| Abstract: | Erythrocytes of different species (chicken, sheep, man, mouse, rat, guinea pig) except rabbit erythrocytes strongly adhere to the marginal zone of mouse spleen follicles in frozen sections. This adherence reaction (AR) is not restricted to red blood cells but is also observed with human lymphocytes. Pretreatment of the tissue sections with trypsin, mercaptoethanol, periodate, chloroform/methanol, acetone, and heating the sections abolishes AR whereas neuraminidase (VCN) treatment of the sections has an amplifying effect. AR is inhibited by preincubation of the neuraminidase- or untreated sections with neuraminic acid (NA). Treatment of the erythrocytes with VCN completely abolishes AR whereas treatment with other enzymes (hyaluronidase, collagenase) is ineffective in this respect. Determination of NA in the erythrocyte membrane before and after VCN treatment reveals a positive correlation between the amount of NA and AR. Rabbit red blood cells have the lowest NA content in their membranes and, in addition, there is little effect of VCN treatment in further reducing it. It is possible that a lectin-like substance is responsible for AR. The biologic significance of AR is hypothetical, but since AR occurs in an area of the spleen playing a role in antigen trapping it is conceivable that this trapping may be mediated by interaction of NA and NA receptor(s). |
