Forssman lipid

The synthetic pentasaccharide showed similar antigenic specificity to the Forssman glycolipid but because of the absence of the lipid portion did not form a stable complex with the Forssman antibody [187],... 

Release of Cell Surface Lipids during Humoral Immune Attack. Lac-toperoxidase-iodinated line-10 tumor cells (0.25 ml of 10 cells/ml) suspended in RPMI 1640 are incubated with 0.25 ml of the appropriate dilution (in RPMI 1640) of rabbit anti-Forssman IgM antibody or specific antiline-10 antibody for 30 min at 0°.The cells are washed twice with 4 ml RPMI 1640 and incubated for 15 min at 37° with 0.5 ml of the appropriate dilution (in RPMI 1640) of GPC or HuC. One-half milliliter PBS is added to the cells, the cells are centrifuged for 5 min at 500 g at 4°, and the radioactivity in the supernatants is quantified. This is a measure of total lipid-and protein-containing macromolecules released from the cells. Controls include tumor cells alone (T), tumor cells treated with antibody alone (TA), tumor cells treated with complement alone (TC), and tumor cells sensitized with antibody and treated with heat-inactivated (30 min at 56°) complement (TAAC). 

The effects of cytotoxic and noncytotoxic combinations of antibody and complement on the release of cell surface lipids can also be studied approximately 40% of a line-10 cell population sensitized with a near excess (1 4 dilution) concentration of anti-Forssman antibody instead of a limiting (1 32 dilution) concentration (as used in the experiments shown in Table VI) will be killed by excess HuC the identity and amounts of lipids released from the TAxsC population were observed to be equivalent to that released from TAumC. ... 

A number of biologically important compounds or complexes of carbohydrates with lipides and sometimes also with proteins have been found in animal tissues (and some bacteria). The Wassermann antigens and the Forssman antigens apparently are materials of this type. The cerebrosides and gangliosides (Chapter X) might be considered to belong to this group. All appear to contain a hexosamine residue. 

When rabbits are injected with other animal tissue, the Forssman haptens are produced. These are able to lyse erythrocytes from sheep (Forssman 1911). One of these Forssman haptens is a ceramide linked to galactose and galactosamine (Papirmeister et al. 1955). The structure of these haptens leaves the question open whether they arise from ceramide polyhexosides, e.g. globosides, by degradation. It should be mentioned that the only noncarbohydrate lipid with haptogenic properties is cardiolipin. The question whether this haptogenic property is due to the free OH-group remains to be answered. 

Graf, L., and M. M. Rapport Immunochemical studies of organ and tumor lipids. VII. The reactivity of anti-human tumor sera with cytolipin H. cardiolipin, and forssman haptens. Cancer Res. 20, 546 (1960). 

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