IgG Fraction Of Serum Research Articles

Platelet to leukocyte adherence phenomena associated with thrombocytopenia

Two patients developed thrombocytopenia associated with an in vitro platelet to leukocyte adherence phenomenon (PLAP). In one patient, whole serum, intact plasma, and the IgG fraction of the serum could induce the PLAP of normal platelets in normal whole blood or buffy coat preparations. Passage of serum over a Sepharose column coupled with antihuman IgG resulted in the loss of all the PLAP activity. Activity could not be recovered from the whole serum or the IgG fraction of serum of the second patient; however, the PLAP was transferred to her newborn infant. In both patients, an unusual pulmonary illness accompanied the PLAP and thrombocytopenia.

Platelet to Leukocyte Adherence Phenomena Associated With Thrombocytopenia

Two patients developed thrombocytopenia associated with an in vitro platelet to leukocyte adherence phenomenon (PLAP). In one patient, whole serum, intact plasma, and the IgG fraction of the serum could induce the PLAP of normal platelets in normal whole blood or buffy coat preparations. Passage of serum over a Sepharose column coupled with antihuman IgG resulted in the loss of all the PLAP activity. Activity could not be recovered from the whole serum or the IgG fraction of serum of the second patient; however, the PLAP was transferred to her newborn infant. In both patients, an unusual pulmonary illness accompanied the PLAP and thrombocytopenia.

Humoral antibody response to cattle to formalinized Staphylococcus aureus vaccine.

Five cows were inoculated intradermally with formalinized Staphylococcus aureus suspension in Freund's complete adjunvant and the development of the humoral antibody response was followed as judged by the agglutination titer of sera, at various intervals post inoculation. Highest titers were observed at 78-87 days post inoculation. Agglutinating activity was found in IgM and IgG fractions (IgG1 and IgG2) of both serum and colostrum. The agglutinating activity of colostrum was significantly higher at 12 than at 24 and 36 h, post partum. However, no such activity was detected in either normal cow serum or colostrum against S. aureus.

Neutralization kinetics of western equine encephalitis virus by antibody fragments

Antibody against western equine encephalitis virus from the isolated and purified IgG fraction of hyperimmune rabbit serum was digested with papain or pepsin and the neutalizing ability of the resulting 5S (F(ab′) 2) and 3·5S (Fab I, II) fragments comparerd to that of the 7S molecule. By plaque reduction assay, the neutralizing capacity and neutralization kinetics of the F(ab′) 2 fragment was as effective as the 7S molecule even if the protein concentration of the F(ab′) 2 was lowered to approximate the mole concentration of the 7S molecule. The neutralizing ability of the Fab fragments was less effective, the kinetics of neutralization slower and the nonneutralizable fraction larger even when the concentration was adjusted to two times that of the whole molecule. An initial shoulder in the neutralization kinetic curve was seen with all the preparations if neutralization was carried out at 4°C but it was less prominent or absent at 37°C. No significant dissociation of the 7S-virus, F(ab′) 2 or Fab II-virus complexes occured on dilution or sonication at the protein concentrations studied. At the lowest concentration of Fab I, significant dissociation of the virus-Fab I complex did occur after 5 min sonication, resulting in a 24–37 per cent nonneutralizable fraction as compared to 3 per cent after the initial incubation period. No significant protection of infant mice occureed with any of the fragments after an hour incubation of the virus-fragment mixtures at 37°C.

Antibody production in goat milk serum after virus instillation of goat mammary gland. VII. Biochemical studies on sham infection with rabies and other non-propagatingagents.

This report describes the development of a method for the production and isolation of neutralizing antibodies against rabies virus (ERA strain) and other agents in the goat mammary gland during active lactation. The rabies virus did not propagate in thegland, but neutralizing antibodies were produced by serial instillations of the antigen. This process was termed 'sham infection.' Antibodies first appeared in the mildabout the 20th day and the titer increased until the 28th day. The antibodies were found to be associated with the lactogammaglobulin. The milk globulins were fractionated by gel chromatography and the fraction containing the antibody was isolated. This fraction was further purified and characterized by immunodiffusion, immunoelectrophoresis, and an analytical ultracentrifugation technique. The neutralizing antibody activityafter the 29th day was associated with the milk serum IgG fraction. This acive fraction was found to have a sedimentation coefficient of 6.8 Svedberg units.

