Ablastin: Antigen tolerance and lack of ablastin control of Trypanosoma musculi during host's pregnancy

A short review is given about recent observations of infections in pregnant laboratory mice with strains of Trypanosoma musculi (= T. duttoni ) isolated in southern Europe. When being infected during the highly sensitive period of mbryogenesis, the female is completely unable to inhibit the reproduction of the trypanosome. Like an excessively growing benign tumor, the normally well-adapted nonpathogenic blood parasite population becomes, under these conditions, harmful to the host. The placenta acts as a “focus” of the trypanosome reproduction. Unusual, incomplete multiple fissions occur as big rosette formations in the placental blood. The possible microecological conditions of the accelerated trypanosome growth are briefly discussed. An American strain of this trypanosome species shows the same behavioral pattern in pregnant hosts.