Immunosuppression due to chronic Lantana camara, L. toxicity in sheep.

Five sheep were intoxicated with powdered L. camara, leaves at the rate of 200 mg/kg body weight daily for 110 days and another group of four sheep were drenched with distilled water daily for equal number of days which acted as control. The cell mediated immunity of intoxicated and control sheep was assessed with the help of 2,4-dinitrofluorobenzene skin sensitivity test and graft-versus-host reaction and the antibody forming potential of both the groups of animals was measured by haemagglutination against chicken red blood cells antigen. In addition, the phagocytic activity of splenic reticulo-endothelial cells was analysed by nitro blue tetrazolium test. The results indicated significant reduction of both cellular and humoral immunity due to L. camara toxicity. The non-specific phagocytic activity of splenic reticulo-endothelial cells also showed significant reduction due to L. camara, L. intoxication. The present communication constitutes the first report of in vivo immunosuppression due to chronic lantana poisoning in sheep.

In vivo and in vitro measurement of cell mediated immunity in Marek's disease: role of reticuloendothelial system.

Dinitrofluorobenzene (DNFB) contact-sensitivity test and leucocyte adherence inhibition (LAI) test were performed in this study as in vivo and in vitro tests to measure the cell-mediated immunity (CMI) in chickens subjected to stimulation of reticuloendothelial (RE) system, depletion of RE system and other experimental groups after being challenged with Marek's disease (MD) virus. It was found that CMI was lower in the birds with depleted RE system and infected control birds, whereas CMI was higher in the birds with activated RE system and vaccinated birds as revealed by DNFB contact-sensitivity test. In cases of LAI test, the number of LAI-positive birds were highest in the chicks with depleted RE system particularly in 3rd and 4th month of age, when the incidence of MD was also maximum.