bluuebunny/crossref_metadata_2025 huggingface dataset:
IgM antibodies recognizing carbohydrate epitopes shared between schistosomula and miracidia of Schistosoma mansoni that block in vitro killing.
Authors: Yi X Y , Omer-Ali P , Kelly C , Simpson A J , Smithers S R
Published: December 2022

A series of monoclonal antibodies (mAb) was raised in mice against Schistosoma mansoni, which recognized a carbohydrate determinant on a major Mr greater than 200,000 schistosomulum surface antigen. These mAb cross-reacted with the surface of cercariae and miracidia and with schistosomula of S. haematobium and S. bovis. Other mAb were generated that only recognized a Mr 20,000 schistosomulum surface antigen; they did not cross-react with eggs or miracidia and were species specific. The anti-Mr 20,000 mAb of the IgG1 isotype exhibited high levels of complement-dependent cytotoxicity to schistosomula in vitro. IgM mAb that recognized carbohydrate epitopes of the Mr greater than 200,000 surface antigen blocked the lethal activity of the anti-Mr 20,000 mAb. The IgM anti-Mr greater than 200,000 mAb also reduced complement-dependent cytotoxicity of serum from mice vaccinated with irradiated cercariae.
Activation of T cell antigen receptor alpha- and beta-chain genes in the thymus: implications for the lineages of developing cortical thymocytes.
Authors: Kinnon C , Diamond R A , Rothenberg E V
Published: December 2022

Mammalian T lymphocytes mature in the thymus through a series of differentiation events that involve both rapid proliferation and extensive cell death. The mechanisms that govern these processes are currently unknown; however, both mitogenesis and death affect particular subpopulations of cells, suggesting the selective amplification and destruction of specific T cell clones. In mature peripheral T cells, proliferation is most commonly triggered by the recognition of antigen through the T cell antigen receptor complex. If antigen recognition also controls proliferation in the thymus, the differential expression of antigen receptor genes during maturation could play some role in determining the fate of developing T cells. In this study, we examined the expression of the alpha- and beta-chain genes of the T cell antigen receptor in different subpopulations of adult thymocytes. We compared two postmitotic populations--one that appears committed to die and one that appears mature--and several blast cell populations that are enriched for precursors of one or another presumptive lineage. We have found that Lyt-2-, L3T4- precursor thymocytes express much lower levels of both alpha- and beta-chain mRNA than the cells likely to be their immediate descendents. Furthermore, our results show that the cells of the major cortical lineage, which have at least a 95% probability of death, nevertheless express high levels of mature mRNA encoding both the alpha- and the beta-chains of the T cell antigen receptor. These results have important implications for the mechanisms involved in the overproduction and elimination of this major class of T lymphocyte.
The monoclonal antibodies Trop-4 and 4F2 detect the same membrane antigen that is expressed at an early stage of lymphocyte activation and is retained on secondary lymphocytes.
Authors: Suomalainen H A
Published: December 2022

The monoclonal antibodies Trop-4 and 4F2 recognize cell surface antigens present on peripheral blood monocytes, activated lymphocytes, and on continuous cell lines, but not on resting lymphocytes in blood. The membrane antigens detected by antibodies Trop-4 and 4F2 were compared by serial immunoprecipitations from membrane lysates of surface labeled T lymphoid cells and by parallel polyacrylamide gel electrophoretic analysis. It is shown that both to these antibodies recognize the heavy subunit of the heterodimeric membrane complex of an 85,000 m.w. glycoprotein disulphide linked to a light subunit of 41,000 m.w. The kinetics of the expression of the antigen was studied by indirect immunofluorescence on peripheral blood T lymphocytes during blast transformation induced by concanavalin A in vitro and during reversion of the lymphocytes back to small "secondary" lymphocytes. Upon activation of T lymphocytes with concanavalin A, the first blast cells staining with the antibodies appear within 6 hr after the initiation of the culture. After 18 hr, all blast cells displayed strong expression of the antigen. Inhibition of DNA synthesis by hydroxyurea treatment did not affect the early blast transformation and the expression of the antigen. When the mitogen-induced blast cells reverted back to small secondary lymphocytes during prolonged culturing for up to 18 days, these cells retained the expression of the antigen detected by antibodies Trop-4 and 4F2, whereas another membrane marker of activation, the transferrin receptor, rapidly disappeared. These findings demonstrate a phenotypical difference between primed, secondary T lymphocytes and resting, unstimulated cells.
Nonspecific suppressor T cells cause decreased mixed lymphocyte culture reactivity in bone marrow transplant patients.
Authors: Harada M , Ueda M , Nakao S , Kondo K , Odaka K , Shiobara S , Matsue K , Mori T , Matsuda T
Published: December 2022

