Dr. Murai Éva szerk.: Parasitologia Hungarica 22. (Budapest, 1989)

Two major conclusions can be drawn from the above subjective overview. One Is to emphasize the necessity to assess mast cell functions in worm rejection as an Integral part of the very complex interplay between all components of immune mechanisms. It Is only under carefully planned and controlled experimental conditions that the subtleties of the immunological web can be analysed. Secondly, the recent recognition of functional mast cell hetero geneity implies that the function of mast cells in parasite Immunity will not necessarily be the same in all species, breeds, Individuals and sites. This highlights the danger of extra polating results obtained in one experiment to the other, and may necessitate reconsideration of the interpretation of some earlier findings. 3) Antibodies About the role of antibodies

, especially of the so-called "protective antibodies", there Is not much news to say. Worm-specific antibodies of the IgE, IgM and IgG isotypes have long been known to be regular functional components of induction and development of the gastrointestinal hypersensitivity reactions. The worm damaging effect of in vitro incubation of the parasites in the serum of immune animals or in media of various antibody and cell combinations, though experimentally shown by some workers (e.g. BOTTJER et al. 19851, cannot be taken as an evidence to show that specific antibodies exhibit direct helminthotoxic action also in In vivo conditions. Locally produced secretory IgA can resist enzymatic degradation. However, no correlation could be seen between the intestinal SIgA response and degree of protection (WEDRYCHOWICZ et al. 1984). Moreover, experimental evidence suggests that SIgA antibodies may facilitate some form of symbiosis between the host and parasite rather than be Important in the host's protective response (BE FUS 1982; BE FUS and BIENENSTOCK 1982). Regulation of gastrointestinal physiology smooth muscle contraction mucosal blood flow and mucus secretion mucosal permeability Immediate hypersensitivity Delayed type hypersensitivity Immunoregulation Tissue repair Angiogenesis Cytotoxicity Myelopoiesis Fibrosis Fig. 3. The range of known mast cell functions