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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]

Acute sialoadenitis, ascribed to local formation of immune complexes, develops in sensitized rats after a single intraductal challenge with the sensitizing antigen. Multiple intraductal challenges induce a state of non-reactivity of the organ characterized by a lack of inflammatory reaction to the sensitizing antigen. This non-reactivity is antigen-specific, since introduction of ovalbumin, after multiple intraductal instillations of bovine serum albumin (BSA), elicits an inflammatory response in animals immunized with the two antigens. At the same time, instillation of BSA into the contralateral gland, which has not been challenged, causes acute adenitis. Anti-BSA antibodies are detected in the serum and parotid saliva at the time of refractoriness of the gland. The phenomenon is a transient one since the faculty of the salivary gland to respond by an inflammatory reaction recovers after a challenge-free period. These experiments bring to light a new phenomenon, the possible mechanisms of which are discussed. [ABSTRACT FROM AUTHOR]

An increase in the level of acid phosphatase, β-glucuronidase and cathepsin D in macrophages was obtained by cultivating the cells in medium containing high serum concentration and by injecting macrophage donors with thioglycollate. A high level of the three hydrolytic enzymes in the stimulated macrophages does not correlate with a high uptake or degradation of the polypeptide antigen (TG)-PRO--L. Moreover, macrophages with a low level of enzymes (unstimulated cells) pinocytose and degrade (TG)-PRO--L more efficiently than macrophages with a high content of hydrolases. Unstimulated macrophages from responder (SJL) mice pinocytose and degrade (TG)-PRO--L more efficiently than macrophages from the non-responder (DBA/1) animals although the two cell populations had similar levels of hydrolases. [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]

Polyanion-immunoglobulin complexes, considered important factors in the pathogenesis of glomerulonephritis common in systemic lupus erythematosus, were found and isolated from sera of NZB mice by selectively binding them to an anion-exchange cellulose (DE52). Accurate quantification of such complexes was possible, in terms of immunoglobulin content, by means of an antiglobulin complement-fixation assay. In sera of NZB mice the concentration of immune complexes increased up to about 11 months of age and then it declined, whereas in the sera of the C57B1 and HaICR strains of mice, which do not develop spontaneous glomerulonephritis, the concentration was lower initially but increased steadily with increasing age and reached an equivalent level at about 27 months. The complexes were composed primarily of immunoglobulins of the IgG class bound to native DNA. The finding of significant levels of circulating immune complexes in mouse strains without renal disease suggests that such complexes, although necessary, might not be sufficient and solely responsible for overt glomerulonephritis. [ABSTRACT FROM AUTHOR]

A distinctive fragment of the HL-A antigen molecule which retains characteristic structural features of the intact molecule has been obtained from soluble HL-A antigens by mild degradation procedures. When molecular fragments of 48,000 Daltons which are derived from cultured human lymphoid cells and carry HL-A alloantigenic activity are exposed to a pH of 2.4 in glycine buffer for 15 minutes at 0-4°, they split and a fragment of 11,000 Daltons can be isolated by gel filtration. This fragment does not carry HL-A alloantigenic activity but does carry HL-A common activity. This common activity had previously been found on papain-solubilized HL-A antigens as well as on intact lymphoid cells. It is immunogenic in rabbits and reacts with antiserum raised in rabbits against lymphoid cell membrane fractions. These small fragments appear to be characteristic, common structural components of HL-A antigen molecules of 48,000 Daltons and hence are designated 'HL-A common-portion fragments'. Similar molecular fragments are found in solutions of the HL-A molecular fragments of 48,000 Daltons that have been stored in buffer at pH 7.8 at 4° for some time. [ABSTRACT FROM AUTHOR]

