Figure 1

Absence of antibodies to XMRV in plasma from persons with and without CFS from the US. a. Antibody titers of positive control anti-sera to purified XMRV antigen in WB testing. Specific antisera tested are provided at the top of each WB. Arrows indicate observed titers for each antiserum. Locations of reactivity to specific viral proteins are indicated. Env (gp69/71), envelope; TM (p15E), transmembrane; MA (p15), matrix; Gag (pr68); CA (p30), capsid. Molecular weight markers (kD) are provided on the right of the WB. Sizes of expected viral proteins are provided to the left of the WB. b. Detection of XMRV antibodies in three experimentally-infected macaques (RII, RYh and RLq). Days post infection and immunization with XMRV are shown with arrows [16]. Locations of reactivity to specific viral proteins are indicated. Env (gp69/71), envelope; TM (p15E), transmembrane; MA (p15), matrix; Gag (pr68); CA (p30), capsid. Molecular weight markers (kD) are provided on the right of the WB. Sizes of expected viral proteins are provided to the left of the WB. c. Representative WB results for CFS cases and persons without CFS. Lane 1, 1:250 dilution of anti-Friend MuLV whole virus, goat polyclonal antisera; lane 2, XMRV negative blood donor plasma; lanes 3, 4, 9, 11 are plasma from persons without CFS; lanes 5 - 8, 10, 12, 14 - 17, 19, 20, 23 - 27 are plasma from persons with severe CFS; lanes 13, 18, 21, and 22 are plasma from persons with unclassified CFS. Locations of reactivity to specific viral proteins are indicated; Env (gp69/71), envelope; TM (p15E), transmembrane; MA (p15), matrix; Gag (pr68); CA (p30), capsid. Molecular weight markers (kD) are provided on the left of the WB.