Milk is known to provide not only excellent nutrition but also protection against infection in mammalian neonates. Whey proteins, such as immunoglobulins, lactoferrin, lysozyme and lactoperoxidase, are well known antimicrobial components in milk. Håkansson et al. (1995) demonstrated that some multimeric human α-lactalbumin derivatives induced apoptosis in immature and tumour cells. Yoo et al. (1997) found that lactoferricin, which had been isolated from peptic lactoferrin as an antimicrobial peptide, induced apoptosis in tumour and immature mammalian cells. Apoptotic cell death is considered to be an important physiological function in the development and homeostasis of multicellular organisms and to be a highly controlled means of eliminating dangerous, damaged or unnecessary cells without causing tissue damage. Therefore, these findings suggest that whey proteins may have beneficial health effects by restricting specific cell population in the body.

Four synthetic peptides which comprise the immunodominant linear epitopes of the EG95 recombinant protein, were investigated for their ability to induce host-protective immunity against Echinococcus granulosus in sheep. Sheep were immunized with either free peptide or peptide conjugated to diphtheria toxoid and challenge infected with E. granulosus eggs. All of the peptides elicited specific antibody, but these did not kill the parasite in in vitro culture assays, nor did the peptides induce protection against challenge infection. In contrast, anti-EG95 antibodies affinity purified against each of the 4 peptides were lethal to the parasite in in vitro culture. These affinity-purified antibodies were shown to contain specific antibody to both peptide and EG95. In in vitro inhibition assays, the peptides did not diminish anti-EG95 antibody binding to EG95 or parasite lysis in oncosphere killing assays. These results suggest that the fine specificities of antibodies raised against the recombinant protein are different to those raised against the peptide immunogens and that the majority of the antibody induced by vaccination with EG95 is raised against conformational determinants.

A rabbit antiserum was raised against a synthetic peptide corresponding to a region near the N-terminus of the Haemonchus contortus inhibitory amino acid receptor subunit, HG1. The antiserum recognized a recombinant form of the N-terminal domain of the subunit on Western blots and reacted with the ventral nerve cord of H. contortus in immunofluorescence experiments. Immunofluorescence was also detected in specific head neurons of H. contortus: these were tentatively identified as ring motor- and inter-neurons, plus a possible sensory neuron equivalent to the AQR cell of Caenorhabditis elegans. In the roundworm Ascaris suum, immunoreactivity was limited to the muscle arms, the post-synaptic component of the neuromuscular junction. The possible ligand of receptors containing the HG1 subunit is discussed in the light of this expression pattern.