Decreased reactivity in mixed lymphocyte culture (MLC) was observed in patients within 1 yr after allogeneic and autologous bone marrow transplantation. Suppressor activity of peripheral blood mononuclear cells (PBMC) from transplant patients was studied by adding these cells as modulator cells to a bidirectional MLC with cells from normal individuals. PBMC from transplant patients markedly suppressed MLC reactivity in a dose-dependent manner. Suppressor activity was present in cells forming rosettes with sheep erythrocytes. Treatment of modulator cells with monoclonal antibodies against T cell differentiation antigens (OKT8, OKIa1) and complement completely abolished suppression of MLC. Suppressor activity was unaffected by 30 Gy irradiation. Suppressor activity declined gradually after transplantation and was inversely correlated with MLC reactivity of each patient at a significant level (p less than 0.01). These observations suggest that OKT8+ Ia+ radioresistant suppressor T cells play a role in the development of decreased MLC reactivity observed during the early post-transplant period.
Studies on the role of antigen-presenting cells in the systemic suppression of contact hypersensitivity by UVB radiation.
Authors: Kripke M L , McClendon E
Published: December 2022

Exposure of mice to UVB radiation produces a highly selective, systemic immunosuppression associated with the appearance of suppressor T lymphocytes. Suppression of delayed hypersensitivity to hapten-coupled syngeneic cells has been shown to result from an altered distribution of antigen-presenting cells. The purpose of this study was to determine whether an alteration in the activity of antigen-presenting cells could account for the systemic suppression of contact hypersensitivity (CHS) by UVB radiation. Fluorescein isothiocyanate (FITC) was used for contact sensitization because it uses different antigen-presenting cells than does oxazolone to induce CHS. Our previous studies demonstrated that CHS to oxazolone was suppressed by UVB irradiation. In these studies, we show that exposure of mice to UVB radiation before epicutaneous application of FITC onto unirradiated skin markedly decreased the CHS response to FITC painted on unexposed ears. Cyclophosphamide-sensitive suppressor T cells were detectable in the spleens of mice exhibiting decreased CHS. The antigen-presenting activity of cells in lymph nodes draining the site of epicutaneous sensitization (DLN cells) was assessed by injecting them into the hind footpads of syngeneic recipients and measuring the CHS response to FITC 6 days later. Viable DLN cells from UVB-irradiated, FITC-sensitized mice were equal to those from unirradiated, FITC-sensitized mice in their ability to induce CHS in normal recipients. No sensitization resulted when killed DLN cells were used for immunization, indicating that sensitization was not caused by reprocessing of antigen by host cells. We conclude that impairment of the CHS reaction in UVB-irradiated mice does not appear to be blocked at an initial step of antigen uptake, processing, or presentation, but must be impaired at some other step in the immunologic pathway.
Phagocytosis of concanavalin A-treated erythrocytes is mediated by the Fc gamma receptor.
Authors: Salmon J E , Kimberly R P
Published: December 2022

