Showing papers on "Antibody published in 1971"

Redistribution and Pinocytosis of Lymphocyte Surface Immunoglobulin Molecules Induced by Anti-Immunoglobulin Antibody

Abstract: Antibody reacting with lymphocyte surface immunoglobulin molecules induces these to gather over one pole of the cell. This suggests a possible mechanism for lymphocyte triggering by antigen and raises questions about cell membrane structure.

The somatic generation of immune recognition.

Abstract: Antibody specificity is determined by structural v-genes that code for the amino acid sequences of the variable regions of antibody polypeptide chains. The present hypothesis proposes that the germ-cells of an animal carry a set of v-genes determining the combining sites of antibodies directed against a complete set of a certain class of histocompatibility antigens of the species to which this animal belongs. The evolutionary development of this set of v-genes in phylogeny is traced back to the requirements for cell to cell recognition in all metazoa. The hypothesis leads to a distinction between two populations of antigen-sensitive cells. One population consists of cells forming antibodies against foreign antigens; these lymphocytes have arisen as mutants in clones descending from lymphocytic stem cells which expressed v-genes belonging to the subset (subset S) coding for antibody against histocompatibility antigens that the individual happens to possess. The other population consists of allograft rejecting lymphocytes that express v-genes of the remaining subset (subset A) coding for antibody against histocompatibility antigens of the species that the individual does not possess. The primary lymphoid organs are viewed as mutant-breeding organs. In these organs (e. g. in the thymus), the proliferation of lymphocytes expressing the v-genes of subset S and the subsequent suppression of the cells of these “forbidden” clones, leads to the selection of mutant cells expressing v-genes that have been modified by spontaneous random somatic mutation. This process generates self-tolerance as well as a diverse population of antigen-sensitive cells that reflects antibody diversity. The proliferation in the primary lymphoid organs of lymphocytes expressing v-genes of subset A generates the antigen-sensitive cell population that is responsible for allo-aggression. The theory explains how a functional immune system can develop through a selection pressure exerted by self-antigens, starting during a period in early ontogeny that precedes clonal selection by foreign antigens. The hypothesis provides explanations for the variability of the N-terminal regions of antibody polypeptide chains, for the dominant genetic control of specific immune responsiveness by histocompatibility alleles, for the relative preponderance of antigen-sensitive cells directed against allogeneic histocompatibility antigens, for antibody-idiotypes, for allelic exclusion, for the precommitment of any given antigen-sensitive lymphocyte to form antibodies of only one molecular species and for the cellular dynamics in the primary lymphoid tissues.

Infectious immunological tolerance.

Abstract: Previous studies have shown that thymectomized lethally irradiated bone marrow grafted mice, reconstituted with thymocytes and pretreated with a large dose of sheep red blood cells (SRBC), are unable to respond to a subsequent immunizing injection of SRBC even after an inoculation of normal thymocytes. If, however, the mice are not thymocyte reconstituted prior to the pretreatment with SRBC, they can respond almost normally to an immunizing injection of SRBC if inoculated with normal thymocytes after the termination of antigen pretreatment.In the present study the immunosuppressive effect of the presence of thymocytes during the antigen pretreatment was studied by adoptively transferring the spleen cells of the antigen pretreated mice to thymus-deprived chimeras. These spleen cells not only did not co-operate with normal thymocytes in the secondary hosts, but they also prevented the co-operation of normal thymocytes with normal bone marrow derived cells. Untreated spleen cells or treated spleen cells from mice not reconstituted with thymocytes did not affect cell co-operation in the secondary hosts. The abrogation of the co-operation in the secondary host was specific in that the addition of spleen cells did not affect the anti-horse red blood cell response. If the primary host made antibody as a result of the pretreatment, the transfer of their spleen cells did not prevent antibody production in the secondary host.

The carrier effect in the secondary response to hapten-protein conjugates. II. Cellular cooperation.

