T lymphocytes and macrophages in the intestinal tissues of dogs infected with Leishmania infantum

• Autor(a) principal: Silva,Diogo Tiago da
• Data de Publicação: 2017
• Outros Autores: Alves,Maria Luana, Spada,Júlio Cesar Pereira, Silva,Aline Cristine da, Silveira,Rita de Cássia Viveiros da, Oliveira,Trícia Maria Ferreira de Sousa, Starke-Buzetti,Wilma Aparecida
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Revista Brasileira de Parasitologia Veterinária (Online)
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S1984-29612017000200159
• topic: T lymphocytes; macrophages; canine visceral leishmaniasis; intestinal tract

Abstract This study was about a semi-quantitative analysis of T lymphocytes (CD4+ and CD8+, FoxP3+ regulatory T cells), and macrophages in the gut wall of dogs naturally infected with Leishmania infantum. Thirteen dogs were divided into three groups: group 1 (G1, n=5), dogs with canine visceral leishmaniasis (CVL) and infected with L. infantum amastigotes in the intestine; group 2 (G2, n=5), dogs with CVL but without intestinal amastigotes; and group 3 (G3, n=3), uninfected dogs (control group). There was no significant difference (p ≥ 0.05) on CD4+ and Treg cell numbers among the groups, whereas the levels of CD8+ T cells and macrophages were significantly higher in dogs from G1 group than in G2 and G3 (p ≤ 0.05), especially in intestinal segments with high parasite burden. Parasite burden correlated positively with levels of CD8+ T cells and macrophages (p ≤ 0.05), but was inversely correlated to levels of CD4+ T lymphocytes and FoxP3+ Treg cells. In conclusion, in the intestine of dogs with CVL, the increase of CD8+ T cells and macrophages population associated with high parasite burdens, but no changes of CD4+ T cells and FoxP3+ Treg cells suggest a possible immunoregulation by the parasite not dependent on Treg cells.