Impaired Fc gamma receptor-mediated phagocytosis has been reported in monocytes from HLA-DR2- and -DR3-positive disease-free individuals compared to normals without these B cell alloantigens. We have noted, however, a decrease in the ingestion of concanavalin A (Con A)-treated rabbit erythrocytes (E-Con A) in the same immunogenetically defined groups (DR2 vs Other: 2.94 +/- 0.84 erythrocytes/monocyte vs 4.16 +/- 1.37, p less than 0.003; DR3 vs Other: 3.35 +/- 1.51 vs 4.16 +/- 1.37, p less than 0.04). These data raised the possibility that carbohydrate-lectin interactions might trigger ingestion mediated by the Fc gamma receptor. To test this hypothesis, we performed receptor modulation and monosaccharide blocking experiments. Modulation of the Fc gamma receptor off the apical cell surface of monocytes by adherence to solid-phase IgG aggregates specifically reduced internalization of E-Con A and IgG-sensitized erythrocytes (EA) to 9.1% and 10.6% of control, respectively (p less than 0.001). Internalization of wheat germ agglutinin-treated erythrocytes, tannic acid-treated erythrocytes, and zymosan was not inhibited. In reciprocal modulation experiments using solid-phase Con A, no effects on phagocytosis of any particle was observed. alpha-Methyl mannoside, 0.1 M in PBS, did not inhibit the internalization of EA but blocked ingestion of E-Con A by 97% (p less than 0.001). Other monosaccharides had little or no effect on the ingestion of any of the phagocytic probes. These data demonstrate that a mechanism integrally involving the Fc gamma receptor mediates the ingestion of E-Con A by human monocytes. This Fc receptor has an oligosaccharide(s) with an exposed mannose which may be functionally significant. Whereas the mannose moiety does not play a crucial role in the interaction of the Fc gamma receptor with the Fc portion of IgG, engagement of the receptor via mannose can initiate internalization. Our findings raise the possibility that nonimmune functions may utilize classical immune system receptors through carbohydrate interactions. Furthermore, the ability of the Fc gamma receptor to trigger internalization is defective in HLA-DR2 and -DR3 normals, whether the receptor is ligated at its classical ligand-binding site or by way of its carbohydrate moieties.
Changes in phospholipid metabolism during B lymphocyte activation.
Authors: Kriz M K , Vitetta E S , Sullivan T J
Published: December 2022

We have examined phospholipid metabolism in murine B lymphocytes stimulated with anti-Ig bound to Sepharose. T cell-depleted splenic B lymphocytes cultured with Sepharose-coupled, affinity-purified goat anti-mouse Ig (GAMIg) increased the incorporation of 32PO4 into phosphatidic acid and phosphatidylinositol within 3 hr and increased [3H]-thymidine uptake at 48 hr. No increase in labeling was observed in phosphatidylethanolamine, phosphatidylcholine, or phosphatidylserine. Based on both negative and positive selection procedures, it was demonstrated that these responses occurred in B lymphocytes. In contrast to the thymidine uptake response of the GAMIg-stimulated B lymphocytes, the phospholipid response did not require the presence of accessory cells or exogenous cytokines. The same selective changes in phospholipid metabolism were observed in neoplastic B lymphocytes (BCL1) after treatment with Sepharose anti-mu, but not with Sepharose anti-Ia or Sepharose normal Ig. The dose-response relationships of 32PO4 incorporation into phosphatidic acid and phosphatidylinositol and [3H] thymidine uptake were nearly identical in BCL1 cells. The results of these experiments indicate that interaction of B lymphocytes with insolubilized anti-Ig results in prompt and selective changes in phospholipid metabolism that appear to be correlated with B lymphocyte proliferation.
Lack of reactivity of rheumatoid arthritis synovial membrane DNA with cloned Epstein Barr virus DNA probes.
Authors: Fox R I , Chilton T , Rhodes G , Vaughan J H
Published: December 2022

