intracellular cAMP level, whereas activation of DP2 decreases this level via the Gi pathway; and it also induces G protein-independent, arrestin-mediated cellular responses. Activation of DP2 by PGD2 causes the progression of inflammation via the recruitment of lymphocytes by enhancing the production of Th2-cytokines. Here we developed monoclonal antibodies (MAbs) against the extracellular domain of mouse DP2 by immunization of DP2-null mutant mice with DP2-overexpressing BAF3, murine interleukin-3 dependent pro-B cells, to reduce the generation of antibodies against the host cells by immunization of mice. Moreover, we immunized DP2-KO mice to prevent immunological tolerance to mDP2 protein. After cell ELISA, immunocytochemical, and Western blot analyses, we successfully obtained a novel monoclonal antibody, MAb-1D8, that specifically recognized native mouse DP2, but neither human DP2 nor denatured mouse DP2, by binding to a particular 3D receptor conformation formed by the N-terminus and extracellular loop 1, 2, and 3 of DP2. This antibody inhibited the binding of 0.5 nM [3H]PGD2 to mouse DP2 (IC50 = 46.3 ± 18.6 nM), showed antagonistic activity toward 15(R)-15-methyl PGD2-induced inhibition of 300 nM forskolin-activated cAMP production (IC50 = 16.9 ± 2.6 nM), and gave positive results for immunohistochemical staining of DP2-expressing CD4+ Th2 lymphocytes that had accumulated in the kidney of unilateral ureteral obstruction model mice. This monoclonal antibody will be very useful for in vitro and in vivo studies on DP2-mediated diseases.