p. bakeri [31, 58, 59]. Already data had been provided that in contrast to the majority of popular laboratory mouse strains, LAF1 mice lost worms within 3 weeks of infection [60] and SJL were capable of expelling primary infections with H. p. bakeri within 6–11 weeks of oral infection [58, 61]. Another strain that was also found to be capable of eliminating primary infection worms rapidly was SWR [62]. Many different strains were ranked in terms of

their capacity to resist primary infections and to express acquired resistance [31, 63, 64, 15], and therefore, it was possible now to correlate antibody responses ABT-263 manufacturer with resistance across mouse strains of varying genotype and responder phenotype. Much as expected, it was soon found that good responder strains produced high levels of parasite-specific IgG1, and poor responders much lower [59, 64, 15], and even within the strong/intermediate responder strains, IgG1 levels correlated

negatively with worm burdens [65]. Until now, most work on H. p. bakeri has made use of polyclonal Abs (particularly IgG1) purified from infection/vaccination sera in neutralization tests in vitro and in vivo. These experiments are technically demanding and far from optimal as sera contain a mixture of antibody isotypes, CDK inhibitor some with inappropriate specificities (such as blocking antibodies) and the potential Tangeritin to trigger inhibitory signals through immunoreceptor tyrosine-based inhibition (ITIM) motifs. It is difficult to ensure the absolute purity of such antibodies, and minor contamination with a highly biologically active isotype may give misleading results. Purifying antibodies from small volumes of mouse sera is time-consuming and results in small yields that are difficult to standardize. Furthermore, antigen-directed, isotype restriction

means that different subclasses will not recognize identical epitope populations. As epitope density has a major influence on the efficiency of effector mechanisms, such as antibody-dependent cellular cytoadherence (ADCC), it has been virtually impossible to determine whether a particular result is representative of the fundamental role played by IgG1. One way forward in achieving a deeper understanding of the precise role of antibodies in H. p. bakeri infection will be to engineer recombinant epitope-matched monoclonal antibodies for each IgG class with which to dissect their function without fear of contamination from other antibody types or other serum components that co-purify on protein G/A columns, as has been done recently in the case of malaria [66, 67]. The last three decades, since the start of the 1990s, have seen an unprecedented pace of change and advances in technologies in biology. Parasite immunologists working with H. p.