The present invention provides novel processes for regulating immune responses in mammalian subjects, e.g., humans, afflicted with diseases such as cancers, infections, e.g., viral infections, bacterial infections, or immune dysfunctions, especially auto-immune disorders, e.g., diabetes, Crohn's disease, rheumatoid arthritis, arteriosclerosis and ulcerative colitis. More particularly, this invention relates to generating elevated levels of an intermediary metabolite, e.g., lipids or conjugated biomolecules, e.g., glycolipids, lipoproteins and glycoproteins other than antibodies, cytokines or hormones. Treatment can be carried by introduction of the intermediary metabolite into the afflicted subject or by a reagent that when administered leads to elevated levels. The treatment regimen can be in vivo or ex vivo.