bluuebunny/crossref_metadata_2025 huggingface dataset:
Biologic activity of antigen receptors artificially incorporated onto B lymphocytes.
Authors: Peacock J S , Londo T R , Roess D A , Barisas B G
Published: December 2022

We describe a method for incorporating monoclonal antibody molecules onto viable murine lymphocytes and summarize the biologic activity of these artificial receptors on B cells. Mouse spleen cells incubated overnight with palmitate conjugates of a monoclonal anti-DNP IgA (protein 315) in the presence of deoxycholic acid incorporate about 50,000 antibody molecules per cell. When concentrations of deoxycholate and palmitoyl-protein 315 are carefully controlled, this labeling procedure does not affect the viability or the normal functions of the receptor-decorated cells. The incorporated antibody specifically binds DNP-antigens, although it appears to be unable to communicate directly with internal cellular components. Yet when these receptor-decorated, unprimed cells are challenged with any one of several DNP-antigens, up to 42,000 per 10(6) B cells differentiate into Ig-secreting cells. This response is about 23-fold greater than that induced in normal cell cultures and is of the same magnitude as that induced by the polyclonal B cell activator LPS. This, in addition to the observation that only about 3.6% of receptor-decorated B cells responding to DNP-conjugated polymerized flagellin (DNP-POL) produce hapten-specific antibody, demonstrates that these antigens cause polyclonal B cell differentiation. Normal spleen cells in the presence of DNP-POL and irradiated spleen cells bearing the artificial receptors do not exhibit the polyclonal antibody response. Also, the response of receptor-decorated B cell is blocked by high but nontoxic concentrations of the nonimmunogenic hapten DNP-lysine. These observations demonstrate that the polyclonal B cell response in this system requires the binding of antigen to artificial receptors on functionally viable cells. The polyclonal B cell response to a thymus-dependent antigen DNP-conjugated bovine gamma-globulin (DNP-BGG) requires the presence of the carrier-primed T cells. On the other hand, T cell depletion by anti-Thy-1.2 monoclonal antibody and complement causes only a slight reduction in the number of receptor-decorated B cells that respond to the relatively thymus-independent antigen DNP-POL. This type of phenomenon is also seen with natural antigen-specific B cells. Thus, polyclonal activation of receptor-decorated B cells exhibits the same gross helper cell requirements as antigenic activation of natural antigen-specific B cells. The results of this study are discussed in the context of the role of membrane-bound surface Ig in antigen-dependent B cell activation.(ABSTRACT TRUNCATED AT 400 WORDS)
HLA-DP can be expressed with or without -DR molecules on a malignant B cell line.
Authors: Pesando J M , Graf L , Hoffman P
Published: December 2022

HLA class II molecules (HLA-DR, -DQ, -DP) appear to differ in their ability to serve as corecognition elements in antigen presentation to T lymphocytes. Expression of these molecules on the autologous malignant B cell lines BALM-3, -4, and -5 was studied by binding of alloantisera and by indirect immunofluorescence and immune precipitation performed with well-characterized monoclonal antibodies. The following phenotypes were identified: BALM-5, HLA-DR+, -DP+; BALM-4, HLA-DR-, -DP+; BALM-3, HLA-DR-, -DP-. When treated with phorbol acetate (TPA), all three cell lines synthesize and express both HLA-DR and -DP molecules, indicating that the structural genes for these molecules remain intact. Thus HLA-DP can be expressed with or without HLA-DR molecules. Immune precipitation studies of metabolically labeled BALM-4 cells detect HLA-DR molecules in cells from TPA-treated but not control cultures, suggesting that TPA acts by inducing the transcription and/or translation of the genes for these class II molecules. HLA-DP molecules are detected in cells from both BALM-4 cultures. Recent studies suggest that BALM-5 but not BALM-3 or BALM-4 cells are HLA-DQ positive. TPA also appears to induce expression of HLA-DQ molecules on the latter two cell lines. The unique class II phenotypes of these autologous B cell lines in the resting state therefore appear to reflect differences in their ability to execute discrete steps leading to the surface expression of individual class II molecules. Variable expression of individual class II molecules by different cell populations may affect their ability to present cell-associated antigens to T lymphocytes.
Inhibition of the lytic activity of perforin by lipoproteins.
Authors: Tschopp J , Masson D , Schäfer S
Published: December 2022

Cytoplasmic granules isolated from cytolytic T lymphocytes (CTL) lyse red blood cells or tumor cell lines in a nonspecific manner. The activity of highly purified granules was inhibited by human or rabbit serum at dilutions as high as 1/10,000. The main inhibitory activity of human serum was isolated by chromatography and was determined to be high density lipoprotein (HDL). HDL not only inhibited at a concentration of 70 ng/ml the lytic activity of isolated granules, but also of the purified, pore-forming protein perforin present in the granules. Purified low density lipoprotein was equally active. Because the CTL granule activity was inhibited by pure egg lecithin vesicles at a concentration equivalent to the phospholipid content of lipoproteins, the lipid portion of lipoproteins is the likely candidate for granule inactivation. Lipoproteins also decreased in a dose-dependent manner the cytotoxic activity of intact cytolytic T cells. However, cytotoxicity was not completely suppressed, and only in the case of CTL exhibiting low efficiency in killing their targets. It is proposed that lipoproteins inactivate perforin and may thereby inhibit a possible lysis of innocent bystander cells.
Mast cell heterogeneity in higher animals: a comparison of the properties of autologous lung and intestinal mast cells from nonhuman primates.
Authors: Barrett K E , Szucs E F , Metcalfe D D
Published: December 2022

