Immune up-regulation and tumor apoptosis by androstene steroids

beta Androstenes steroid up-regulates immunity to increase resistance against lethal infection and lethal radiation, and mediates a rapid recovery of hematopoietic precursor cells after radiation injury. beta Androstenetriol increases the levels of the TH1 cytokines, IL-2, IL-3, IFNgamma and counteracts hydrocortisone mediated immune suppression. In contrast, 17alpha androstenediol inhibits proliferation and mediates apoptosis in tumor cells of murine and human origin. Its epimer 17beta androstenediol does not. The antiproliferative functions of 17alpha androstenediol are not dependent on either the estrogen or androgen receptors. Our findings show that beta androstenes and analogs protect the host from lethal infection by DNA or RNA viruses such as, herpesvirus type 2, coxsackievirus B4, influenza, and arthropod home viruses. These androstenes also protected the host from lethal bacterial infections by Enterococcus faecalis, Pseudomonas aeruginosa, and Klebsiella pneumonia and from parasites infections, i.e. Cryptosporidium parvum, and malaria. In vivo, the level of potency follows the order: dehydroepiandrosterone <<< androstenediol < androstenetriol with the latter being up to one hundred thousand times more potent in protecting the host from infections than the first. In vitro, their effects are also dramatically different from one another with only beta androstenetriol potentiating the cellular response by increasing lymphocyte activation and counteracting hydrocortisone immune-suppressive activity. Conceptually, the androstenes form a new and different subclass of steroid hormones with unique physiological properties. Following host injury, the balance between the epimers and isomers is a determining factor in the overall regulation of hematopoiesis, TH1/TH2 balance, and host resistance to infections and tumor growth. (C) 2002 Elsevier Science Inc. All rights reserved.