Rheumatoid arthritis (RA) synovial membranes contain a 62,000 dalton (62 Kd) molecule that shares an antigenic epitope with the EBNA-1 antigen of Epstein Barr virus (EBV). This cross-reactive epitope(s) is defined by a monoclonal anti-EBNA-1 antibody (MoAb P135) and by a rabbit antibody directed against a (glycine-alanine)-containing synthetic peptide from the internal repeat region-3 (IR-3) of EBNA-1. To determine whether this 62 Kd protein may result from EBV infection of RA synovial membranes, we used cloned DNA probes from the Bam M, Bam V, and Eco D regions of EBV. These probes did not show detectable reactivity with RA synovial membrane DNA in Southern blotting or slot blotting experiments. Reconstruction experiments performed with purified EBV DNA demonstrated the ability to detect 0.03 pg of viral DNA per 20 micrograms of normal genomic DNA, or approximately 1 EBV copy per 100 cells. In contrast, we found a low but significant level of reactivity of RA synovial membrane DNA with the EBV-encoded Bam K probe that encodes the EBNA-1 antigen. However, this probe also was reactive with normal genomic DNA to a similar extent. These results suggest that the 62 Kd antigen in RA synovial lining cells is probably encoded by cellular genes similar to the IR-3 region of EBV and does not result from EBV infection of the RA synovial membrane.
All human monocytes have the capability of expressing HLA-DQ and HLA-DP molecules upon stimulation with interferon-gamma.
Authors: Gonwa T A , Frost J P , Karr R W
Published: December 2022

We have simultaneously studied expression of all three classes of human Ia (HLA-DR, DP, and DQ) on normal human B cells and monocytes (M phi) by using two-color immunofluorescence and flow cytometry. Expression was investigated on freshly isolated cells and after incubation of cells for 48 and 96 hr in interferon-gamma (IFN-gamma). All freshly isolated B cells express high levels of DR, DQ, and DP, and these levels are unchanged by incubation with IFN-gamma for 48 hr and 96 hr. In contrast, freshly isolated M phi are on the average 91% DR+, 32% DQ+, and 15% DP+. Incubation with IFN-gamma increases Ia expression on M phi to 98% DR+, 75% DQ+, and 58% DP+ at 48 hr, with virtually all cells becoming positive for all three Ia antigens at 96 hr. Furthermore, after the 96-hr incubation, antigen density increases 10-fold for DR, 15-fold for DQ, and 15-fold for DP in M phi to reach levels of expression comparable with B cells. These studies demonstrate that all peripheral blood monocytes have the capacity to become HLA-DQ and HLA-DP positive; IFN-gamma regulates expression of all three classes of human Ia in M phi; and IFN-gamma does not significantly modulate Ia expression in B cells.
Evidence for shared antigenic determinants on rabbit and human interleukin 1 (IL 1).
Authors: Simon P L , Lee J C
Published: December 2022

An antiserum to human interleukin 1 (IL 1) was prepared by immunizing a goat with the isoelectric point (pI) 6.9 type of IL 1 in Freund's complete adjuvant. Serum-mediated inhibition of the biological activity of IL 1 appeared within 4 wk after the first immunization, and showed a progressive rise in titer over a 9-mo period. The inhibitory moiety was purified by sequential ammonium sulfate fractionation and DEAE-Sephacel ion exchange chromatography, and the activity was found to co-purify with the IgG fraction of the serum. The antibody neutralized the biological activity of the pI 6.9 type of human IL 1 derived from either human placental tissue or human peripheral blood adherent cells, but did not neutralize the pI 5.2 type of IL 1 derived from either source. When used as an affinity reagent, the antibody selectively absorbed the pI 6.9 human IL 1, but not the pI 5.2 human IL 1. Furthermore, the antibody neutralized the pI 7.4 type of IL 1 derived from rabbit alveolar macrophages, but had no activity against the pI 4.6 IL 1 derived from the same source. No inhibitory activity against rat spleen cell-derived IL 1 or murine P388D1 cell line-derived IL 1 was detected. These experiments support the concept that the differing pI types of IL 1 derived from the same species are both biochemically and antigenically distinct molecules, and IL 1 of similar pI type derived from different species may share antigenic determinants.
A suppressive lymphokine of platelet cytotoxic functions.
Authors: Pancré V , Auriault C , Joseph M , Cesbron J Y , Kusnierz J P , Capron A
Published: December 2022