The issue of mast cell heterogeneity has been investigated in nonhuman primates by a comparative examination of lung and intestinal mast cells. These cells were obtained in parallel from the respective tissues of individual monkeys by an identical enzymatic dispersion technique. Mast cells derived from the lungs differed from those derived from the intestine in that the majority of the former cell type could be stained with toluidine blue at pH 4 to 5, whereas the intestinal mast cells in the dispersed preparations required a more acidic pH (less than 1) to display metachromasia. In addition, the lung cells exhibited an increased content of the mast cell mediator histamine. Nonhuman primate lung mast cells were also quantitatively more responsive to an immunologic challenge than their intestinal counterparts in that they released a higher percentage of cellular histamine and generated more leukotriene C4 on stimulation. Considerable inter-animal variation was observed between the magnitude of mediator release from both mast cell types after anaphylactic activation, but evidence for the presence in nonhuman primates of the phenomenon of releasability was not obtained. The responsiveness of both cell types to a range of potential nonimmunologic secretagogues and anti-allergic agents, including compound 48/80, substance P, theophylline, and isoprenaline, was essentially similar. We conclude that mast cell heterogeneity in higher animals may be reflected more by cytochemical rather than by functional differences between mast cell classes.
Mast cell "disappearance" in chronic murine graft-vs-host disease (GVHD)-ultrastructural demonstration of "phantom mast cells".
Authors: Claman H N , Choi K L , Sujansky W , Vatter A E
Published: December 2022

Mast cells were studied during the induction of chronic graft-vs-host disease (GVHD) induced in mice across minor histocompatibility barriers. B10.D2 spleen cells (or control BALB/c cells) were injected into irradiated (600 rad) BALB/c recipients. Serial skin biopsies were taken over 26 days, during which time changes occurred resembling scleroderma, namely, dermal fibrosis, a mononuclear cell infiltrate, and loss of fat and appendages. Mast cells, when stained with toluidine blue, "disappeared" from GVHD, but not from control skin. Ultrastructural analysis showed that mast cells in GVHD skin were indeed present but underwent degranulation. Some mast cells showed only pale expanded sacs, indicating granule depletion. Because these cells could not be seen by toluidine blue staining but were plainly present, we have called them "phantom mast cells." Cellular activation occurred in many GVHD mast cells as shown by increased cytoplasmic activity, with numerous Golgi complexes, ribosomes, granular endoplasmic reticulum, and small vesicles. No identifiable mast cells were seen after day 19. No significant changes were seen in the mast cells of syngeneic control mice. We believe that immunologic processes in chronic GVHD cause a slow release of mast cell granule contents, which is different from anaphylactic degranulation. The depleted mast cells (invisible by toluidine blue staining) are also activated, perhaps in an attempt to replete their stores of granule contents. We discuss the relation of mast cell changes to fibrosis.
Identification of a genetic locus, Rsm-1, controlling protective immunity against Schistosoma mansoni.
Authors: Correa-Oliveira R , James S L , McCall D , Sher A
Published: December 2022

Mice of most inbred strains develop moderate to high levels of resistance to challenge infection on vaccination with radiation-attenuated cercariae of Schistosoma mansoni. P strain mice, however, fail to display significant protective immunity after exposure to the same vaccine. To examine the genetic basis of this polymorphism in host immunity, vaccine-induced resistance was examined in (C57/BL6J X P/N)F1, F2, and reciprocal backcross generations. The defective immunity which characterizes the P strain parent was found to be inherited in a fully recessive manner and to be controlled by a single genetic locus, which we have designated Rsm-1. Linkage analyses revealed that Rsm-1 is not genetically associated with the major histocompatibility complex (chromosome 17), the immunoglobulin heavy chain locus (chromosome 12), or a single locus influencing defective anti-schistosomulum IgM antibody responses in the P parental stock. These data provide the first example of single gene control of vaccine-induced immunity against a helminth infection. Because P mice are also defective in their capacity to develop tumoricidal macrophages and in their immunity to Leishmania major, genes encoded by the Rsm-1 locus may play a general role in resistance to infection and malignancy.
Characterization of an immunosuppressive factor from malignant ascites that resembles a factor induced in vitro by carcinoembryonic antigen.
Authors: Medoff J R , Clack V D , Roche J K
Published: December 2022

Oncodevelopmental antigens may cause immunologic suppression in the host through release of suppressor molecules from the host's own immunoregulatory cells. This concept has been difficult to study until recently when carcinoembryonic antigen was shown to induce the release of such molecules from normal circulating human mononuclear cells in vitro. However, the amount of the suppressor moiety generated was too small to adequately characterize, and its presence in vivo, i.e., in the cancer-bearing host, was unknown. Therefore, we sought to isolate and characterize a similar or identical macromolecule from ascites having an elevated CEA level in patients with cancer. A single malignant ascites, when precipitated at 0 to 35% ammonium sulfate saturation, was the source of suppressive factor for purposes of isolation and standardization. Suppression was quantitated by reduction of [3H]thymidine incorporation by phytohemagglutinin-stimulated normal human peripheral blood mononuclear cells. Sephadex G-200 chromatography revealed probable aggregation of the factor in isotonic buffers; aggregation was reduced in the presence of 8 M urea. Purification was achieved by precipitation with 5% trichloroacetic acid (TCA). The suppressor factor remained soluble in TCA and demonstrated a 95-fold increase in specific activity. Analytical sodium dodecyl sulfate polyacrylamide gel electrophoresis demonstrated a single protein band of 50,000 daltons. Ascites from three additional cancer patients gave identical results. Physicochemical characterization of the suppressor moiety revealed stability at 70 degrees C for 30 min and at pH 2 and pH 10 for 24 hr. Delipidation by chloroform-methanol extraction, proteolytic enzyme digestion, and protamine sulfate precipitation did not affect activity, suggesting that lipid, simple peptides, and nucleic acids were not crucial. However, periodate oxidation irreversibly destroyed suppressor activity, suggesting the importance of carbohydrate to the molecule and offering one explanation for protease resistance. Similarities in m.w. (50,000 daltons), isoelectric point (pI = 3.4), physical properties (heat and acid stability and resistance to proteases), and immunologic activity of this factor with that released from lymphocytes after in vitro exposure to carcinoembryonic antigen indicates they may be identical. Our results suggest that early aberrant events induced in the immunoregulatory network by tumor-associated antigens may be relevant and may lead to better understanding of immunosuppression in the cancer-bearing host.
Immunodominance in the T cell response to multiple non-H-2 histocompatibility antigens. III. Single histocompatibility antigens dominate the male antigen.
Authors: Wettstein P J
Published: December 2022