Lymph node cells from preimmunized rabbits were cultured with varying concentrations of antigen in autologous serum which had been collected before immunization. [3H]Thymidine was added after 18 hours of culture and the cells were harvested at 24 or 66 hours for the determination of the radioactive labelling of acid-precipitable material. Preheating serum (56°, 20 minutes) enhanced labelling in both control and antigen-treated cultures. This 'heat effect' had an early (24 hour) non-specific component, independent of antigen concentration, and a late (66 hour) specific component which was most evident at high antigen concentrations. The conditions of preheating serum (temperature and time) required to produce the heat effect were similar to those required to remove haemolytic activity against rat erythrocytes. However, at certain temperatures and times there were discrepancies. These discrepancies, and data from experiments in which preheated and unheated sera were mixed in varying proportions, or interchanged in different sequences, were explicable on the basis of (i) a requirement for complement in stoichiometric quantities dependent on the number of cells being inhibited, (ii) the involvement of the majority of the cultured cells in the early non-specific component of the heat effect, but only cells capable of proliferating in response to added antigen in the late specific component, (iii) the secretion of complement by cultured cells. Preheating serum (66&deg:, 20 minutes) depressed labelling in control and antigentreated cultures and reduced agglutinating activity against both autologous and heterologous erythrocytes. The results are discussed in relationship to models which require that the size of a specific lymphocyte clone be positively or negatively regulated by the concentration of antigen specific for that clone. With increasing antigen concentration three effects on cells bearing specific receptor sites are distinguished. (i) Cell stimulation under conditions of antigen concentration and cell receptor specificity such that only a few antigen molecules can bind to cells. (ii) Complement-dependent inhibition under conditions such that more antigen molecules can bind to cells. (iii) Complement-independent inhibition under conditions, possibly unphysiological, such that very large quantities of antigen molecules can bind to cells. [ABSTRACT FROM AUTHOR]

To obtain further evidence that complement is involved in both the early, non-specific and the late, specific, components of the heat effect (Forsdyke, 1973b), lymph node cells from preimmunized rabbits were cultured with varying concentrations of antigen in autologous preimmunization serum treated with one of three specific complement inhibitors, inulin, Zymosan or cobra venom factor. The Zymosan particles were removed before use of the serum in cultures, but the other inhibitors were not removed. Inulin only slowly removed haemolytic activity from serum and enhanced the late response to high concentrations of specific antigen. The inulin concentrations required to remove haemolytic activity were similar to those required to enhance the response to antigen. Zymosan-pretreated serum enhanced labelling with 3H]thymidine in both control and antigen-treated cultures to a proportionate extent. No late specific enhancement of labelling was detected, probably because of the secretion of complement by cultured cells. The interpretation of data obtained when Zymosan was left in cultures was complicated by Zymosan acting as an antigen and inducing a primary response to itself. Cobra venom factor reduced the labelling of both control and antigen-treated cultures so that the non-specific component of the heat effect was not detectable. However, the response to high concentrations of specific antigen was enhanced. It is concluded that although each complement inhibitor shows unique individual characteristics in the system, on balance the results support the view that the activity responsible for both components of the heat effect is complement. [ABSTRACT FROM AUTHOR]

Lymph node cells from immunized rabbits were cultured with varying concentrations of antigen in preheated (56°, 30 minutes) autologous serum which had been collected before immunization. [3H]Thymidine was present for the last 6 hours of the 24-hour culture period and the radioactive labelling of acid-precipitable material was then determined. Changes in labelling due to variations of culture conditions were interpreted according to whether they were specific for control or antigen-treated cultures or non-specific. Cell concentration and serum concentration were predominantly non-specific variables influencing the labelling in control and antigen-treated cultures to a proportionate extent. However, at serum concentrations below 5 per cent labelling was disproportionately inhibited in antigen-treated cultures; there were further minor disproportionate inhibitions at higher serum concentrations. Labelling was inhibited by increasing the concentration of serum from 25 to 50 per cent, mainly due to a non-diffusible competitive inhibitory activity. Isotope-dilution analysis of the effects of serum on labelling over a wide range of serum concentrations indicated that the relationship was a complex one with at least three step-wise stimulations of the maximum labelling rate being produced by increasing the serum concentrations from 0 to 25 per cent. Labelling in antigentreated cultures containing post-immunization serum was less than labelling in cultures containing an equal volume of preimmunization serum, but labelling in control cultures was enhanced by post-immunization serum. These results are shown to be compatible with the proposals (i) that labelling in control cultures reflects the response of cells to low concentrations of endogenous antigens, and (ii) that preimmunization serum and post-immunization serum contain ‘natural’ and ‘acquired’ antibodies respectively, which normally buffer cell-borne receptor sites against reaction with endogenous and exogenous antigens. [ABSTRACT FROM AUTHOR]

Intact IgG antibody can terminate established immune responses, whereas F(ab')2 antibody cannot do so. The difference between the two antibodies appears to be qualitative. F(ab')2 antibody, but not pepsin-digested normal serum, can interfere with the suppression and termination of immune responses induced by intact IgG antibody. These results are discussed in terms of the tripartite inactivation model. [ABSTRACT FROM AUTHOR]

