Go to  Advanced Search

ICAM-1 interactions in immune response

Show full item record

Files in this item

Files Size Format Description   View
ubc_1995-0133.pdf 7.119Mb Adobe Portable Document Format   View/Open
 
Title: ICAM-1 interactions in immune response
Author: Smith, Carol Anne
Degree Master of Science - MSc
Program Microbiology and Immunology
Copyright Date: 1995
Abstract: Intercellular adhesion molecule-1 (ICAM-1, CD54) and its interactions with LFA-1 and Mac-1 are critical for the proper functioning of our immune system. In addition to these associations, other molecules such as a-actinin of the actin cytoskeleton, and a sialoglycoprotein, CD43, have been suggested to bind human ICAM-1 but the precise nature of these interactions and their physiological significance are not known. This thesis has examined the possible associations of ICAM-1 with these later two molecules, in the murine system, to further elucidate the mechanisms responsible for the upregulation of ICAM-1 adhesion during inflammatory and immune responses. Punctate distribution of ICAM-1 on the surface of fibroblasts suggested the association of ICAM-1 with cytoskeletal components. However, detergent extraction of cell lines expressing endogenous ICAM-1, as well as those transfected with truncated ICAM-1 lacking the cytoplasmic domain or recombinant ICAM-1 anchored by glycdsyl-phosphatidyl inositol, suggested there is very little or no association of ICAM-1 with the cytoskeleton. In all cases, ICAM-1 was completely soluble. To determine if ICAM-1 associated with another molecule which in turn associated with the cytoskeleton, chemical cross-linking studies were performed. In Western blot analysis, a band of approximately 200 KD was observed which suggests ICAM-1 may self associate in a fibroblast and T cell hybridoma cell line. It was concluded that murine ICAM-1 does not associate with the cytoskeleton in the cell types tested and that there must be some other underlying mechanism responsible for the punctate distribution of ICAM-1 on fibroblasts. Whether this affects cell adhesion remains to be determined. The report demonstrating the binding of human ICAM-1 to a leukocyte sialoglycoprotein, CD43, lead to further investigation of this interaction in the murine system in this thesis. Fibroblasts transfected with murine CD43 were unable to adhere to soluble immobilized ICAM-1 in an adhesion assay. As well, soluble ICAM-1 coated microspheres were unable to bind to CD43+ fibroblasts. The results of these studies conclude murine CD43 interaction with ICAM-1 can not be detected by these conventional methods and thus bring into question the original reports on CD43/ICAM-1 interaction. A new model system was established in an attempt to detect a more sensitive interaction that may not withstand an adhesion assay. This system utilized cell death via the cross-linking of an ICAM-1/Fas chimeric molecule as a read out for an association. Although this system was unable to determine whether CD43 and ICAM-1 interact, it did suggest that LFA-1/ICAM-1 interaction may be one of monovalency. This however, requires further investigation.
URI: http://hdl.handle.net/2429/3611
Series/Report no. UBC Retrospective Theses Digitization Project [http://www.library.ubc.ca/archives/retro_theses/]

This item appears in the following Collection(s)

Show full item record

All items in cIRcle are protected by copyright, with all rights reserved.

UBC Library
1961 East Mall
Vancouver, B.C.
Canada V6T 1Z1
Tel: 604-822-6375
Fax: 604-822-3893