Immunization of mice with multiple non-H-2 histocompatibility antigens results in the generation of cytolytic T lymphocytes that are specific for a limited number of immunodominant antigens. The experiments presented in this communication were designed to reveal immunodominance in pairwise combinations of autosomal and sex-linked non-H-2 histocompatibility (H) antigens. Priming and boosting responders with the male antigen, H-Y, paired with the H-4.2, H-7.1, or H-3.1 antigens, resulted in the generation of cytolytic T cells specific for the autosomal H antigens but not the H-Y antigen. Furthermore, co-immunization and boosting of C57BL/6 female responder spleen cells with BALB.B male cells resulted in the generation of cytolytic T cells specific for the BALB.B immunodominant antigens but not H-Y. No dominance was observed in H-4-plus H-7-incompatible combinations. Co-immunization of three different H-3 congenic strains with H-3.1 plus H-Y demonstrated that an efficient anti-H-3.1 T cell response is required for observing H-3.1 immunodominance over H-Y. Co-expression of H-3.1 and H-Y on the same priming and boosting cells was required for immunodominance. In fact, immunization with H-3.1 and H-Y presented on different cells resulted in normal generation of H-Y-specific cytolytic T cells, but no generation of H-3.1-specific cytolytic T cells resulted unless H-Y-specific cells were stimulated in the mixed lymphocyte cultures. These observations suggest that in vitro T cell responses to paired, non-H-2 H antigens may be independent, competitive, or synergistic, depending on the identity of the antigens and the priming and boosting conditions.
Hybrid resistance to parental mast cell precursors in the skin of (WB X C57BL/6)F1-W/Wv mice.
Authors: Sonoda S , Nakano T , Kanakura Y , Sonoda T , Asai H , Kitamura Y
Published: December 2022

When bone marrow cells of (WB X C57BL/6)F1-+/+ (WBB6F1-+/+) and WB-+/+ (WB) mice were directly injected into the skin of genetically mast cell-deficient WBB6F1-W/Wv mice, mast cell clusters appeared at the injection sites. However, the number of WB bone marrow cells necessary for appearance of mast cell clusters was significantly larger than when bone marrow cells of WBB6F1-+/+ mice were used. When WB bone marrow cells were mixed either with WB thymus cells or with silica particles, the proportion of injection sites at which mast cell clusters appeared increased to the level that was observed after the injection of the same number of WBB6F1-+/+ bone marrow cells. When suckling WBB6F1-W/Wv mice of less than or equal to 18 days of age were used as recipients, bone marrow cells of WBB6F1-+/+ and WB mice produced mast cell clusters with a comparable efficiency. Both syngeneic thymus cells and silica particles are known to abrogate the hybrid resistance that is observed in the spleen against parental hematopoietic stem cells. The hybrid resistance in the spleen is not detectable in suckling mice, either. Thus, the poor growth of mast cell precursors in the skin and the poor growth of hematopoietic stem cells in the spleen seem to be regulated by the same mechanism.
Absence of polymorphism between HLA-B27 genomic exon sequences isolated from normal donors and ankylosing spondylitis patients.
Authors: Coppin H L , McDevitt H O
Published: December 2022

Ninety percent of individuals with ankylosing spondylitis (AS) express HLA-B27. To determine if HLA-B27 coding sequences from normal vs AS individuals show differences that might relate to the etiology of the disease, the gene coding for this allele was cloned from three different partial genomic libraries. These libraries were made with DNA from three different cell lines expressing HLA-B27: MRWC (HLA-B27, 14), obtained from an AS patient; KCA (HLA-B27, w44), obtained from a known normal individual; and MVL (HLA-B27, 27), a homozygous consanguineous cell line of unknown origin. To increase the number of clones coding for the HLA-B locus, partial libraries were made using a complete Eco RI digestion of genomic DNA in the lambda vector 607. The libraries were screened with two probes; one probe hybridizes to all HLA-A, B, C class I genes, and the other to a small subpopulation of class I genes, including the B locus. DNA from clones hybridizing with both probes was transfected into murine L cells. Cell surface expression of HLA-B27 on murine L cells was detected with a polymorphic monoclonal antibody (ME1) specific for HLA-B27, 7, 22. DNA from those clones positive for HLA-B27 by transfection was subcloned into the Xba I site of M13mp18 and the DNA sequence for exons 2 through 4 (encoding domains alpha 1, alpha 2, and alpha 3) was determined by the dideoxy technique by using synthetic oligonucleotide primers or the M13 primer. The resulting sequences show no difference between HLA-B27 alpha 1, alpha 2, alpha 3 domains from a known AS patient and a known normal individual.
Characterization of the cell surface receptors for human B cell growth factor of 12,000 molecular weight.
Authors: Mehta S R , Grant S R , Maizel A L
Published: December 2022

