Showing papers on "Antibody published in 1984"

The CD4 (T4) antigen is an essential component of the receptor for the AIDS retrovirus

Abstract: Acquired immune deficiency syndrome (AIDS) is characterized by opportunistic infections and by 'opportunistic neoplasms' (for example, Kaposi's sarcoma). Persistent generalized lymphadenopathy (PGL) is epidemiologically associated with AIDS, especially in male homosexuals. A subset of T lymphocytes positive for the CD4 antigen (also termed T4 antigen), is depleted in AIDS and PGL patients. A retrovirus found in T-cell cultures from these patients is strongly implicated in the aetiology of AIDS because of the high frequency of isolation and the prevalence of specific antibodies in the patients. Here we have detected cell-surface receptors for the AIDS retrovirus (human T-cell leukaemia virus-III (HTLV-III) and lymphadenopathy-associated virus-1 (LAV-1) isolates) by testing the susceptibility of cells to infection with pseudotypes of vesicular stomatitis virus bearing retroviral envelope antigens, and by the formation of multinucleated syncytia on mixing virus-producing cells with receptor-bearing cells. Receptors were present only on cells expressing CD4 antigen; among 155 monoclonal antibodies tested, each of the 14 anti-CD4 antibodies inhibited formation of syncytia and blocked pseudotypes. Productive infection of CD4+ cells with HTLV-III or LAV-1 markedly reduced cell-surface expression of CD4. In contrast, receptors for HTLV-I and HTLV-II were not restricted to CD4+ cells, were not blocked by anti-CD4 antibodies; cells productively infected with HTLV-I and HTLV-II expressed surface CD4. Hence, we conclude that the CD4 antigen is an essential and specific component of the receptor for the causative agent of AIDS.

Chimeric human antibody molecules: mouse antigen-binding domains with human constant region domains

Abstract: We have created mouse-human antibody molecules of defined antigen-binding specificity by taking the variable region genes of a mouse antibody-producing myeloma cell line with known antigen-binding specificity and joining them to human immunoglobulin constant region genes using recombinant DNA techniques. Chimeric genes were constructed that utilized the rearranged and expressed antigen-binding variable region exons from the myeloma cell line S107, which produces an IgA (kappa) anti-phosphocholine antibody. The heavy chain variable region exon was joined to human IgG1 or IgG2 heavy chain constant region genes, and the light chain variable region exon from the same myeloma was joined to the human kappa light chain gene. These genes were transfected into mouse myeloma cell lines, generating transformed cells that produce chimeric mouse-human IgG (kappa) or IgG (kappa) anti-phosphocholine antibodies. The transformed cell lines remained tumorigenic in mice and the chimeric molecules were present in the ascitic fluids and sera of tumor-bearing mice.

Antigenic analysis of hematopoiesis. III. A hematopoietic progenitor cell surface antigen defined by a monoclonal antibody raised against KG-1a cells.

Abstract: The anti-My-10 mouse monoclonal antibody was raised against the immature human myeloid cell line KG-1a and was selected for nonreactivity with mature human granulocytes. Anti-My-10 immunoprecipitated a KG-1a cell surface protein with an apparent Mr of approximately 115 kD. We describe the binding of this antibody to human hematopoietic cell types and show that My-10 is expressed specifically on immature normal human marrow cells, including hematopoietic progenitor cells. My-10 is also expressed by leukemic marrow cells from a subpopulation of patients. Thus, this antibody allows the identification and purification of hematopoietic progenitor cells from normal human marrow and the subclassification of leukemia.

Antibodies reactive with human T-lymphotropic retroviruses (HTLV-III) in the serum of patients with AIDS

Abstract: In cats, infection with T-lymphotropic retroviruses can cause T-cell proliferation and leukemia or T-cell depletion and immunosuppression. In humans, some highly T4 tropic retroviruses called HTLV-I can cause T-cell proliferation and leukemia. The subgroup HTLV-II also induces T-cell proliferation in vitro, but its role in disease is unclear. Viruses of a third subgroup of human T-lymphotropic retroviruses, collectively designated HTLV-III, have been isolated from cultured cells of 48 patients with acquired immunodeficiency syndrome (AIDS). The biological properties of HTLV-III and immunological analyses of its proteins show that this virus is a member of the HTLV family, and that it is more closely related to HTLV-II than to HTLV-I. Serum samples from 88 percent of patients with AIDS and from 79 percent of homosexual men with signs and symptoms that frequently precede AIDS, but from less than 1 percent of heterosexual subjects, have antibodies reactive against antigens of HTLV-III. The major immune reactivity appears to be directed against p41, the presumed envelope antigen of the virus.

