title: Suppression of humoral immune response to hepatitis B surface antigen vaccine in BALB/c mice by 1-methyl-tryptophan co-administration.
abstract: OBJECTIVE
  Indoleamine 2,3-dioxygenase (IDO) suppresses adaptive immune response. The purpose of this study was to determine the effect of the IDO inhibitor namely 1-methyl-DL-tryptophan (DL-1-MT) on antibody production after vaccination with hepatitis B surface (HBs) antigen.
  
  
  METHODS
  Four groups of BALB/c mice were immunized with a HBs antigen vaccine. In the first group the vaccine had no DL-1-MT, whereas in the other three groups the vaccine contained 1 mg, 10 mg and 20 mg DL-1-MT. Blood samples were collected 5 weeks post-vaccination and anti-HBs antibodies in the serum were measured by ELISA.
  
  
  RESULTS
  Compared to the three groups of mice that were immunized with the vaccines containing DL-1-MT, serum anti-HBs level was much higher in the mice that were immunized with the vaccine with out DL-1-MT.
  
  
  CONCLUSIONS
  Inhibition of IDO at the time of vaccination decreased humoral immune response to HBs antigen vaccine. The idea that IDO activity is simply immunosuppressive may need to be re-evaluated.
authors.affiliation: Nephrology Department, Medical School, University of Thessaly, Larissa.
authors.forename: T
authors.initials: T
authors.lastname: Eleftheriadis
authors.forename: T
authors.initials: T
authors.lastname: Sparopoulou
authors.forename: G
authors.initials: G
authors.lastname: Antoniadi
authors.forename: V
authors.initials: V
authors.lastname: Liakopoulos
authors.forename: I
authors.initials: I
authors.lastname: Stefanidis
authors.forename: G
authors.initials: G
authors.lastname: Galaktidou