Actually, about 5% of alpha-beta+ CD3+ cells are CD4-CD8-, in healthy adults. These cells are not just cells that have downregulated CD4 or CD8, but probably comprise a distinct lineage. We have been able to identify naive and memory subsets with these double negative (DN) T cells, and functional responses of some of those subsets. I assert that they are distinct lineages because the naive cells with the DN compartment have a distinct (but broad) V-beta repertoire (distinct from CD4+ or CD8+, or even the CD8-dull lineages). Of course, there are CD4-CD8- gamma delta's as well; one should use a gamma-delta antibody together with CD3 to distinguish these before quantitating DN cells. mr At 1:18 PM -0700 8/22/00, Jeffrey A Vos wrote: >To my knowledge, in non-neoplastic conditions, CD4-/CD8- T cells are almost >always gamma/delta cells. Loss of CD4 or CD8 in an alph/beta cells is >suggestive of an aberrant phenotype or possibly lymphoma. Increased >gamma/delta cells are increased in several inflammatory conditions especially >those that are granulomatous. Examples include tuberculosis, MAI, leprosy, >and Crohn's disease. I wasn't aware of the ethnic variations. Thank you. >Jeff Vos >Pathology Resident
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