Abstract: The adoptive secondary response of mice to conjugates of NIP (4-hydroxy-5-iodo-3-nitro-phenacetyl-) and DNP (2,4-dinitrophenyl-) is here used to elucidate the mechanism of cellular cooperation. The framework into which the experiments fit can be formulated as follows. Priming immunization raises a crop not only of specific antibody-forming-cell-precursors (AFCP) but also of specific helper cells. Upon secondary stimulation the helper cells serve a role as handlers or concentrators of antigen, thus enabling AFCP which would otherwise be incapable of reacting to initiate antibody synthesis. In this act of cooperation both cells recognise antigen; in the system examined here the helpers recognise carrier determinants and the AFCP recognise either the hapten or other carrier determinants. The first aim of the experiments was to raise populations of helpers and AFCP of distinguishable specificity. Mice were primed with NIP-Ovalbumin (OA) mixed with chicken γ-globulin (CGG) and bovine serum albumin (BSA); in comparison with controls primed with unmixed NIP-OA, their cells after transfer were relatively more sensitive to secondary stimulation with NIP-CGG or NIP-BSA and similar findings were obtained in cross-checks of these carriers. For reasons which are not entirely clear, non-transferred cells did not show the same effect. In further experiments cells primed with one conjugate (e. g. NIP-OA) were mixed with cells primed with another protein (e. g. BSA), transferred and challenged with the hapten conjugated to the second protein (i. e. NIP-BSA). In comparison with controls lacking the protein-primed cells, the mixture regularly showed greater sensitivity to stimulation. NIP and DNP were tested in many of the possible combinations with BSA, OA and CGG with the same result. The mixture system was used in the further analysis. Tests with allotype-marked protein-primed cells showed that these cells did not participate in the production of the anti-hapten antibody and could therefore properly be regarded as helpers. Tests of specificity showed that physical union of the hapten and carrier were required: cells primed with BSA, for example, would not help NIP-OA-primed cells to make a response to NIP-HSA even when stimulated at the same time with BSA. Transfer of less than one-tenth of the spleen gives a maximum helper effect, whereas AFCP activity continues to rise as larger numbers of cells are transferred. Helper cells are therefore normally present in excess. Helper activity is more resistant than AFCP activity to irradiation, drugs and semi-allogeneic cell transfer across an H-2 barrier. This suggests that helper cells play a relatively passive role in the immune response. Several observations indicate that helper cells are thymus-derived mediators of cellular immunity. Passively transferred antibody did not substitute for helper cells. After immunization helper activity developed faster than AFCP activity. Spleen cells obtained from lethally-irradiated, thymocyte-repopulated, immunized donors provided help. Cells from the thymus-derived fraction of thymus/marrow chimeras also appear to provide help. Thus, the hapten-carrier cooperative response maps onto the well-established synergy of thymus and marrow in the response to foreign erythrocytes.

Occurrence of malignancy in immunodeficiency diseases. A literature review.

Abstract: The incidence of malignancy in patients with primary immunodeficiencies is roughly 10,000 times that of the general age-matched population. It is apparent from this review of the literature that each type of immunodeficiency has a distinctive constellation of malignancies associated with it. In light of recent studies demonstrating both immunologically aggressive lymphocytes and the presence of blocking antibodies in the blood of neuroblastoma patients, a major role for immunity in ontogenesis seems almost certain. The role of such antibodies in the formation of lymphoid malignancies, such as occur so frequently in patients with immunologic deficiencies who often do not produce antibodies of any type well, remains unclear.