The in vitro stimulation of mononuclear cells from human peripheral blood with mitogens is known to induce the release of factors (monokines and lymphokines) that possess distinct biologic activities. The present data describe the presence in Con A- and antigen-stimulated T cell supernatants (of man or rat) of a factor able to inhibit, in a dose-dependent manner, the platelet cytotoxicity toward the young larvae of Schistosoma mansoni. The production of oxygen metabolites by IgE-coated platelets, stimulated by anti-IgE or the specific antigen, was, likewise, strongly inhibited by this lymphokine. The producing T lymphocyte subpopulation was identified as OKT 8+. This suppressive lymphokine of platelet functions had an m.w. of 15,000 to 20,000 and a pI of 4.6. It was heat- and acid-stable and sensitive to trypsin and proteinase K, but neuraminidase had no effect on its activity. This platelet suppressive activity was specifically absorbed by platelet membrane, suggesting its action through the binding to a receptor.
Regulation of the BALB/c anti-p-azophenylarsonate antibody response by monoclonal anti-idiotype. I. Anti-idiotope fine specificity.
Authors: Brown A R , Sealy R E
Published: December 2022

Five monoclonal anti-idiotype antibodies were prepared against the IgG1 monoclonal antibody, 5AF6, the prototype molecule representing the BALB/c 5AF6 idiotype family of antibodies specific for the p-azophenylarsonate (Ar) hapten. Three were of BALB/c origin and two were derived from allotype congenic strain CB.20. All five anti-idiotopes (id) reacted with the 5AF6 immunogen but not with four other BALB/c anti-Ar sharing other id with 5AF6. Four of the five showed some reactivity with three monoclonal anti-Ar derived from A strain mice that represent a minor component of the anti-Ar from that strain. Reactivity patterns of these anti-id indicated that all five reacted with different id on the 5AF6 molecule, yet all five were sufficiently close to the Ar-binding site for their binding to be blocked by the Ar hapten alone. Furthermore, all five anti-id could compete with each other for binding to 5AF6, indicating that the five id detected by these anti-id were in close proximity. Four of the five anti-id reacted with id produced by conformations requiring both the appropriate heavy and light chains. The fifth anti-id reacted with a heavy chain id stabilized by the presence of any light chain. The implications of such a diverse anti-id response against a single antibody molecule on anti-id network interactions are discussed.
Regulation of the BALB/c anti-p-azophenylarsonate antibody response by monoclonal anti-idiotype. II. Idiotope expression in serum and its regulation.
Authors: Brown A R , Sealy R E
Published: December 2022

Five murine monoclonal antibody (mAb) anti-idiotypes (id), shown in the accompanying report by binding studies to be reactive with five different id on a single member of the 5AF6 family of BALB/c antibodies against the p-azophenylarsonate (Ar) hapten, were used to examine the distribution of their recognized id among anti-Ar in BALB/c and other mouse strains immunized with keyhole limpet hemocyanin-Ar (KLH-Ar). Differences in id expression in BALB/c and other strains substantiate that all five monoclonal anti-id reacted with different id. This suggests that the anti-id repertoire for a single antibody molecule may be extensive. Two of the anti-id reacted with id that were found in virtually all KLH-Ar immunized BALB/c mice, but constituted only a subset (approximately 33%) of the antibodies representing the 5AF6 family. The other three anti-id reacted with id infrequently expressed among BALB/c anti-Ar. Other mouse strains producing 5AF6 family anti-Ar antibodies also produced antibodies recognized by mAb 2CB8 and 6BA1; however, the three id infrequently expressed in BALB/c mice were produced in higher quantities and in a greater percent of mice. Monoclonal anti-id were capable of suppressing a portion but not all of the 5AF6 family of anti-Ar antibodies. Four of the five anti-id suppressed a greater fraction of the 5AF6 family than that id represented in a normal immune response, suggesting that suppression was mediated via an id other than that recognized by these monoclonal anti-id. Overall, the results indicate that an extensive repertoire of anti-id can be produced against a single id antibody, but suppression induced by treatment with these anti-id in this model is presumably mediated via another as yet unidentified id determinant(s).
Reactivity of E. coli-derived trans-activating protein of human T lymphotropic virus type III with sera from patients with acquired immune deficiency syndrome.
Authors: Barone A D , Silva J J , Ho D D , Gallo R C , Wong-Staal F F , Chang N T
Published: December 2022