Immune response-associated production of neopterin. Release from macrophages primarily under control of interferon-gamma.

Abstract: Neopterin, a compound derived from GTP, represents a precursor molecule of biopterin that is an essential cofactor in neurotransmitter synthesis. We have recently reported that in vivo as well as in vitro immune responses are accompanied by an increased release of neopterin and that this phenomenon can be used for the biochemical monitoring of diseases accompanied by hyperimmune stimulation. This article deals with the cellular origin and the control of this immune response-associated neopterin release in vitro. Using highly purified or monoclonal cellular reagents we demonstrate that macrophages (M phi) stimulated with supernatants from activated T cells release large amounts of neopterin into culture supernatants. Further experiments involving induction of neopterin release from M phi with various human recombinant interferons (IFNs) or neutralization of the effect of T cell supernatants with various monoclonal anti-IFN antibodies revealed immune IFN as the active principle. It thus appears that a metabolic pathway so far exclusively known in context with the generation of an essential cofactor of neurotransmitter-synthesis during immune responses is also activated in M phi under stringent control by immune IFN-like lymphokines.

Epstein-Barr virus receptor of human B lymphocytes is the C3d receptor CR2.

Abstract: Identity of the Epstein-Barr virus (EBV) receptor with the complement receptor type 2 (CR2) was established in three sets of experiments using the monoclonal antibodies, HB-5 and anti-B2, which recognize a Mr 145,000 B-lymphocyte membrane protein that is CR2. First, the rank order for binding of fluoresceinated EBV to four lymphoblastoid cell lines (SB, JY, Raji, and Molt-4) was identical to the rank order for binding of HB-5 and anti-B2 by analytical flow cytometry. Second, pretreatment of cells with HB-5 followed by treatment with goat F(ab')2 fragments to mouse IgG blocked binding of fluoresceinated EBV on SB, a B-lymphoblastoid cell line. Virus attachment was not inhibited by HB-5 alone, second antibody alone, rabbit anti-C3b receptor, or UPC10 (an irrelevant monoclonal antibody). Third, transfer of CR2 from SB to protein A-bearing Staphylococcus aureus particles, to which HB-5 had been absorbed, conferred on them the specific ability to bind 125I-labeled EBV. We conclude that CR2 is the EBV receptor of human B lymphocytes.

Therapy with monoclonal antibodies by elimination of T-cell subsets in vivo

Abstract: A major aim in immunology has been to understand how the immune system evokes characteristic responses to infection, foreign tissue grafts and tumours. The current view of immunoregulation is based mainly on studies of lymphocyte subsets, either in vitro or by adoptive transfer to irradiated recipients. Many reagents are available for defining T-cell subsets, but only recently have there been helper T-cell-specific antibodies against the mouse equivalent of the Leu3/T4 (man) and W3/25 (rat) antigens. It is clear that monoclonal antibodies will eventually replace antilymphocyte globulin for immunosuppression in organ grafting, but although there has been some clinical success, most monoclonal reagents cause only transient reductions in their target cells in vivo. This uncertainty in the potency of monoclonal antibodies has led some workers to consider them as targeting agents for such highly cytotoxic drugs as ricin A (ref. 21). We show here that unmodified monoclonal antibodies can be extremely effective at depleting cells in vivo and can be used for the selective manipulation of different aspects of the immune response.

Immunocytological and biochemical characterization of a new neuronal cell surface component (L1 antigen) which is involved in cell adhesion.

