Search

In the previous paper we showed that the immune response to sheep red cells (SRBC) was degenerate; serum antibodies showed increasing loss of specificity, signalled by cross-reactions with horse RBC (HRBC), with time after immunization and with hyperimmunization. In the present report we have analysed the role T cells may play in this process. To do this we studied the antibodies made by mice deprived of T cells by irradiation as well as those made by normal mice immunized with SRBC in distilled water, which was shown to depress the DNA synthetic response of T cells. In both instances the mice with fewer responding T cells made less antibody which could agglutinate HRBC than did the appropriate controls. This was true even when no difference in anti-SRBC titre was apparent. In addition we showed that the antibody made by mice with reduced numbers of T cells was less effective at passive suppression of the immune response to SRBC than was similarly titred (against SRBC) antibody made by normal mice. Thus, certain sub-populations of antibodies, normally made in response to SRBC, immunization, are particularly thymus dependent. We have discussed why we think they are those of particularly high affinity. [ABSTRACT FROM AUTHOR]

Red cells sensitized with naturally occurring or 'immune' fowl antibody were lysed by fresh fowl serum. This fowl complement could not be replaced by that of human, rabbit or guinea pig. Both naturally occurring and 'immune' antibodies to red cells in the mammalian species tested did not lyse with fowl complement. Lysis by fresh fowl serum of sheep red cells sensitized with mammalian antibody is due to the presence of naturally occurrent antibody to these cells in the fowl serum; the enhancement of this lysis by the mammalian antibody will be described more fully in the next paper. Naturally occurring antibody to sheep red cells present in turkey serum and 'immune' antibody to fowl red cells were not lytic with fresh turkey serum, with fowl complement, with guinea-pig complement or with any combination of these. Some properties of fowl complement are given. [ABSTRACT FROM AUTHOR]

Whilst the ability of isoantibodies to agglutinate mouse red cells in saline medium does depend in part upon the properties of the antibody molecules, the concentration of antigen upon the red cell and certain genetically determined properties of the cell surface are of even greater importance. The red cells of mice of any strain will give positive results in the human serum:dextran system whilst reactions in a saline medium are unusual. In this paper the term ‘incomplete antibody’ is used to denote antibodies that can only be detected in conjunction with other antibodies in the human serum:dextran system. The time of appearance of antibodies to homografts of an ascites sarcoma, an ascites leukosis and a solid mammary carcinoma has been studied. Incomplete antibody as defined above has been detected by two methods. In the blocking test incomplete antibody is allowed to react with red cells before contact with complete antibody, a positive result being observed as a fall in titre when the treated red cells are subsequently exposed to complete antibody. In the second type of test, the synergic test, incomplete antibody is mixed with suitably diluted complete antibody and fitrated against suitable red cells, a positive result being a significant rise in titre as compared with complete antibody mixed with normal serum. Antibodies produced by the antigen donors did not give significant blocking or synergic effects. Incomplete antibodies are sometimes detectible on the third day and with regularity on the fourth day. Antibodies ‘complete’ for A strain red cells may appear at any time from the fifth day onwards. There is sometimes a drop in fitre of varying duration on the sixth day. This corresponds with the commencement of marked inflammatory changes on the graft bed. The maximum titre is attained at about two weeks. Antibodies may disappear in under three months or persist as long as a year. The function of antibodies in homograft reactions varies with the target tissue. However, they appear before the onset of anatomical signs of homograff response regardless of the type of target cell. [ABSTRACT FROM AUTHOR]

This paper describes a method for simultaneous measurement of the accumulation of plasma protein and erythrocytes in skin reactions of hypersensitivity to bovine γ-globulin (BGG) and tuberculin PPD in the guinea-pig. The procedure consists in giving 125I-labelled plasma albumin and 51Cr-labelled autologous erythrocytes together by intravenous injection into guinea-pigs bearing skin lesions of allergic inflammation at different times and for different periods during the development of the skin reactions. Isotope accumulation in excised skin reactions is measured by scintillation counting at different stages during the evolution of hypersensitivity responses. Skin reactions of combined anaphylactic and Arthus hypersensitivity to BGG were characterized by pronounced increased vascular permeability principally in the first hour. In established 24-hour hypersensitivity reactions to both antigens (BGG and PPD) there was continuing accumulation of both plasma albumin and erythrocytes. During the development of the tuberculin reaction, an intermediate phase of isotope accumulation occurred between 6 and 9 hours after skin testing; serum transfer studies showed that this intermediate peak was not attributable to circulating antibody alone. These isotope tracer techniques were also applied to study vascular permeability in systemically transferred reactions of delayed hypersensitivity and in the vascular response to the intradermal injection of an inflammatory factor generated by antigen-activation of sensitized lymphocytes. It was concluded that isotope tracing provided objective and sensitive methods for analyzing microvascular responses in allergic inflammation. [ABSTRACT FROM AUTHOR]