Quiescent normal human B cells have been shown to require an activation step before proliferating in response to B cell growth factor (BCGF) of 12,000 m.w. (12 kd). One effect of cell activation has been the putative acquisition of specific cell surface growth factor receptors. In this report, the existence of such receptors has been confirmed by using purified radioiodinated BCGF-12 kd. BCGF-12 kd receptors on activated B cells have been shown to be distinct form those interacting with IL 2. Scatchard analysis revealed both high affinity receptor sites with an apparent Kd of 28.6 pM and low affinity receptor sites with Kd of 1.2 nM on freshly prepared, anti-IgM activated peripheral blood B cells. Human B cells grown in culture for extended periods of time in the presence of BCGF-12 kd also displayed high affinity receptor sites (Kd, 41.4 pM) and low affinity receptor sites (Kd, 0.9 nM). The action of BCGF-12 kd therefore appears to be mediated by binding to its lineage-specific receptors on the cell surface.
Effects of cyclosporine on responses of murine B cells to T cell-derived lymphokines.
Authors: O'Garra A , Warren D J , Holman M , Popham A M , Sanderson C J , Klaus G G
Published: December 2022

Cyclosporine (CS) inhibits the stimulation of both T and B lymphocytes by certain agents, but not by others. Here we have studied the effects of the drug on the responses of murine B cells to T cell-derived B cell growth and differentiation factors. We show that activation of resting B cells by B cell-stimulatory factor-1 (BSF-1) is resistant to CS, whereas stimulation by anti-Ig antibodies is not, which is in agreement with earlier findings. Furthermore, B cell proliferation elicited by co-stimulation with anti-Ig plus BSF-1 remains drug susceptible. In contrast, the stimulation of large (presumably preactivated) B cells by B cell growth factor II to synthesize DNA or to secrete Ig is inhibited by low concentrations of CS. These results therefore contrast with earlier findings with human B cells, and with those using T cells from various species, which showed that the responses of preactivated cells to growth factors are resistant to the drug. It thus appears that in the mouse CS can affect all stages of B cell stimulation.
In vivo and in vitro expression of an interleukin 2 receptor by murine B and T lymphocytes.
Authors: Finkelman F D , Malek T R , Shevach E M , Mond J J
Published: December 2022

Interleukin 2 (IL 2), which is well established to be a T cell growth factor, has more recently been shown to stimulate B lymphocyte growth and differentiation in vitro. Responsiveness of B and T cells to IL 2 has been associated with expression of a cell membrane IL 2 receptor (IL 2R). To investigate the role of IL 2 in B cell growth and differentiation in vivo, a system was used in which the injection of mice with a goat antibody to mouse IgD (GaM delta) induces polyclonal T-independent B cell proliferation first, and later induces polyclonal T-dependent B cell proliferation and IgG secretion. IL 2R expression by splenic B and T lymphocytes from GaM delta injected mice was studied by a dual label immunofluorescence technique. Although GaM delta was found to be a strong inducer of B cell IL 2R expression in vitro, even in serum-free medium, and stimulated up to 50% of splenic T cells to express considerable quantities of IL 2R in vivo, it failed to induce more than minimal B cell IL 2R expression in vivo. Concanavalin A and bacterial lipid A also induced B cells to express IL 2R to a much greater extent in vitro than in vivo. Although these agents and GaM delta acted synergistically to stimulate B cell IL 2R expression both in vitro and in vivo, a single agent induced B cell IL 2R expression to a considerably greater extent in vitro than did all three agents acting together in vivo. In vitro GaM delta-induced B cell IL 2R expression was not suppressed by inclusion of IL 2 in the culture medium but was suppressed by the presence of 10% normal mouse serum or plasma. These observations suggest that polyclonal T-dependent B cell proliferation and antibody secretion may not require an interaction between B cells and IL 2; the in vivo environment may downregulate IL 2R expression by B cells: and in vivo B cell IL 2R expression and consequently, induction of B cell responsiveness to IL 2, may require stimuli beyond those sufficient to induce B cell IL 2R expression and IL 2 responsiveness in vitro.
Proliferation in vitro and interleukin production by 14 day fetal and adult Lyt-2-/L3T4- mouse thymocytes.
Authors: Ceredig R
Published: December 2022

When 14 day fetal mouse thymocytes, which are phenotypically Lyt-2-/L3T4-(2-4-), were stimulated in vitro with a combination of phorbol myristate acetate (PMA) and the calcium ionophore ionomycin, they proliferated without addition of exogenous interleukins and/or growth factors. Addition of exogenous IL 2 resulted in a slight enhancement of fetal thymocyte proliferation. By using factor-dependent indicator cell lines, this proliferation was shown to be accompanied by the production of IL 2 and IL 3. However, phenotypic analysis by using flow microfluorometry and monoclonal antibodies to Lyt-2 and L3T4 showed little differentiation among proliferating 2-4-fetal thymocytes. Interestingly, the in vitro growth of PMA + ionomycin-stimulated fetal thymocytes appeared to be IL 2 dependent in that it was inhibited by a monoclonal antibody to the IL 2 receptor. The results obtained with fetal thymocytes were compared with those obtained when using 2-4- thymocytes from adult mice.
Differential effects of type I IFN and IFN-gamma on the binding of tumor necrosis factor to receptors in two human cell lines.
Authors: Tsujimoto M , Feinman R , Vilcek J
Published: December 2022

