Modulation of ROS Production by Environmental Factors

In order to distinguish the influence of environmental pollution from natural variability of echinoderm immune responses, it is crucial to delineate the endogenous or exogenous factors that affect these responses. For instance, injury, acute temperature shock, acidic pH or heavy metal shock were shown to affect the sea urchin immune system (Matranga et al. 2000, 2002). Moreover, a year-round study of a particular immune response is necessary in order to identify periods that might be characterised by increased variability compared to others. Therefore, we investigated the effects of environmental factors and the annual variability of ROS production by amoebocytes of the starfish Asterias rubens (Coteur et al. 2004).

The ROS production by amoebocytes is efficiently stimulated by the presence of bacteria or bacterial wall components such as lipopolysaccharide (LPS) but not by the soluble stimulant phorbol-myristate-acetate (PMA, a

Fig. 1. Bacteria-stimulated reactive oxygen species (ROS) production (mean ± SE, n=10) in starfishes collected monthly in Ambleteuse (France) in function of the water temperature measured at each sampling occasion. RLU Relative light units

Fig. 1. Bacteria-stimulated reactive oxygen species (ROS) production (mean ± SE, n=10) in starfishes collected monthly in Ambleteuse (France) in function of the water temperature measured at each sampling occasion. RLU Relative light units

protein kinase C activator) (Coteur et al. 2002). Other factors such as water temperature affected the production of ROS both in experimental conditions and in the field. The ROS production in starfish maintained in very cold waters (< 6 °C) was dramatically increased compared to starfish held at (even slightly) higher temperatures and this effect was also observed in the field during the coldest month of the year (Fig. 1).

It is thus a threshold-type effect that precludes the use of ROS production in the field during this period since very high natural variations can occur in limited time.Another factor that partially determines the immune response is the water salinity as ROS production decreases with increasing salinity. However, handling stress, gender and parasitism by a castrating ciliate did not influence amoebocyte ROS production in our experimental setup (Coteur et al. 2004).

How To Bolster Your Immune System

How To Bolster Your Immune System

All Natural Immune Boosters Proven To Fight Infection, Disease And More. Discover A Natural, Safe Effective Way To Boost Your Immune System Using Ingredients From Your Kitchen Cupboard. The only common sense, no holds barred guide to hit the market today no gimmicks, no pills, just old fashioned common sense remedies to cure colds, influenza, viral infections and more.

Get My Free Audio Book


Post a comment