A novel scavenger of nitric oxide decreases heme protein nitrosylation and prolongs graft survivial during cardiac transplant rejection

lymphocytes (20x106IV) were injected 9 days after aortic transplantation into animals with or without anti-a4 and anti-b2 monoclonal antibodies. All animals were sacrificed on day 10 and evaluated by histology and g counting. Results: All allografts had significant infiltration of the adventitia by mononuclear cells at day 10 as compared to control aorta. There was an average of 220675 51Cr cpm and 224668 111In cpm labeled T cells in transplanted aorta as compared to 41637 cpm in control aorta (p,0.05). Anti a4/b2 treatment resulted in significant reduction in labeled T cell infiltration with a 91% reduction in naive and 72% reduction in allo-exposed T cell accumulation. Anti a4/b2 resulted in 92% and 95% reduction in T cell accumulation in LPS and TNF-a injected control dermal sites respectively. Discussion: In summary, we have demonstrated that T lymphocytes infiltrate vascular tissue early after transplantation and this infiltration appears to be mediated via a4 and b2 integrin mechanisms. This represents the first direct evidence of the role of CAMs in trafficking of T cells in transplanted allografts.