More information about Dr. Ansar Ahmed’s Laboratory:

Previous Original papers that are cited in over 100 publications - Source ISI Web of Sience:

Cited in 426 publications -Ansar Ahmed S, Penhale WJ, Talal N: “Sex hormones, Immune responses and Autoimmune responses: Mechanisms of Sex Hormone Action”. American Journal of Pathology 121:5 31-559, 1985.

Cited in 313 publications -Ansar Ahmed S, Gogal, R.M. Jr., Walsh, J.E. A new rapid and simple non-radioactive assay to monitor and determine the proliferation of lymphocytes: An alternative to ³H-thymidine incorporation assay.

Journal of Immunological Methods 170: 211-224, 1994.

Cited in 122 publications- Ansar Ahmed S, Dauphinee MJ, Talal, N.: Effect of short term administration of sex hormones on normal and autoimmune mice.Journal of Immunology 134: 204-210,1985 (,.)

Cited in 112 Publications-Lucas JA, Ansar Ahmed S,, Casey ML, MacDonald PC: Prevention of autoantibody formation and prolonged survival in New-Zealand black New-Zealand white F₁-mice fed dehydroisoandrosterone Journal Of Clinical Investigation 75 (6): 2091-2093 1985

Importance of studies involving the interaction of estrogens with the immune system:

v The immune system is a potential target for estrogens: Estrogenic compounds occur as natural (17-bestradiol), synthetic (diethylstilbestrol, ethynyl estradiol), and environmental (found in plastics, detergents, pesticides, industrial and agricultural chemicals etc.) compounds. Exposure can occur through natural, pharmaceutical, estrogen replacement therapy, estrogen - based oral contraceptives and environmental sources. It is critical to understand how estrogens regulate the immune system since altered immune systems may impact overall health, response to antigens, vaccines, and tumors.

v Estrogen may be linked to the female predominance of autoimmune diseases: A notable feature of many, albeit not all, autoimmune diseases (e.g. systemic lupus erythematosus and autoimmune thyroiditis) is that they tend to occur predominantly in women compared to men. This sex-based susceptibility pattern has been confirmed in several animal models. While the precise reasons for increased female susceptibility to certain autoimmune diseases are not known, hormones (such as estrogens) may play a role in some diseases.

v The immune system may be susceptible to imprinting by estrogens: Fetal development is unequivocally recognized as the most critical stage of life since any changes during this period can profoundly impact an individual’s health in adult life. Fetal exposure to estrogenic compounds can potentially alter the immune system. Modulation of the fetal immune system can have long-lasting effects into adulthood.

Ongoing Research Projects:

Project 1: Natural estrogen: 17-bestradiol, a natural estrogen, modulates the responses of splenic lymphocytes to pro-inflammatory cytokines such as interferon-gamma. This cytokine plays a critical role in Th-1-Type Immunity and is incriminated in many autoimmune diseases. Specifically, we are examining interferon-gamma-induced changes in cell signaling events in murine lymphocytes, activation of transcription factors, and induction of gene expression.

Project 2: Synthetic estrogens: Prenatal exposure to synthetic estrogen (diethylstilbestrol) has been associated with the manifestation of a variety of neoplastic and reproductive abnormalities. Concerns have been raised whether these individuals also manifest immune-related changes or pathologies. We utilize an animal model to address this question by examining detailed cellular and molecular events.

Project 3: Environmental estrogens: Environmental estrogens considered to be endocrine disruptors. These weak estrogenic chemicals are ubiquitous, persistent in the environment, and present in industrial chemicals, plastics, detergents, pesticides, soy products, etc. Concerns have been raised with regard to their impact on health. Their potential effects on the immune system are not known. Specifically, it is not known if these effects vary with age, gender, and immune status. These aspects are currently being examined in our laboratory.