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Experimental mucosal disease of cattle: changes in cell proliferation in lymphoid tissues and intestinal epithelium
E M Liebler-Tenorio1, J F Pohlenz
1Institut für Pathologie, Tierärztliche Hochschule Hannover, Germany.
Insights
Investigating cell proliferation in bovine viral diarrhea virus (BVDV)-induced mucosal disease (MD), this study found reduced proliferation in lymphoid tissues but increased proliferation in intestinal crypts during early and late stages of MD. These changes highlight BVDV
Area of Science:
- Veterinary Pathology
- Immunohistochemistry
- Cell Biology
Background:
- Bovine viral diarrhea virus (BVDV) infection can lead to mucosal disease (MD) in cattle.
- Lesions in MD primarily affect lymphoid follicles and intestinal crypts, sites of high cell proliferation.
- Understanding proliferation changes is crucial for characterizing MD pathogenesis.
Purpose of the Study:
- To investigate changes in the number and distribution of proliferating cells in cattle with BVDV-induced mucosal disease.
- To utilize immunohistochemistry for detecting the Ki-67 proliferation-associated nuclear antigen.
- To compare proliferation patterns in lymphoid tissues and intestinal crypts during different phases of MD.
Main Methods:
- Obtained tissues from 30 cattle with persistent non-cytopathogenic BVDV infection.
- Induced mucosal disease in 22 cattle via inoculation with cytopathogenic BVDV strains.
- Examined tissues from control, early phase, and late phase MD cattle using Ki-67 immunohistochemistry.
Main Results:
- Control cattle showed high Ki-67 positivity in lymphoid follicles and intestinal crypts.
- Early MD phase: Decreased Ki-67+ cells in lymphoid follicles; increased cells in some intestinal crypts.
- Late MD phase: Few Ki-67+ cells in lymphoid follicles; increased cells in most intestinal crypts, with some acellular foci.
Conclusions:
- BVDV-induced mucosal disease significantly alters cell proliferation dynamics in cattle.
- A decrease in lymphoid proliferation contrasts with an increase in intestinal crypt proliferation during MD.
- These proliferation changes are indicative of severe tissue damage and dysregulation in MD pathogenesis.
Abstract:
In mucosal disease of cattle, the initial and most severe lesions are found in the lymphoid follicles and intestinal crypts, both sites showing a high cell proliferation rate. In the present study, the changes in the number and distribution of proliferating cells were investigated immunohistologically, by demonstrating the proliferation-associated nuclear antigen, Ki-67. Tissues were obtained from 30 cattle, all of which had a persistent natural infection with non-cytopathogenic (ncp) bovine virus diarrhoea virus (BVDV), and 22 of which were subsequently inoculated with antigenically closely related strains of cytopathogenic (cp) BVDV to produce mucosal disease (MD); the remaining eight cattle served as uninoculated controls. Twelve of the inoculated cattle were killed before the onset of clinical signs of MD ("early phase"), and 10 when they were moribund ("late phase"). In the controls, the lymphoid follicles in lymph nodes and Peyer's patches consisted predominantly of Ki-67-positive cells; high numbers of such cells were observed in the crypts of the small intestine and moderate numbers in the crypts of the large intestine. In the early phase of MD, the number of Ki-67-positive cells in the lymphoid follicles and in the domes of the Peyer's patches gradually decreased; but in the mucosa, foci of crypts with increased numbers of Ki-67-positive cells were observed. In the late phase of MD, only a few Ki-67-positive cells were present in the lymphoid follicles. There was an increase in the number of Ki-67-positive cells in most crypts in the small and large intestine, but foci of crypts without Ki-67-positive cells occurred.