Abstract: Sarcoidosis is associated with CD4.sup.+ T lymphocytes which express the T cell receptor V.sub..alpha. 2.3 chain. Thus, a method for diagnosing sarcoidosis is provided which comprises contacting cells of a subject with a first monoclonal antibody, or an antigen-binding fragment or derivative, specific for an epitope of the variable region of the T cell receptor V.sub..alpha. 2.3 chain and detecting the binding of the antibody. Also provided is a method for treating sarcoidosis in which a monoclonal antibody, or an antigen-binding fragment or derivative thereof, specific for an epitope of the variable region of the T cell receptor V.sub..alpha. 2.3 chain is administered. Sarcoidosis is also treated by administering a therapeutically effective amount of a protein or a peptide comprising an amino acid sequence of the variable region of the T cell receptor V.sub..alpha. 2.3 chain, or a functional derivative of the protein or peptide, or an antisense oligonucleotide which is complementary to the T cell receptor V.

Abstract: The invention is directed to monoclonal antibodies reactive with a member of the V.beta.3 family variable region of the beta chain of the TCR. More particularly, the invention provides for detection of the V.beta.3.1 subfamily. In a specific embodiment the invention provides for detection of V.beta.3.1, without cross-reacting with other V.beta.3 family variable regions. In a specific embodiment, the monoclonal antibodies of the invention do not react with V.beta.3.2. In particular, the invention provides monoclonal antibodies, termed 5E4 and 8F10, which react with the variable region of a member of the V.beta.3 family. In various embodiments of the invention, these antibodies, or fragments or derivatives thereof, can be used to bind with a member of the V.beta.3 family TCR variable region amino acid sequences, either as part of an intact TCR or peptide, or T cell-surface molecule, or a fragment thereof.