Immunobiology of African Trypanosomiasis

Specific antibody levels and antigenic recognition of Wistar rats inoculated with distinct isolates of Trypanosoma evansi

“…It already was described for T. evansi and other salivarian trypanosomatids in other hosts, that the humoral immune response, mainly IgM, plays an important role in the control of the circulating parasites (Roelants & Pinder 1984, Uche & Jones 1994. In our experiments, this correlation was not so clear since the infected rats displayed comparable antibody titers.…”

Intradermal Infections of Mice by Low Numbers of African Trypanosomes Are Controlled by Innate Resistance but Enhance Susceptibility to Reinfection

“…It is well established that in intraperitoneal infections by T. brucei [10, 31] or T. congolense [18, 23], there is an absolute requirement for antibodies to VSG for the control of parasitemia. To determine whether anti-VSG antibodies might be required for the resistance against intradermal infection with few parasites, wild-type C57BL/6 mice, B cell–deficient mice (μMT) and RAG2 −/− C57BL/6 mice were used.…”

“…Past research into the immunobiology of mice experimentally infected with African trypanosomes has mostly been based on the immune responses of mice infected via the intraperitoneal route [4, 8, 10, 22–25]. Although these studies have provided great insight into the host-parasite relationship, they have ignored the very early immunological events triggered by the infecting parasites.…”

Low-Dose Intradermal Infection with Trypanosoma congolense Leads to Expansion of Regulatory T Cells and Enhanced Susceptibility to Reinfection

“…During infection, trypanosomes constantly modify their variant surface glycoprotein (VSG) during host antibody response, resulting in the fluctuating waves of parasitemia that characterize African trypanosomiasis (7)(8)(9). Furthermore, infection with African trypanosomes is associated with profound immunosuppression, which increases the susceptibility of the host to the parasite and secondary infections (10)(11)(12). Understanding the mechanisms that regulate resistance and/or susceptibility to the disease could reveal novel interventions that might lead to effective disease control (13).…”

“…In contrast, C57BL/6 mice are relatively resistant and are able to control several waves of parasitemia and survive for more than 4 months after infection (14,15). Most studies in this model utilize the intraperitoneal route of infection and have led to some interesting discoveries (10)(11)(12)(13). However, the fact that natural infection occurs naturally through the skin of the animal suggests that observations made with the intraperitoneal route of infection may not correctly reflect the real events that occur following skin infection.…”