Three
monoclonal antibodies, originally studied because of their neuron-specific staining in the leech central nervous system, are characterized further here, both immunocytochemically and biochemically, with Western blot staining using the central nervous system and peripheral tissues. The three
antibodies react both with neurons and select epithelial tissue in the central nervous system, gut, and penis. Antibody Lan3-8 reacts with neurons in the nerve cord and gut but with epithelial cells in the penis; it binds to a 65K molecule in all three tissues. Lan3-2 and Laz2-369 are considered as a related pair because in the central nervous system the former
stains all (four) and the latter generally only half (two) of the neurons in a standard midbody
ganglion responding to nociceptive stimulation. In the gut, both
antibodies label patches of epithelial cells and Laz2-369 stains a previously unknown type of gut neuron. While a given antibody stains different bands in gut and central nervous system immunoblots, comparing the bands of both
antibodies for the same tissue extract makes it apparent that there are similarities in the molecular species that both
antibodies recognize. For each
monoclonal antibody, the histologically identified tissue
antigens need to be correlated with
proteins identified on Western blots. Of particular interest are the broad 130K bands to which Lan3-2 and Laz2-369 bind. The question is raised whether the molecular species in these bands represent a family of
proteins that serve a specific nociceptive cell function.