Abstract: Monoclonal and polyclonal L1 antibodies react by indirect immunofluorescence with the cell surface of cultured tetanus toxin-positive neurons from post-natal cerebella of mice, but not with glial fibrillary acidic protein-positive astrocytes, O4 antigen-positive oligodendrocytes or fibronectin-positive fibroblasts or fibroblast-like cells. During cerebellar development L1 antigen is detectable on tetanus toxin-positive cells as early as embryonic day 13 after 3 days in culture. In sections of the early post-natal cerebellum, L1 antigen is found on pre-migratory neurons in the internal, but not in the external part of the external granular layer. In the adult cerebellum, L1 antigen is predominantly localized in the molecular layer and around Purkinje cells. Fibers in white matter and the granular layer are also L1 antigen-positive. Granule cell bodies and synaptic glomeruli are weakly antigen-positive. Several cell lines derived from neuroblastoma C1300 also express L1 antigen. The antigen is not detectable by enzyme-linked immunosorbent assay in tissue homogenates of liver, kidney, lung, heart, sperm or thymus. With polyclonal L1 antibodies, cross-reactive determinants are found in brains of rat, guinea pig, hamster, chicken, rabbit and man, but not in frog, while monoclonal antibody reacts detectably only with mouse brain. The molecular species recognized by both monoclonal and polyclonal antibodies display two prominent bands by SDS-PAGE under reducing and non-reducing conditions with apparent mol. wts. of 140 and 200 kd. L1 antigen isolated from cultured cerebellar cells consists mainly of a band in the 200-kd range and a faint one at 140 kd. L1 antigen from neuroblastoma N2A shows two bands with slightly higher apparent mol. wts. All molecular forms of L1 antigen can be labeled by [3H]fucose and [3H]glucosamine. Ca2+-independent re-aggregation of cerebellar cells from early post-natal C57BL/6J mice and of the continuous cell line N2A derived from the murine neuroblastoma C1300 is inhibited by Fab fragments of the polyclonal, but not of monoclonal antibody, both of which are known to react with the surface membrane of these cells.

Production of functional chimaeric mouse/human antibody

Abstract: The availability of monoclonal antibodies has revived interest in immunotherapy. The ability to influence an individual's immune state by administering immunoglobulin of the appropriate specificity may provide a powerful approach to disease control and prevention. Compared with immunoglobulin from other species, human immunoglobulin (Ig) might be best for such therapeutic intervention; it might function better with the recipient's effector cells and should itself be less immunogenic. The success of the mouse hybridoma system suggests that immunoglobulin of virtually any specificity can be obtained from a properly immunized animal. In the human system, however, immunization protocols are restricted by ethical considerations, and it is not yet clear whether human antibody-producing cell lines of the required specificity can be obtained from adventitiously immunized individuals or from in vitro immunized cells. A method which might circumvent these difficulties is to produce antibodies consisting of mouse variable regions joined to human constant regions. Therefore, we have constructed immunoglobulin genes in which the DNA segments encoding mouse variable regions specific for the hapten trinitrophenyl (TNP) are joined to segments encoding human μ and κ constant regions. These ‘chimaeric’ genes are expressed as functional TNP-binding chimaeric IgM. We report here some of the properties of this novel IgM.

Human hepatitis B vaccine from recombinant yeast

Abstract: The worldwide importance of human hepatitis B virus infection and the toll it takes in chronic liver disease, cirrhosis and hepatocarcinoma, make it imperative that a vaccine be developed for worldwide application. Human hepatitis B vaccines are presently prepared using hepatitis B surface antigen (HBsAg) that is purified from the plasma of human carriers of hepatitis B virus infection. The preparation of hepatitis B vaccine from a human source is restricted by the available supply of infected human plasma and by the need to apply stringent processes that purify the antigen and render it free of infectious hepatitis B virus and other possible living agents that might be present in the plasma. Joint efforts between our laboratories and those of Drs W. Rutter and B. Hall led to the preparation of vectors carrying the DNA sequence for HBsAg and antigen expression in the yeast Saccharomyces cerevisiae. Here we describe the development of hepatitis B vaccine of yeast cell origin. HBsAg of subtype adw was produced in recombinant yeast cell culture, and the purified antigen in alum formulation stimulated production of antibody in mice, grivet monkeys and chimpanzees. Vaccinated chimpanzees were totally protected when challenged intravenously with either homologous or heterologous subtype adr and ayw virus of human serum source. This is the first example of a vaccine produced from recombinant cells which is effective against a human viral infection.

A unique natural human IgG antibody with anti-alpha-galactosyl specificity.

Abstract: A new natural anti-alpha-galactosyl IgG antibody (anti-Gal) was found to be present in high titer in the serum of every normal individual studied. The antibody was isolated by affinity chromatography on a melibiose-Sepharose column. The reactivity of the antibody was assessed by its interaction with alpha-galactosyl residues on rabbit erythrocytes (RabRBC). The specificity was determined by inhibition experiments with various carbohydrates. The anti-Gal interacts with alpha-galactosyl residues, possibly on glycolipids of human RBC (HuRBC), after removal of membrane proteins by treatment with pronase. In addition, the anti-Gal bind specifically to normal and pathologically senescent HuRBC, suggesting a physiological role for this natural antibody in the aging of RBC. The ubiquitous presence of anti-Gal in high titers throughout life implies a constant antigenic stimulation. In addition to the theoretical interest in the antibody, the study of the anti-Gal reactivity seems to bear immunodiagnostic significance. Decrease in the antibody titer was found to reflect humoral immunodeficiency disorders.