Immunoglobulins on the surface of lymphocytes : i. distribution and quantitation

Abstract: The distribution, and quantity of immunoglobulins on the surface of lymphocytes has been studied by means of immunofluorescence and a quantitative radio-immunoassay. Surface immunoglobulins were found on approximately 45% of spleen and marrow lymphocytes and 7–14% of lymphocytes from lymph nodes, peripheral blood, and peritoneal exudate. Thymic lymphocytes contained undetectable amounts of immunoglobulin. In the spleen the different immunoglobulins were present in the following order: γG2 > γG1 > M > γA > γG3. The surface immunoglobulin was largely removable by brief treatment with trypsin. Quantitative analysis indicated that 50,000–150,000 molecules of immunoglobulin were present on an individual cell. A variety of observations make it likely that this lymphocyte-associated immunoglobulin. is a product of the cell to which it is attached rather than a form of cytophilic antibody.

The Immunologic Release of Constituents from Neutrophil Leukocytes: I. The Role of Antibody and Complement on Nonphagocytosable Surfaces or Phagocytosable Particles

Abstract: The interaction of rabbit neutrophils with immune complexes induced release of constitutents to the outside of the cell. Two situations were studied. In one, the neutrophils adhered to immune complexes dispersed along nonphagocytosable surfaces; in the other, the cells were allowed to engulf phagocytosable particles coated with antibody or complement. In each case, release of constituents from the neutrophil granules occurred. IgG antibody was as effective in stimulating release of enzymes as was C3, although they react with different receptors on the neutrophil membrane. Smaller quantities of immunologobulins were required to induce release if bound to the nonphagocytosable surface than if phagocytosed by the neutrophils in suspension.

Immunoglobulins on the surface of lymphocytes: IV. Distribution in hypogammaglobulinemia, cellular immune deficiency, and chronic lymphatic leukemia

Abstract: The distribution of peripheral blood lymphocytes that contain surface Ig has been studied by means of immunofluorescence in humans Normal individuals, individuals with sex-linked and acquired agammaglobulinemia, selective IgA deficiency, cellular immune deficiencies, and individuals with chronic lymphatic leukemia (CLL) were studied Approximately 28% of the peripheral blood lymphocytes from normal individuals contained surface Ig On an average 15% contained IgG, 6%, IgA, and 8%, IgM; and the kappa: lambda ratio was 2:1 Lymphocytes from patients with CLL appeared to be “monoclonal” in that the cells from a given individual had a single Ig associated with them (eg, kappa IgM) In three-quarters of the cases the H chain class was IgM; in the remaining one-quarter no H chain could be detected on the cell surface The L chain class was kappa in 12 cases and lambda in 8 Four patients with sex-linked agammaglobulinemia and one with “acquired” agammaglobulinemia had markedly decreased numbers of cells with surface Ig (0-4%) In contrast, the three patients with selective IgA deficiency and no detectable serum IgA contained normal numbers of cells (6-8%) with surface IgA Five patients with cellular deficiency states, including two with Wiskott-Aldrich syndrome, contained a normal or low percentage of cells with surface Ig

Cell surface immunoglobulin. II. Isolation and characterization of immunoglobulin from mouse splenic lymphocytes

Abstract: The proteins on surfaces of living splenic lymphocytes from normal BALB/c mice were iodinated enzymatically Such cells were fractionated into two sub-populations: one composed almost exclusively of small lymphocytes and the other mainly of large lymphocytes and plasma cells Specific immunoprecipitation of radiolabeled surface Ig obtained from lysates of these cell populations indicated that approximately 2–3% of the acid-precipitable radioactivity from the cell surface is Ig Moreover, 95% of the H chain radioactivity from the Ig of the small lymphocyte fraction and 90% from the large lymphocyte-plasma cell fraction was characterized as µ by precipitation with anti-µ sera as well as by molecular weight determination on polyacrylamide gels in sodium dodecyl sulfate The Ig was recovered from the cell surface in the form of an IgM monomer Control experiments suggested that the monomer did not result from depolymerization of 19S IgM by the methods used to radiolabel and isolate the molecule 3H-tyrosine labeling of IgM produced by meyloma cells and radio-iodination of IgM in solution gave the same ratios of µL radioactivity as radiolabeling of IgM on cells, indicating that the tyrosine residues of L and µ-chains of cell surface IgM are available to the lactoperoxidase during the iodination This is consistent with the hypothesis that cell surface IgM is entirely on the outside of the plasma membrane presumably attached to it by its Fc fragment These results, together with previous reports by others, suggest that IgM, in its monomeric form, is the main antigen-specific receptor on lymphocytes of normal mice

Demonstration of two distinct components in the early antigen complex of Epstein-Barr virus-infected cells.

