Note: This is William Boyd's own recollection of how some lectins were first shown to be blood group specific(). Not only is the story interesting, but the studies he references are long out of print and not electronically indexed, so it is a bit of "lost science." -Peter D'Adamo
"It is very appropriate that I present my work on lectins (plant agglutinins) here, because in a very real sense Dr. Landsteiner is the "Father" of the lectins.
It had been known for a long time that extracts of certain plant seeds agglutinate the erythrocytes of various animals, including man. Stillmark,() reported the hemagglutinating activity of extracts of the castor bean (Ricinus communis) in 1888. The early history of the plant agglutinins has been reviewed by Krupe () and Bird.() There are at least three early papers not referred to by these authors: namely, by Muenk () and Dorset and Henley.(,) [See also: Makela,() Makela and Krupe,() Krijpe,(2) Saint-Paul() and Bird.()
Landsteiner had observed fairly early that these extracts did not always agglutinate the blood of different species equally and wrote, for publication in 1914, a paper entitled 'Pflanzliche Hammagglutinine." This paper reached the stage of page proof, but owing to the war of 1914 was never published. In the first edition of his book on the specificity of serological reactions (1933) "Die Spezifizitat der Scrologischen Reaktionen," Landsteiner summarized some data of this paper in a table (TABLE 1).
|Agglutinin from ||Rabbit ||Pigeon ||Agglutinin from||Horse ||Pigeon|
|Beans ||125||2000||Abrus ||128||256|
|Lentils ||160||0||Castor bean ||4||512|
TABLE I: Titers of different plant agglutinins for the red cells of different species. ()
One day toward the end of 1945, looking at this table in the second English edition of Landsteiner's book, I was seized with the idea that if such extracts could show species specificity, they might even show individual specificity; that is, they might possibly affect the red cells of some individuals of a species and not affect others of the same species. Therefore, I asked one of my assistants to go out to the corner grocery store and buy some dried lima beans. Why I said lima beans instead of the more common pea beans or kidney beans I shall never know. But if we had bought practically any other bean we would not have discovered anything new.
The lima beans were ground and extracted with salt solution. The resulting extract agglutinated erythrocytes of some human individuals, but those of others only weakly, if at all. It was immediately evident that the differences were correlated with blood groups.
The ease with which this discovery was made misled me, and aside from a rather oblique reference to it in the second edition of my Fundamentals of Immunology,() which I was working on at the time, I did not publish this observation until 1949, when I reported on an investigation of 262 varieties of plants belonging to 63 families and 186 genera.
The first plant found to be blood-group specific was Phaseolus limensis, which, however, was not reported in detail () until 1949. In 1948 Renkonen () published an account of his independent studies of 57 species belonging to 28 genera. He reported Vicia cracca extracts to be specific for the blood-group-A antigen, and Laburnum alpinum, Cystisus sessifolius, and Lotus tetragonolobus to be specific for the H blood-group factor. Krupe published a large number of original observations. Makela (8) published a monograph giving the results of his tests on a large number of seeds, and Tobiska () and Adamkova and Tobiska () published their results of tests with 200 plants. A complete list of all the plants tested in my laboratory was recently published." Five reviews have appeared (2,4,8,10,)
I proposed that these blood-antigen-specific plant agglutinins (which are also specific precipitins) be called "lectins" -from the Latin legere, to pick out or choose -intending thus to call attention to their specificity without begging the question as to their nature."
FIGURE I: Boyd's work book.