An Immunohistochemical Study of Anti-human-laminin Monoclonal Antibodies

Immunohistochemical distribution of laminin was examined in human renal and placental tissue using anti-human-laminin monoclonal antibodies （1D8 and 6G5）, which recognized different parts of non-reduced laminin molecule. Both antibodies staind glomerular mesangial matrix and placental trophoblast basement membrane, however, glomerular basement membrane, Bowman's capsule, and tubular basement membrane were not stained. Fetal vessel wall in placenta had only limited reactivity with these two antibodies. Both tissue reduction and oxidation enhanced the reactivity of basement membrane to 1D8 but not that to 6G5. Expanded mesangial matrix in patients with diabetic nephropathy or IgA nephropathy were also stained with 1D8 and 6G5. These data suggest that laminin in extracellular matrix has immunological heterogeniety, which may be derived from masking of lammin epitopes by other matrix components or from heterogeniety of laminin chain itself