Fig. 1.

T. b. brucei resistance to TLF-1 correlates with decreased uptake and reduced levels of TbbHpHbR mRNA. (A) Northern blot hybridization analysis with specific probes for VSGs and β-tubulin. Lane 1, T. b. brucei 427–221^S; lane 2, T. b. brucei 427–800^R; lane 3, T. b. brucei 427–060^R. β-Tubulin was used as a control. (B) In vitro susceptibility of the T. b. brucei cell lines to TLF-1. Two-hour lysis assays were carried out with increasing concentration of TLF-1 [expressed as units (2)]. T. b. brucei 427–221^S is marked by a black triangle; T. b. brucei 427–800^R a red circle; T. b. brucei 427–060^R a green square. (C) Analysis of Alexa Fluor–488–conjugated TLF-1 uptake by FAC. T. b. brucei 427–221^S minus TLF-1 is blue; T. b. brucei 427–221^S plus TLF-1 is black; T. b. brucei 427–800^R plus TLF-1 is red; and T. b. brucei 427–060^R plus TLF is green. Each cell line was designated by the expressed VSG and its susceptibility to TLF-1. (D) Northern blot analysis of total RNA with probes specific for TbbHpHbR (Hp/Hb receptor) and β-tubulin mRNAs. Lanes are as in A.