Thermal regulation of the immune response was studied in toads following single injections of bacteriophage f2. The immune response was markedly inhibited in animals kept at 15° as compared to the controls (25°). The appearance of serum antibodies was delayed in animals kept at 15° for the first post-immunization week but their peak antibody levels were similar to those in toads maintained at 25° throughout. Transfer of animals from 25° to 15° 2 weeks after immunization only temporarily depressed the serum antibody levels but caused a marked delay in conversion from heavy to light antibodies. Our results are in keeping with the hypothesis that lowered environmental temperatures inhibit a variety of metabolic processes which may be concerned with the utilization of antigen and/or the synthesis of antibodies. [ABSTRACT FROM AUTHOR]

Immunochemical identification of a distinct immunoglobulin class associated with mouse reaginic antibody and designated IgE has been performed. An antiserum against mouse reaginic antibody was prepared in rats by immunization with homologous peritoneal mast cells sensitized with mouse reaginic antibody. This antiserum, after adequate absorption, recognized only one component existing in mouse serum or fractions of serum containing reaginic antibody. This component was not any of the already known γ1, γ2, IgA or IgM immunoglobulins; its immunoglobulin nature was indicated by its antigen-binding capacity in radioimmunodiffusion analysis. Fractionation experiments (zone electrophoresis, gel filtration on Sephadex G-200) showed that there was a strict association between reaginic anaphylactic activity and IgE immunoglobulin. Molecular weight of IgE was found to be about 200,000. In biological tests, anti IgE neutralized anaphylactic activity attributed to reaginic antibody, but not that attributed to γ1-antibody. Anti-IgE degranulates normal and sensitized mouse peritoneal mast cells, and rat peritoneal mast cells after they have been sensitized by mouse reaginic antibody. [ABSTRACT FROM AUTHOR]

The localization of HL-A histocompatibility antigens at the surface of human lymphocytes in electron microscopy has been studied using hybrid antibodies to bind electron-dense particles (ferritin and plant viruses) to anti-HL-A antibody. A discontinuous distribution of the markers is observed at the cell surface, which is identical with that described for H-2 antigens on mouse lymphocytes with the same technique. Double labelling experiments suggest that the areas of the cell surface where HL-A antigens are detected contain also the heterologous lymphocyte antigens detected by an anti-thymocyte serum and that HL-A antigens are not renewed at a detectable level during the period of the labelling procedure in the areas of the cell surface which are not labelled primarily with ferritin-anti-IgG-anti-HL-A complexes. The interpretation of the discontinuous labelling of HL-A antigens with direct immunoferritin techniques is discussed. [ABSTRACT FROM AUTHOR]

Human lymphocytes were fractionated on gradients of bovine serum albumin (BSA). Cells obtained from the more dense layers bound antigen specifically. Cells capable of interacting with antigen contained antibody which was separable with the nuclear components of the cell. Immune cells contained antibody which was specific for the immunizing antigen. Cell-bound antibody mediated and, in the presence of isologous antibody, slightly enhanced the uptake of antigen. Specific antibody passively bound to cell membranes did not promote uptake of antigen. Antigen which bound to lymphocytes in vitro was not enzymatically digested within the cell but became bound to acid-insoluble nuclear DNA. [ABSTRACT FROM AUTHOR]

The variation in the serum level of specific IgG, IgM and IgA antibodies during different stages of hydatid disease has been demonstrated by a technique of fluorescent microscopy that uses monospecific anti-human immunoglobulin conjugates and freeze-dried antigens. The technique is easy to perform and our results suggest that the test is sensitive and specific. Specific IgG antibodies are present in patients with either current or past infections. IgM antibodies, detected during periods of antigenic activity, disappear soon after removal of the cyst. In many cases IgA antibodies also disappear soon after removal of the cyst. Cross-reactions between the antigens and antibodies of hydatid disease and schistosomiasis are shown to be present mainly in the IgG immunoglobulin and only to a much smaller extent in the IgA. [ABSTRACT FROM AUTHOR]

The inert matrix of polymerized normal rabbit serum was given defined antigenicity by allowing selected human proteins to diffuse into small pieces of the gel. After fixation and paraffin embedding, serial sections with uniform distribution of reactive antigen were obtained. Such sections are recommended for determination of specificity and optimal working titre of fluorescent antibodies; as substrate for titration of serum antibodies; and as standards for quantification of tissue antigens. [ABSTRACT FROM AUTHOR]

