Anti-antibodies

Previous studies have indicated that immune 7G-opsonins constitute the main molecular class of antibody involved in phagocytosis and killing of infecting organisms in subacute bacterial endocarditis of man (1-3). High titers of 7G-opsonins were documented among patients infected with a wide variety of Gram-positive bacterial species, including Streptococcus viridans, Microaerophilic streptococcus, Staphylococcus aureus, Staphylococcus epidermidis, and Diplococcus tmeumoniae (1). Moreover, antiopsonic effect was consistently noted when isolated human 19S anti-7-globulin factors or rabbit antisera specific for "yG were added to phagocytic systems (2). In vitro competition between heat-labile serum factors and human anti-'y-globulin factors could be readily demonstrated. Since anti-'y-globulin factors as well as the complement component sequence show primary reactivity for structures present on the Fc portion of "yG, it seemed important to explore the role of the Fc region of "y-globulln in phagocytosis. An attempt was therefore made to examine the specific contribution of Fc structures in conferring specific opsonic activity to 7S q,-globulin molecules. The effects of enzymatic digestion, mild reduction with mercaptoethanol, or treatment of ~,G-opsonin with the oxidizing agent sodium metaperiodate were studied. It appeared that several procedures capable of degrading or altering sites on the Fc portion of 7S "y-globulin abolished opsonic activity. Materials and MethodsOpsonins.--In most instances, patients with active bacterial endocarditis furnished the specific immune opsonins. Because only certain strains of bacteria showed a high degree of reproducibility and consistency in the phagocytosis system, all of the experiments utilized *

Section: Discussionmentioning

confidence: 99%

Phagocytosis in Subacute Bacterial Endocarditis

Quie

Messner

Williams

1968

“…According to the definition adopted (always more or less arbitrarily), it seems that either the antiidiotypic antibodies, or the anti-allotypic antibodies, or both, or even neither, would have to be considered anti-antibodies. In a recent review under this heading, which necessarily includes various subjects, Gell and Kelus have proposed to restrict the meaning of the word "anti-antibody" to "an antibody which will react as such with an Ig molecule because that molecule is an antibody, not just because it is a -/-globulin" (24). But this definition does not allow us safely to include anti-idiotypic antibodies in the defined notion, nor to exclude them from this notion.…”

Section: Similarities and Differences Between Idiotypy And Other Phenmentioning

confidence: 99%

Idiotypy of Rabbit Antibodies

Oudin

Michel

1969

108

Idiotypy shares with allotypy the characteristic that antigenic specificities proper to it in one category of proteins, as one given class of immunoglobulins, are not carried by the protein molecules of this category in all the individuals of the same animal species. But, in contrast to allotypy which has been observed in several other kinds of proteins after its discovery among immunoglobulins, idiotypy is by definition restricted to antibodies.One of the most two important features of idiotypy--also the most striking difference between idiotypy and immunoglobulin allotypy--is that an idiotypic specificity found in antibodies against one given antigen has been found neither in the serum of the nonimmunized animal, nor in antibodies against another, noncrossreacting antigen. It was this striking difference that first made the authors conscious that what they observed in rabbits was definitely different from conventional allotypy (1).A second important feature of idiotypy, which contrasts also with conventional allotypy, is that each idiotypic spedfieity, carried by antibodies of one given rabbit against Salmonella typki, has not been found yet (at least not exactly under the same form) in antisera of other rabbits against the same antigenic material, x * Aided by a grant (67-00-605) of the Deq~gation G~n&ale ~ la Recherche Scientifique e t Technique (Comit~ de Biologic Mol&-ulaire).x The reluctance of the authors to propose a new term for the new phenomenon before being quite sure that this was necessary made them present their first results as a peculiar kind of allotypy in which each allotypic specificity would be restricted (a) to a single antibody, and (b) to a single individual. Actually, the newly observed phenomenon was fundamentally different from aUotypy, and the use of the same term for both would have been extremely confusing in the necessarily elaborate discussions which involve the three different kinds of antigenic specificities carried by the same immunoglobulin molecule (i.e. isotypic, allotypie, and idiotypic specificities). Consequently, it was found necessary to coin a new word of the same family as those proposed in 1956 (2) and in 1960 (3, 4, 5). In the same way as in "allotypic" or "isotypic," where "typic" (from rwro~, print or type) stands for antigenic specificity, "allo" (from tXko~, other) stands for different, and "iso" (from ~ros, the same) stands for similar, "idiotypic" was proposed (6, 7). The first part of the word (idio, from ~8~o,, peculiar) is justified by the extreme peculiarity of the antigenic specificities in question. An idiotype is a peculiar kind of protein antigen defined by its idiotypic specificity. In this paper, we will 595 on

“…The existence of antibodies directed against individual-specific determinants of other antibodies is well recognized (14)(15)(16)(17). These specificities are usually called idiotypes.…”

Section: Discussionmentioning

confidence: 99%

Cellular Receptors: Binding of Radioactively Labeled Anti-Alloantiserum

Binz

Lindenmann

1972

It has been shown previously that antisera raised in (A X B) F~ animals (whereby A and B designate two strains of inbred rats) against alloantibodies A anti-B are capable of specifically blocking the recognition of B antigens by A lymphoid cells (1). The test system used to measure antigenic recognition in vitro was the PAR (product of antigenic recognition) assay (2), basically a short-term mixed lymphocyte culture. The anti-receptor activity of such anti-alloantibodies was indistinguishable, by this test, from that of sera induced in (A X B)F~ rats by the injection of receptor-bearing parental strain lymphoid cells. This led to the conclusion that receptors present on lymphoid cells and those presumed to exist in the antigen-combining region of alloantiserum might be antigenically similar (1).The existence of antibodies specifically directed against recognition structures (RS) 1 on lymphoid cells bears on fundamental aspects of immunology; it therefore seemed useful to seek confirmation by experiments entireh, independent of the PAR test. The most straightforward approach appeared to be a demonstration of the uptake of radioactively labeled anti-alloantibodies by lymphoid cells. This uptake should occur preferentially by those cells presumed to carry receptors of similar combining specificity to the alloantibody against which the labeled anti-alloantibody was directed. The present communication shows that this premise was sustained. Materials and MethodsAnimals.--Rats of the following inbred strains were domestically maintained: Lewis, DA, and BN. Adults of either sex were used in the experiments. F1 hybrids were raised as required.Alloantisera.--Full-thickness skin grafts were performed from one rat strain to another (3). These grafts were rejected within 9-11 days. 3 wk after a single skin graft, animals were bled, and the serum was heated at 56°C for 30 min, Millipore filtered (Millipore Corp., Bedford, Mass.), and stored at --20°C.Anti-Alloantisera.--Alloantiseruln, for instance of specificity DA anti-Lewis, was injected into (DA X Lewis)F1 animals. On day 0, each animal to be immunized received 10 intradermal injections of 0.1 ml of plain alloantiserum distributed over the skin of the back (1). On day 14, animals were bled and the serum pool was inactivated and Millipore filtered as described for alloantisera. The alloantisera serving as antigens, the hybrids immunized, and the specificity of the anti-alloantisera obtained are shown in Table I.