MALNUTRITION AND GLUCOCORTICOIDS THERAPY IMPAIR HOST IMMUNE RESPONSE DURING TRICHINELLA SPIRALIS INFECTION

Trichinosis is an important food-borne zoonotic disease worldwide, caused by a nematode
Trichinella spiralis. Malnutrition and glucocorticoids (GC) therapy are the commonest causes
to diminish human immune responses.
This study evaluated the effects of malnutrition as well as GC therapy on host immune response
during T. spiralis infection.
One group of albino mice (mal-nourished) received a protein-deficient diet (6.5% casein),
other three groups (control non infected, infected well-nourished and infected GC-treated mice)
received a control diet (20% casein). GC-treated mice were given dexamethasone intraperitoneally
at a dose of 25ug/day for three weeks before infection and continued to receive dexamethasone
throughout the experimental time. Mice were orally infected with250 larvae/mouse and
sacrificed on 7th & 21st day post infection (p.i.) and adults in intestine and larvae in diaphragm
were examined. Cytokines and pro-inflammatory mediators ’sera were measured by ELISA.
The results showed that mean number of adult worms in intestine and larvae in diaphragm
were significantly higher in mal-nourished and GC-treated than well-nourished mice. Infected
mal-nourished and infected GC-treated mice, had lower serum concentration of Th1 (IFN-y &
IL-12) and Th2 (IL-4 & IL-10) cytokines than corresponding well-nourished group. Similar results
were obtained with pro-inflammatory mediators (TNF-α, IL-1β & IL-6) that were lower in
infected mal-nourished and infected GC-treated than infected well-nourished mice.