Chicken anaemia virus (CAV) is the most important confounding pathogen in Marek's disease virus (MDV) infection. The effect of CAV co-infection at 4 weeks of age after inoculation of virulent MDV (vMDV, KS strain) or very virulent MDV (vvMDV, Md/5 strain) in 1-day-old chicks was investigated by pathological and immunohistochemical studies. CAV increased the mortality rates induced by vMDV or vvMDV. The packed cell volume was reduced significantly in vMDV-CAV infection; however, no reduction or non-significant reduction was observed in vMDV infection. Bone marrow hypoplasia was related to CAV co-infection and none of the birds inoculated with vMDV or vvMDV had hypoplasia. Severe atrophy of the thymus and bursa of Fabricius was observed in the vvMDV-CAV and vvMDV groups. Complete regeneration of the thymus cortex and bursa of Fabricius in the vMDV group was noted and was in contrast to sequential lymphoid depletion after CAV inoculation in the vMDV-CAV group. The spleen was either regenerated, lymphoid depleted or had lymphoproliferative lesions. Lymphoid depletion in the spleen was not detected in the vMDV group; however, it was prominent in the vMDV-CAV and vvMDV-CAV groups during the first 2 weeks after CAV inoculation. CAV inclusions and antigens were detected in the thymus cortex and spleen of vMDV-CAV and vvMDV-CAV groups during the experiment. Severe depletion of CD8(+) T cells was observed in depleted spleen and thymus. The neoplastic foci appeared around splenic arterioles and venules, and stained mainly by CD4 antibody; however, CD8(+) T cells were singly dispersed or were present in clusters. It could be concluded that CAV was responsible for bone marrow hypoplasia, severe anaemia and hindrance of lymphoid organ regeneration in MDV-CAV co-infection.
16 July 2021 in Environmental Science and Pollution Research
Subclinical infection of chicken anemia virus (CAV) at 4 to 6 weeks of age, after maternal antibodies have waned, is implicated in several field problems in broiler flocks. In order to understand the pathogenesis of subclinical infection with CAV, an immunopathological study of CAV-inoculated 4-week-old SPF chickens was performed. Sixty 4-week-old SPF chickens were equally divided into CAV and control groups. The CAV group was inoculated intramuscularly with the MSB1-TK5803 strain of CAV. Neither mortality nor anemia was detected in the CAV and control groups. In the CAV group, no signs were observed, except that some chickens were grossly smaller compared with the control group. Sporadic thymus lobes appeared to be reddening and atrophied. Within the first two weeks p.i. of CAV, there was a mild to moderate depletion of lymphocytes in the thymus cortex and spleen in some chickens. Moreover, lymphoid depletion of the bursa of Fabricius, proventriculus and cecal tonsils was observed. Hyperplastic lymphoid foci were observed in the liver, lungs, kidneys and heart at the 4th week p.i. of CAV. Immunohistochemically, a moderate lymphoid depletion of CD4+ and CD8+ T cells in the thymus cortex and spleen was observed in some chickens within two weeks p.i. of CAV. CAV inclusions and antigens were detected infrequently in the thymus cortex and spleen. It could be concluded that the immunosuppression in subclinical infection with CAV occurs as a result of reduction of cellular immunity.
The potential effects of the fullerene C60 nanoparticle (C60) as well as virgin olive oil (VOO) against the cyclophosphamide‐ (CP‐) induced cytotoxic and mutagenic effects were evaluated by two main methods: molecular intersimple sequence repeat (ISSR) assay and cytogenetic biomarkers. Thirty adult male rats were divided to five groups (control, CP, C60, CP + C60, and CP + VOO). CP was i.p. injected with a single dose of 200 mg/kg; C60 and VOO were given orally (4 mg/kg dissolved in VOO and 1 ml, resp.) in alternative days for 20 days. The ISSR analysis revealed an increased in the DNA fragmentation level for liver and heart tissues represented by 21.2% and 32.6%, respectively, in the CP group. The DNA polymorphism levels were modulated and improved in CP + C60 (8.9% and 12%) and CP + VOO (9.8% and 12.7%) for hepatic and cardiac tissues, respectively. The bone marrow cytogenetic analysis revealed that C60 and VOO had significantly decreased the frequency of CP‐induced chromosomal aberrations (chromosomal ring, deletion, dicentric chromosome, fragmentation, and polyploidy). Fullerene C60 and VOO have ability to reduce DNA damage and decrease chromosomal aberrations. In conclusion, fullerene C60 and VOO have protective effects against the CP‐induced mutagenicity and genotoxicity. Fullerene C60 and VOO open an interesting field concerning their potential antigenotoxic agents against deleterious side effects of chemotherapeutics.