A Natural Antibody That Reacts in Vitro With a Sedimentable Constituent of Normal Tissue Cells

Abstract

Continued serological investigations of the sedimentable constituents of normal and neoplastic tissues have shown that the blood serum of normal rabbits will fix complement in mixture with saline extracts of normal rabbit tissues. The phenomenon has proved referable, not to anticomplementary effects of serum or antigen nor to so called non-specific complement fixation, but to a naturally occurring serum principle, hitherto unrecognized, which reacts specifically in vitro with a sedimentable constituent of normal tissue cells. The principle exists in the blood of nearly all adult rabbits but is absent from that of rabbits less than 1 month old. It can be salted out from serum with ammonium sulfate and is destroyed when heated at 65°C. for 20 to 30 minutes. Its titer was found to run parallel in general with that of two natural antibodies also present in normal rabbit's blood (natural Wassermann reagin, natural anti-sheep hemolysin); but absorption tests showed it to be distinct from these. Because of its properties, the serum principle has been termed the natural tissue antibody. The substance with which the natural tissue antibody reacts is regularly present in saline extracts of many normal tissues,—those of rabbits and of other species as well. Kidney and liver tissues always yield it in abundance, while spleen, brain, and testicle provide somewhat less; heart and voluntary muscle extracts contain relatively little, and non-nucleated erythrocytes and skin are practically devoid of it. The results of affinity and absorption tests indicate that it is nearly or quite the same from whatever tissue or species derived. It is readily sedimentable in the high-speed centrifuge, little or none remaining in the supernatant liquid of potent suspensions spun at 25,000 R.P.M. (45,400 g) for 1 hour. It either does not come away into alcohol or is inactivated thereby, is readily destroyed by heat (56–70°C. for 30 minutes), and diminishes notably in antigenic potency upon standing overnight in saline suspension or when the tissues containing it are kept in glycerol. Its properties suggest that it may be a protein. The implications of the findings are discussed in relation to the formation of the natural antibody and its place amongst serological phenomena, to so called "non-specific" fixation of complement and other serological complexities, and with particular reference to the character of the sedimentable constituents of normal and neoplastic tissue cells.

Induced Antibodies That React in Vitro With Sedimentable Constituents of Normal and Neoplastic Tissue Cells

“…prior to implantation (Table IV), and from that of normal control rabbits, as previous experiments had shown (2).…”

“…The induced antibodies and the sedimentable tissue constituents with which these react have been studied by means of a standardized complement fixation test (2). "Healthy" normal and neoplastic tissues were used as a source of antigens; these were procured with aseptic precautions and extracted while fresh or after storage for periods up to several months at --22 ° C. The saline extracts were made fresh for each experiment by grinding tissues in sterile mortars and adding 20 or more volumes of salt solution; they were cleared in the centrifuge and used unheated.…”

“…From the experiments just described (Tables I to III) it would appear that the sera of rabbits carrying transplanted V2 carcinomas may contain more than one type of antibody. Like the sera of most normal adult rabbits, they usually contain the natural tissue antibody which is heat-labile (inactivated upon heating at 65 ° C. for 30 minutes) and which reacts in vitro with saline extracts of various normal and neoplastic tissues (2). In addition, they frequently develop antibodies of a second type--the special object of this study.…”

“…To learn the nature and significance of this cell component, and whether other cancers contain substances of similar sort, have been the aims of further investigations. A preceding paper has dealt with one of the complexities encountered in these studies,--namely, a natural antibody which is usually to be found in the blood of normal adult rabbits and which reacts in vitro with a sedimentable constituent of normal and neoplastic tissue cells (2). The present report is concerned with induced antibodies having similar affinities which appear occasionally in the blood of rabbits carrying various transplanted cancers.…”

Autoimmune Graft Rejection

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Autoantibodies against various antigens of the body were found in healthy animals and human beings as well as in the course of different diseases [9,10,6]. Various attempts were made to find a correlation between the autoantibodics and tissue damage [2,4,17].

The present study deals with results of skin autotransplants in rats and rabbits previously immunized with autologous and heterologous skin.

Materials and Methods

Local outbred white rats weighing 100 g of a strain developed at the Hebrew University and outbred rabbits of 1.5 kg were used.

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