This paper describes a form of red cell lysis differentiated from classical complement haemolysis by its occurrence in the absence of antibody on the cells and in the presence of EDTA. This type of haemolysis has been called reactive haemolysis. It is the result of the interaction, in the presence of red cells, of at least two serum factors called ‘reactor’ and ‘indicator’, respectively. Reactor only becomes active after incubation at 37° of serum with certain agents, notably antibody-coated bacteria, zymosan and agarose, in conditions similar to those required for complement activation. The potential for the formation of activated reactor could be demonstrated infrequently in healthy subjects but more frequently in sera from hospital patients. Activated reactor behaved as a protein sedimenting between 7S and 19S, and of α2-β1, electrophoretic mobility in agar. Indicator factors were present in all human sera studied, as well as in the sera of a number of mammalian species. They were demonstrable at high dilutions of the serum and required no prior activation for their action. They occurred maximally in the 7S fractions of serum proteins and migrated in the β2 position on electrophoresis. Reactive haemolysis was first observed and can most conveniently lie demonstrated in a red cell-agarose gel. It can also be demonstrated in the test tube following partial purification of activated reactor and indicator factors. Studies in the test tube indicated that a .soluble labile lytic factor was responsible for this type of haemolysis, [ABSTRACT FROM AUTHOR]

The studies reported here indicate that tanned red cells coated with a mixture of chromatographically purified ovalbumin and conalbumin give agglutination titres which are directly related to the amount of antibody (as meas- ured by quantitative precipitation) present against either of these antigens in mixed sera. With whole (unabsorbed) mixed sera, these coated cells record the titre of the major antibody present, whether this is anti-ovalbumin or anti-conalbumin. There was no evidence of greater sensitivity to anti-conalbumin. A trace of ovalbumin in a preparation of conalbumin used to coat cells is fully sufficient to enable them to react with any anti-ovalbumin in a serum. Twice recrystallized ovalbumin still contains some conalbumin. Sera raised against it may contain unexpectedly high levels of anti-conalbumin and this could cause confusion in tanned red cell tests. [ABSTRACT FROM AUTHOR]

A number of fucose-containing glycolipids (fuco-lipids), which are similar in composition to those of human normal and malignant gastrointestinal tissue, have been isolated from whole small intestines of individual dogs. Dogs from which these fuco-lipids were isolated fell into two types according to the qualitative sugar composition of their fuco-lipids. Glycolipids from type I dogs contained glucose, galactose, glucosamine, galactosamine and fucose, while those from type II dogs contained the same sugars but lacked galactosamine. Fucolipids isolated from type I and II dogs were tested for both canine blood group and human A, B, H and Lea and Leb blood group activity. At the concentrations tested, only human blood group A activity was found in significant amounts, and only in those fucolipids which contained galactosamine (type I dogs). Of the fuco-lipids with human blood group A activity, some had activity comparable to that of glycoprotein blood group substances, while others had lower, but significant, activity. These latter fucolipids also had marked chromatographic differences, indicating that they are of several different structural types, a finding similar to the A active glycolipids of human red cell stroma. None of the isolated intestinal fuco-lipids had canine blood group activity. A fuco-lipid with Lea activity was also isolated in relatively large amounts from a normal human whole small intestine. [ABSTRACT FROM AUTHOR]

Experiments are described which show that effete red cells will not adhere to autochthonous macrophages which have been treated with trypsin. If, following trypsin treatment, the macrophages are incubated in the presence of normal guinea-pig serum, activity is restored and the adherence reaction with effete red cells can again be demonstrated. Activity is not restored by incubation with Hanks's solution following trypsin treatment. These results suggest that the adherence reaction is mediated by a component of normal guinea-pig serum which becomes adsorbed to the macrophage surface. Evidence is presented suggesting that the linkage between the serum component and the macrophage surface is protein in nature. The active component is removed from guinea-pig serum by absorption with effete red cells. [ABSTRACT FROM AUTHOR]

Fowls which tolerate foreign erythrocytes, but which have not received a transplant of variable cells, eventually lose tolerance when the supply of erythrocytes is discontinued. The loss follows, at an interval, after the foreign erythrocytes have been eliminated by the normal mechanism for removal of aged cells; earlier loss can be brought about by eliminating the foreign cells with passive antibody. The interval required for loss varies, for tolerance of homologous erythrocytes, from less than 5 to over 215 days. The age of the tolerance bird, and hence the duration of exposure to antigen, is the main factor influencing the interval required; the preceding level of tolerance exerts comparatively little effect. An attempt to terminate tolerance by adoptive immunization was only partially successful. [ABSTRACT FROM AUTHOR]

The kinetics of the reaction between C' I-esterase inhibitor and an intermediate complex of sensitized sheep erythrocytes and human complement are described. The rate of reaction was directly proportional to the concentrations of both inhibitor and intermediate complex, but was insensitive to changes in pH over the range 7.4 - 8.7 and in ionic strength from 0.15 - 0.24. The rate of reaction was accelerated b an increase in temperature over the range 22° - 37°. The experimental evidence was consistent with a mechanism picturing the reaction of C' I-esterase inhibitor with C' I-esterase bound to the intermediate complex. A theoretical treatment is described from which values for various kinetic and thermodynamic quantities may be calculated. [ABSTRACT FROM AUTHOR]

The value of sera containing immuno-conglutinin or conglutinin in demonstrating complement-binding by human blood group iso-antibodies was investigated. Provided that a suitable complement was used, positive results were obtained with all human sera which had been shown by other methods to contain complement-binding antibodies. When human red cells were sensitized with human complement-binding blood group antibody and then treated with horse serum as a source of complement, the strongest reactions were obtained with rabbit immuno-conglutinin; the reactions with bovine serum (containing conglutinin) were distinctly weaker, and the reactions with human sera containing immuno-conglutinin were weaker still. When rabbit complement was used instead of horse complement, stronger reactions were obtained, but it was difficult to avoid ‘false positive’ reactions. When human complement was used, good reactions were obtained with rabbit immuno-conglutinin, but the reactions with bovine conglutinin and human immuno-conglutinin were completely negative. [ABSTRACT FROM AUTHOR]