Low and high affinity cellular receptors for interleukin 2. Implications for the level of Tac antigen.

Abstract: Interleukin 2 promotes proliferation of T cells by virtue of its interaction with a high-affinity cell surface receptor. This receptor is a 55,000 mol wt glycoprotein that is also recognized by the murine monoclonal antibody, anti-Tac. Quantitative binding studies with radiolabeled IL-2 and anti-Tac, however, initially indicated far more antibody binding sites per cell than IL-2 binding sites. Extension of the IL-2 binding analysis to concentrations several thousand-fold higher than that necessary for the T cell proliferative response demonstrated the existence of a class (or classes) of low-affinity IL-2 binding sites. Inclusion of the low-affinity IL-2 binding greatly reduced the quantitative discrepancy in the ligand binding assays. That the low-affinity binding, as well as the high-affinity interaction, was associated with the Tac molecule was indicated by the finding that the antibody could substantially or totally block the entire spectrum of IL-2 binding and by the finding that IL-2 could in turn block all radiolabeled anti-Tac binding. The low-affinity sites were found on activated T cells, several human and murine T cell lines and two examples of Tac-positive B cells. The physiological role of the low-affinity IL-2 binding sites and the molecular changes in the Tac protein that give rise to the affinity differences remain open to investigation.

A retrospective study on transmission of adult T cell leukemia virus by blood transfusion: seroconversion in recipients.

Abstract: Possible transmission of adult T cell leukemia virus (ATLV) by blood transfusion was studied retrospectively. Of 41 recipients of whole blood or blood components containing cells from donors having antibodies to antigen that is associated with ATLV (anti-ATLA), 26 (63.4%) produced anti-ATLA. However, no anti-ATLA was detected in all 14 recipients of fresh-frozen plasma prepared from anti-ATLA-positive donors. None of 252 recipients of blood with cell components from anti-ATLA-negative donors produced anti-ATLA. The development of anti-ATLA in the recipients may correspond to antibody production after establishment of primary infection with ATLV that is associated with cells in blood from anti-ATLA-positive donors who are ATLV carriers.

Differential reactivity of a novel monoclonal antibody (DF3) with human malignant versus benign breast tumors.

Abstract: We have defined a human breast tumor associated antigen using a murine monoclonal antibody (MAb DF3) prepared against a membrane-enriched fraction of a human breast carcinoma. This antigen has a MW of 290 kD and is detectable on the cell surface of human breast carcinoma cells using a live cell radioimmunoassay and fluorescence flow cytometry. More important, immunoperoxidase staining with MAb DF3 clearly distinguishes malignant and benign breast lesions. A cytoplasmic staining pattern has been observed with 40 of 51 (78%) breast carcinomas, but only one of 13 fibroadenoma or fibrocystic disease specimens. In contrast, reactivity of benign breast lesions with MAb DF3 primarily occurs along apical borders on ductules. These results demonstrate that the DF3 antigen is present on apical borders of more differentiated secretory mammary epithelial cells and in the cytosol of less differentiated cells.

Monoclonal antibody analysis of mononuclear cells in myopathies. I : Quantitation of subsets according to diagnosis and sites of accumulation and demonstration and counts of muscle fibers invaded by T cells

