Helminth IMs

The development of therapeutic IMs from bacteria and viruses is a widely investigated area of research, for reasons previou% discussed. In comparison, thoi less helminth IMs have been described to-date, there are some aspects of the interplay between helminths and the human host that would surest they are an IM source of si iificant promise. A fundamental feature of worm infections is that rather than being typified by transient acute infections, they modulate host immunity via the synthesis and secretion of various parasitic IMs that chronically usurp the immune response for years to decades. It is this capacity for long-term immune suppression that surest a potential for use of helminth IMs as treatments in chronic inflammatory conditions. 

Tabk 4. Comparative biohgical differences between certain parasitic helminths and viruxs 

Location Vasculature Lymphatics Intestinal lumen Obligate intracellular 

Infection Skin penetration Insect bite Ingesting eggs Respiratory, alimentary or urogenital tract, skin or eye 

Intermediate host/ vector Snail Mosquito None Generally none, some transmit through insects 

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A rational approach to exploit the immime modulatory activity of helminths is the characterization of the IMs from helminths that can mimic the desirable anti-inflartunatory eflects of infection. In this article we have outlined various helminth IM described to-date. In the future, the identification of new helminth-derived IM has the potential to lead to the development of novel therapeutic strat es fr>r the treatment of a range of human immunological and nonim-munolr cal disorders. 

The anti-helminthic agent levamisole has im-munostimulant properties. It increases chemotaxis and phagocytosis of macrophages and polymorphonuclear leukocytes and stimulates lymphocytes function. It has proved to be effective in treating RA. Its most common adverse effect is the occurrence of rashes. 

Ultrastructure of the zones of contact between the helminth and the intestine during bothriocephaliasis in carp.] In Russian. Doklady Vsesoyuznoi Akademii Sel skokhozyaistvennykh Nauk im. V. I. Lenina, 4 35-7. [HA/53/2679]... 

Neglected diseases are a group of infectious diseases that are endemic in the low-income populations in the developing world. They cause death to about 500,000 to Im people every year, a death rate that is comparable to that of the HIV/AIDS pandemic. They are easily preventable but are a big problem in the affected areas. There are supposed to be about 13 distinct diseases but they can be classified as those caused by trypanosomal parasites, helminth parasites, bacteria and viruses. 

Table 5. Examples of IM from helminths that modulate immune responses...

In parasitic helminths, several different carbohydrate and hpid molecules from the parasitic surface or ES product are potent modulators of the host immune response. The most widely investigated helminth carbohydrate is Lacto-N-fucopentaose III (LNFPIII) and, while with respect to helminth lipid IMs, schistosomal lysophosphatidylserine (lyso-PS) is the best characterized. ... 

All these considerations lead us to recommend the greatest care for im-muno-intervention using anti-IgE antibodies (87-89) in areas with high rates of helminth infections. Besides the potential risk of decreasing immune defense mechanisms in individuals exposed to helminth infections, the massive production of IgE-anti-IgE complexes in individuals with high IgE levels could lead to the undesirable activation of inflammatory cells and the occurrence of deleterious events. 

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