Chicken anti-bovine serum albumin antibody was isolated by precipitation with albumin at pH 8.6 in 13 per cent NaCl, solution of the precipitate at pH 11.3-11.5 in 0.9 per cent NaCl, and separation of the antibody from the antigen by gel filtration at the same pH. The purified antibody precipitated its antigen and was precipitated by rabbit antiserum to chicken serum. [ABSTRACT FROM AUTHOR]

Serum samples from twenty dogs infected with Echinococcus granulosus were tested for the presence of homocytotropic skin-sensitizing antibodies. Five of the twenty sera were positive in this test, while none of the sera from twenty normal dogs was positive. The antibody was thermolabile and susceptible to 2 mercaptoethanol reduction. Reaginic antibodies to cestode antigens have not been described previously in dogs, though they are frequently associated with helminth infection in other animals and may play a role in acquired resistance. [ABSTRACT FROM AUTHOR]

The delayed-type iso-hypersensitivity that guinea-pigs acquire spontaneously towards a β-globulin antigen of other guinea-pigs has been measured in vitro. Serum containing the antigen specifically triggers lymphocytes from naturally iso-hypersensitive animals to undergo blastogenic response. This reaction is similar to that of lymphocytes cultured in the presence of antigen to which cell donors have been intentionally immunized. Thus, the in vitro technique of DNA synthesis may be used to detect both artificially induced and naturally occurring delayed-type hypersensitivities. In addition, naturally existing delayed hypersensitivity offers a plausible explanation for reports of spontaneous transformation of lymphocytes by homologous or heterologous serum and of certain other in vitro phenomena involving interaction of lymphoid cells from non-immunized donors. [ABSTRACT FROM AUTHOR]

Natural antibodies to the somatic antigens of Escherichia coli have been demonstrated in IgM, IgG and IgA porcine immunoglobulins. Antibody activity in all classes has been found in adult serum, milk whey and colostral whey and is transmitted from the latter fluid to the serum of post-suckling piglets. [ABSTRACT FROM AUTHOR]

The formation of rabbit antibodies, capable of sensitizing homologous skin, (reagins), was completely inhibited by passive administration of serum containing large quantities of 7S antibody 24 hours before or after antigen injection. No evident effect on reagin formation was noted when passive antibody was administered 8 days after antigen injection although some suppression of agglutinating antibody synthesis was observed. In rabbits not treated with passive antibody the injection of haemocyanin resulted in the tbrrnation of reagins reaching maximum serum concentrations 1 and 3 weeks following antigen injection. Both the 'early' and 'late' reagins persisted for a long time in the skin of injected rabbits, they appeared to have similar molecular size and both were devoid of PCA activity when injected into decomplemented rabbits. There was some indication that the 'early' reagins may be more heat-labile than the 'late' ones. A secondary reagin response was obtained in several animals which had shown a primary reagin response, but not in rabbits with inhibited primary response. The reagins formed in response to secondary antigen stimulation disappeared rapidly from the circulation, simultaneously with the rise in agglutinating antibody titres. The possible implications of the findings for the immunological treatment of allergic disorders is discussed. [ABSTRACT FROM AUTHOR]

Pooled chicken antiserum to bovine serum albumin contained antibodies capable of binding eighteen sites on the albumin molecule. Quantitative study of the reactivity of albumin following gradual coupling to tyrosyl, histidyl and lysyl residues, indicated that these residues are in close relationship to the antigenic centres, and that the centres and their respective antibodies are heterogeneous. [ABSTRACT FROM AUTHOR]

Radio-iodination is not a satisfactory method of labelling mouse antibody, which is peculiarly susceptible to destruction during the process of iodination. An alternative which causes very little loss of antibody is the attachment of a tritium-labelled amino acid to mouse γG by peptide linkage. This is accomplished by reaction of γG with DL-alanine N-carboxy anhydride under mild conditions. The method is applicable to estimation in vitro of the relative amounts of H-2 antibody absorbed by viable cells, and of the relative amounts of H-2 antigen on viable cells. Non-specific uptake is virtually eliminated by: (i) prior absorption of the labelled product in vivo, (ii) pre-incubation of the cells in 20 per cent foetal bovine serum and its inclusion in the suspending medium, and (iii) performance of absorption procedures in the cold. [ABSTRACT FROM AUTHOR]

