Tomoko Okuda

Structural polymorphism of mouse complement C2 detected by microscale peptide mapping: Linkage to H-2

Complement C2 was isolated from 17 mouse strains by immunoprecipitation and sodium dodecyl sulfate-polyacrylamide gel electrophoresis and examined for structural polymorphism by using micro-peptide mapping. By comparing the peptide maps of tryptic digests of C2 from various strains, two allotypic variations were detected. B 10 and 14 other mouse strains demonstrated C2.1 type, while a wild mouse line (M.Mol-Ohm) and one BIO congenic strain, B10.MOL.OHM, which carries the H-2 derived from M.Mol-Ohm, demonstrated C2.2 type. (B10 × Bl0.MOL.OHM)F1 demonstrated codominantly expressed C2 type (C2.1.2). Desialation of mouse C2 did not abolish the observed variation of mouse C2. It is concluded that an H-2-linked codominant locus controls the structure of mouse complement C2, further confirming the extensive homology of the major histocompatibility complex among higher vertebrate species.

Complement receptor expression of primates and non-primates detected by the rosette formation technique

The expression of complement receptors were studied on erythrocytes and platelets from 14 non-human primates and 3 non-primate species by rosette formation. It was found that the reactivity of erythrocytes with the cell bound complement is deeply dependent on which species are used as the complement source. The erythrocytes from Prosimian do not react with any kind of complement, while their platelets react with many kinds of complement. New World monkey erythrocytes do not react with indicator cells binding complements from guinea pig or man, while some of them react with indicators binding complements from non-human primate species. Contrarily Old World monkey erythrocytes react with complements from guinea pig, man and non-human primate. Hominoidea erythrocytes reacted with all the complements tested. Rabbit expresses C3 receptors on their erythrocytes for rabbit C3 and on their platelets for rabbit, guinea pig or mouse C3. Guinea pig expresses receptors on their erythrocytes for guinea pig and mouse C3, and on their platelets for guinea pig, mouse, rabbit and human C3. It becomes clear that not all of erythrocytes from primate and platelets from non-primate always express complement receptors as has been stated in the text books.