Selective expression of a novel surface molecule by human Th2 cells in vivo.
The search for reliable marker molecules discriminating between human Th1 and Th2 cells identified a gene encoding a novel member of the G protein-coupled leukocyte chemoattractant receptor family, which is selectively expressed in Th2 but not Th1 lineage cells, thereby named CRTH2 (chemoattractant receptor-homologous molecule expressed on Th2 cells). Studies with anti-CRTH2 mAbs demonstrated that CRTH2 was expressed in a small population (0.4-6.5%) of CD4+ T cells in fresh PBMCs of healthy adults, but no remarkable expression was seen in B cells and NK cells. In some cases, CD8+ T cells ( approximately 3.5%) expressed CRTH2. Phenotypes of CD4+ T cells expressing CRTH2 were CD45RA-, CD45RO+, and CD25+, similar to those of Ag-activated effector/memory T cells. Freshly isolated CRTH2+ CD4+ T cells produced Th2- but little or no Th1-type cytokines upon stimulation with PMA and ionomycin. In addition, an allergen-induced proliferative response in fresh PBMCs was significantly and selectively reduced by subtracting CRTH2+ cells. Together, these results indicate that CRTH2 is selectively expressed in vivo in an activated state of Th2 cells including allergen-responsive Th2 cells, suggesting its pivotal roles in ongoing Th2-type immune reactions.
Nagata
K
K
R & D Center, BioMedical Laboratories, Kawagoe, Saitama, Japan. nagata@alk.co.jp
Tanaka
K
K
Ogawa
K
K
Kemmotsu
K
K
Imai
T
T
Yoshie
O
O
Abe
H
H
Tada
K
K
Nakamura
M
M
Sugamura
K
K
Takano
S
S
D000328:Adult; D000485:Allergens / Q000008:administration & dosage; D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal / Q000096:biosynthesis; D001483:Base Sequence; D002460:Cell Line; D016207:Cytokines / Q000096:biosynthesis / Q000494:pharmacology; D017931:DNA Primers / Q000235:genetics; D018076:DNA, Complementary / Q000235:genetics; D015870:Gene Expression; D006801:Humans; D008213:Lymphocyte Activation; D008969:Molecular Sequence Data; D051381:Rats; D044042:Receptors, Formyl Peptide; D011971:Receptors, Immunologic / Q000737:chemistry / Q000235:genetics*; D018000:Receptors, Peptide / Q000235:genetics; D011982:Receptors, Prostaglandin; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D018417:Th1 Cells / Q000276:immunology; D018418:Th2 Cells / Q000276:immunology*