The injection of sheep red cells and capsular antigen of Pasteurella pestis leads to increase in the absolute and relative number of plasma cells in the draining lymph node and spleen. An equation is proposed which is compatible with the linear relationship which is observed between the logarithm of the antigen dose and the square root of the number of plasma cells. An index of homogeneity is derived from this equation which is related to the number of different antigenic determinants and different antigenic molecules in the immunogen. This index varied in the predicted way when mice were immunized with relatively pure and crude preparations of capsular antigen. [ABSTRACT FROM AUTHOR]

The effect of an horse anti-mouse thymocyte globulin (ALG) preparation on the primary and secondary immune responses to sheep erythrocytes (RBC) was studied in 2-3-month-old male A/HeJ, C57B1, BALB/c, DBA/1, CBA and C3H mice. A wide variation in the primary and secondary responses of the individual strains was noticed but in ail cases these were significantly suppressed by ALG pretreatment. The capacity of the ALG to suppress the primary immune response was not overcome by increasing the antigen dose from 3 × 107 to 3 × 109 sheep RBC. [ABSTRACT FROM AUTHOR]

Peritoneal exudate lymphocytes (PEL) of guinea-pigs injected with Freund's complete adjuvant (FCA) were capable of liberating skin reactive factor (SRF) and macrophage migration-inhibitory factor (MIF) when cultured for 24 hours in the presence of sheep red cells (SRC) preincubated with lymph node cells (LNC) of guinea-pigs immunized with SRC in FCA. Similar release of soluble mediators was found in the following situations: (a) incubation of non-immune PEL with SRC sensitized with the exclusion peak of Sephadex G-200 fractionated immune LNC supernatant; (b) incubation of non-immune LNC with complexes of SRC and anti-SRC IgG, prepared from serum of animals immunized with SRC in CFA, and (c) incubation of non-immune LNC with a mixture of SRc urea extract and anti-SRC IgG. SRC incubated for 24 hours with immune LNC and freed of lymphocytes by selective filtration through a Millipore filter, were able to provoke an inflammatory reaction in the skin of normal guinea-pigs, which was delayed in character. These findings are interpreted as suggestive evidence for the non-identity of the mediator-producing and antigen-reactive cells and as support for the hypothesis that a complex composed of antigen and an antibody-like material, secreted by stimulated antigen-reactive lymphocutes, is responsible for the release of soluble mediators in cell-mediated immune reactions. [ABSTRACT FROM AUTHOR]

Irradiated (NZB × BALB/c)F1 mice were injected with syngeneic bone marrow cells, syngeneic or parental thymus cells, and sheep red cells. The antibody plaque-forming cell response depended on the number of sheep cells and the age and strain of the thymus cells. Young or adult BALB/c thymus, and young hybrid thymus, responded best to low numbers of sheep cells; with higher numbers they became tolerant. Adult hybrid thymus, and young or adult NZB thymus, responded better to high numbers of sheep cells. Hybrid mice irradiated and restored with BALB/c bone marrow developed thymus cells with the reactivity of BALB/c thymus. It is argued that NZB mice, and older hybrids, may develop autoimmunity because of an abnormality of tolerance induction manifested in their thymus cells, but of bone marrow origin. [ABSTRACT FROM AUTHOR]

The red cell uptake of IgG on the basis of absorption experiments appears to be due to two populations of IgG molecules. One population is readily absorbable by red cells. The quantity of this type of IgG varies from preparation to preparation and appears to depend on the method used for preparing the IgG. It appears that this population of IgG molecules represents denatured or aggre- gated IgG, although no direct evidence of aggregation was obtained in these studies. The other population of red cell absorbable IgG appears to be proportional to the IgG concentration and cannot be depleted by successive red cell absorption of the IgG solution. A similar pattern of reactivity with red cells was found using [131I] IgM. Labelled subunits of IgM and fragments of IgG (Fab and Fc), differed from IgG and IgM in that they did not contain a population consisting of a variable quantity of readily absorbable molecules. [ABSTRACT FROM AUTHOR]

This article presents the study of canine erythrocyte antibodies. An adaptation of the Polybrene technique for typing of canine erythrocytes is reported in this paper. Dog whole blood was anticoagulated with acid-citrate-dextrose in a proportion of 1:9 The samples were stored at 40, and used within 10 days. Manual typing and titrations were performed. Adaptation of this technique to canine blood study required two modifications: 15 per cent bovine serum albumin was substituted for homologous normal serum; the concentration of Polybrene was reduced to 0.033 mg/ml. Results demonstrated that the Polybrene technique is from 12.5 (anti-A) to 3200-fold (anti-He) more sensitive than the manual technique.

