The present invention provides a method of treating or preventing inflammation in a subject, comprising administering to the subject an effective amount of cholera toxin subunit B. The present invention also provides a method of decreasing the activity of interferon gamma in a subject, comprising administering to the subject an effective amount of cholera toxin subunit B. Further provided is a method of decreasing the activity of IL-12 in a subject, comprising administering to the subject an effective amount of cholera toxin subunit B. Additionally, the present invention provides a method of treating or preventing a Th1 T-cell mediated autoimmune disorder in a subject, comprising administering to the subject an effective amount of cholera toxin subunit B.