NK-2.1: an NK-associated antigen detected with NZB anti-BALB/c serum.

Abstract

NZB/B1NJ mice immunized with BALB/c spleen cells produced antibodies to an NK-associated antigen(s). Antisera without detectable autoantibody lysed fewer than 5% of BALB/c spleen cells (SC) but mediated C-dependent depletion of Nk cell activity, as measured in a /sup 51/Cr-released assay with YAC-1 targets. To determine if NZB anti-BALB/c antibodies recognized an allele of the previously described locus NK-1, 136 (BALB/c x NZB)F/sub 2/ progeny were screened for sensitivity to NZB anti-BALB/c serum and anti-NK 1.1 (BALB/c x C3H F/sub 1/ anti-CE serum) and C. Segregation analysis of anti-sera sensitivity and coat color phenotype of 63 (BALB/c x NZB)F/sub 2/ indicated that sensitivity to NZB anti-BALB/c serum was linked to the agouti(a) locus on chromosome 2. Based on these data, the authors designate the antigen detected by NZB anti-BALB/c serum as NK-2 and the activity of the serum as anti-NK-2.1. Eighteen strains were tested for reactivity with anti-NK 2.1 and anti-NK-1.1. Nine were NK-1.1/sup +/, NK-2.1/sup -/, six were NK-1.1/sup -/, NK-2.1/sup +/. NK-2.1/sup +/ cells, selected with the fluorescene-activated cell sorter, were enriched in NK activity compared to NK-2.1/sup -/ SC.