The experiments described demonstrate that the in vitro lysis of chicken erythrocytes (CRC) by allergized mouse spleen cells (ASC) is an antibody-dependent phenomenon. Supernatants obtained from cultures of ASC were shown to contain antibody which could effect antibody-dependent cell-mediated cytotoxicity. The cytolysis observed with ASC was inhibited by both an IgG fraction and a F(ab')2 portion of rabbit anti-mouse IgG. No inhibition was obtained by pretreating the ASC with AKR anti-C3Hθ serum and guinea-pig complement. [ABSTRACT FROM AUTHOR]

The reactions of two monoclonal IgM lambda cold agglutinins, Sch and Sher, have been studied in detail with human and animal erythrocyte antigens. Although they were unusual in having lambda and not kappa polypeptide chains, they could be assigned to the anti I and anti-Pr1 groups of cold agglutinins. The findings with serum Sher indicated that the Pr1 antigen may be more complex than previously thought. The occurrence of unexpectedly large numbers of specificities among monoclonal anti-I, anti-i and anti-Pr antibodies is discussed and it is suggested that each monoclonal antibody may recognize only a limited portion of a complex red cell antigen. [ABSTRACT FROM AUTHOR]

Mice infected with the nematode Trichinella spiralis or normal mice treated either with the serum of infected animals or with a parasite extract contained fewer spleen rosette-forming cells (RFC) to sheep erythrocytes than the controls, Bone marrow cells from infected mice were considerably less efficient than normal cells in reconstituting thymectomized, irradiated animals. [ABSTRACT FROM AUTHOR]

The induction in mice of a humoral immune response to intact sheep erythrocytes, both in vivo and in vitro, requires participation of thymus-derived (T) lymphocytes. In an in vitro system, spleen cells from both neonatally thymectomized and adult thymectomized irradiated bone marrow protected mice were successfully immunized, using washed sonicated sheep erythrocyte membrane fragments as antigen. This obviation of the requirement for T lymphocytes in the immune response, coupled with previous work on macrophage independence, indicates that sonicated membrane fragments were capable of directly immunizing bone marrow-derived (B) lymphocytes in vitro. These results further confirm the signal importance of antigenic structure in determining the cellular requirements for an immunological response; whereas antigens of particulate or monomeric form require the presence of both T cells and macrophages, polymeric antigens of intermediate size such as polymerized flagellin and sonicated sheep erythrocyte membranes require neither of these accessory cells. The results caution against the use of erythrocytes as models of thymus-dependent antigens. The data further suggest that reports of late antibody responses of relatively normal magnitude in thymectomized animals given larger doses of heterologous erythrocytes may have been due to direct immunization of B lymphocytes by degraded erythrocyte antigen. [ABSTRACT FROM AUTHOR]

HgA-positive red cells were treated in vitro with approximately 10 μmoles N-ethylmaleimide (NEM) per ml cells for 1 hour at 37° and then injected into the circulation of HgA-negative rabbits; all the cells were cleared within 24 hours After 1-3 months the animals were given a series of injections of untreated HgA-positive red cells at 3-monthly intervals. Five out of seventeen rabbits showed progressively diminishing survival of HgA-positive red cells with the development of anti-HgA. On the other hand, in eight rabbits red cell survival following three consecutive injections of untreated red cells was normal or almost normal and in four further rabbits survival was initially subnormal but became progressively longer and was almost normal following a third injection of cells. Thus, in as many as twelve out of seventeen animals (70 per cent) the survival of HgA-positive red cells following a third injection of untreated cells was normal or almost normal whereas this pattern was previously observed in only seven out of fifty-one animals (14 per cent) not given an initial injection of NEM-treated cells. It is concluded that the injection of NEM-treated HgA-positive red cells to HgA-negative rabbits induces a degree of immunological tolerance to the HgA antigen. [ABSTRACT FROM AUTHOR]

HgA-negative rabbits were given an intravenous injection of HgA-positive red cells followed within 30 minutes by an intravenous injection of IgG anti-HgA. Several weeks later a second injection of HgA-positive red cells, without antibody, was given; the survival of these red cells was compared with the survival of red cells given to animals which had received no passive antibody. As judged by a relatively good survival of the second injection of red cells, primary immunization to HgA was at least partially suppressed when the dose of anti-HgA given with the first injection of red cells was such that 260-750 μg antibody was bound per ml red cells. In three groups of animals given HgA-positive cells and anti-HgA in doses such that 20-40 μg antibody was bound per ml red cells there was apparently no suppression of the antibody response. It is concluded that the amount of specific IgG antibody required for the suppression of primary immunization is at least ten times greater, in terms of μg antibody per ml red cells, for the rabbit antigen HgA than for the human antigen Rh; the difference may be due partly to the greater number of HgA antigen sites on the rabbit red cell compared with the number of Rh(D) sites on the human red cell. [ABSTRACT FROM AUTHOR]

Long-term IgM and IgG responses to sheep red blood cells (SRBC) were determined in New Zealand Black (NZB) mice, using the plaque technique. As compared with other strains a prolonged spleen plaque-forming cell (PFC) response was found in young and old NZB mice. This phenomenon was found in the primary as well as in the secondary response and concerned IgM as well as IgG production. These observations are discussed in relation to the production of IgG antibodies of a low avidity. [ABSTRACT FROM AUTHOR]

