Current Pharmaceutical Design, Volume 9, No. 2, 2003
Contents
Executive Editor:
Pr. Michel Salzet
Comparative Immunology Pp. 119-131
Edwin
L. Cooper
Leeches: Immune Response, Angiogenesis and
Biomedical Applications Pp.
133-147
Magda
de Eguileor, Gianluca Tettamanti, Annalisa Grimaldi, Terenzio Congiu, Roberto
Ferrarese, Gianpaolo Perletti, Roberto Valvassori,
Annelid Neuroimmune System Pp. 149-158
Christophe Lefebvre and Michel
Salzet
Antimicrobial Compounds of Low Molecular Mass
are Constitutively Present in Insects: Characterisation of b -Alanyl-Tyrosine Pp. 159-174
K. Meylaers, A. Cerstiaens, E. Vierstraete, G. Baggerman, C.W. Michiels, A. De Loof and L. Schoofs
Probiotics as Biotherapeutic Agents: Present
Knowledge and Future Prospects
Pp. 175-191
A. Mercenier, S. Pavan and B. Pot
Study of Atrazine Effects on Pacific Oyster,
Crassostrea gigas, Haemocytes
Pp. 193-199
B.
Gagnaire, T. Renault, K. Bouilly, S. Lapegue and H. Thomas-Guyon
Abstracts
[Back to top] Comparative Immunology
Edwin
L. Cooper
Comparative Immunology has gained wide acceptance in biology, as an
offspring of immunology and an amalgam of immunology and zoology. The prescient
experiments of Metchnikoff on phagocytosis in invertebrates during the 19th
century served to splinter immunology into its two main components: cellular
and humoral. There is much interest in the immune system of invertebrates as
representing early models or precursors of the innate system of vertebrates
that by contrast possess the innate system as well as the more highly evolved
adaptive system. With respect to mechanisms, we think of the invertebrate
system as innate, natural, non-specific, nonanticipatory, and non-clonal.
Innate immunity operates through leukocytes that are not components of the
macrophage T and B interrelationships that characterize vertebrate adaptive
immunity that is adaptive, induced, specific, anticipatory, and clonal. This symposium
on invertebrate immunology has provided an overview of what is current and
crucial to understanding the larger field of comparative immunology.
Comparative immunology is now an established field, here since Metchnikoff but
officially since about 1977, with a journal (Developmental and Comparative
Immunology) (DCI) and an International Society of Developmental and Comparative
Immunology (ISDCI). During this short but vigorous history several national,
adherent societies have been organized in Japan, Italy and Germany with
sporadic interest in a national group in the USA. Nevertheless, comparative
immunology is here as vital to zoology in general and to immunology in
particular as we delve deeper into unique but also shared characteristics.
[Back to top] Leeches: Immune Response, Angiogenesis and
Biomedical Applications
Magda
de Eguileor, Gianluca Tettamanti, Annalisa Grimaldi, Terenzio Congiu, Roberto
Ferrarese, Gianpaolo Perletti, Roberto Valvassori, Edwin L. Cooper and Giulio
Lanzavecchia
The innate immune response is the first line of defence strategies in
invertebrates against attack of infectious agents. A detailed analysis of the
immune mechanisms involved in annelids has been performed in oligochaets, but few data are available in
polichaets and hirudineans.
The aim of this review is to describe the responses of leeches to
different kinds of stimuli (infections following non-self agent attacks,
surgical lesions, grafts). Furthermore, the use of this invertebrate as a novel
experimental model to be used to screen drugs and genes, which are responsible
for positive and negative modulation of angiogenesis, is discussed.
[Back to top] Annelid Neuroimmune System
Christophe
Lefebvre and Michel Salzet
Neuropeptides have been found in nervous central or immune systems of
Annelids. Since these signaling molecules are found free in the hemolymph, they
are considered as hormones. Hormonal processes along with enzymatic processing
similar to that found in vertebrates occur in annelids. Furthermore, amino acid
sequence determination of annelids precursor gene products reveals the presence
of the respective peptides that exhibit high sequence identity to their
mammalian counterparts. Nevertheless, specific neuropeptides to annelids or
invertebrates have also been in these animals. These peptides are flanked by
potential proteolytic signal sites for the various known enzymes confirming
that annelids neuropeptide precursors are processed in a similar manner to that
described in mammals i.e. implicating prohormone convertase enzymes.