Abstract: Examination of numerous sera from patients with infectious mononucleodis (IM), Burkitt's lymphoma (BL) or nasopharyngeal carcinoma (NPC) for antibodieh to Epstein-Barr virus (EBV) induced early antigens (EA) revealed two distinct patterns of immunofluorescence in abortively EBV-infected Raji cells. One showed diguse (D) staining of the nucleus and cytoplasm of invaded cells, the other (R) was restricted to masses in the cytoplasm. Although D- or R-reactive Raji cells became detectable at similar times after exposure to EBV, the percentages of D-positive cells initially exceeded R-positive cells but ultimately both were nearly equal in number. R-positive cells almost invariably contained also D. In EBV-exposed RPM1 64–10 cells, frequently only D was synthesized. D antigen, in contrast to R, resisted fixation by methanol or ethanol, whereas R proved more resistant than D to proteolytic enzymes. Comparative serum titration on acetone, respectively ethanol-fixed Raji-EBV cell smears revealed that the transitory anti-EA response observed in many IM patients was restricted almost exclusively to anti-D. Anti-EA positive sera from NPC patients also showed dominantly anti-D activity whereas, in BL sera, anti-R was usually, but not always, dominant, often being the only antibody to the EA complex present. Preliminary tests with pronase-treated Raji-EBV cell smears indicated that dominantly anti-D reactive sera from IM patients were free of anti-R whereas such sera from NPC or BL patients usually gave positive reactions which in part, however, failed to conform with the R pattern. The possible implications of these results have been discussed.

Preparation and Properties of Antisera against the Lipid‐A component of Bacterial Lipopolysaccharides

Abstract: The lipid-A component of lipopolysaccharides, when presented in a suitable form, acts as an immunogen in rabbits, giving rise to the production of circulating antibodies. Highest anti-lipid-A titers were obtained on immunization with acid-treated bacterial cells coated with lipid A. Anti-lipid-A activity of the immune sera could be assayed by passive hemolysis of lipid-A-sensitized erythrocytes in the presence of complement. On filtration of the immune globulins on Sephadex G-200, antibodies against lipid A were detected in the IgM and IgG fractions. Lipid A preparations derived from various Salmonella and one Echerichica coli strain exhibited strong serological cross reactions with anti-lipid-A antisera. Furthermore, lipid-A antiserum also cross-reacted with all lipopolysaccharides tested, although in some cases to a low degree. On the other hand, only 8 out of 13 antibacterial antisera interacted with lipid-A-coated red cells. Finally, it was found that anti-lipid-A antibodies are effective in sensitizing E. coli 0111 bacteria for intraperitoneal phagocytosis.

Systemic lupus erythematosus: prototype of immune complex nephritis in man

Abstract: Serological studies, immunofluorescence studies, and immunochemical assays of glomerular eluates indicate that several antigen-antibody systems may be involved in the pathogenesis of the tissue lesions of SLE. The NDNA-anti-NDNA system appears to be operative in most patients with active SLE. In addition, antibodies to SDNA are found with considerable frequency in SLE sera and glomerular eluates. It is not known if these antibodies fix to NDNA which has been denatured after deposition in glomeruli or if SDNA-anti-DNA complexes are deposited initially. NDNA antigen has been demonstrated in both serum and glomerular deposits, and SDNA determinants have also been found in glomerular deposits. In addition, there is evidence that rheumatoid factor contributes to the immune complex deposition in certain patients either by fixing to preformed immune complexes or as part of an independent gamma-globulin-anti-gamma-globulin system. It is anticipated that the definition of these immune systems, and the assessment of their relative toxicity will provide insight into underlying etiologic factors as well as provide a sound basis for therapy in this form of glomerulonephritis.