Successive injections of HgA-positive red cells were given at intervals of 2-3 months to HgA-negative rabbits. In forty-four out of fifty-one animals, red cell survival became progressively shorter and, in the majority of instances, anti- HgA was found in the serum. Characteristically, the first survival curve was initially normal but showed 'collapse' after a mean interval of 17 days; following subsequent injections, cells were cleared at an accelerated rate. In the remaining seven HgA-negative rabbits the survival of HgA-positive red cells was either repeatedly normal or was subnormal after the first one or two injections and became almost normal following further injections. In four out of six of these animals, following additional injections of HgA-positive cells given in with FCA, anti-HgA became detectable in the serum, Thus, some animals which appeared to he non-responders to HgA as judged by normal survival of HgA-positive red cells after i. v. injection alone showed some response when antigen was also given in, with adjuvant. [ABSTRACT FROM AUTHOR]

The blood groups are described of three sheep chimaeras produced by injection of blastomere cells into fertilized eggs of different parental origin. Evidence is presented that these chimaeras had a blood type which could only have been derived from both sets of parental genes. Two antigenically distinct red cell populations were identified in all three sheep and chimaerism of serum transferrin and albumin types was also present in two of them. One sheep had a mixture of red cell potassium types and another of haemoglobin types. Soluble R and U blood group substances were present together in the saliva of all three sheep and on the red cells of two of them. The relative proportions of the two red cell populations changed with age of the sheep, the blastomere-derived population becoming less. In one sheep one transferrin type also declined. A fourth sheep studied was not a blood chimaera but was apparently composed of blood derived entirely from that of the transplanted blastomere cells. All four sheep were phenotypically male but studies of cultured leucocytes showed that female cells were present in two of the chimaeras (34 per cent and 89 per cent respectively). [ABSTRACT FROM AUTHOR]

Surface immunoglobulin can be demonstrated on almost all sheep erythrocyte rosette-forming cells in CBA and AKR mice, either by inhibition of antigen binding by anti-immunoglobulin or by immunofluorescence. When surface immunoglobulin on a rosette-forming cell is `capped' by anti-immunoglobulin, the bound red cells migrate with the immunoglobulin, demonstrating that the receptor-combining site and immunoglobulin antigenic determinants share the same mobile unit in the membrane. These observations strongly support the concept that the antigen receptor is surface immunoglobulin (at least for B cells), and illustrate the usefulness of the `capping' technique for studying the associations between membrane elements. [ABSTRACT FROM AUTHOR]

The regulation of the immune responses by antibody administered passively on peritoneal exudate cells (PEG) was studied in guinea-pigs. The immunogenicity of sheep red blood cells (SRBC) associated with PEC for the induction of delayed hypersensitivity (DH) to soluble erythrocyte antigen was enhanced when PEG were incubated with anti-SRBG antibody. In contrast, the antibody response to SRBC was depressed. This phenomenon was only observed with specific antibody and was partially blocked when PEG covered with anti- SRBC antibody were incubated with rabbit anti-guinea-pig globulin serum. Comparable amounts of anti-SRBC antibody injected separately had no enhancing effect. Anti-SRBC sera from which the cytophilic antibody activity had been removed were inactive. PEG-associated SRBC were usually more immunogenic than the same amount of `free' SRBC for the induction of delayed hypersensitivity and always more immunogenic for antibody production. These observations suggested that macrophage cytophilic antibody might be involved in the regulation of the immune response and play a role in the preferential induction of delayed hypersensitivity in the studied system. [ABSTRACT FROM AUTHOR]

Lymphokines have a number of effects in vitro, which may be related to their role as mediators of delayed hypersensitivity. These mediators are also released in vivo. Authors of the article have described the effect of Lymphokines on in vivo and in vitro antibody production. The present article shows the effect of supernatants which contain lymphokines on the development of delayed hypersensitivity to unrelated antigen. Animals were injected into the ear vein with 1ml of 25 percent suspension of three tines washed sheep red blood cells with or without various supernatants.

Several observers have reported that red cells coated with a specific blood-group antibody may take up a second blood-group antibody non-specifically, an effect known as the 'Matuhasi-Ogata phenomenon'. In the present work, this effect was investigated using either 125I-labelled antibodies of various specificities or a 131I-labelled preparation of IgG lacking relevant antibodies. In confirmation of much previous work, it was found that red cells took up appreciable amounts of IgG non-specifically; however, this uptake was not increased by previous coating of the red cells with specific antibody. When the IgG taken up non-specifically included a blood-group antibody in relatively high concentration, an eluate subsequently prepared from the red cells contained sufficient of the antibody to be detectable. Thus, the finding of unexpected antibodies in eluates may be due to non-specific uptake of IgG rather than to adherence of antibodies to antigen-antibody complexes. [ABSTRACT FROM AUTHOR]

Differences in reactions in the mixed agglutination test with anti-A sera from different individuals were found to be unrelated to the titre against human or pig A red cells or simply to the presence or absence of either 7S or 19S antibody. It was found that 7S anti-A was capable of producing mixed agglutination, but that 19S fractions more frequently produced mixed agglutination than the 7S fraction from the same serum. Treatment of sera with 2-mercapto-ethanol abolished the capacity to produce mixed agglutination from some sera, whilst other sera were unaffected. Some anti-A sera gave the same titre of mixed agglutination with both secretor and non-secretor buccal cells, but other sera reacted more strongly with secretor than with non-secretor cells. Production of mixed agglutination by 7S antibodies was also demonstrated with fractions of rabbit antisera against Forssman antigen and against bovine red cells. [ABSTRACT FROM AUTHOR]

