Isolated nucleic acid molecules encoding ICAM-2

#1. Field of the Invention

#The present invention relates to the intercellular adhesion molecule-2 ("ICAM-2") which is involved in the process through which populations of lymphocytes recognize and adhere to cellular substrates so that they may migrate to sites of inflammation and interact with cells during inflammatory reactions. The present invention additionally relates to ligand molecules capable of binding to ICAM-2 intercellular adhesion molecules, and to uses for the intercellular adhesion molecule, and the ligand molecules.

#2. Description of the Related Art

#FIGS. 1A and 1B show binding of transfected COS cells expressing ICAM-1 and ICAM-2 to LFA-1-coated plastic. FIG. 1A COS cells transfected with ICAM-1 cDNA were panned on LFA-1-coated plates and the expression of ICAM-1 was analyzed by indirect immunofluorescence flow cytometry with anti-ICAM-1 monoclonal antibody RR1/1 as primary MAb. Unpanned cells (dotted line), non-adherent cells (dashed line), adherent cells (solid line). FIG. 1B .sup.51 Cr labelled transfected COS cells expressing ICAM-1 or ICAM-2 were bound to LFA-1-coated plastic in the presence of MAb.

#FIG. 2 shows the nucleotide and amino acid sequence of ICAM-2. The amino acid sequence is numbered beginning with the first residue following the predicted cleavage site of the signal peptide. The hydrophobic putative signal peptide and transmembrane sequences (TM) are underlined. Potential N-linked glycosylation sites are boxed. The putative polyadenylation signal AATACA is overlined. Potential N-linked glycosylation sites are boxed. The putative polyadenylation signal AATACA is overlined. Both strands of the ICAM-2 cDNA were sequenced within CDM8 by sequential synthesis of complementary oligonucleotide primers and dideoxynucleotide chain termination sequencing (Sanger, F. et al., Proc. Natl. Acad. Sci. USA 74: 5463-5467 (1977)) according to the manufacturer's recommendations (Sequenase, U.S. Biochemical).

#FIGS. 3A, 3B, and 3C show the results of RNA and DNA hybridization analyses. Northern (FIGS. 3A and 3B) and Southern (FIG. 3C) blots were hybridized to the 1.1 kb .sup.32 P labeled ICAM-2 cDNA (FIGS. 3A and 3C) and rehybridized to the 3 kb .sup.32 P labeled ICAM-1 cDNA (FIG. 3B). (FIGS. 3A and 3B) 6 .mu.g of poly(A).sup.+ RNA from the Burkitt lymphoma cell line, Ramos (lane 1), endothelial cells (lane 2), endothelial cells stimulated for three hours with LPS (lane 3), an EBV immortalized B-lymphoblastoid cell line, BBN (lane 4), epithelial carcinoma cell line, HeLa (lane 5), T lymphoma cell lines, Jurkat (lane 6) and SKW-3 (lane 7), and a promonocyte cell lines, U937 (lane 8). (C) 6 .mu.g of genomic DNA from B cell lines BL-2 (lanes 1 and 4), ER-LCL (lanes 2 and 5) and Raji (lanes 3 and 6) digested with EcoRI (lanes 1-3) or HindIII (lanes 4-6). ICAM-2 and ICAM-1 mRNAs are indicated by arrows.

#One aspect of the present invention relates to the discovery of a natural binding ligand to LFA-1. Molecules such as those of CD-18 family, which are involved in the process of cellular adhesion are referred to as "adhesion molecules."

#The leukocyte adhesion molecule LFA-1 mediates a wide range of lymphocyte, monocyte, natural killer cell, and granulocyte interactions with other cells in immunity and inflammation (Springer, T. A. et al., Ann. Rev. Immunol. 5: 223-252 (1987)).

#LFA-1 is a receptor for intercellular adhesion molecule 1 (ICAM-1), a surface molecule is constitutively expressed on some tissues and induced on others in inflammation (Marlin, S. D. et al., Cell 51: 813- 819 (1987); Dustin, M. L. et al., J. Immunol. 137: 245-254 (1986); Dustin, M. L. et al., Immunol. Today 9: 213-215 (1988); U.S. patent application Ser. No. 07/019,440, filed Feb. 26, 1987 and U.S. patent application Ser. No. 07/250,446, filed Sep. 28, 1988, both applications herein incorporated by reference).