A quantitative method for determining specific antibody in the different classes of immunoglobulins is described. The technique is based on the binding of all antibody present in an immune serum with antigen, and the sub- sequent precipitation of the bound immunoglobulins with a heterologous antiserum specific for the antigen employed. The concentration of each immunoglobulin class is determined by means of single radial immunodiffusion, before and after removal of its antibody-active portion. The accuracy of the measurements is essentially that of the immunodiffusion technique, and the whole analysis, applied to four immunoglobulin classes, requires only 0·06 ml of serum. The applicability of the technique has been tested using sera from mice immunized with ferritin by different routes. Antibody activity was predominant in the IgG1 and IgG2 immunoglobulin classes. However, measurable anti-ferritin activity in the IgM and IgA classes was also found in a limited number of sera. [ABSTRACT FROM AUTHOR]

Precipitin lines were observed in double diffusion tests between mouse gut tissue homogenates and serum from the same animal. Other tissues failed to produce this result. The line-forming components of the tissue are lipoidal while serum reactants are free of lipid. Purified γ-globulin, IgG, does not react with tissue constituents. An IgM component can be identified as one reactant. Lipo- polysaccharides extracted from E. coli 014, Forssman antigen and Kidd-Friede- wald antigen could not be demonstrated as reactants. It appears that certain tissue components which may be lipoproteins, and lipid free serum components, one of which is IgM, react in a way which resembles immunological interactions but which arc believed not to be so. [ABSTRACT FROM AUTHOR]

Rabbit and chicken anti-human thrombocyte sera absorbed exhaustively with human plasma, fibrinogen, erythrocytes, leucocytes and liver powder, were used for the investigation of organ specific antigens of human thrombocytes. The absorbed chicken anti-human thrombocyte serum revealed a very high agglutinating and fluorescence activity, which aided the characterization of two different types of organ-specific antigens of thrombocytes; antigens common to human and animal platelets, and antigens specific for human platelets only. The two types of antigens were found in all platelet fractions examined, the membrane, granule and soluble fractions. [ABSTRACT FROM AUTHOR]

Summary. A comparison has been made between the reactivity of cross-reacting antibody from group O sera titrated against A cells and the reactivity when titrated against cells of group B. It is considered that the experimental findings require the postulation that cross-reacting antibodies which are produced in response to stimulation by antigen A have a different configuration from those produced in response to antigen B. The results also suggest that elution of antibody from cells at 56° may cause minor changes in spatial configuration which diminish the ability of some antibodies to combine with some subgroups of the A system. [ABSTRACT FROM AUTHOR]

The addition of 10 mg of ovalbumin (HEA), bovine γ-globulin (BGG) or rat γ-globulin (RGG) to a mycobacterial wax D adjuvant emulsion inoculated intracutaneously reduced the induction of adjuvant arthritis from a 95 per cent incidence in control rats to 18·5, 26·6 and 33 per cent, respectively. There was notably less protection from bovine plasma albumin, rat serum albumin or heat denatured rat serum albumin. With a 5-mg dose of HEA arthritis was reduced to 37·5 per cent. Lower dosages were not protective. Little or no protection resulted from pre-treatments with HEA or BGG intramuscularly, with BGG in incomplete adjuvant intracutaneously or from the latter given separately but concurrently with wax D adjuvant. The inhibitory effects of the various proteins may be attributed to their adsorption by wax D in vitro before inoculation. Alternatively the protein may compete as an immunogen with an immunogenic moiety of the wax D. [ABSTRACT FROM AUTHOR]

Subcellular preparations of mouse thymocytes were compared with respect to their power to raise in rabbits antisera which prolonged the survival of skin homografts. Of the fractions studied thymocyte ‘membrane’ gave the most consistently good results, whereas thymocyte ‘mitochondria’ gave rise to sera which were toxic in high dose. Whole mouse liver homogenate or liver subcellular fractions did not elicit potent antisera. It is concluded that thymocyte ‘membrane’ best fulfils the requirements for an ideal material for immunization thus far studied and provides a convenient starting point for further purification. [ABSTRACT FROM AUTHOR]