The reaction of the rheumatoid factor (RF) with 7S γ-globulin antibodies of nine persons immunized with sheep erythrocytes was studied. All of a panel of rheumatoid sera with high Waaler-Rose titres agglutinated sheep cells sensitized with the human anti-sheep cell antibodies and O Rh positive cells sensitized with the 'diagnostic' anti-CD serum Ripley. The RF measurable with these systems could be absorbed to diphtheria toxoid-human antitoxin precipitate, whereas the absorption with egg albumin-rabbit anti-egg albumin precipitate did not result in any appreciable titre reduction. However, the eluate from the rabbit precipitate was highly active in these systems, whereas Rh positive cells sensitized with anti-Rh sera suitable tot Gm(a) typing were not regularly agglutinated. A markedly greater concentration of native than of heat-aggregated γ-globulin was needed for inhibition of the agglutination by the RF of cells heavily sensitized with the human anti-sheep ceil antibodies. No appreciable difference in this respect was seen when using lightly sensitized cells. Only the heavily sensitized cells fixed complement. The 'natural' 7S γ-globulin antibodies against sheep cells were neither suited for demonstration of RF nor did they fix complement. Sheep cells coated with 7S γ-globulin antibodies of a Gm(a+) person were agglutinated by a non-rheumatoid anti-Gm(a) serum, and this system was well suited for Gm(a) typing, whereas cells coated with antibodies of a Gm(a-) person were not agglutinated. Rheumatoid anti-Gm(a) sera agglutinated cells sensitized with antibodies of both Gm(a+) and Gm(a-) persons. Using cells coated with Gm(a+) antibodies, some distinction between Gm(a+) and Gm(a-) sera could be obtained under carefully controlled conditions. The use of a Gm(a-) coat resulted in a slight difference in the inhibiting capacity, which had no relation to the serum's Gm(a) type. The results suggest that the reaction of the RF with sheep cells heavily sensitized with human anti-sheep ceil antibodies is essentially an interaction of the RF with immune aggregated γ-globulin, whereas when using lightly sensitized cells the individual γ-globulin molecules play a prominent role. [ABSTRACT FROM AUTHOR]

An in vitro technique is described with demonstrates a difference in the interaction of fresh and stored, effete, red cells with autologous macrophages. The stored erythrocytes adhere to macrophages whereas fresh erythrocytes do not. The effects on this difference of the medium in which the red cells are stored, and of the storage temperature, are described. Results are presented which indicate that serum opsonic factors are not necessary for the adherence of the stored red cells to macrophages. [ABSTRACT FROM AUTHOR]

Erythrocytes labelled with chromium51 were injected into embryos and young chicks and a similar challenge given soon after the majority of the initial dose had been eliminated. While tolerance was the typical response in embryos and chicks up to 3 days of age, immunity could be induced in most chicks from this time onwards. The intensity of the immune response increased rapidly until the 12th day of age. No maternal antibody could be detected. Pretreatment of the embryo with testosterone impaired the immune response of 14-day-old chicks. [ABSTRACT FROM AUTHOR]

The uptake of haemolytic fowl C' by fowl anti-BSA and BSA has been detected and measured with sheep red cells sensitized with fowl haemolysin. It was, however, very small compared with the amount of guinea-pig C' taken up by similar amounts of rabbit anti-BSA, and not directly related to the amount of precipitating antibody in any particular antiserum; nor did it occur when preformed resuspended specific precipitates were added to the C' solution. Fixation of guinea-pig C' by fowl anti-BSA could not be demonstrated, either with fresh antiserum, or with heated antiserum in the presence of normal fresh fowl serum. Uptake of haemolytic fowl C' was shown to coincide with a great increase in specific precipitation when this was done in 0.9 per cent NaCl. This increase was produced partly by the addition of a non-specific serum factor, and partly by more complete precipitation of the antibody. Specific precipitates formed in 0.9 per cent NaCl in the presence of fresh normal fowl serum (NFS) contained much larger amounts of a macroglobin component than precipitates formed in the absence of NFS or in 8 per cent NaCl. [ABSTRACT FROM AUTHOR]

Analyzes rheumatoid factor. Antigenic components of papain digestion of human gamma globulin; Incubation of sheep red cells with rheumatoid arthritis sera; Failure of cells to agglutinate when resuspended in saline; Antigenic characteristics of beta [sub 2] M globulin.

Measurement of the rate of elimination of 51Cr-labelled erythrocytes provides a reliable test of immunity in fowls. Chickens can be rendered tolerant of homologous and turkey erythrocytes, as judging by this test, by receiving a series of transfusions of irradiated blood. The series were arranged so that foreign cells remained present in the circulation from the time of hatching. Tolerance induced by this treatment is generally incomplete, but can last indefinitely. In some chickens the manifestation of tolerance of turkey erythrocytes is delayed, probably because of passive transmission of antibody from the damn. Chickens old enough to react against small transfusions of homologous blood can still be rendered tolerant by massive transfusions. Tolerance of the erythrocytes from an individual donor extends only slightly to those from other donors. Tolerance acquired in this way, through transfusion of irradiated blood, stands in contrast to the more stable and complete tolerance that can be acquired through administration of variable cells. Viable cells, on the other hand, provide a less sensitive test, for birds which tolerate skin homografts often eliminate rapidly erythrocytes from the same donor. [ABSTRACT FROM AUTHOR]

