Agglutinins in the earthworm Lumbricus terrestris: naturally occurring and induced

A naturally occurring hemagglutinin against rabbit and rat erythrocytes is contained in the coelomic fluid of the earthworm Lumbricus terrestris. The hemagglutinin reacts with some chicken and human erythrocytes, but not others, and does not react with the erythrocytes of seven other vertebrates. Hemagglutinins appear in increased amounts within 24 hr after injection of rat, rabbit, horse and sheep erythrocytes, and some chicken and human erythrocytes, and are the highest (approximately four- to sevenfold) with rabbit erythrocytes. The response is brief, and increased or more rapid responses do not occur after multiple injections. Cross reactivity and absorption data indicate a close or possibly identical relationship between agglutinins induced against different erythrocyte types. Effects of heating, enzyme and chemical treatment on induced anti-rabbit erythrocyte agglutinins indicate at least two and perhaps three different agglutinins. Two of the agglutinins are protein, one trypsin-sensitive and the other trypsin-resistant. Agglutinin activity is reduced in the absence of divalent cations. Sensitivity to heat varies with the type of agglutinin. The naturally occurring agglutinin is a protein, trypsin-resistant and unaffected by heating at 100 degrees C for 30 min. These hemagglutinins constitute one of the earthworm's humoral factors that may participate in immune responses.