Abstract: In 76 muscle specimens (normal controls, 9; Duchenne dystrophy, 11; scleroderma, 11; dermatomyositis, 13; polymyositis, 15; inclusion body myositis, 17), mononuclear cells were analyzed at perivascular, perimysial, and endomysial sites of accumulation. Monoclonal antibodies reactive for B cells, T cells, T cell subsets, killer (K) or natural killer (NK) cells, and the Ia antigen were used for cell typing. Macrophages were identified by the acid phosphatase reaction. Few extravascular mononuclear cells occurred in normal muscle. In all inflammatory myopathies, a mixed exudate of T cells, B cells, and macrophages was present. Mature K/NK cells were rare in all diseases. In dermatomyositis, polymyositis, and inclusion body myositis, there was a positive gradient for T cells, T8+ cells, and activated T cells and a negative gradient for B cells and T4+ cells between perivascular and endomysial sites. In scleroderma the predominant perimysial exudate consisted mostly of T cells and macrophages. The percentage of B cells at all sites, and the T4+/T cell ratio in the endomysium, were significantly higher in dermatomyositis than in the other diseases. In polymyositis and inclusion body myositis, the endomysial exudate contained a large number of T cells, T8+ cells, and activated T cells but only sparse B cells. T cells accompanied by macrophages focally surrounded and invaded nonnecrotic fibers in polymyositis and inclusion body myositis. Rare fibers in Duchenne dystrophy and a very few fibers in dermatomyositis and scleroderma were similarly affected. We infer that (1) T-B, T-T, and T-macrophage cooperativities are likely to exist in muscle in different myopathies; (2) T cell-mediated fiber injury plays a role in polymyositis and inclusion body myositis; (3) T cell-mediated fiber injury can also occur in inherited diseases, such as Duchenne dystrophy; and (4) a local humoral response may occur in muscle in dermatomyositis and possibly in polymyositis and inclusion body myositis.

Familial protein s deficiency is associated with recurrent thrombosis

Abstract: Recent studies have demonstrated that protein C deficiency is associated with recurrent familial thrombosis In plasma, activated protein C functions as an anticoagulant This anticoagulant response requires a vitamin K-dependent plasma protein cofactor, referred to as protein S Since the anticoagulant activity of activated protein C is dependent on protein S, we hypothesized that patients lacking functional protein S might have associated thrombotic disease Two related individuals with otherwise normal coagulation tests are described whose plasma is not effectively anticoagulated with activated protein C Addition of purified human protein S to their plasma restores a normal anticoagulant response to activated protein C We have developed a rapid one-stage clotting assay for protein S to quantitate the level of protein S in their plasma Plasma is depleted of protein S by immunoadsorption with immobilized antiprotein S antibodies The resultant plasma responds poorly to activated protein C, but is effectively anticoagulated in a dose-dependent fashion upon addition of purified protein S or small quantities of plasma The affected individuals possess less than 5% protein S activity Using Laurell rockets, protein S antigen was detected in the plasma but was at reduced levels of 13 and 18% in the two individuals When the barium eluate of the patient plasma was chromatographed on quaternary aminoethyl Sephadex, a single peak of protein S antigen devoid of protein S anticoagulant cofactor activity was detected early in the chromatogram In contrast, the barium eluate from normal donors separated into two peaks, one emerging early and also devoid of anticoagulant cofactor, and the second peak with anticoagulant activity emerging later The first peak of protein S antigen, from both the normal donor and the patient, chromatographed in the region of the complement component C4-binding protein-protein S complex These studies suggest that protein S deficiency may result in recurrent thrombotic disease

Somatic mutation and the maturation of immune response to 2-phenyl oxazolone

Abstract: Studies on the development of the immune response suggest that the repertoire of expressed antibody specificities is strongly influenced by antigen (reviewed in ref. 1). One way in which this influence is manifested is by a progressive increase in the affinity of antibody for antigen with time after immunization. This phenomenon, termed the 'maturation' of the immune response, must be due to a change in the structure of the antibody being synthesized. However, the precise nature of the changes involved and the genetic mechanisms used to produce them have not been clearly defined. We have now investigated the maturation of the immune response to the hapten 2-phenyloxazolone by mRNA sequencing of specific hybridomas. We conclude that somatic mutation of germ-line encoded genes plays a major role in the generation of antibodies with increased affinity for oxazolone with time after immunization.

Monoclonal antibodies against human milk‐fat globule membranes detecting differentiation antigens of the mammary gland and its tumors

Abstract: Mouse monoclonal antibodies have been raised against human milk-fat globule membranes (HMFGM) to obtain reagents for mammary tumor diagnosis. A panel of 17 anti-HMFGM antibodies was selected for further investigation. Antibody-blocking studies indicated that with these antibodies at least nine different non-overlapping epitopes could be distinguished on six different molecules, MAM-1 to MAM-6. Electron microscopic studies of the cellular localization of the antigens detected by some of these antibodies revealed that they were present on the cell membrane mainly, on the microvilli, lining intercellular and intracytoplasmic lumina. The reactivity of the antibodies was studied on normal and tumor tissues and on in vitro cell lines. All antibodies reacted with the resting mammary gland while eight antibodies also bound to breast tumors. None of the antibodies was specific for the mammary gland or its tumors only, but most antibodies also reacted with other epithelial cells, especially of secretory tissues. When tested on a variety of cell lines a distribution reflecting the tissue distribution could be demonstrated. One of the antibodies reacted with nearly all carcinomas and their metastases and did not react with lymphomas, sarcomas, neuroblastomas, melanomas or nervous system tumors. The specificity of the antibodies, tested individually, was not sufficient for further differential diagnosis of the carcinomas, but when some of these antibodies were used in a panel they contribute to an important improvement of the diagnosis.

