Expression of murine beta 7, alpha 4, and beta 1 integrin genes by rodent mast cells.
The screening of a rat mast cell cDNA library with a probe selected to recognize those genes preferentially or exclusively expressed by mast cells identified a rat gene sequence, RF-17, that shared homology with the beta-integrins. This integrin was expressed in rat tissues enriched for mast cells and T cells. The rat RF-17 sequence was used to isolate the murine homologue from a spleen cDNA library. The murine gene encodes a protein of 806 amino acids that is the probable homologue to the human beta 7 chain. Transcripts specific for the murine gene are found in the thymus, spleen, and lung. To attempt to identify the gene product for this new integrin chain, we examined the murine T cell line TK-1, which expresses a novel integrin heterodimer, lymphocyte Peyer's patch high endothelial venule adhesion molecule (LPAM-1), of a known alpha 4 chain and an unknown beta P chain, for expression of murine beta 7 (RF-17). This cell line expresses high levels of RF-17 transcripts, suggesting that beta P is encoded by the beta 7 gene. Bone marrow cells induced to differentiate into mast cells via IL-3 express the beta 7 gene as well as the genes encoding the murine integrin alpha 4 and beta 1 proteins. Surface staining analysis indicates that these cells express an alpha 4-containing integrin complex throughout the differentiation process. These data suggest that the Peyer's patch homing LPAM-1 receptor expressed by a subset of T cells consists of the beta 7 gene product and the alpha 4 chain, and that this integrin chain complex is also found on the surface of maturing mast cells. The presence of beta 1 transcripts also suggests that these maturing mast cells possess the LPAM-2 integrin complex (alpha 4/beta 1) as well. The experimental strategy described in this manuscript has, thus, identified a novel murine beta-integrin chain that is expressed by rodent T cells and mast cells.
Gurish
M F
MF
Department of Rheumatology and Immunology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115.
Bell
A F
AF
Smith
T J
TJ
Ducharme
L A
LA
Wang
R K
RK
Weis
J H
JH
D000595:Amino Acid Sequence; D000818:Animals; D000951:Antigens, Neoplasm / Q000235:genetics; D001483:Base Sequence; D001854:Bone Marrow Cells; D003001:Cloning, Molecular; D015870:Gene Expression; D006801:Humans; D007231:Infant, Newborn; D039641:Integrin beta Chains; D019012:Integrin beta1; D016023:Integrins / Q000235:genetics*; D008407:Mast Cells / Q000502:physiology*; D051379:Mice; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides / Q000737:chemistry; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D016415:Sequence Alignment; D012995:Solubility
D000951:Antigens, Neoplasm; D039641:Integrin beta Chains; D019012:Integrin beta1; D016023:Integrins; D009838:Oligodeoxyribonucleotides; D012333:RNA, Messenger; C091368:integrin beta7