Immunoglobulin classes of antibodies toAspergillus fumigatusin patients with pulmonary aspergillosis

An indirect immunofluorescence test was used to determine the titre and immunoglobulin classes of antibodies to Aspergillus fumigatus in human serum. In 15 patients with aspergillosis, significant titres of IgG but not IgA or IgM antibodies were found. The IgG, IgA and IgM fractions of serum from 2 patients with aspergillosis were separated. This confirmed that antibodies to A. fumigatus reside in highest titre in the IgG fraction. Precipitating antibodies to A. fumigatus in these patients also belonged to the IgG class of immunoglobulin.

Cytotoxicity with antibody-glucose oxidase conjugates specific for a human colonic cancer and carcinoembryonic antigen.

AbstractRabbit or goat antibodies to a human colonic cancer cell line (HT‐29) and to carcinoembryonic antigen (CEA) were studied with respect to their ability to cause complement‐mediated and enzyme‐mediated cytotoxicity. IgG fractions of normal sera and antisera to CEA and HT‐29 were prepared and conjugated to glucose oxidase, an enzyme which permits specific iodination of cell membranes in the presence of glucose, iodide, and lactoperoxidase. Cytotoxicity was evaluated with several established tumor‐cell lines in vitro by measuring the uptake of 125 I‐iododeoxyuridine after 24 h in tissue culture. Specific iodination and cytotoxicity were observed with both enzyme‐antibody conjugates, but the enzyme‐antibody conjugate specific for CEA was much less effective than that for HT‐29. Complement‐mediated cytotoxicity was obtained with both antibodies, but with anti‐CEA antibody effects were obtained only at high antibody concentrations. The attachment of enzyme to antibody produced manifold enhancement of the inherent cytotoxicity of the antibody.

Autogenous immunity to endogenous RNA tumor virus: differential reactivities of immunoglobulins M and G to virus envelope antigens.

The autogenous humoral immune response of mice to their endogenous leukemia virus has been examined in terms of the reactivities of individual classes of antibody present in normal B6C3F(1) serum. Whole serum and the immunoglobulin (Ig) M and IgG fractions of serum from animals of different age groups were compared by radioimmune precipitation assays and viral infectivity neutralization assays. Both IgM and IgG fractions were able to precipitate virus, although not as effectively as whole serum. Virus-specific antibody levels, as well as total antibody concentrations in whole serum, appeared to increase with age. Sodium dodecyl sulfate gel electrophoresis analysis was performed with immune precipitates obtained when whole serum or 19 or 7S fractions from animals of different age groups were reacted with disrupted virus. The 19S antibody fraction reacted with three antigenic determinants on the viral envelope. These antigens have apparent molecular weights of 17,000, 43,000, and 68,000. The last two appear to be glycoproteins and may correspond to the M(2) and M(1) antigens. In contrast, the 7S component reacted only with the 17,000-molecular-weight protein. Neutralization assays against BALB:virus-2, a xenotropic endogenous mouse type C virus, revealed that 19S and whole serum but not the 7S fraction possessed neutralizing activity. These findings indicate that there are differential reactivities of IgM and IgG antibodies in normal serum of B6C3F(1) mice, with respect to both recognition of viral envelope antigens and neutralization of endogenous MuLV. These results are consistent with the hypothesis that the autogenous humoral immune response is a systemic host function that may be important in the regulation of endogenous type C virus expression in vivo.

Protection of mice against syngeneic lymphomata: I. Use of antibodies.