Geladas were fed or injected with an antigen that contained Burrows' type 2 cholera toxin. Rising agglutinin and vibriocidal titres were observed in the serum, peripheral and mesenteric lymph nodes, spleen and lymphatic tissue of the upper intestine. Oral administration stimulated a more intensive vibriocidal activity in the mesenteric lymphatic nodes and intestinal lymphatic tissue, and within a shorter time than parenteral injection of the same antigen. Immune globulin synthesis paralleled largely the number of immunologically active cells. The agglutinin titres reflected the level of immune globulins and the numbers of globulin producing cells, whereas vibriocidal titres appeared independent of both. In terms of antibody site serum IgG was weight for weight more vibriocidal than serum IgM. [ABSTRACT FROM AUTHOR]

Mice (Sobey) bred to select lack of antibody production against bovine serum albumin have been examined for their responsiveness over a wide range of antigen doses. With low doses of antigen both Sobey mice and an outbred line of Swiss White mice produce similar amounts of antibody. Antigen in amounts greater than 500 μg produce tolerance more effectively in Sobey mice and this is the reason for their unresponsiveness at high antigen dose levels. [ABSTRACT FROM AUTHOR]

Slowly sedimenting components with a sedimentation velocity of about 7S and reacting with specific antisera against IgM were found in six pathological human sera. Four of these came from patients with different forms of reactive macroglobulinaemia of infectious origin. Similar components were produced from purified IgM preparations by bacterial action, and to a lesser extent by spontaneous splitting at room temperature. The conditions for such a splitting were, however, absent for most of the sera investigated in this study. The possibility that slowly sedimenting IgM-like components are artefacts, is discussed. [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]

Antisera to specific proteins in herpes simplex infected cells were produced by immunization of rabbits with infected rabbit kidney cells. These antisera were highly virus specific and produced up to twelve lines in immunodiffusion tests against infected cell extracts. Acrylamide electrophoresis and immunoelectrophoresis revealed up to ten virus specific proteins of varying size. [ABSTRACT FROM AUTHOR]

Donor guinea-pigs were immunized with antigen in Freund's complete adjuvant. Three weeks later these donor guinea-pigs showed strong delayed hypersensitivity to the antigen. Peritoneal exudate cells (macrophages) and serum were then transferred intravenously from the immunized donors to normal recipients. Good 24-hour skin reactions were obtained in the recipients which had received cells and serum from donors immunized with bovine serum albumin, y-globulin, ovalbumin and haemocyanin. The reaction transferred by immune cells and serum was greater than the reaction transferred by either singly. This synergy was not found with PPD or blood group substance as antigen. Good transfers of 24-hour skin reactions to PPD were obtained with peritoneal exudate cells both alone and with serum. Good transfers could not be obtained with blood group substance. The synergic action of cells and serum in the passive transfer of 24-hour skin reactions was specific. The ability of peritoneal exudate cells to transfer 24-hour skin reactions was present at 1 week and greater at 3 weeks. In contrast the ability of serum to enhance passive transfers was absent at 1 week and present at 2 and 3 weeks. The histology of reactions passively transferred by spleen, lymph node and peritoneal exudate cells in the presence and absence of serum was studied. Serum alone produced a predominantly polymorphonuclear infiltrate which was maximal at 18-24 hours and almost absent at 48 hours. Cells alone produced only a very slight reaction. The combination of cells and serum produced lesions at 4 and 18 hours resembling those caused by serum alone. At 24 hours however the histiocytes and lymphocytes were more numerous than in the pure serum reaction and by 48 hours the infiltrate consisted of histiocytes and lymphocytes. It was concluded that, with certain antigens, there is a synergic effect of immune cells and serum in the passive transfer of 24-hour skin reactions and reasons are given for considering that these passively transferred 24-hour skin reactions are indeed delayed hypersensitivity reactions. [ABSTRACT FROM AUTHOR]

Normal and splenectomized rats were injected by the intravenous route with small amounts of soluble antigen (egg albumin) or particulate antigen (toad red cells) plus Bordetella pertussis vaccine and bled at various times afterwards. The reaginic antibody was assayed by passive cutaneous anaphylaxis using a 72-hour period between antibody and antigen injection and the haemolytic antibody by determining the highest dilution of serum giving complete lysis in presence of complement. It was observed that although splenectomized animals responded with a very much diminished production of haemolytic antibody their production of reaginic antibody was very similar to that of the non-splenectomized animals. It is suggested that the spleen plays little or no role in the production of rat reaginic antibody. [ABSTRACT FROM AUTHOR]

