Observations on the Occurrence, Characteristics and Specificity of Natural Agglutinins

Abstract

1. A study has been made of natural agglutination as exemplified by the reactions of the serum of nine animal species with a variety of bacteria.2. End-titres are recorded, and the fact is noted that sera of different animal species show an order of agglutinating activity which is almost constant for all organisms used. Ox, pig and horse sera give consistently strong reactions, while specimens from rabbit, guinea-pig and rat react weakly or not at all. Sheep, human and cat sera occupy an intermediate position. Variations are noted, however, with different individual specimens of serum from the same species.3. Organisms of the series tested can also be grouped in order according to their apparent susceptibility to agglutination by normal sera.4. The serum of young animals is found to be deficient in the agglutinating principle.5. The agglutinating effect shows a thermolability intermediate between that of complement and the immune agglutinins. Complete inactivation occurs as a rule after exposure to 60° C.–65° C. for half-an-hour. For certain strains the serum principle is inactivated at much lower temperatures.6. Lability curves show marked irregularity. In certain cases a zone of relative inactivation is produced at a temperature of 55° C.7. The natural agglutinating substance is found to be present in greater degree in the carbonic acid insoluble fraction of serum than in the carbonic acid soluble fraction. In this respect it differs from the immune agglutinins, which are chiefly located in the carbonic acid soluble moiety.8. The agglutinating principle for each organism can be absorbed completely by the homologous strain, when a variable lowering of the end-titre for other unrelated organisms results. A similar lowering of activity for these organisms may be produced by treating the serum with non-specific physical absorbents. Charcoal and Kieselguhr were used to demonstrate this.9. By the technique of double absorption it can be shown that agglutination depends on non-specific and specific factors and it is concluded that normal serum agglutinates bacteria in virtue of a twofold mechanism:(a) A non-specific effect reacting in varying degree with all organisms and removable by treatment with a finely divided absorbent.(b) A series of specific effects reacting as true “natural antibodies.” These specific antibody-like principles exist for a wide variety of organisms. Absorption of any one organism removes the homologous effect leaving the remainder quantitatively unimpaired.10. The question of bacterial variation and receptor analysis in relation to the natural agglutinins is being studied and will be reported on at a later date.

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

“…The literature on "non-specific" complement fixation reactions has been dealt with by Noguchi (19) and Gussenbauer (20), in various text books (21), and recently by Takenomata (22), Mackie and Finkelstein (23), and Gibson (24). In addition to anticomplementary effects due to chemical inactivation or destruction or adsorption of complement, there are other, so called non-specific, complement fixation reactions in which substances present in the serum of normal animals and man will fix complement in mixture with a variety of "non-antigenic" substances, amongst them peptone, glycogen, various extracts of tissues and bacteria, amino acids, cholesterol, and alcohol.…”

The Occurrence of Natural Antibodies to Rumen Bacteria

“…Attempts have been made to define patterns of natural antibodies against Enterobacteriaceae (Gibson, 1930;Landy & Weidanz, 1964) amongst the sera of different animal species. Although it was not possible to make clear-cut distinctions between the animals, there were indications that each species might have its own pattern.…”

Serological Surveillance of Children with CSF Shunting Devices

“…A naturally-occurring antibody to such organisms as E. coli is absent from the serum of very young animals and appears spontaneously later (Gibson 1930). Also, it is well known that newborn babies do not respond satisfactorily to diphtheria toxoid (Blum 1932).…”