Serological demonstration of h-y (male) antigen on mouse sperm.

Abstract: WE have recently overcome certain technical difficulties in applying the cytotoxicity test to mouse spermatozoa and have been able to show directly that H-2 antigens are expressed on these cells1, thus confirming less direct evidence leading to the same conclusion2. We have since applied the cytotoxicity test to sperm with antisera directed against a number of other systems of mouse alloantigens, TL3, θ4, Ly-A5 and Ly-B5, but none of these has given a positive reaction with sperm. This is not surprising because these are all “differentiation antigens”6 expressed primarily on lymphoid cells. Another antigenic system which distinguishes one mouse from another is H-Y. The H-Y antigen is carried by male cells only and is responsible for the rejection of male tissues by females of the same inbred strain7.

The relationship between antigenic structure and the requirement for thymus-derived cells in the immune response

Abstract: Certain antigens such as polymerized flagellin are capable of producing relatively normal antibody levels in thymectomized mice, whereas others, including heterologous erythrocytes require the presence of T cells in a helper capacity. The mechanism of thymus-independent antibody production was investigated by comparing the primary IgM responses of spleen cells from ATXBM, XBM, and normal mice to various physical forms of the flagellar antigens of Salmonella adelaide in vitro. No reduction in antibody-forming cell levels to polymerized flagellin over a wide dose range was observed in ATXBM cultures, although the same spleen cells did not respond to an optimal dose of sheep red cells. In contrast, when flagellar determinants were presented in a monomeric form or as flagellin-coated donkey red cells, a highly significant difference was observed between the antibody responses of spleen cells from ATXBM mice and XBM or normal controls. The results suggested that the requirement for T cells in antibody production is not a property of specific antigenic determinants, but depends on the mode of antigenic presentation. The validity of this conclusion was confirmed by using another antigenic determinant (DNP) coupled either to the thymus-independent carrier, POL, or to the thymus-dependent carrier, DRC. Spleen cells from XBM mice produced comparable AFC levels to both forms of DNP, but the results from ATXBM cultures showed a marked difference. The anti-DNP response to DNP-DRC was greatly reduced compared to controls, whereas that to DNP-POL was normal even after prolonged thoracic duct drainage of the ATXBM donors and pretreatment of their spleen cells with anti-θ-serum and complement. The data presented here imply that the role of T cells in humoral immunity is the presentation of antigen to B cells in such a manner as to initiate optimal antibody synthesis.

Regulation of Homocytotropic Antibody Formation in the Rat: I. Feed-Back Regulation by Passively Administered Antibody

Abstract: Homocytotropic antibody formation against dinitrophenylated Ascaris extracts (DNP-As) was selectively suppressed by the passive administration of homologous antibody against the same antigen. Unrelated antiserum or cross-reacting antibodies against haptenic group or carrier determinants had no suppressing effect. The suppression was preferentially directed to the homocytotropic antibody response, while the hemagglutinating γM antibody formation was unaffected. The effect was most significant when the antibody was administered simultaneously with, or a few days after, the initial antigen injection, whereas previous administration was less effective. The synthesis of homocytotropic antibody was terminated by the passive administration of antibody at the time when the PCA titer was at the maximum. The suppressive activity was detected in the 7S γG fraction of hyperimmune antiserum, while the early 19S or intermediate fractions had little activity. Heterologous antibody to the same antigen showed a similar inhibitory effect, but about twice as much antibody was required for the same degree of suppression. The results indicate the presence of so-called “feed-back” regulation in the homocytotropic antibody response. The possible mechanisms and biologic significances of this regulation are discussed.

