Lead disrupts T cell function.Farrer DG, Hueber SM, McCabe MJ Jr. 2005. Lead enhances CD[4.sup.+] T cell proliferation indirectly by targeting antigen presenting cells and modulating antigen-specific interactions. Toxicol Appl Pharmacol 207:125-137. Although lead has been banned from use in products like house paint, gasoline, and water pipe solder in the United States, it is still present in older housing, and is used in products in other countries. Besides its widely studied neurotoxicity neurotoxicity /neu·ro·tox·ic·i·ty/ (noor?o-tok-sis´it-e) the quality of exerting a destructive or poisonous effect upon nerve tissue.neurotox´ic, lead is also a well-known immunotoxicant, though little is known about its mechanism of action. Now NIEHS grantee grantee n. the party who receives title to real property (buyer, recipient, donee) from the seller (grantor) by a document called a grant deed or quit claim deed. (See: grant) Michael McCabe and colleagues at the University of Rochester have discovered how lead may work to disturb T cell function in the body. Previous studies have suggested that lead's immunotoxic effects may occur at exposures even lower than those required for neurotoxicity to occur; thus, suboptimal immune function may affect people who do not even realize they have been exposed to lead. Older adults and lactating, pregnant, and postmenopausal women are at greater risk for lead exposure as lead stored in the bones is released back into the blood and soft tissues. Children are also at heightened risk for lead exposure because they engage in more hand-to-mouth activity and absorb a larger proportion of ingested lead across the intestinal epithelium than do adults. The Rochester researchers used flow cytometry flow cytometry a technique for counting cells suspended in fluid as they flow one at a time past a focus of exciting light. cy·tom·e·try (s -t m to analyze T cell division in cell cultures derived from lead-treated mice. T cells help regulate the body's immune system by attacking bacteria, viruses, foreign tissue, and tumor cells. At day 4 of treatment, the frequency of proliferating T cells was much greater in treated than in nontreated cultures. Lead appeared to target a type of cell known as antigen presenting cells, and its effect was based on specific peptide-major histocompatibility histocompatibility /his·to·com·pa·ti·bil·i·ty/ (-kom-pat?i-bil´it-e) that quality of being accepted and remaining functional; said of that relationship between the genotypes of donor and host in which a graft generally will not be rejected, a relationship determined by the presence of compatible HLA antigens. complex conjugate. The results suggest that lead may pose even more long-term health threats than originally thought.
|
|
||||||||||||||||||

-t
m
Printer friendly
Cite/link
Email
Feedback
Reader Opinion