The effect of IFN-alpha and IFN-beta on the expression of cell surface receptors for tumor necrosis factor (TNF) was examined in two human cell lines. In HeLa cells, IFN-alpha and IFN-beta increased 125I-TNF binding, whereas in HT-29 cells these two IFN either slightly decreased or had no effect on 125I-TNF binding. In contrast, IFN-gamma increased 125I-TNF binding in both cell lines. Both IFN-alpha and IFN-beta exerted an antagonistic effect on IFN-gamma-induced stimulation of TNF receptor expression in HT-29 cells, but did not inhibit TNF receptor induction by IFN-gamma in HeLa cells. IFN-gamma and, to a lesser extent, IFN-beta were synergistic with TNF in producing cytotoxic/cytostatic activity in HT-29 cells. Despite the inhibitory effect of IFN-beta on the IFN-gamma-induced stimulation of TNF receptor expression, IFN-beta did not inhibit the synergistic enhancement of TNF cytotoxicity by IFN-gamma in HT-29 cells. The dissociation between the effects of IFN-beta on TNF receptor expression and on the cytotoxic activity of TNF in HT-29 cells suggests that TNF receptor modulation is not a major mechanism of synergism between IFN and TNF.
Distinct epitopes on the T cell antigen receptor of HPB-ALL tumor cells identified by monoclonal antibodies.
Authors: Lanier L L , Ruitenberg J J , Allison J P , Weiss A
Published: December 2022

The T cell antigen receptor is a approximately 90,000 dalton disulfide linked heterodimer that is non-covalently associated with the CD3 complex. Prior studies have demonstrated that anti-CD3 or -Ti antibodies can mimic antigen and induce cellular proliferation and the secretion of lymphokines. An early event in activation via CD3/Ti is a rapid increase in concentration of intracellular Ca2+ levels. In the present studies, we have produced a panel of monoclonal antibodies (MAb) against the Ti expressed on HPB-ALL tumor cells. All MAb immunoprecipitate a approximately 90,000 dalton disulfide linked heterodimer and induced co-modulation of Ti and CD3. On the basis of competitive binding studies, four distinct epitopes on the Ti of HPB-ALL were identified with MAb L38, L39, L41, and L42. These epitopes were additionally discriminated on the basis of reactivity with normal polyclonal T cell populations and functional effects on HPB-ALL. L39 reacted with a monomorphic epitope present on approximately 2 to 5% of peripheral blood T lymphocytes from all donors examined and was specifically mitogenic for peripheral blood T cells expressing this epitope. L39+ T cells in blood included both CD4+ and CD8+ lymphocytes. In contrast, L38, L41, and L42 failed to react with peripheral blood T cells and were not mitogenic for peripheral blood lymphocytes. Anti-Leu-4, L38, L39, and L41 MAb all induced a rapid increase in (Ca2+)i in HPB-ALL tumor cells, similar to previous findings with anti-CD3 and anti-Ti MAb against various tumor cells and peripheral blood T cells. In contrast, L42 MAb did not induce a substantial increase in (Ca2+)i. Failure of L42 to induce a substantial increased (Ca2+)i could not be attributed to the apparent titer, avidity, or isotype of the antibody. These findings suggest that induction of increased (Ca2+)i upon binding of Ti is epitope dependent. Furthermore, these data demonstrate that several distinct public and private epitopes can be identified on the T cell antigen receptor.
The valence for ligand of the human mononuclear phagocyte 72 kD high-affinity IgG Fc receptor is one.
Authors: O'Grady J H , Looney R J , Anderson C L
Published: December 2022

The valence for ligand of the 72 kD high-affinity IgG FcR present on human mononuclear phagocytes was evaluated. Lysates of U937 cells whose high-affinity FcR had been saturated with equivalent quantities of 125I-IgG1 kappa and unlabeled IgG1 lambda or with 125I-IgG1 lambda and unlabeled IgG1 kappa were incubated with Sepharose-anti-kappa. Eighty-nine percent of the applied 125I-IgG1 kappa was bound, whereas 0.35% of the applied 125I-IgG1 lambda bound (mean of two experiments), indicating that if the receptors are occupied with ligand, the receptors bind only one ligand molecule at a time. Two experiments were performed to show that the receptors were ligand-occupied. First, a monoclonal antibody directed against the 72 kD FcR (FcRmab32) was added to lysates of U937 cells saturated with equal quantities of 125I-IgG1 lambda and IgG1 kappa. This anti-FcR antibody caused a dose-dependent sevenfold increase in the amount of 125I-IgG1 lambda bound to the anti-kappa immunoadsorbent (presumably by cross-linking receptors bearing 125I-IgG1 lambda with receptors bearing IgG1 kappa), whereas monoclonal antibodies (MMA and IV3) directed against two other determinants on U937 caused no such increase. In the second experiment, Sepharose-FcRmab32 adsorbed 60% of the 125I-IgG1 kappa and 46% of the 125I-IgG1 lambda applied in a U937 lysate (bearing high-affinity FcR), whereas only 3% of 125I-IgG1 kappa and 6% of 125I-IgG1 lambda applied in a K562 lysate (bearing no high-affinity FcR) were adsorbed. We interpret these data to indicate that in detergent solution the valency of the high-affinity FcR on U937 cells is one.
Structure and expression of Fc gamma receptors on mouse suppressor T cell hybridomas.
Authors: Kulczycki A , Trial J , Connolly J M , Sharp S , Kapp J A
Published: December 2022