Characterization of Sialosylated Lewisx as a New Tumor-associated Antigen

Abstract: A monoclonal antibody CSLEX1 which reacts with sialosyl Lex but not with sialosyl Lea has been produced. The CSLEX1 antigen has a tissue distribution similar to that of Lex, appearing characteristically in the proximal tubules of the kidney and on granulocytes. It is tumor associated in that 14 of 34 (41%) of tumor lines tested reacted with the CSLEX1 antibody, and 50 of 74 (68%) of tumor tissues tested reacted with the antibody. Loss of immunoperoxidase staining of tissues after neuraminidase treatment showed that the antibody is reacting to sialyl derivatives. The antibody reacted in solid-phase radioimmunoassay to sialosyllactofucopentaosyl(III)ceramide and sialosyldifucosylganglioside (6B). These results indicate that the CSLEX1 epitope has the following structure: (formula: see text) This structure had not previously been known to be tumor associated.

1 alpha,25-dihydroxyvitamin D3 suppresses proliferation and immunoglobulin production by normal human peripheral blood mononuclear cells.

Abstract: Activated B and T lymphocytes from normal human subjects are known to have the specific high-affinity receptor for 1,25-dihydroxyvitamin D3 (1,25-(OH)2-D3). In an attempt to determine a functional role for the sterol in such cells, we studied the effect of 1,25-(OH)2-D3 on DNA synthesis and Ig production by normal human peripheral blood mononuclear (PBM) cells activated in vitro by the polyclonal lymphocyte activators pokeweed mitogen and phytohemagglutinin, and the specific antigen dermatophyton O. A dose-dependent inhibition of [3H]thymidine incorporation was observed in cells incubated with 1,25-(OH)2-D3 in concentrations ranging from 10(-10) to 10(-7) M. Production of IgG and IgM, determined by enzyme-linked immunosorbent assay, was similarly inhibited by increasing concentrations of 1,25-(OH)2-D3. Half-maximal inhibition of DNA and Ig synthesis was found at 10(-10) to 10(-9) M 1,25-(OH)2-D3. This suppressive effect was specific for 1,25-(OH)2-D3; of the other vitamin D metabolites examined, only 10(-7) M 24R,25 dihydroxyvitamin D3 (24,25-(OH)2-D3) had a similar inhibitory effect. 1,25-(OH)2-D3 was not cytotoxic and did not affect unactivated PBMs. These data demonstrate that 1,25-(OH)2-D3 is a potent inhibitor of human PBM Ig production in vitro and suggest that this action is mediated through the hormone's antiproliferative effect on Ig-producing B cells and/or helper T cells.

Generalized systemic and mucosal immunity in mice after mucosal stimulation with cholera toxin.

Abstract: Cholera toxin (CT) has been found to be an extremely potent immunogen for mucosal IgA responses when administered via the intestine. This study has examined both mucosal and systemic immune responses after feeding CT and compared these responses with those obtained after feeding keyhole limpet hemocyanin (KLH), another protein that is strongly immunogenic in mice. Feeding CT to mice resulted not only in IgA antibody in intestinal secretions but also resulted in substantial plasma IgG and IgA antibody levels. Feeding KLH in much larger quantity resulted in little or no antibody response in intestinal secretions or plasma. Lymphoid cells from various tissues of mice fed CT were cultured in vitro for 10 days and the supernatant was tested for antibody to CT. Spontaneous antibody synthesis (no antigen added to cultures) was present in cultures of each cell type, but IgG anti-CT was found mainly in cultures of spleen and mesenteric lymph node cells and IgA anti-CT mainly in cultures of Peyer's patch and lamina propria cells. Peyer's patch cells cultured with CT as antigen synthesized both IgG and IgA anti-CT, suggesting that the antibody response to both isotypes originated in this site. Helper T cell activity for both IgA and IgG anti-CT was detected in spleens, mesenteric lymph nodes, and Peyer's patches. Lastly, when KLH and CT were fed to mice at the same time, an intestinal IgA anti-KLH and plasma IgG anti-KLH response was stimulated, a response pattern similar to that occurring to CT after CT was fed alone. We conclude that mucosal stimulation by CT generates both a systemic IgG and mucosal IgA response to this antigen, and that CT can cause a similar pattern of response to an unrelated protein antigen when both are administered into the intestine at the same time. The data favor the idea that both the IgG and IgA responses originate in GALT and then disseminate to other tissues. We propose that CT accomplishes these effects by altering the regulatory environment within GALT.

