[Preparation and characteristic analysis of monoclonal antibodies against human growth hormone].
Four hybridomas stably secreting monoclonal antibodies (McAbs) against human growth hormone (hGH) have been obtained by fusion of immunized mice spleen cells with myeloma SP2/0 cells. After inoculation of hybridoma cells to BALB/c mice i.p., the ascitic fluids were collected and characterized, the titre of the 4 McAbs being in the range of 0.6-10.0 X 10(5). As determined by Ouchterlony analysis, all the 4 McAbs were IgG1. They varied in affinities, with equilibrium constants from 0.53 X 10(9) to 9.0 X 10(9) L/mol. McAb-1 showed 52.5% cross-reactivity with human placental lactogen (hPL). McAb-2, McAb-3 and McAb-4 displayed no crossreactivity with hPL and human prolactin (hPRL). Antigenic determinants recognized by the 4 McAbs were mapped through their reactions with hGH fragment consisting of residues 1-43, cross-reaction with hPL, hPRL and antibody-antibody competition test. The results showed that the antigenic determinants of the McAbs are not located in the site of hGH comprising residues 1-43 but on the three non-overlapping antigenic sites of hGH. As shown in receptor assay, all the 4 McAbs exhibited specific inhibition on the binding of pregnant rabbit liver GH receptor to 125I-hGH. It seems likely that receptor-binding site is larger than the antigenic determinant or there are more than one site on hGH surface capable of binding to the hormone receptor. The McAbs could only bind with the peak 2 (MW22000) but not the peak 1 (MW 45000) of old 125I-hGH after gel filtration.(ABSTRACT TRUNCATED AT 250 WORDS)
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D000818:Animals; D000911:Antibodies, Monoclonal / Q000096:biosynthesis*; D003429:Cross Reactions; D000939:Epitopes; D005260:Female; D013006:Growth Hormone / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D011247:Pregnancy; D011817:Rabbits; D011986:Receptors, Somatotropin / Q000276:immunology
D000911:Antibodies, Monoclonal; D000939:Epitopes; D011986:Receptors, Somatotropin; D013006:Growth Hormone