Randomly sheared DNA fragments from HTLV-III proviral DNA were cloned into an E. coli open reading frame (ORF) expression vector. The inserted ORF DNA was expressed in E. coli transformants as a polypeptide fused to the lambda CI protein at the amino terminus and to beta-galactosidase at the carboxyl terminus. The reactivity of the recombinant peptides with antibodies from sera of AIDS patients was determined by the Western blot technique. The coordinates of the DNA inserts of the immunoreactive clones were then determined by DNA sequencing. A clone, ORF 628, was found to contain a short DNA segment located between the sor and env genes (nucleotide positions 5367 to 5597), a region previously thought to be noncoding. Inspection of the DNA sequences of this clone and of other HTLV-III isolates revealed the presence of a small ORF located between nucleotide position 5411 and 5625, capable of encoding a polypeptide of 72 amino acids. The biosynthesis of the polypeptide of ORF 628 initiates from an ATG codon within the HTLV-III insert. The fusion protein of ORF 628 was partially purified by affinity chromatography on CH Sepharose 4B coupled to a beta-galactosidase ligand, and tested against a panel of sera from AIDS patients by Western blot analysis. Approximately 35% of the sera from patients with AIDS or ARC contained antibodies reactive with the peptide. The DNA region spanned by ORF 628 is now thought to be the major functional element of the trans-activator gene, tat.
Anti-Ig induces release of inositol 1,4,5-trisphosphate, which mediates mobilization of intracellular Ca++ stores in B lymphocytes.
Authors: Ransom J T , Harris L K , Cambier J C
Published: December 2022

Evidence from a variety of laboratories indicates that crosslinking of B cell mIg induces a rapid increase in intracellular free calcium (Ca++i). This mobilized Ca++ appears to act in concert with diacylglycerol (DAG; also released upon mIg cross-linking) to optimally activate Ca++/phospholipid-dependent protein kinase C, which plays a pivotal role in B cell activation. Here we report analysis of the source of this mobilized calcium and the mechanism responsible for its release into the cytosol. We observed the cross-linking of mIg induces the release of inositol 1,4,5-trisphosphate (InsP3), presumably as a result of action of phospholipase C on plasma membrane phosphatidylinositol 4,5-bisphosphate (PtdInsP2). The release of InsP3 and the elevation of Ca++i are coincidental, suggesting that they may be causally related. Finally, we demonstrate that submicromolar doses of InsP3 induce release of Ca++ from permeabilized cells that had preaccumulated 45Ca++ in the endoplasmic reticulum. On the basis of these findings we suggest that mIg cross-linking leads to mobilization of Ca++, in part by causing hydrolysis of PtdInsP2, yielding InsP3, which in turn causes release of calcium from the endoplasmic reticulum.
Murine lymphokine-activated killer (LAK) cells: phenotypic characterization of the precursor and effector cells.
Authors: Yang J C , Mulé J J , Rosenberg S A
Published: December 2022

Murine and human lymphocytes incubated in recombinant interleukin 2 (RIL 2) generate a population of cytotoxic cells (lymphokine-activated killer cells [LAK]), which are able to lyse a wide array of fresh tumor cells but do not lyse fresh normal cells. Intravenous administration of these cells with the concomitant administration of RIL 2 can eliminate established pulmonary and hepatic metastases in mice. To characterize the cell that has in vitro LAK activity, we subdivided murine lymphocytes by lysing select subpopulations with the use of complement and antibodies against lymphocyte surface markers or by fluorescence-activated cell sorting. Thy-1.2-negative splenocytes were found to generate near normal amounts of LAK activity after RIL 2 incubation. Small and inconsistent LAK cell activity was generated from Thy-1.2-positive splenocytes. Ia-positive and surface immunoglobulin-positive splenocytes had little or no LAK precursor capability and did not appear to be necessary for LAK activation. Treatment of splenocytes with anti-asialo GM1 (anti-ASGM1) heterosera and complement markedly decreased their ability to generate LAK activity. At the effector stage, cytotoxic cells were of the Thy-1.2-positive, Ia-negative phenotype. Ia-depleted cells were separated into subpopulations bearing or not bearing the gamma Fc receptor (gamma FcR). The majority of cytotoxicity resided in gamma FcR-positive cells. Thus the precursors of murine LAK cells are "null" lymphocytes bearing neither T nor B cell surface markers but develop the Thy-1.2 cell surface marker in vitro, in association with the development of lytic activity for fresh tumor cells after stimulation by RIL 2.
K562 killing by K, IL 2-responsive NK, and T cells involves different effector cell post-binding trigger mechanisms.
Authors: Shanahan F , Brogan M D , Newman W , Targan S R
Published: December 2022