Antigen-specific and idiotype-specific mouse suppressor T cell hybridomas were analyzed for the presence and specificity of Fc gamma receptors (Fc gamma R) by EA rosetting and by flow microfluorometry with the use of monoclonal antibodies. We found that four hybridomas expressed Fc gamma R specific for IgG1 and IgG2b, one of which became Fc gamma R- during prolonged culture. Four other hybridomas and the fusion parent, BW5147, consistently lacked Fc gamma R. The 125I-labeled Fc gamma R were isolated from surface radioiodinated hybridoma cells solubilized with 1% Nonidet P-40, were purified by using single or repetitive chromatography on mouse IgG-Sepharose columns, and were analyzed by SDS-PAGE. An 125I-labeled 56,000 to 61,000 Mr macromolecule was isolated from each of the Fc gamma R+ hybridomas, but from none of the Fc gamma R- hybridomas nor from BW5147 cells. This macromolecule rebound to insolubilized mouse IgG1, IgG2b, and human Fc fragments, but not to insolubilized mouse IgG2a, IgG3, or IgA or human F(ab')2 fragments, consistent with the specificity observed for Fc gamma R on intact hybridoma cells. The mouse suppressor T cell Fc gamma R differs in size and specificity from mouse B cell Fc gamma R. A 70,000 Mr protein expressed on all hybridomas and on BW5147 cells was radiolabeled and, despite preclearing with ovalbumin-Sepharose, bound to the mouse IgG-Sepharose columns, presumably due to mouse antibodies to gp-70. This macromolecule was completely and specifically removed by using goat antiserum to gp-70.
Epitopic and paratopically directed anti-idiotypic factors in the regulation of resistance to murine schistosomiasis mansoni.
Authors: Phillips S M , Fox E G , Fathelbab N G , Walker D
Published: December 2022

In this study we investigated aspects of targets and regulatory mechanisms of immunologically mediated resistance to schistosomiasis. The interactions of antigen, monoclonal antibodies (MAb), and anti-idiotypic antibodies were studied by using competitive inhibition ELISA, radioimmunoprecipitation, and direct-binding ELISA techniques. MAb, either protective or nonprotective against challenge with Schistosoma mansoni, recognize either discrete or shared epitopes. MAb that recognize the same specific epitope may or may not express the ability to adoptively transfer resistance to syngeneic recipients. These results suggest that the functional as well as the epitopic specificity must be considered in an evaluation of protective mechanisms. The antibodies also can be characterized by both unique and cross-reacting idiotypic determinants. In addition, a relationship between antigen and anti-idiotypic antibody activity has been demonstrated. The immunologic analogy between antigenic epitopes and anti-idiotypic antibodies has been demonstrated by the ability of these two moieties to reciprocally inhibit the recognition of paratope-associated idiotypes, expressed by the protective MAb. This anti-idiotypic activity can be demonstrated in serum of infected animals. In this study we have identified two specific epitopes related to protection, and we illustrate here the steric relationship between antigen and anti-idiotypic antibody. The presence of idiotypically directed regulatory pathways within actively infected animals suggests that the immune response can be differentially regulated at the clonal level.
Gene transfer of immunoglobulin light chain restores heavy chain secretion.
Authors: Pepe V H , Sonenshein G E , Yoshimura M I , Shulman M J
Published: December 2022

Several lines of evidence suggest that immunoglobulin (Ig) light (L) chain plays a role in the secretion of heavy (H) chain. For example, myeloma variant lines, which synthesize the Ig H chain but not the L chain, fail to secrete H chain protein. Here we have tested directly the role of chain assembly in the control of Ig secretion by the transfer of functional L chain genes into two such L chain-defective myeloma mutants. A lambda 2 or kappa L chain gene was introduced into variant lines of the mouse myelomas MOPC 315 (IgA, lambda 2) or PC7 (IgM, kappa), respectively. Although the two mutant lines are unable to secrete the H chain they produce, rescue of secretion of complete Ig protein molecules (IgA or IgM) was observed after transfection. These results imply that the secretory apparatus of these cells is intact and that the failure to secrete free H chain reflects a structural feature intrinsic to that protein. The implications of these results with respect to control of secretion of multi-subunit proteins are discussed.
Characterization of the physical interaction between antigen-specific B and T cells.
Authors: Sanders V M , Snyder J M , Uhr J W , Vitetta E S
Published: December 2022

It has been assumed that physical interaction between B cells and helper T cells in the presence of specific antigen is an early and essential step in the physiologic antibody response to thymus-dependent antigens. The present studies were designed to examine this physical interaction by employing carrier-specific T hybridoma cells that can provide help to highly enriched hapten-binding B cells. Direct conjugation of the B and T cells can be visualized at both the light and electron microscopic level and the number of conjugates can be directly quantified. Before their effective conjugation with T cells, the B cells must be incubated with specific antigen for 4 to 6 hr. After this time, the T cells form conjugates with the B cells within 5 min. Conjugate formation requires hapten specificity, carrier specificity, covalent linkage between hapten and carrier, and is MHC restricted. Two types of T-B conjugates were observed by electron microscopy: an antigen-independent attachment of B cell microvilli to small portions of the T cell surface and an antigen-dependent, intimate apposition of large areas of the plasma membranes of the T and B cells. The kinetics of development of the two modes of interaction suggest that the second type may be important for signal transduction, since the number of T and B cells showing intimate interactions increases with time. Monoclonal antibodies directed against Thy-1.2, LFA-1 alpha, L3T4, and I-A partially block conjugation of the two cell types, suggesting that these surface molecules are involved in T-B interaction.
Effects of 5-fluorouracil on B lymphocyte lineage cells.
Authors: Vetvicka V , Kincade P W , Witte P L
Published: December 2022

