BACKGROUND Dysregulation of positive and negative selection, antigen presentation, or apoptosis in the thymus can lead to immunosuppression or autoimmunity. Diethylstilbestrol (DES), dexamethasone (DEX), cyclophosphamide (CPS), and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) are immunosuppressive chemicals that induce similar immunotoxic effects in the thymus, however, the mechanism of toxicity ...

Ochratoxins are secondary metabolites of Aspergillus and Penicillium, that are hazardous to health through contamination of dietary foods. Ochratoxin A (OTA) remains the single most potent member of this group of mycotoxins. OTA has a long half-life in humans and is thus easily detected in serum. Dietary intake studies have confirmed link between endemic nephrotoxicity in humans to their daily ...

Aquatic birds are commonly affected by oil spills. Despite rehabilitation efforts, the majority of rehabilitated common guillemots (Uria aalge) do not survive, whereas mute swans (Cygnus olor) tend to have higher postrelease survival. Polyaromatic hydrocarbons (PAHs) present in crude oil and diesel are immunotoxic in birds affecting cell-mediated responses to immunogens. Because it is a target ...

A variety of in vivo and more recently in vitro assays have been described to assess cell mediated immunity (CMI). Two methods routinely employed in our laboratory to assess CMI following exposure to chemicals in rodents include delayed hypersensitivity and in vitro lymphoproliferation. Preliminary studies indicate that depressed delayed hypersensitivity responses, as performed by a radiometric...

The transfusion of T cells, also called adoptive T cell therapy, is an effective treatment for viral infections and has induced regression of cancer in early-stage clinical trials. However, recent advances in cellular immunology and tumor biology are guiding new approaches to adoptive T cell therapy. For example, use of engineered T cells is being tested as a strategy to improve the functions o...

Economic development, including resource extraction, can cause toxic exposures that interact with endemic infectious diseases. Mercury is an immunotoxic metal used in the amalgamation of gold, resulting in both occupational exposures and environmental pollution. A cross-sectional medical survey was conducted in 1997 on 135 garimpeiros in Para, Brazil, because of their risks of both mercury expo...

The intricate balance that is the hallmark of the immune system shows vulnerability to any chemical, including pesticides, that can cause structural and functional alterations to the system. The immunotoxic effects of xenobiotics include: histopathologic effects in immune tissues and organs; cellular pathology; altered maturation of immunocompetent cells; changes in B and T cell subpopulations;...