Immunoglobulin gene rearrangement as a diagnostic criterion of B-cell lymphoma

Abstract: We describe the use of the Southern blot hybridization technique to diagnose B-cell lymphoma by detecting clonal immunoglobulin gene rearrangements in lymph node and other biopsy tissues. DNA was isolated from a wide variety of neoplastic and non-neoplastic specimens and analyzed for the presence of rearranged immunoglobulin genes using radiolabeled DNA probes specific for the heavy- and light-chain immunoglobulin constant region genes. Among the specimens examined, clonal immunoglobulin gene rearrangements were found only in biopsy samples of B-cell lymphoma and not in samples containing reactive lymphoid processes or non-B-cell cancers. In lymphomas, the presence of rearrangements for either the kappa or lambda light-chain gene correlated with expression of one or the other of these chains when cellular immunoglobulins could be detected by frozen-section immunophenotyping techniques. The analysis of immunoglobulin gene rearrangements offers several advantages over conventional diagnostic methods for lymphomas, including improved sensitivity in detecting minor populations of neoplastic lymphocytes composing as little as 1% of the total cell population. In addition, clonal immunoglobulin gene rearrangements are demonstrable in a subset of lymphomas that lack detectable surface or cytoplasmic immunoglobulin, thus offering positive evidence for both malignancy and the B-cell origin of these tumors. Our studies indicate that detection of immunoglobulin gene rearrangements is a valuable method for diagnosis and classification of various lymphoproliferative disorders that are difficult to evaluate histologically or that lack distinctive antigenic markers.

Preparation and characterization of monoclonal antibodies reactive with porcine PBL.

Abstract: Partially inbred miniature swine have been developed in this laboratory as a large animal model for immunologic studies. For many of these studies, a source of large quantities of well standardized antibodies to lymphocyte cell surface markers would be extremely helpful. Screening of a large panel of murine anti-human monoclonal antibodies (MAb) for anti-pig cross-reactions was nonproductive. We have therefore prepared a panel of MAb from mice immunized with pig thymocytes. Twenty-six stable MAb were produced that reacted with Ficoll/Hypaque-purified porcine lymphocytes. Reactivity was detected by complement-mediated cytotoxicity and/or cell surface binding ELISA. FMF analysis was performed on unseparated, glass-adherent, nylon wool-adherent, or nylon wool-nonadherent PBL and on cell preparations from lymphoid organs. In addition, the m.w. of the antigens detected by certain of these MAb were determined by immunoprecipitation of extracts of 125I surface-labeled cells. The majority of the MAb were not subpopulation specific. Included in these were 74-11-10 (IgG2b), which was specific for a polymorphic class I MHC determinant, and 76-3-2 (IgG1), which reacted with either a monomorphic class I MHC determinant or beta 2-microglobulin. Another MAb, 74-9-3 (IgM), precipitated a high m.w. complex of three polypeptide chains that appeared similar to that of the common leukocyte antigen. Of special interest were six MAb that were specific for various subpopulations of PBL: 76-7-4 (IgG2a) reacts with peripheral B cells, and 60% of thymocytes but not peripheral T cells, a pattern consistent with the murine ThB antigen; 74-22-15 (IgG1) and 76-5-28 (IgM) react with macrophages and granulocytes; 76-6-7 (IgM) reacts with T cells, macrophages, and granulocytes but not B cells, a combination of reactivities not previously reported in other species; 74-12-4 (IgG2b) and 76-2-11 (IgG2a) react specifically with T cells. 74-12-4 precipitated an antigen of 55,000 m.w., and 76-2-11 precipitated an antigen of 35,000 m.w. The m.w. and tissue distributions suggest that 74-12-4 recognizes porcine T helper cells, whereas 76-2-11 recognizes cytotoxic and/or suppressor T cells.