[Back to top] Antimicrobial Compounds of Low Molecular Mass
are Constitutively Present in Insects: Characterisation of b -Alanyl-Tyrosine
K. Meylaers, A. Cerstiaens, E. Vierstraete, G. Baggerman, C.W. Michiels, A. De Loof and L. Schoofs
The number of bacterial and fungal strains that have developed
resistance against the classical antibiotics continues to grow. The intensified
search for new antibiotic lead compounds has resulted in the discovery of
numerous endogenous peptides with antimicrobial properties in plants, bacteria
and animals. Their possible applications as anti-infective agents are often
limited by their size, in reference to production costs and susceptibility to
proteases. In this article, we report recent isolations of antimicrobial
compounds from insects, with molecular masses less than 1 kDa. Experimental
approaches are discussed and the first data on the antimicrobial properties of b-alanyl-tyrosine (252 Da), one of such low molecular mass compounds isolated
from the fleshfly Neobellieria bullata, are presented. We also offer evidence
for the constitutive presence of antimicrobial compounds in insects of different
orders, in addition to the previously identified inducible antimicrobial
peptides.
[Back to top] Probiotics as Biotherapeutic Agents: Present
Knowledge and Future Prospects
A. Mercenier, S. Pavan and B. Pot
Since the early observations of Elie Metchnikoff, a wealth of
experiments have described the use of selected microorganisms, mainly belonging
to the lactic acid bacteria family, for the prevention or treatment of a
variety of pathological situations. Nevertheless, the mechanisms underlying the
proposed actions remain vastly unknown, partly as a consequence of the
complexity of the gastro-intestinal ecosystem with which these biotherapeutic
agents are expected to interact, but also because of the increasing variety of
strains considered to have potential probiotic characteristics. During the past
decades, however, the beneficial effect of specific strains in preventing or
treating intestinal disorders has been substantiated by well-controlled
clinical trials. Increasing evidence, including human studies, is also
supporting the immunomodulatory role attributed to given lactic acid bacterial
strains. The desire by consumers to use natural methods for health maintenance
rather than long-term chemotherapeutic agents (i.e. antibiotics), linked to
their expectation that food becomes a source of prolonged well-being, supports
the speculation that the probiotic market will expand rapidly. Much of this
growth will also depend on the reliability of claims that these products will
bare. Therefore, the legislator will have to provide clear rules and
regulations which will depend on measurable biomarkers and criteria based on
scientific evidence. These commercial and legislative needs will hopefully
provide scientists with the resources necessary to conduct the
multidisciplinary research required to establish facts and mechanisms of action
for carefully selected probiotic strains. These research results will probably
be as essential for the positioning of probiotic preparations as either a food,
a food supplement or as pharmaceutical preparation.
[Back to top] Study of Atrazine Effects on Pacific Oyster,
Crassostrea gigas, Haemocytes
B. Gagnaire, T. Renault, K. Bouilly, S. Lapegue and H.
Thomas-Guyon
Shellfish farming is an important economic activity around the world.
This activity often takes place in areas subjected to various recurring
pollutions. The recrudescent use of herbicides in agriculture including
atrazine implies pollutant transfer towards aquatic environment in estuarine
areas. Harmful effects of such substances on animals in marine environment,
particularly on cultured bivalves, are poorly documented. Bivalve molluscs such
as mussels and oysters have been postulated as ideal indicator organisms
because of their way of life. They filter large volumes of seawater and may
therefore accumulate and concentrate contaminants within their tissues.
Moreover, development of techniques allowing effect analysis of such compounds
on bivalve biology may lead to the development of diagnosis tools adapted to
analyze pollutant transfer towards estuarine areas. In this context, influence
of atrazine on defence mechanisms was analyzed in Pacific oysters, Crassostrea
gigas. Atrazine was tested in vitro and in vivo on oyster haemocytes, and its
effects were analyzed by flow cytometry. Haemocyte viability, cell cycle and
cellular activities were monitored. Atrazine induced no significant effect in
oyster under tested conditions except for peroxidase activity.