Strain differences in the fine specificity of mouse antihapten antibodies

Abstract

Abstract Mice of six strains were immunized with (4‐hydroxy‐3‐nitrophenyl)acetyl (NP) groups coupled to chicken globulin. The fine specificities of these antibodies were characterized by estimating relative affinities for related compounds, (4‐hydroxy‐3, 5‐dinitro‐phenyl)acetyl (NNP), (5‐bromo‐4‐hydroxy‐3‐nitrophenyl)acetyl (NBrP) and (4‐hydroxy‐5‐iodo‐3‐nitrophenyl)acetyl (NIP) groups. These measurements were carried out on both serum and single plaque‐forming cell antibodies. At least three patterns of fine specificity could be recognized among these strains. C57BL/6 produced 7 S (IgG) anti‐NP that consistently had 3–10 times higher affinity for NIP than for NP, and higher affinity for NNP and NBrP than for NP (heteroclitic). By doing affinity measurements on serum and plaque‐forming cell antibodies, we could demonstrate that the majority of the 7 S (IgG) anti‐NP produced by C57BL/6 mice was heteroclitic at both early and later stages of immunization. Moreover, the antibody from this strain exhibited only a slight change in affinity during the immune response, while the other strains underwent clearcut maturation (progressively increased affinity for NP and increased discrimination between NP and the related compound). Nine F 1 hybrid mice between C57BL/6 and CBA produced anti‐NP antibody that was very similar to C57BL/6 anti‐NP.