A concept of humoral immunity among ruminants and an approach to its investigation.

My goal has been to piece together bits of information, both old and new, so as to provide you with some concepts of humoral immune function. Specifically I have described concepts of secretory immunity in two different organ systems, the lower respiratory tract and the mammary gland. Should these concepts not even survive this meeting or be proven incorrect by future research, I hope I have at least stimulated your thinking with an alternative view and challenged you to saw off the limb I have put myself on with the concepts I have presented. More than mere conjectural hypotheses, I have presented some data on the ELISA out of my belief that one approach to establishing concepts in humoral immunity depends on the ability to accurately and quantitatively measure the distribution of antibodies among isotypes. I have also shared with you some preliminary data on the transport of SIgA into bile and other secretion which will hopefully encourage others to finally establish the quantitative significance of locally synthesized versus serum-derived IgA in the various exocrine secretions of ruminants. Finally, I have dared to take ruminant immunoglobulin homology "back to sea"; perhaps this last topic will stimulate your palate if not your mind.