Immunoelectrophoretic analyses and complement titrations of whole human serum show that a number of physical, chemical and immunological agents affect the ß1C/ß1A-globulin system which is considered to represent the third component of complement (C′3. The transformation from ß1C-globulin to ß1A-globulin is the normal result of ageing, while antigen-antibody complexes, polylysine, hydrazine and cobra venom accelerate this change. In addition, α-globulin fragments of ß1A-globulin appear after interaction of normal sera with antigen-antibody complexes, treatment with cobra venom, and by storage under nitrogen in glass tubes or in polyethylene containers. Similar α-fragments are seen in the aged sera of some patients with glomerulonephritis or renal allografts. With prolonged storage these α-fragments can reform ß1A-globulin. On the other hand, 2-mercaptoethanol and penicillamine produce complete dissolution of ß1C into rapidly migrating, poorly defined fragments in the α-globulin and albumin regions, and transform ß1A into a stable ß2-globulin. The reduced fragments of ß1C-globulin, if not alkylated, can subsequently form the ß2-globulin, but not the ß1A-globulin. These results indicate that ß1C-globulin is composed of several subunits, some of which are joined by disulphide bonds, but that the α-globulin fragments seen in some pathological sera are not a result of disulphide bond reduction. [ABSTRACT FROM AUTHOR]

γG-globulins† from human syphilitic sera when treated with pepsin are still capable of flocculating cardiolipin antigen but lose their ability to fix guinea-pig complement in the presence of antigen. [ABSTRACT FROM AUTHOR]

After intravenous injection of 1010 plaque forming particles of ∅X174 bacteriophage into White Rock fowls, immune elimination began at 30 hours and viable phage was cleared from the circulation by 50–52 hours, the approximate time at which detectable antibody appeared. Little change was noted in the serum neutralizing activity in the interval from 44 to 217 days after injection, at which time the birds were reinjected with ∅X174. Sephadex Peak I (19S globulin) accounted for most of the early activity of the primary response. By Day 9 most of the activity had shited to Peak II (7S globulin). In the secondary response, the shift had occurred by Day 4. Both 19S and 7S globulin fractions showed an increase in activity when compared to the same days of the primary response, but the 7S increase was proportionately greater. All sera and serum fractions (whether 19S or 7S) were sensitive to reduction with 2-mercaptoethanol, but became less sensitive during the course of immunization. With regard to the production of 19S antibody, White Rock fowls showed a different response to the particulate antigen ∅X174 compared with the response to injection of the soluble antigen, bovine serum albumin. There is evidence of immunological memory in the 19S response to ∅X174. [ABSTRACT FROM AUTHOR]

Doses of 1·5 mg of prednisolone to newborn rats cause massive thymic involution and peripheral blood lymphocyte depletion without excessive mortality. By 3 weeks thymic mass, thymocytes and peripheral blood lymphocyte levels have all recovered fully, but antibody responsiveness to typhoid ‘H’ antigen is still depressed. As late as 10 weeks diminished levels of a serum immuno-globulin provisionally identified as IgA and depressed ‘H’ agglutinin titres are found in male but not in female treated rats. [ABSTRACT FROM AUTHOR]

A cold agglutinin with anti-I specificity is present in a high percentage of cord sera. Evidence is produced that this antibody, like the ‘naturally-occurring’ anti-I present in adult serum, is not a γG-globulin; thus the antibody, both in cord serum and in adult serum, is inactivated by treatment with 2-mercaptoethanol, is not eluted with γG-globulin using DEAE-cellulose chromatography and is recovered in the fast sedimenting fractions after ultracentrifugation. Furthermore, the antibody does not disappear from the circulation of newborn infants as do γG antibodies which cross the human placenta. These findings indicate that the antibody in cord serum is a γM-globulin and that its production often begins before birth. [ABSTRACT FROM AUTHOR]

C′l haemolytic activity and radioactivity were detected in EDTA eluates of immune precipitates formed in the presence of either whole guinea-pig serum or euglobulin fraction labelled with 35S in vivo. Eluted C′l and 35S were fixed by sensitized sheep cells which subsequently lysed on exposure to guinea-pig C′ reagents lacking C′l. The dissociated material contributed only a minute fraction of the protein N taken up by Ag-Ab precipitates from fresh C′. [ABSTRACT FROM AUTHOR]