131I-labelled anti-Rho (D) antibody was made to react with suspensions of spermatozoa and red blood cells from Rho (D) positive and negative donors at 37° for 1 hour. Spermatozoa from Rho (D) positive donors did not take up more 131I anti-Rho (D) than was bound by spermatozoa from Rho (D) negative donors. The mean value for Rho (D) positive donors was 0.0142 ± 0.0061 X 10-2 μg. nitrogen per 106 spermatozoa, and the comparable value for Rho (D) negative donors was 0.0189 ± 0.0130 X 10-2 μg. nitrogen per 10-6 spermatozoa. Red blood cells from Rho (D) positive donors took up thirty to forty times more 131I anti- Rho (D) antibody than was taken up by spermatozoa from Rho (D) positive donors, whereas red blood cells from Rho (D) negative donors took up only 0.5 to 1.7 times more 131I anti-donors. Pre-treatment of spermatozoa with trypsin increased by two to three times the quantity of 131I anti- Rho (D) antibody bound to spermatozoa from both Rho (D) positive and negative donors. The quantitative increase was similar for spermatozoa from Rho (D) positive and negative donors. No evidence for the presence of Rho (D) antigen on human spermatozoa was obtained using 131I anti- Rho (D). [ABSTRACT FROM AUTHOR]

An investigation is described of the interaction of a highly purified human serum inhibitor of C' I-esterase with various intermediate complexes of sensitized sheep erythrocytes and human or guinea-pig complement. The inhibitor reacted with and blocked specifically the activity of C' I on these complexes. There was a direct correlation, by several criteria, between the ability of the inhibitor to block esterolytic activity of C' I-esterase in solution and its ability to inhibit C' I activity on the intermediate complexes, implying the participation of C' I-esterase in immune haemolysis. Prior interaction of the inhibitor with complexes between sensitized erythrocytes and C' I and C' 4 prevented subsequent reaction of these complexes with C' 2. However, once the complex between sensitized erythrocytes and C' I, C' 4 and C' 2 had been formed, the inhibitor was no longer effective in preventing haemolysis. These data suggested a biochemical function for C' I-esterase in reaction involving C' 4 and C' 2 but not in further steps leading to immune haemolysis. [ABSTRACT FROM AUTHOR]

The relationship of the haemolytic activity of complement (C′) to the concentration of sensitized erythrocytes (EA) has been found subject to precise mathematical definition, on the basis of data obtained from simultaneous C′ titrations carried out with twelve different EA concentrations ranging from107 EA/ml. to 2 × 109 EA/ml. Increase in EA concentration is accompanied by increase both in the amount of C′ required for 50 per cent haemolysis (RD50 C′), and in the value of σ (reciprocal of the slope of the curve relating probit percentage haemolysis to log C′). The relationship of RD50 C′ to EA concentration is an exponential one; the equation expressing this relationship contains a parameter which is interpreted as consistent with the existence of a threshold value of C′ which should be taken into account in assessing RD50 C′. An explanation of the increase in RD50 C′ and σ with increase in EA concentration is offered. [ABSTRACT FROM AUTHOR]

Haemagglutination of penicillin-sensitized red cells by certain human sera is followed in a variable period of time by dispersal of the agglutinates. This is accompanied by loss of haemagglutinin activity from the supernatant fluid. Certain substances including albumin, sodium salicylate and glycerol tend to inhibit the haemagglutination reaction. The effect of the latter two substances suggests the possibility of a hydrogen bonding mechanism between the surface-absorbed penicillin and antibody. Loss of activity from positive sera is a function of cell concentration, time of reaction and temperature. Both penicillin and the product of penicillin-penicillinase reaction inhibit the haemagglutinin activity of positive sera. Evidence is presented which suggests that the prosthetic group involved in penicillin-penicillinase combination differs from that in penicillin-antibody union. In addition, penicillin adsorbed to the red cell surface appears to be protected from the inactivating effect of penicillinase. Whether haemagglutinin for antibiotic-sensitized cells is of immune or non-immune origin is, as yet, unestablished. It is possible to produce haemagglutinin in rabbits by injection of sensitized red cells and, after adsorption, such sera will agglutinate only antibiotic-sensitized cells. However, of seven sera causing haemagglutination of chloramphenicol-sensitized cells, six were from patients with no past history of chloramphenicol therapy. It is possible that this type of antibody may play a part in certain cases of unexplained haemolytic anaemia. [ABSTRACT FROM AUTHOR]

A sensitive indirect haemagglutination technique is described which depends upon attachment of the protein antigen to the erythrocyte with difluorodinitrobenzene. The attachment of human gamma globulin to human erythrocytes has been thoroughly studied using sera containing the Rose-Waaler factor as the agglutinator. It has also been shown that horse and rabbit serum proteins and egg white may be attached to cells by the reagent. The technique is simple and sensitive but an absorption step is necessary to remove a non-specific agglutinin to cells which have been treated with the reagent. [ABSTRACT FROM AUTHOR]