Protection tests using passively administered antibody have been carried out using 2 mouse lymphomata. The classic model ("Gorer System") used alloantiserum which was absorbed in vivo to make it tumour specific before use. In order to provide a system suitable for our work, the model was changed by stepwise transitions to tumour specific immunoglobulin made from xenoantiserum absorbed in vitro, since such a procedure is also applicable to human patients. The time lapse used between challenge and treatment in the allo-system was generally ± 2 h but in the xeno-system could be extended to + 18 h. The xenoantisera could not be absorbed in vivo but required 3 to 5 × 10(3) spleens per 100 ml serum to absorb in vitro to render them tumour specific. The protective antibody was in the IgG (not IgM) fraction of serum. Maximal tumour specific antibody (measured by in vivo protection) appeared after the third injection of rabbits for one lymphoma, but after the fifth for another. The sera were not cross-reactive among 3 lymphomata tested, of which 2 were of the same H-2 genotype.

The influence of 2-mercaptoethanol (2-ME) treatment of IgG antibody on its ability to induce cytotoxicity in nonsensitized lymphocytes

The effect of 2-ME treatment of IgG on its ability to induce cytotoxicity in non-committed lymphocytes was studied. An IgG fraction of a rabbit anti-BPO serum was tested with BPO-coated chicken erythrocytes as target cells and human peripheral blood lymphocytes as effector cells. 2-Mercaptoethanol alters the properties of the Fc fragment of the IgG antibody molecule by cleaving inter-H-chain-disulfide bonds. Treatment of the antibodies with 2-ME resulted in a significant reduction of their capacity to induce cytotoxicity of lymphocytes against the respective antigen-antibody complex. 2-Mercaptoethanol treatment may prevent conformational changes of the Fc part of the antibody molecule essential for its interaction with the Fc receptor on the effector lymphocyte.

Renal transplantation between histoincompatible rats.

Enhancing antibodies in the serum of rats following allogenic kidney transplantation were detected by their ability to inhibit the unidirectional mixed lymphocyte reaction (UMLR) and to prolong, upon passive transfer, allograft survival time. Inhibition of the UMLR was associated with blocking activity since IgG fractions of serum with enhancing activity consistently inhibited the UMLR by more than 40%. IgG fractions of serum with no demonstrable blocking activity consistently failed to inhibit the UMLR by more than 40%. Transferable enhancing antibodies were present 17 days after trans-plant in rats dying of rejection within 35 days of transplantation. Rats exhibiting a pro-longed allograft survival had no transferable enhancing antibodies between 60 and 180 days post-transplant. Cytotoxic antibodies could not be demonstrated by either in vitro or in vivo tests in allografted rat sera during the early post-transplant period. Enhancing antibodies appear to serve an immunoregulatory function by modifying the cell-mediated allograft rejection response.

Evidence that the ciliary inhibitor of cystic fibrosis is not an antibody.

An inhibitor of ciliary activity is present in the serum of cystic fibrosis (CF) patients and heterozygotes. Fractionation of CF serum has indicated that the inhibitor is associated with the serum IgG fraction. This study compared the activity of the CF inhibitor to that of rabbit antibody preparations directed against oyster cilia. The aim of this investigation was to determine whether the ciliary inhibitory mechanism in cystic fibrosis is related to a typical immunological reaction. Results from experiments utilizing fluorescent antibody techniques demonstrated that an antiserum directed against oyster ciliated epithelium binds immunologically with both human bronchial and oyster epithelial tissue. Results from experiments utilizing immunofluorescent tracing, passive hemagglutination, double immunodiffusion, and papain digestion, however, indicated that the interaction between the oyster cilia and the CF serum inhibitor was not a typical antigen-antibody reaction.

The Effects of Lymphocytes, Sera and Long-Acting Thyroid Stimulator from Patients with Graves' Disease on Retrobular Fibroblasts

ABSTRACT Lymphocytes, both living and freeze-thawed, stimulated glycosaminoglycans (GAG) production and glucose utilization by monolayer fibroblast cultures derived from human retrobulbar connective tissue. Freeze-thawed lymphocytes from patients with Graves' disease, most of whom had active ophthalmopathy, were significantly (p < 0.05) more potent in this system than lymphocytes from normal subjects. The stimulating qualities of the lymphocytes could not be related to any clinical feature of the disease. Living lymphocytes from patients did not differ significantly from those of normal individuals in potency to stimulate the retrobulbar fibroblasts. Sera, including LATS containing sera, and IgG fractions of sera containing LATS produced changes in the cultures which were no different than those observed for comparable specimens from normal individuals. Graves' ophthalmopathy, in which accumulations of GAG play a prominent role, may develop from the interaction of lymphocytes and orbital connective tissue...

