CROSS-REACTIVITIES AMONG SOME MAMMALIAN HAPTOGLOBINS STUDIED BY A MONOCLONAL-ANTIBODY

Mouse monoclonal antibody antihuman-Hp, product of clone 2.36.71.41 wa s found to recognize, however, with different affinities, the immunolo gical determinant on haptoglobin of some mammals (goat, sheep, cow, ho rse, rabbit). The following differences in immunological cross reactiv ities were noticed: (i) haptoglobins present in sera of goat, sheep an d cow (Artiodactyla, Bovidae) react in enzyme-linked immunosorbent ass ay (ELISA) and form precipitates in agarose gel; (ii) horse (Perissoda ctyla) and rabbit (Lagomorpha) haptoglobins react in ELISA, but they d o not form precipitates; and (iii) haptoglobins of dog, fox, cat (Carn ivora) and pig (Artiodactyla, Suidae) are not recognized by the tested monoclonal antibody either in ELISA or in agarose gel. This study sug gests that monoclonal antibody, clone 2.36.71.41, recognizes the struc ture on haptoglobin around the disulphide bond linking two alpha chain s. Antigenic structure of Bovidae haptoglobins is rather similar to hu man haptoglobin 2-2 (circular polymers) than to 2-1 type (linear polym ers). Monoclonal antibody 2.36.71.41 could be used for classification of mammalian haptoglobins by epitope structure. It can distinguish pol ymeric haptoglobins similar to human type 2-2 from other mammalian hap toglobins. (C) 1998 Elsevier Science Inc.