12th Ljudevit Jurak
International Symposium on
June 1-2, 2001
|CHANGES IN POPULATION AND SUBPOPULATION OF T LYMPHOCYTES
IN THE INTESTINE OF PIGS INFECTED WITH HOG CHOLERA VIRUS (HCV)
|P.J. Sanchez-Cordón, S. Romanini, E.
Ruiz-Villamor*, F.J. Salguero, L. Carrasco, J.C. Gómez-Villamandos
Department of Veterinary Pathology, Veterinary Faculty, University
of Córdoba,Cordoba, Spain
*Laboratorio Central de Veterinaria, Santa Fe, Granada, Spain
|AIM OF THE STUDY: To study the lesions and their relationship with
the presence of viral antigen in the intestine of pigs infected with HCV,
as well as the evolution and alteration in the population and subpopulation
of T lymphocytes in the intestine during the disease.
MATERIALS & METHODS: 44 pigs were inoculated by the intramuscular
route with HCV and killed 2 days post-inoculation (dpi) to 23 dpi.
4 animals were used as uninfected controls. Samples of different intestinal
areas were fixed in formalin, Bouin’s solution and glutaraldehyde (2’5%)
and routinely processed for a histopathological and ultrastructural study.
Immunochemical study with antibodies CD3, CD4 and CD8 (against T lymphocytes)
and WH303 (against gp55 HCV) was developed according to ABC technique.
Tunel technique and an electron microscope were used to study cellular
RESULTS: The histopathological study showed lymphoid depletion in Peyer’s
patch from 5 dpi until the end of the experience. In the lymphoid follicles,
apoptosis of lymphocytes were obvious from 5 to 14 dpi, with a significant
decrease at 14 dpi onwards. Dilated crypts were observed between
11 to 15 dpi. Immunopositive cells against gp-55 were mainly monocytes,
macrophages, lymphocytes and fibroblasts. The viral infection
was confirmed by ultrastructural study. Moreover, from 2 dpi monocyte-macrophage
cells showed subcellular changes indicative of secretory and phagocytic
activation. The distribution of T lymphocyte was similar in different
intestinal areas during the disease. The number of immunostained cells
to CD3, CD4 and CD8 was progressively increased until the end of the experience.
The most significant result was the increased number of lymphocytes inside
lymphoid follicles, together with the apoptosis of the T cells.
CONCLUSION: The depletion of intestinal lymphoid follicles was related
to apoptosis, which coincided with the presence of viral infection in intrafollicular
macrophages and a small number of lymphocytes as well as an increased number
of intrafollicular T lymphocytes. The depletion of T lymphocytes in the
middle and at the end of the disease was related with apoptosis too.
This paper has been supported by a grant from DGESIC (PB98-1033)