BLOCKING AND REDISTRIBUTION ("CAPPING") OF ANTIGEN RECEPTORS ON T AND B LYMPHOCYTES BY ANTI-IMMUNOGLOBULIN ANTIBODY

Antigen-binding T and B lymphocytes were studied by combined autoradiography and immunofluorescence; mouse spleen lymphocytes binding the antigens, [(125)I]MSH or [(125)I]TIGAL, were incubated with rhodamine-labeled anti-Ig reagents or with a rhodamine-labeled IgG fraction of anti-theta serum. B cells were identified as Ig+ or theta-, T cells as Ig- or theta+. It was found that: (a) 20% (1-2 mo after priming) to 30% (3.5-4 mo after priming) of the antigen-binding cells were T cells. (b) The range of antigen molecules bound by B and T cells was similar. (c) Binding of antigen to B and T cells was inhibited by polyvalent anti-Ig, anti-micro, or anti-L reagents. Binding to T cells was more readily inhibited than to B cells. Normal rabbit serum, antimouse lymphocyte serum, or anti-theta did not inhibit antigen binding. (d) When Ig at the surface of B cells was induced, by noninhibiting concentrations of anti-Ig reagents, to redistribute into polar caps and the cells subsequently exposed to [(125)I)antigen under noncapping conditions, the [(125)I]antigen silver grains were distributed in caps superimposed on the Ig fluorescent cap. Of crucial importance, antigen was found in cap in the same proportion of T cells as B cells. Significant capping of antigen receptors was not induced in B or T cells with normal rabbit serum or by anti-Ig reagents absorbed with mouse Ig. The main conclusions of this series of experiments using direct visualization of antigen-binding B and T lymphocytes is that T cells have antigen-specific receptors, probably of IgM nature, and that the number of these receptors appears to range in the order of thousands.

Development of anti-human FSH antibody in a patient with isolated FSH deficiency.

Antibodies to human FSH were documented in the serum of a patient previously shown to have isolated FSH deficiency. These antibodies developed subsequent to the administration of a second course of Human Menopausal Gonadotrophins (Pergonal 500). Using the ammonium sulfate precipitation method, antibodies were detected in the first week after cessation of Pergonal 500 therapy. Characterization of the antibody showed that (a) it was associated with the IgG fraction of the patient's serum; (b) addition of excess Pergonal 500 lead to rapid dissociation of 125I-FSH binding to serum; (c) pituitary FSH (LER-1366) and 2nd IRP-hMG, but not Hartree human LH, displaced 125I-FSH tracer bound to serum and (d) there was no binding of tracer insulin, hGH and LH by serum. Antibody has remained detectable over a 5-month period of observation.

Immunochemical studies of Sindbis virus variants

We have demonstrated that the small plaque (SP) variant of Sindbis virus is more extensively neutralized by complete antibody and serum IgG fractions than is the large plaque (LP) variant. The Fc portion failed to demonstrate any neutralizing potential and did not block subsequent neutralization by IgG or Fab fragments. The LP and SP variants of Sindbis gave identical patterns upon isoelectric focusing. Treatment of the virus with intact serum IgG or isolated Fab fragments was found not to have an irreversible effect on the net charge of the virus population. The selective processes involved in the maturation of the nucleocapsid implicate the incorporation of charged host determinants which are then reflected in the charge of the virion. It is suggested that the virus core has a preferential affinity for those components of the plasma membranes which have an isoelectric point at pH 3.6.

Depressed cell-mediated immunity in patients with primary intracranial tumors. Characterization of a humoral immunosuppressive factor.

