In conclusion, the work presented here suggests that, having established themselves as a replicating population in the tsetse midgut, trypanosomes may require a NO signal and/or the presence of L-cysteine to promote migration to the salivary glands and maturation into mammalian infective forms. WD has been traditionally seen as a gastrointestinal disease characterized by polyarthritis, fatigue, weight loss, and anemia, followed by a progressive Isoacteoside syndrome of abdominal pain, distension, steatorrhea, and severe cachexia. In about 15% of reported cases, gastrointestinal symptoms are lacking, and the disease appears as cardiac manifestations such as myocarditis, pericarditis and negative blood culture endocarditis, or as neurological manifestations including dementia, lethargy and neurological deficits. The evolution of WD is chronic with relapses despite empirical antibiotic treatment. The Scopoletin bacterial etiology of WD was first established in 1961 by the detection of ����bacillary bodies���� in the intestine of patients. The causative agent of WD was identified in 1992 as a gram-positive bacterium, phylogenetically close to the Actinobacter clade as determined by a molecular approach. In 2000, it was isolated from a patient with WD and successfully cultured. In 2001, the name of Tropheryma whipplei was officially ascribed to the WD agent, and the complete sequencing of two strains of T. whipplei was performed in 2003. The diagnosis of WD has been based for many years on the presence in intestinal biopsies of large, foamy macrophages containing periodic acid-Schiff -positive inclusions in the lamina propria, but these PAS-positive inclusions may also be detected in other tissues. Although the recent development of molecular tools has improved bacterial detection in tissues, the diagnosis of WD remains invasive. The current treatment is trimethoprim-sulfamethoxazole given for at least one year. The antibiotic treatment of WD is empirical and the choice of drug and the duration of treatment are controversial.IL-16 is synthesized as a precursor of 69 kDa, named pro-IL-16, which is a substrate for caspase 3, the central effector of apoptosis. The cleavage of pro-IL-16 by caspase 3 releases the biologically active form of the molecule, which consists of a secreted fragment of 56 kDa. IL-16 is an immunomodulatory cytokine released at the inflammatory site.