Related Experiment Videos
Tubular expression of intercellular adhesion molecule-1 during renal allograft rejection
1Transplantation Immunology Laboratory, Queen Elizabeth Hospital, Woodville, South Australia.
Insights
Intercellular adhesion molecule-1 (ICAM-1) is upregulated on kidney allografts during rejection, appearing on tubular cells alongside HLA class II antigens. However, its presence in non-rejecting grafts limits clinical monitoring utility.
Area of Science:
- Immunology
- Transplantation Biology
- Cell Adhesion Molecules
Background:
- Cell adhesion molecules are critical for immune responses.
- Intercellular adhesion molecule-1 (ICAM-1) is a key adhesion molecule involved in immune cell interactions.
- Understanding ICAM-1 expression in kidney allografts is important for assessing transplant outcomes.
Purpose of the Study:
- To examine the expression of ICAM-1 in normal and allografted kidneys.
- To compare ICAM-1 expression with HLA class II antigens during kidney transplantation.
- To evaluate the potential of ICAM-1 and HLA class II as biomarkers for kidney allograft rejection.
Main Methods:
- Utilized a specific monoclonal antibody against ICAM-1.
- Employed an indirect immunoperoxidase technique for ICAM-1 detection.
- Analyzed kidney biopsies from normal, pre-implantation, and post-transplantation allografts.
Main Results:
- In normal kidneys, ICAM-1 was primarily expressed on vascular endothelial cells (VEC) and parietal epithelium.
- Allograft rejection was associated with de novo ICAM-1 expression on renal tubular epithelial cells, mirroring HLA class II antigen expression.
- Increased endothelial ICAM-1 and HLA class II expression was observed during rejection.
- Tubular expression of ICAM-1 and HLA class II in some non-rejecting biopsies limited their clinical utility for monitoring.
Conclusions:
- ICAM-1 expression on renal tubular cells parallels HLA class II antigen expression during kidney allograft rejection.
- The upregulation of ICAM-1 and HLA class II is likely cytokine-mediated but may involve other mechanisms.
- Monitoring ICAM-1 and HLA class II in post-transplant biopsies has limited clinical usefulness due to expression in non-rejecting grafts.
Abstract:
Molecules responsible for adhesion between cells are known to play an important role in the immune response. The expression of one of these molecules, intercellular adhesion molecule-1 (ICAM-1), was examined on normal and allografted kidneys using a specific monoclonal antibody and an indirect immunoperoxidase technique. The expression of this molecule was compared to that of HLA class II antigens. On normal kidneys and most allograft biopsies taken immediately before implantation, ICAM-1 was expressed only on vascular endothelial cells (VEC) and parietal epithelium of Bowman's capsule. In the 11 kidneys where biopsies were available before and after transplantation, the appearance of rejection was associated with de novo expression of ICAM-1 on renal tubular epithelial cells that closely paralleled that of HLA class II antigens. In addition, an increase in endothelial cell expression of these molecules was also seen in rejection. In 23 random allograft biopsies, most of those with rejection showed tubular expression of both HLA class II antigens and ICAM-1. However, the presence of these molecules on tubules in several biopsies that did not show rejection limits the clinical usefulness of monitoring these antigens in posttransplant biopsies. The upregulation of these molecules is presumed to be secondary to the release of cytokines by cells infiltrating the allograft, although other mechanisms may be operating that explain the expression of these molecules in nonrejecting grafts.