Immune response to rabbit coccidiosis: a comparison between infections with Eimeria flavescens and E. intestinalis

Abstract

Abstract. Seven-to eight-week-old rabbits were infected with Eimeria intestinalis Cheissin, 1948, a highly immunogenic coccidium, or Eimeria flavescens Marotel et Guilhon, 1941, which is weakly immunogenic. Immune response was investigated at 7, 14 and 21 days post inoculation (DPI). The level of serum immunoglobulins, lymphocyte proliferation stimulated by parasite antigens and weight of mesenteric lymph nodes (MLN) showed similar dynamics in rabbits inoculated with both coccidia species. The amount of serum IgG and IgM, but not IgA, was increased from 14 DPI. The lymphocytes from MLN of infected animals significantly reacted to stimulation with parasite antigen 14 and 21 DPI and MLN were enlarged at 14 DPI. Thus, both parasite species elicited immune response characterized by these parameters in a similar manner despite of their different immunogenicity. The only apparent difference in the responses was in the percentage of CD8+ lymphocytes in the specific site of parasite development (the last third of the small intestine in E. intestinalis, caecum in E. flavescens), which increased in rabbits infected with E. intestinalis but not with E. flavescens. This parameter reflects the status of local immunity and hence the results suggest that the local reaction plays an important role in induction of protective immunity to coccidia in rabbits.

Dependence of the immune response to coccidiosis on the age of rabbit suckling

“…The antigens used in the lymphocyte proliferation test were prepared from purified oocysts as already described (Pakandl et al 2008). To remove accompanying bacteria, which can produce lipopolysaccharides (LPS), the oocysts were treated with sodium hypochlorite (10%) and washed five times in phosphate-buffered saline (PBS).…”

“…The sera were finally diluted 1:160 with 1.0% bovine serum albumin in PBS and the level of serum immunoglobulins G, M, and A was assessed as previously described (Pakandl et al 2008). The ratio A to A 0 [absorbance of the samples to absorbance of blank (PBS)] was then calculated.…”

“…The lymphocytes were recovered from aseptically removed mesenteric lymph nodes (MLN) and cultivated without addition of soluble antigen or in presence of the antigen in 10, 5, 1, and 0.2 μg/ml concentrations (Pakandl et al 2008). The assay was performed on triplicate.…”

“…Our previous study showed that the migration of sporozoites of Eimeria coecicola and E. intestinalis from the site of their entry to the intestine (predominantly duodenum for both species) towards the target site [ileum in E. intestinalis, gutassociated lymphoid tissue (GALT) in E. coecicola] is impeded in the immune animals. We have recently published a comparative study of the immune response in rabbits infected with either E. intestinalis or Eimeria flavescens, including experiments performed after weaning (Pakandl et al 2008).…”

Effect of Using an Anticoccidial and a Prebiotic on Production Performances, Immunity Status and Coccidiosis in Broiler Chickens

“…Many defense mechanisms are involved in the protection from coccidian infection. The cellular immune response supported by the T lymphocytes enhances resistance to coccidiosis (Pakandl et al, 2008) and cytokines intensify the level of this protection. The increase in Interferon gamma levels (IFN-γ, transcripted in the spleen and cecal tonsils) is particularly associated with protective immunity against coccidiosis (Yun et al, 2000;Lillehoj et al, 2004).…”