Revised classification of the DLA loci by serological studies.

Peripheral blood mononuclear cells from DLA typed dogs were treated with rabbit-anti-dog-beta 2-microglobulin and subsequently with goat-anti-rabbit-immunoglobulin in order to aggregate the DLA class I molecules on the cell membrane (lysostrip). Utilizing a panel of 70 defined DLA-A and DLA-B antisera, lymphocytes treated in this way showed resistance to complement dependent lysis with monospecific DLA-A sera only, whereas reactivity of DLA-B antisera was not blocked; on the contrary, complete lympholysis with each DLA-B antiserum was recognized. Thus, the DLA-B antigens, evidently not associated with beta 2-microglobulin, are designated as candidates for class II gene products. The different reactions of DLA-C antisera after lysostrip did not allow a precise assignment of this antigen series as yet.