Solanum glaucophyllum intoxication: an animal model to study the 1,25-dihydroxyvitamin D3 immunomodulatory effects.

FONTANA P; GIMENO E; LAGUENS G; BARBEITO C; DI GIROLAMO W; CORONATO S; PORTIANSKY E.

Cordoba

Congreso; VII Congreso Latinoamericano de Inmunologia; 2005

In addition to its central function in calcium metabolism the 1,25-dihydroxyvitamin D (vitD3) has pronounced immunoregulatory properties. VitD3 is the active principle of Solanum glaucophyllum (Sg), a calcinogenic plant that causes intoxication in bovine livestock. The goal of the present work was to test immune system modifications due to VitD3 in Sg-intoxicated cattle. Two years-old heifers received two weekly doses of 25 g of Sg leaves powder during 15, 30 or 60 days. A group was intoxicated during 15 days but sacrificed at 60 days pi (recovery group). Control animals were sacrificed at 0 and 60 days. Phagocytosis tests, dendritc cells (DC) isolation from lymph nodes and spleen, inmmunohistochemistry (anti S100, cytokeratin and thymulin) and histochemistry (lectins, syrius red) were performed. The phagocytic activity in peritoneal macrophages was progressively reduced in the intoxicated animals with time. A significant decrease in the number of DC S100+ was observed both in isolated cells as well as in lymph node and spleen. Lectinhistochemical studies revealed that binding to lectin-PNA showed the greatest differences between groups. Cortical thymocytes binding to lectin-PNA reduction was correlated to the progressive decrease of cortical thymus area with intoxication time. Thymic epithelial cytokeratin+  and thymulin+ cells were relatively increased in comparison with controls and syrius red+ collagen were increased and infiltrated  the atrophic thymus. PNA bound to T dependent areas in spleen and lymph nodes and germinal centers decreased with intoxication time. Recovery group showed similar results than controls. These results demonstrate that vitD3 induces immune system alterations in this animal model.