A simple and convenient method for producing anti-activated lymphocyte alloantisera which does not require prior absorption.

A BALB/c B cell lymphoma, 2PK-3, was found to be activation lymphocyte alloantigen (Ala-1)-positive by virtue of its ability to absorb out the cytotoxic anti-Ala-1.1-like antibody activity of an antiserum against activated BALB/c (Ala-1.1) lymphocytes. Injection of 2PK-3 cells from the spleens or ascites of lymphomatous BALB/c mice into H-2d compatible DBA/2 mice led to the rapid development of an antiserum with properties identical to anti-Ala-1.1 alloantisera. Thus, it did not significantly kill normal spleen cells from any one of 7 different strains tested, but killed over 85% of Con A- or LPS-stimulated spleen cells of 4 Ala-1.1 positive strains; activated lymphocytes of Ala-1.2 were not affected. Furthermore, these properties were seen with unabsorbed antisera. The results indicate that the Ala-1 phenotype may, in some cases, be retained on neoplastic lymphocytes and that such cells, being rapidly and easily obtained in vivo in large quantities, can serve as a convenient source of immunogen for the development of anti-Ala-1 alloantisera in certain donor-recipient combinations.