The aim of these studies was to determine the sensitivity of B lymphocyte lineage precursor cells in mice to 5-fluorouracil (5-FU). Selective effects could be very helpful in dissecting precursor-product relationships between these and the rare multipotential stem cells from which they derive. Numbers and functions of particular types of cells were determined at intervals after a single treatment (3 mg) and, as expected, myeloid-committed stem cells were very severely affected. Day 8 spleen colony-forming cells (CFU-S) and colony-stimulating factor-responsive macrophage progenitors were reduced by 98% within 24 hr, whereas presumptive early stem cells (day 14 CFU-S) were much more resistant. B cells, which were probably recently formed in bone marrow and which are not thought to be actively dividing, were also 5-FU-sensitive, but perhaps less so than pre-B cells and immunoglobulin-negative lymphocytes bearing a B lineage marker. Approximately 5 wk were required for the normal cellular composition of marrow to return to normal. Transplantation of marrow from 5-FU-treated mice suggested that the slow regeneration of B lymphocytes might partially result from residual drug effects or damage to microenvironmental elements which are required for B lineage differentiation. Acute reductions of lymphocytes in the thymus were also documented, and the larger cells declined most rapidly and regenerated most slowly in that tissue. Of particular interest was the differential susceptibility of B cells in various lymphoid tissues to 5-FU. Whereas lymph node B cells were minimally affected, one-half of the splenic B cells disappeared within 48 hr of drug injection. Intrinsic differences in 5-FU sensitivity were confirmed by treatment of lymphocytes in vitro, and this suggests that particular B cell sets may be metabolically distinct. This drug should find additional experimental application in studies of B lymphocyte formation and functional heterogeneity.
Limiting dilution analysis of the stem cells for T cell lineage.
Authors: Katsura Y , Kina T , Amagai T , Tsubata T , Hirayoshi K , Takaoki Y , Sado T , Nishikawa S I
Published: December 2022

Stem cell activities of bone marrow, spleen, thymus, and fetal liver cells for T cell lineage were studied comparatively by transferring the cells from these organs through i.v. or intrathymus (i.t.) route into right leg- and tail-shielded (L-T-shielded) and 900 R-irradiated recipient mice, which were able to survive without supplying hemopoietic stem cells. Cells from B10.Thy-1.1 (H-2b, Thy-1.1) mice were serially diluted and were transferred into L-T-shielded and irradiated C57BL/6 (H-2b, Thy-1.2) mice, and 21 days later the thymus cells of recipient mice were assayed for Thy-1.1+ cells by flow cytofluorometry. The percentage of recipient mice possessing donor-type T cells was plotted against the number of cells transferred, and the stem cell activity in each cell source was expressed as the 50% positive value, the number of donor cells required for generating donor-type T cells in the thymuses of 50% of recipient mice. In i.v. transfer experiments, the activity of bone marrow cells was similar to that of fetal liver cells, and about 100 times and nearly 1000 times higher than those of spleen cells and thymus cells, respectively. In i.t. transfer experiments, the number of cells required for generating donor-type T cells was much lower than that in i.v. transfer experiments, although the ratio in 50% positive values between i.v. and i.t. transfers differed among cell sources. In i.t. transfers, the 50% positive value of bone marrow cells was five times, 400 times, and 500 times higher than that of fetal liver cells, spleen cells, and thymus cells, respectively. Our previous finding that stem cells are enriched in the spleens of mice which were whole body-irradiated and marrow-reconstituted 7 days earlier was confirmed also by the present limiting dilution assay carried out in i.v. as well as i.t. transfers.
Induction and regulation of contact hypersensitivity by resident, bone marrow-derived, dendritic epidermal cells: Langerhans cells and Thy-1+ epidermal cells.
Authors: Sullivan S , Bergstresser P R , Tigelaar R E , Streilein J W
Published: December 2022

Circumstantial evidence suggests strongly that epidermal Langerhans cells (LC) alone among epidermal cells (EC) are responsible for generating an immunogenic signal for contact hypersensitivity (CH) after epicutaneous application of hapten. However, data obtained from previous studies performed with intact skin or isolated EC do not address the immunogenic capacity of a second dendritic, bone marrow-derived population of cells that resides within the epidermis, Thy-1+ epidermal cells. To identify the cellular source(s) of the antigenic signals emerging from the epidermis, purified preparations of LC, Thy-1+ cells, and keratinocytes were prepared from CBA/J mouse skin. Each cell type was derivatized in vitro with TNBS and inoculated via various routes into syngeneic mice that were assayed for the induction of CH and specific unresponsiveness. IA+ LC, when derivatized with hapten and inoculated into mice, induced CH without evidence of down-regulation regardless of the route of immunization. Derivatized Thy-1+ EC did not deliver a positive signal for CH. Rather, Thy-1+ EC possessed the capacity to initiate down-regulation of the CH response when they were delivered i.v. We conclude that all cellular elements necessary for the induction and regulation of CH after epicutaneous application of hapten to skin reside within the epidermis. The resident, dendritic, bone marrow-derived populations within the epidermis have the capacity to determine the outcome of an epicutaneous antigenic encounter.
Opposing immunoregulatory functions of CD8+ lymphocytes: a requirement for monocytes in suppressor cell induction.
Authors: Elmasry M N , Fox E J , Rich R R
Published: December 2022