Tumor immunity in patients with primary intracranial tumors was assessed in relation to the general status of host immunocompetence. Lymphocyte sensitization to tumor-specific membrane antigens was demonstrated by the proliferative response of lymphocytes in the presence of autochthonous tumor cells. Paradoxically, one-half of the patients could not be sensitized to a primary antigen, dinitrochlorobenzene; existing delayed hypersensitivity was also depressed, as measured by skin tests and lymphocyte transformation in response to common antigens. A heat-stable factor in patients' sera blocked cell-mediated tumor immunity. In addition, these "enhancing" sera consistently suppressed the blastogenic response of autologous and homologous lymphocytes to phytohemagglutinin and to membrane antigens on allogeneic cells in the one-way mixed lymphocyte culture. When patients' leukocytes were washed and autologous plasma replaced with normal plasma, reactivity in the mixed lymphocyte culture increased to normal values. In vitro immunosuppressive activity in patients' plasma or sera correlated with depressed delayed hypersensitivity. After removal of the tumor, suppressor activity disappeared. IgG fractions of patient sera contained strong immunosuppressive activity. These data suggest that the suppressor factor may be an isoantibody elicited by the tumor that also binds to receptors on the lymphocyte membrane. In addition to specifically blocking cell-mediated tumor immunity, enhancing sera may broadly depress host immunocompetence.

Investigation of the antigenicity of the carbohydrate moiety of chicken ovalbumin

Evidence for the antigenicity of the carbohydrae moiety of ovalbumins was sought by methods capable of detecting specific antibodies. These methods include: (a) the immunoelectrophoretic reaction of the ovalbumins with IgG fraction of goat antichicken ovalbumin serum in the presence and absence of Concanavalin A, (b) the ability of 14C-acetylglycopeptides from chicken ovalbumin to be coprecipitated with the goat immunoglobulins, using the Farr technique, and (c) the ability of the 14C-acetylglycopeptides to be coprecipitated with the goat immunoglobulins, using rabbit antigoat IgG. In no instance was there any evidence for the presence of carbohydrate-specific antibodies. The data strongly suggest that the carbohydrate moiety of chicken ovalbumin is not antigenic in the goat. The failure to detect specific antibodies in goat antiovalbumin IgG is discussed in relation to availability of the carbohydrate moiety for reaction with antibody, to alteration of the carbohydrate's conformation in the glycopeptides relative to its conformation in native ovalbumin, and in relation to the role of the carbohydrate moiety in the phylogeny of avian ovalbumins.

Pure Red Cell Aplasia and Thymoma: Loss of Serum Inhibitor of Erythropoiesis Following Thymectomy

Abstract A 32-yr-old black female with pure red cell aplasia and thymoma showed complete hematologic remission after thymectomy. Bioassay of preoperative serum and urine in exhypoxic polycythemic mice revealed the presence of significant levels of erythropoiesis-stimulating factor (ESF or erythropoietin). Antierythropoietin completely neutralized the erythropoietic effect of these samples. Utilizing both normal and exhypoxic polycythemic mice, the preoperative serum and urine were also found to contain a potent inhibitor of erythropoiesis. However, no such activity was demonstrated in saline extracts of the tumor tissue. The inhibitor was present in the serum IgG fraction. Serum to which excess ESF had been added, after prior neutralization of endogenous ESF with anti-ESF, failed to stimulate erythropoiesis in the polycythemic mouse.

Hemolytic Anemia Associated With Cephalothin

Two patients developed Coombs' positive hemolytic anemia while receiving cephalothin sodium therapy. An anticephalothin antibody was detected in the IgG fraction of sera and in the red blood cell (RBC) eluates in both patients. This complication of cephalothin therapy is rare, and must be differentiated from the positive Coombs' reaction seen in the majority of patients receiving cephalothin. In any patient receiving cephalothin, unexplained hemolysis must include a search for anticephalothin and antipenicillin antibodies on the RBC before the drug can be implicated in any hemolytic episode.