Régulation des populations de Nématodes gastro-intestinaux ...

Résultats
(L4 to adults) were present in all groups of lambs. Higher percentages of L4 and immature
stages were observed in INRA 401 group A (P = 0.011) and BBB group B (P < 0.05)
suggesting a delayed worm development (Table 3). Female worms harbored by previously-
infected INRA 401 lambs were significantly shorter and contained fewer eggs in utero than
those in INRA 401 primary-infected lambs (P < 0.05). This difference was not noticed
between the two BBB groups. While they were statistically lower than those in INRA 401
group B lambs (P < 0.01), numbers of eggs in utero for worms in the BBB groups were
comparable to those of the previously-infected INRA 401 lambs (Table 3). A similar pattern
of statistical difference to eggs in utero was noted for female worm size except that worms in
BBB group B lambs were also found shorter than those in INRA 401 group A lambs.
3.1.3. Development of H. contortus eggs in infective larvae.
The proportions of H. contortus eggs developing into third stage larvae after 10 days
of culture ranged from 24.5 to 44.4% but were not different between breeds and groups.
3.2. Patterns of cytokine gene expression
3.2.1. Cytokines in the total abomasal lymph node and isolated CD4+ cells
Expression patterns or transcription intensities were similar between the cDNA
samples stemming from the total abomasal lymph node and those stemming from CD4+ cells
isolated from this lymph node, suggesting that mRNA expression at the level of this cell type
reflects correctly the mRNA transcription of the whole lymph node (data not shown). Then,
only values obtained in the total abomasal lymph node are given.
3.2.2. Cytokine mRNA transcription in abomasal lymph node and abomasal fundic
mucosa
For both breeds, H. contortus infections were followed by a significant increase in Th2
cytokine (IL-4, IL-5 and IL-13) gene expressions (Figure 3). This over-expression was
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