Certain sera from individuals receiving large doses of penicillin have been found to contain a factor which can cause agglutination of human red cells sensitized with penicillin. Such sera were detected by a preliminary white tile screening technique and subsequently titrated in tubes. The haemagglutinating factor appeared to be heat stable (56·0° for 6 hours at least) and active over a pH range of approximately 4·8 to 9·0. In the presence of complement certain strongly positive sera caused haemolysis of the red cells. The addition of penicillin inhibited the haemagglutination reaction but this effect was reversible by the addition of penicillinase. Certain agglutinating sera gave positive complement fixation tests but no visible precipitates were obtained by tube or double diffusion agar gel techniques. Attempts to obtain active eluates from agglutinated sensitized cells were unsuccessful. It was also found that the haemagglutinating factor did not appear to have any inhibiting effect on the bactericidal action of penicillin. Starch-gel electrophoresis of positive sera demonstrated haemagglutinating activity in two pre-albumin zones. One such zone, pre-albumin-2, has been shown to be acidic-alpha-I-glycoprotein whereas the nature of pre-albumin-I remains obscure. In twenty-two of twenty-three sera so tested agglutinating activity was confined to these two zones. In the remaining serum, in addition to activity in the two pre-albumin zones, positive agglutination of sensitized cells was also brought about by the gamma-globulin fraction, and this serum was the only one which gave a positive antiglobulin test. The interpretation of these electrophoretic findings is not altogether clear and requires further elucidation. [ABSTRACT FROM AUTHOR]

The immunological relationship between a protein toxin and the components of the Boivin or ‘O’ somatic antigen isolated from Vibrio cholerae has been studied. Evidence is given which suggests that the protein toxin is in fact the protein component of the Boivin antigen. Protein toxins isolated from seroo logically unrelated vibrios appear to share a common antigenic component. [ABSTRACT FROM AUTHOR]

A method is described for making serial estimations of serum complement. Titrations were made in a standardized haemolytic system and the 50 per cent haemolysis end point obtained by relating the probit percentage haemolysis to the reciprocal of the corresponding serum dilution. Possible variable factors such as changes in pH and red cell concentration were studied and it was found that the most important source of error arose from the use of different batches of sheep red cells. This was overcome by running a lyophilized standard reference serum in parallel with all titrations and expressing the unknown sera in terms of this standard. Observations were then made on a group of selected subjects to form the basis for a study of changes in patients suffering from renal disease. [ABSTRACT FROM AUTHOR]

The use of 51Cr as a label for sheep red cells was tested in thirteen sheep in which small volumes of labeled cells were injected. A considerable loss of radioactivity from the circulating blood was noted especially during the first few days, which seemed to be due to the elution of chromium from the cells. This was supported by certain in vitro experiments. The method, however, offered a practical possibility for determining the incompatibility of homologous red cells. The strength of the naturally occurring antibodies was determined by an in vitro haemolytic test. These antibodies were associated with an elimination of the appropriate injected cell, the rate depending upon the strength of the antibody. The method should prove useful in selecting bloods for transfusion. The rate of elimination of injected cells was followed before and after immunization. In most cases the elimination was virtually complete, but examples have been met with in which a proportion of the cells remained circulating in the presence of antibody. [ABSTRACT FROM AUTHOR]

Bacterial lipopolysaccharides and 'O' somatic antigens usually require treatment with alkali for maximal adsorption on erythrocytes in preparation for indirect haemagglutination. Although heating enhances sensitizing activity, owing partly to increasing dispersion, it is always less effective than alkali treatment. The presence of a protein component or of the chloroform soluble lipid 'A' does not inhibit erythrocyte sensitizing activity and no change in sugar constituents has been detected as a result of treatment. The specific polysaccharide of Aerobacter aerogenes, which contains no lipid, requires alkali treatment for activity; in this case the effect of alkali is to remove O-acetate (4 per cent). The loss of weight on treatment is also 4 per cent and no other differences can be detected by examining the infrared-absorption spectra of treated and untreated samples. For other materials investigated a loss of O-acetyl has been detected, except where alkali treatment is not required to elicit maximal activity, e.g. the Pasteurella pestis lipopolysaccharide which contains about 50 per cent of lipid 'A'. By reacetylation of alkali treated polysaccharides it has been shown that O-acetyl residues inhibit adsorption on to erythrocytes, but in some instances higher fatty acids are also removed to some extent by treatment with alkali. [ABSTRACT FROM AUTHOR]

Antibody reacting against syngeneic erythrocytes (RBC) was elicited in several strains of mice by immunizing the mice with rat RBC. In nearly all mice sustained production of antibody reacting against syngeneic RBC required that the mice be continually stimulated with rat RBC. We suggest that this is further evidence that naturally-occurring immunological tolerance can be terminated temporarily by immunization with antigens cross-reacting with self. The results support the concept that clones of antibody-producing cells potentially reactive against self, exist in the normal mouse. [ABSTRACT FROM AUTHOR]

Sheep erythrocytes coated with a mycobacterial glycopeptide obtained from culture filtrates were found to possess an affinity for guinea-pig anti-ovalbumin γ2-immunoglobulin. Untreated erythrocytes did not possess this affinity. The significance of the dual affinity of mycobacterial glycopeptide for cell sur- faces and guinea-pig immunoglobulin is discussed in relation to the mode of action of mycobacterial adjuvants. [ABSTRACT FROM AUTHOR]

Cell kinetics of the 2,4,6-trinitrophenyl (TNP)-erythrocyte response in non-immune, immune, and vinblastine-treated immune BDF1 mice were studied by measuring hapten- and carrier-RFC and hapten- and carrier-PFC responses at various time intervals. Injection of a single dose of horse red blood cells alone enhances the anti-TNP response. [ABSTRACT FROM AUTHOR]