Canine precipitating and non-precipitating antisera against bovine serum albumin where studied by quantitative isotope precipitin and coprecipitation techniques. Canine precipitating antisera yielded curves of incomplete precipitation of antigen in antibody excess. Non-precipitating canine antibody can inhibit precipitation of antigen by rabbit precipitating antibody under certain conditions. Canine precipitating antibody contains a &gamma-globulin fraction which results in complete precipitation of antigen in antibody excess. It is suggested that canine non-precipitating antibody is a faster moving globulin which is present in canine precipitating antisera and the combined effect of canine non precipitating and precipitating antibodies results in the characteristic types of canine precipitin curve. [ABSTRACT FROM AUTHOR]

Specific interchange takes place between 131I-marked antibody combined with cellular antigens and the free unmarked antiserum antibody in three systems studied: (A) bovine cells with (i) human infectious mononucleosis serum and (ii) rabbit anti-bovine serum and (B) human Rh D-positive cells with Rh incomplete anti-D serum. The rate of interchange is much lower than the initial combination of an unmarked antibody with an unoccupied antigenic site, and also is slower in the Rh incomplete system than in the other systems studied. Rabbit anti-bovine red cell antiserum partly interchanges with 131I-marked infectious anti-body on bovine cells, but the reverse interaction does not apparently take place at all. Possible reasons are put forward to explain this. The infectious mononucleosis interchange reaction has a large temperature coefficient (about 4·9) which corresponds to a heat of reaction of 29,000 cal. [ABSTRACT FROM AUTHOR]

Dissociation rate measurements were determined on antisera following single and multiple intravenous injections of antigen and after injection of antigen incorporated into adjuvant. It was found that regardless of the amount, route, or number of injections the dissociation characteristics of all sera were similar, reaching the same maximum binding strength within the same time period following immunization. The relative production of 19S and 7S antibody was studied and it was found: (a) insufficient 19S antibody is formed to account for the change in dissociation characteristics that occur following immunization; (b) at the same stage of immunization, 19S and 7S antibody have similar rates of dissociation from antigen, but 19S antibody combines more slowly with antigen than 7S antibody; (c) the haemagglutination technique show's no correlation with binding or precipitin methods when estimates as to the relative amounts of 19S and 7S antibody present in sera are made. [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]

Dried ceils of Pasteurella multocida type I were extracted with 2.5 per cent aqueous solution of sodium chloride. Acidification of the extract with HCl to pH 3.8 yielded a fraction containing protein with some polysaccharide and lipopolysaccharide. This was removed by centrifugation. Addition of ethanol to the supernatant precipitated a polysaccharide containing fructose, mannose, glucose and glucosamine. This polysaccharide could be further fractionated into products containing varying proportions of glucosamine and fructose. It is produced by both ‘blue’ non-capsulated and ‘fluorescent&lrsquo; capsulated phases of the same strains. From the former it is almost entirely released into the surrounding medium instead of remaining bound to the surface layers of the bacteria. The purified (heterogeneous) polysaccharide fraction is precipitable and fixes complement with homologous sera. When added in repeated amounts to rabbit and cattle sera against whole bacteria until no further precipitate formed it reduced but did not abolish the mouse-protective power of the sera. It did not immunize mice to challenge when injected subcutaneously or intraperitoneally in doses ranging from 2 to 100 μg. [ABSTRACT FROM AUTHOR]

An in vitro assay procedure for evaluating the antibody response to glomerular basement membranes, lung basement membranes and tendon fibrils indicated a sharing of identical or similar antigenic components. At least 70 per cent of the glomerular basement membrane-binding antibodies are absorbable by tendon fibrils, and eluates from such tendon preparations are not nephrotoxic. Within the species employed (man, rabbit and dog) for glomerular basement membrane sources, there appears to be no species specificity as regards the presence of the nephrotoxic component. Immunization of sheep with either canine or rabbit glomerular basement membrane leads to the elaboration of a haemagglutinin for the respective species. [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]

Reverse passive cutaneous anaphylaxis experiments were performed in guinea pigs with rabbit gamma globulin and human gamma globulin as antigens and horse, sheep or hen sera containing antibodies against these antigens. These antibodies were unable to directly sensitize the guinea-pig skin but when the reverse technique was used, namely, the antigen (gamma globulin) was injected before the antibody, characteristic anaphylactic reactions were obtained. It is concluded that, if a suitable antigen is used, which can be fixed to the host by the reverse technique, sera from species which cannot directly sensitize the guinea pig can nevertheless give typical anaphylactic reactions. [ABSTRACT FROM AUTHOR]