MEMBRANE RECEPTORS OF MOUSE LEUKOCYTES .1. 2 TYPES OF COMPLEMENT RECEPTORS FOR DIFFERENT REGIONS OF C3

  • 1 January 1978
    • journal article
    • research article
    • Vol. 120  (3) , 879-885
Abstract
Mouse leukocytes were studied for membrane receptors for the 3rd C [complement] component [C3] by rosette formation with C and antibody coated erythrocytes (EAC). Methods were devised for the preparation of EAC complexes containing either mouse C3b or mouse C3d. EAC 1-3dmo [mouse] were prepared from EA treated with whole mouse serum while EAC 1-3bmo were produced from EAC 142hu [human] treated with whole mouse serum containing sodium suramin. The specificity of the EAC complexes for mouse leukocytes was confirmed by inhibition experiments using fluid phase human C3d. Low concentrations of fluid phase human C3d inhibited EAC1-3dmo rosettes but failed to inhibit EAC 1-3bmo rosettes. Eight-fold higher concentrations of fluid phase C3d caused partial inhibition of EAC1-3bmo rosette formation with lymphocytes, but not with other types of murine leukocytes. Mouse leukocytes apparently contain the same 2 types of C receptors as do human and guinea pig leukocytes. Mouse CR1 [type 1 complement receptor] is specific for a non-C3d region of C3b, (possibly analogous to human C3c) whereas mouse CR2 is specific for C3d and the C3d region of C3b.