Association of autoantibodies to different nuclear antigens with clinical patterns of rheumatic disease and responsiveness to therapy

Abstract: Using a hemagglutination test which can detect antibodies to (a) native and denatured deoxyribonucleic acid (DNA) and (b) an extractable nuclear antigen (ENA), a comparative study of patterns of autoantibody formation has been done in systemic lupus erythematosus (SLE) and related rheumatic diseases. Antibody to native DNA was present in the serum in 96% of patients with active SLE and disappeared during remissions. Antibody to ENA was found in 86% of those patients with SLE nephritis who responded to treatment but in only 8% of those who did not. The highest titers of antibody to ENA were found in patients having a mixed connective tissue disease syndrome with features of SLE, scleroderma, and myositis. The latter syndrome was notable for the absence of renal disease and for a striking responsiveness to corticosteroid therapy. Hemagglutination testing of 277 sera from normal persons and patients with a wide variety of acute diseases other than SLE revealed the presence of antibody to native DNA in only 1.4% and antibody to ENA in only 0.4%. These results yield significant correlations among the pattern of autoimmune reactivity, the clinical form of the rheumatic disease, and responsiveness to treatment. They implicate the qualitative nature of the patient's immune response as a conditioning factor in the type of disease. Together with other correlations they may allow classification of rheumatic diseases into more biologically meaningful groups and lead to more selective methods of therapy.

THE SEPARATION OF DIFFERENT CELL CLASSES FROM LYMPHOID ORGANS : IV. The Separation of Lymphocytes from Phagocytes on Glass Bead Columns, and Its Effect on Subpopulations of Lymphocytes and Antibody-Forming Cells

Abstract: Four separate effects can be demonstrated when lymphoid cell suspensions are passed through columns of siliconed glass beads. (a) A temperature-dependent "active adherence" of phagocytic cells, such as macrophages and polymorphs. (b) A temperature-independent and selective trapping by "physical adherence" of particular classes of lymphoid cells, including certain antibody-forming cells. (c) A "size-filtration" effect that traps larger cells, but only becomes significant with beads below 100 µ in diameter. (d) A selective retention of damaged cells, which occurs with all columns under all conditions tested. An active adherence column technique has been developed to separate phagocytes from lymphocytes while minimizing selection within the lymphocyte population by physical adherence or size filtration. In less than 10 min at 37°C it reproducibly produces a preparation of mouse spleen lymphocytes >500-fold depleted of active macrophages, and approximately 50-fold depleted of active polymorphs, with good over-all cell recoveries and cell viability. The lymphocyte fraction appears fully active in its ability to initiate immune responses to at least two different antigens, but is changed in over-all composition and selectively depleted in certain classes of antibody-forming cells.

In Vitro Approaches to the Mechanism of Cell-Mediated Immune Reactions

Abstract: Publisher Summary This chapter focusses on the study of cell-mediated immunity in vitro, principally in terms of explaining the effector process of the response. To organize the observations in many species and systems, four general assumptions has been made. First, the diversity of information for cell-mediated immunity is carried by lymphocytes, and is of the same order of magnitude and specificity as for circulating antibodies. Second, all cell-mediated immune reactions have a common basis, including the tuberculin-type reaction, contact hypersensitivity, cellular resistance to infection, allograft rejection, and tumor immunity. Third, the increase in responsiveness after a process of sensitization or immunization is consistent with a clonal selection by the antigen of reactive cells. Information for cell-mediated immunity is carried by thymus-dependent lymphocytes, but whether their specificity is generated by genes informational molecules from other cells or antigen itself remains unclear. Fourth, the mechanisms of effector reactions mediated by delayed-type hypersensitivity and humoral antibody are fundamentally different. Explicit discrimination between these two mechanisms must be made wherever possible, not only in vivo but in vitro as well.

Immunoglobulin M and Secretory Immunoglobulin A: Presence of a Common Polypeptide Chain Different from Light Chains

Abstract: Unique polypeptide chains have been isolated from S-sulfonated light-chain fractions of human serum immunoglobulin M and colostral immunoglobulin A. Their electrophoretic mobilities, molecular weights, peptide maps, amino acid compositions, and antigenic determinants are very similar or perhaps identical but differ from those of light chains and secretory piece.