We have found that the induction of suppressor T cell (Ts) function in pokeweed mitogen (PWM)-stimulated cultures of peripheral blood mononuclear cels (PBMC) depends on the concentration of monocytes in inductive cultures. When cultured for 7 to 8 days in a physiologic concentration of monocytes (10 to 15%) suppressor cells differentiated with the surface phenotype CD8+ DR+ Leu-7- Leu-8+ Tp44-. Suppressor function, as assessed in secondary cultures of fresh PWM-stimulated CD4+ cells, was partially radiosensitive, and its induction could be partially inhibited by treatment with indomethacin. Culture supernatants of PWM-pulsed CD4+ cells could induce CD8+ suppressor cells only when monocytes were included in cultures for supernatant production. In marked contrast, if the monocyte concentration of PWM-stimulated T cells was reduced to less than 5%, CD8+ cells harvested from such cultures substantially augmented proliferation of PWM-stimulated CD4+ cells in assay cultures. Amplifier cells from monocyte-depleted cultures, were also DR+Tp44-. Suppressive activity of the CD8+ subset was restored simply by addition of monocytes to purified T cells, reconstituting the concentration present among unfractionated PBMC. Addition of IL 1 could not replace the requirement of monocytes for suppressor cell induction either in PWM-stimulated primary cultures or in culture supernatants. The data thus demonstrate that the regulatory activity of CD8+ lymphocytes is critically dependent on the conditions of cellular activation; at concentrations of monocytes normally present in peripheral blood, PWM stimulation induced potent suppressor activity, whereas under conditions of moderate monocyte depletion the regulatory activity of the same phenotypic subset of CD8+ cells was reversed. The experiments thus suggest that the functional consequences of an activating stimulus may depend on regulatory effects of monocytes in CD8+ suppressor cell induction.
Cloned auto-Ia-reactive T cells elicit lichen planus-like lesion in the skin of syngeneic mice.
Authors: Saito K , Tamura A , Narimatsu H , Tadakuma T , Nagashima M
Published: December 2022

To explore the physiologic or pathologic roles of autoreactive T cells, we examined immunological functions of several autoreactive mouse T cell clones in vitro and in vivo. All of the T cell clones were Lyt-2-, L3T4+ and showed self-I region-restricted proliferative responses (one clone was self-I-E restricted, the other clones were self-I-A restricted). One clone derived from C57BL/6 mouse and reactive to the self-I-Ab product (clone bb1-2) showed cross-reactivity to the I-Ak product. Among four such auto-Ia-reactive T cell clones examined, one clone produced fairly large amounts of interleukin 2 (IL 2) in response to syngeneic stimulator cells, and mediated help for the in vitro cytotoxic T cell (CTL) responses of syngeneic thymocytes, whereas this clone did not mediate in vitro antibody responses of syngeneic B cells. The other three clones were producers of small amounts of IL 2 and did not mediate the in vitro CTL responses. Among the three clones, clone bb1-2 showed strong regulatory function, and clone kk-1 (B10.BR origin and self-I-Ak reactive) showed weak regulatory function in vitro antibody responses of syngeneic B cells. The physiologic or pathologic roles of autoreactive T cells in vivo were explored by injecting subcutaneously clone kk-1 T cells or clone bb1-2 T cells into the footpads of the respective syngeneic mice. Clone kk-1 T cells injected into syngeneic mice elicited swelling of the footpad and marked accumulation of mononuclear cells in the dermis, leaving the epidermis intact, as in the delayed-type hypersensitivity reaction. As a notable finding, clone bb1-2 T cells injected into syngeneic mice elicited marked swelling of the footpad and lichen planus-like skin lesions, i.e., infiltration of lymphocytes in the epidermis and epidermal cell damage. The lymphocytes infiltrating in the epidermis were evaluated, as were the injected clone bb1-2 T cells expressing the Lyt-1.2 phenotype, by examination of the skin lesions elicited in C3H/He mice (H-2k, Lyt-1.1, 2.1) by the clone T cells. Clone bb1-2 T cells exerted in vitro cytotoxicity against H-2b and H-2k target cells, whereas clone kk-1 T cells did not show any cytotoxic activity, indicating a correlation between the cytotoxic activity of clone bb1-2 T cells and their ability to elicit lichen planus-like lesions.(ABSTRACT TRUNCATED AT 400 WORDS)
Lupus serum and normal human serum contain anti-DNA antibodies with the same idiotypic marker.
Authors: Madaio M P , Schattner A , Shattner M , Schwartz R S
Published: December 2022

We have previously shown that serum from patients with active SLE contain high levels of Id-16/6 and anti-DNA antibodies. In this study we investigated whether serum Id 16/6 is related to anti-DNA antibodies. Sera from 12 patients with active SLE were absorbed individually with poly(dT) cellulose (to purify anti-DNA antibodies) and rabbit (R) anti-Id-16/6 Sepharose (to purify Id 16/6 Ig). Removal of all anti-DNA activity removed most of the Id-16/6. Conversely, removal of all Id 16/6 removed most of the anti-DNA activity. Although there was no measurable anti-DNA antibody activity in normal serum, such antibodies were isolated by absorption with poly(dT) cellulose. The eluted immunoglobulins also had Id 16/6 activity. Similarly, Id 16/6 with anti-DNA activity were isolated from normal serum by absorption with R anti-Id 16/6 Sepharose. We conclude that a large fraction of anti-DNA antibodies in SLE serum are Id-16/6+, and that most Id 16/6 immunoglobulins in lupus serum have anti-DNA activity. Our observations suggest that lupus anti-DNA antibodies result from an overproduction of autoantibodies that are present in normal people.