The monoclonal antibody 13.3 specifically blocks the trigger process of the NK-K562 cytolytic sequence at a post-binding effector cell level. This antibody was used to define differences in the lytic trigger processes of NK and other mechanisms of K562 lysis. Monoclonal antibody 13.3 inhibited lysis of K562 target cells by freshly isolated peripheral blood lymphocytes (PBL) and purified large granular lymphocytes (LGL), but had no inhibitory effect on antibody-dependent cell-mediated cytotoxicity to K562 by these effectors. Lectin-dependent cellular cytotoxicity (LDCC) to this target cell was also unresponsive to 13.3. The 13.3-induced inhibition of NK-K562 lytic activity persisted when PBL were activated in culture with interleukin 2 (IL 2) for periods up to 48 hr. After 48 hr of culture, the degree of inhibition diminished progressively in medium containing fetal calf serum but not in medium containing autologous serum. This 13.3-unresponsive lytic activity in cultured PBL could be attributed to more than one cell type and was present in both the LGL and Fc gamma receptor-depleted T cell fraction. Thus, K562 lysis by freshly isolated human lymphocytes via NK, K, and LDCC mechanisms is characterized by heterogeneity of the post-binding effector cell trigger mechanism. K562 lysis by lymphocytes cultured with IL 2 is similarly heterogeneous.
Mapping of SJL/J reticulum cell sarcoma tumor-associated Ia antigens by T cell hybridomas: characterization of tumor-specific and shared epitopes detected on IE+ allogeneic cells.
Authors: Ohnishi K , Bonavida B
Published: December 2022

Previous studies have suggested that reticulum cell sarcoma (RCS) tumor cells of SJL/J (IA + IE-) mice express neospecificities that are related to antigenic specificities characteristic of IE+ allogeneic cells. These neospecificities have also been suggested to play a role in the strong syngeneic antitumor proliferative response as well as in regulating RCS growth in vivo. The present studies characterize four RCS tumor-specific T cell hybridoma clones prepared from the fusion of BW5147 thymoma with T cells derived from lymph nodes of tumor-bearing mice. Upon stimulation, these hybridomas secrete IL 2 in the supernatant. Two hybridomas responded to RCS to IE+k and to IE+d allogeneic cells, respectively, and the other two hybridomas were tumor specific. The specificity of these hybridomas was assessed by response to both spontaneous and transplantable RCS lines and failure to stimulate a response by either normal or LPS-induced B cell blasts from the host SJL/J cells. The epitopes recognized by the T cell hybridomas were examined by the ability of several monoclonal antibodies to inhibit the IL 2-induced response by the T cell hybridomas. Antibodies directed against the IABs polypeptide of the IA hybrid molecule blocked the antitumor response by all four hybridomas. However, the response to allogeneic IE+ cells was not blocked by anti-IAs antibody but was blocked by antibodies directed against either the IAk,d or IEk,d hybrid molecules or the corresponding alpha- or beta-chains. The response to both RCS and allogeneic cells was blocked by monoclonal antibodies directed against L3T4 antigens on the T cells. Based on the exquisite specificity of the T cell receptors, the results here demonstrate that RCS tumor cells express on their surface both tumor-specific I-A-associated epitopes and Ia-associated antigenic specificities that are shared with IE+ allogeneic cells. The present studies of adapting T cell hybridomas and blocking antibodies proved useful to characterize and map distinct tumor-associated epitopes on the surface of tumor cells. These findings, when combined with structural studies, should help unravel the molecular complexity of tumor-associated antigens.
Differential association between two human MHC class I antigens and an adenoviral glycoprotein.
Authors: Severinsson L , Martens I , Peterson P A
Published: December 2022