Elevated antibody titers to epstein‐barr virus in Hodgkin's disease

Abstract: Sera from 63 patients with Hodgkin's disease and 42 patients of comparable age with other lymphomas were tested for antibody to Epstein-Barr virus (EBV) by indirect immunofluorescence. The geometric mean titer (GMT) of EBV antibody in the patients with Hodgkin's disease was significantly higher (1:367) than the GMT of the other lymphoma patients (1:132) and 85 normal controls (1:90). Higher EBV titers in untreated patients with Hodgkin's disease were associated with a longer duration of symptoms, more advanced disease, shorter survival, and a histologic picture of lymphocyte depletion. Treated patients had significantly higher titers than untreated patients. When the same sera were tested for antibody to 4 other herpes viruses (herpes simplex type I and type II, cytomegalovirus, and varicella), no differences in titer between patient and control groups were found. Although this study associates elevated EBV titers with those factors relating to a poor prognosis in patients with Hodgkin's disease, the data do not distinguish between an etiologic role for EBV and that of a passenger virus which produces high titers as a result of the disease process.

Growth of Candida albicans in Saliva: Stimulation by Glucose Associated with Antibiotics, Corticosteroids, and Diabetes Mellitus

Abstract: the advent of broad-spectrum antibiotics has been commented upon by many authors [1-5], but the precise cause has not yet been defined. It has been suggested that antibiotics may suppress phagocytosis and production of anticandidal antibody [6, 7] or may directly stimulate fungal growth [8]. However, the most widely accepted explanation has been the alteration in flora of the host which normally inhibit fungal growth [9-11]. This study was undertaken to investigate the factors that stimulate and inhibit candidal growth in normal human saliva. Saliva was also obtained

The localization of spectrin on the inner surface of human red blood cell membranes by ferritin-conjugated antibodies.

Abstract: Spectrin, a major protein constituent of mammalian red blood cell membrane preparations, has been localized on the inner surface of human red blood cell membranes by techniques that utilized specific ferritin-conjugated antibodies and fixation of membranes shortly after hemolysis so as to allow penetration of the ferritin-antibody labels. The labeling of spectrin was shown to be specific by the following criteria. (a) Nonhomologous ferritin-conjugated antibodies did not specifically bind to either membrane surface. (b) Blocking the membrane-bound spectrin with excess unconjugated antispectrin antibodies prevented ferritin-antibody labeling. (c) Removal of spectrin by treating the membrane preparation with a low ionic strength buffer containing ethylenediaminetetraacetate and β-mercaptoethanol prevented labeling by specific ferritin-conjugated antibodies.

Requirement of thymus-dependent lymphocytes for potentiation by adjuvants of antibody formation.

Abstract: THE mode of action of immunological adjuvants is of theoretical as well as practical importance. Adjuvants can not only increase immune responses; they can also bring about change from one type of immune response to another. For example, doses of bovine serum albumin (BSA) that in the absence of adjuvant induce tolerance, in the presence of adjuvants induce antibody formation1,2. To understand how adjuvants switch on antibody formation it may be necessary to determine which of the cells involved in the immune response are affected by adjuvants. Earlier experiments3–5 led to the conclusion that the cells initially involved in the action of adjuvants are macrophages. This interpretation was based on observations that particulate adjuvants (such as bacteria) are ingested by macrophages but not by lymphocytes. Non-particulate or particulate adjuvants taken up by macrophages in culture and injected into syngeneic mice increased the antibody response of the recipients to two proteins (Maia squinada haemocyanin or bovine serum albumin (BSA)); in contrast, adjuvants taken up by lymphoid cells used to reconstitute immune responses in irradiated recipients had no demonstrable effect on antibody formation.