Immunoendocrine host-parasite interactions during helminth infections: from the basic knowledge to its possible therapeutic applications.

Most of the current research on parasitic infections that affect humans and domestic animals has been focused on vaccines, diagnostic methods, epidemiology, new drug design, and recently, with the advancement of genomics and proteomics, on the evolutionary origins of parasites. However, the basic biology of many parasites of medical and veterinary importance has not been intensively studied. Some efforts have been made to obtain information on the parasite-host relationship; however, knowledge of the intricate neuroimmunoendocrine interactions of the host-parasite network, the consequences of this interaction on the host and parasite physiology, and its possible applications needs further investigation. We review here the literature, our own studies on the host-parasite neuroimmunoendocrine network, and how this basic knowledge can be used to design new treatments, by way of using hormones, antihormones, and hormone analogues as a possible novel therapy during parasitic diseases, with special emphasis on helminth parasites. Besides the biological interest, these investigations may contribute to the future identification of alternative treatments for several parasitic diseases. This complicated neuroimmunoendocrine network management during parasitic infections, and its physiological and behavioural consequences upon the host, may be operative in other mammalian infections. Such complexity may also help to explain the often conflicting results, observed between infections with respect to the role of the host sex and age, and hints to other avenues of research and strategies for their treatment and control.