The glycoprotein E19, encoded in early region 3 of adenovirus-2, forms complexes with major histocompatibility complex class I antigens. As a result of the complex formation, the intracellular transport of the class I antigens is abrogated, and adenovirus-infected cells display gradually diminishing quantities of cell surface-expressed class I molecules. To assess whether the E19 protein interacts equally well with different class I antigens, the associations between the viral protein and HLA-A2 and HLA-B7 antigens have been estimated. By infecting transfected HeLa cells expressing various amounts of HLA-A2 and HLA-B7 molecules, respectively, with various infectious doses of adenovirus-2, experimental conditions could be established that allowed quantitative estimates of the interactions to be determined. It was found that HLA-A2 molecules and the E19 protein interacts with a binding constant that is more than twice as high as that for HLA-B7 antigens and the viral protein. It is suggested that the pathogenicity of the virus may be dependent on the HLA-type of the infected individual.
Construction of human-mouse T cell hybrids that express human T cell-associated surface antigens and allow the chromosomal localization of these antigens.
Authors: van Dongen J J , Geurts van Kessel A H , Wolvers-Tettero I L , Versnel M A , van Oudenaren A , Schoenmaker E , Hagemeijer A
Published: December 2022

We have constructed somatic cell hybrids between the murine T cell line BW5147 and cells from patients suffering from T cell acute lymphoblastic leukemia. The obtained hybrid clones were analyzed for expression of human T cell antigens and presence of human chromosomes. T cell hybrids derived from fusion between the BW5147 cell line and bone marrow cells from a patient with pre-T acute lymphoblastic leukemia (TdT+/HLA-DR+/Tp41+/T11+/T1-/T6-/T4-/T8-/T3-) appeared to express the human T cell antigen Tp41, which can be recognized by the monoclonal antibodies 3A1 and WT1. Although this panel of hybrid cells contained all human chromosomes, no other T cell antigens were expressed. Fusion of the BW5147 cell line with peripheral blood cells from a patient with a more mature T cell acute lymphoblastic leukemia (TdT+/HLA-DR+/Tp41+/T11+/T1+/T6-/T4+/T8+/T3-) resulted in a panel of hybrid clones that expressed not only the Tp41 antigen, but also the human T cell antigens T1 and T4; two hybrids even expressed the T3 antigen. This panel of hybrids also contained the whole human genome. The two panels of human-mouse T cell hybrids allowed us to assign the genes coding for the human T cell antigens Tp41, T1, and T4 to human chromosomes 17, 11, and 12, respectively. Furthermore, these data support our previous suggestion that the expression of human lymphoid differentiation antigens in human-mouse lymphoid hybrids is influenced by the differentiation stage of the fusion partners.
Antibody-producing human-human hybridomas. III. Derivation and characterization of two antibodies with specificity for human myeloid cells.
Authors: Andreasen R B , Olsson L
Published: December 2022

Peripheral blood mononuclear cells from a patient with acute myeloid leukemia (AML) and spleen cells from a patient with chronic myeloid leukemia (CML) were fused with HAT-sensitive human B lymphoma cells (RH-L4) in attempts to generate human monoclonal antibodies (Mab) against antigens with high specificity for myeloid leukemia cells. Forty-seven of 246 hybridomas secreted Ig that bound to AML cell surface constituents, as determined by FACS analysis of viable cells that were FITC-stained with the human Mab as the first-step reagent and FITC-conjugated rabbit anti-human Ig as second-step. Two of the 47 human Mab (one from each patient and designated AML-19 and CML-20, respectively) bound to both autologous and allogeneic myeloid leukemia cells. No significant binding was observed to cell surface constituents on human bone marrow cells, granulocytes, lymphocytes, erythrocytes, thymocytes, monocytes, lymphoblastic leukemia cells, fibroblasts, malignant B and T lymphocytic cell lines, and murine bone marrow cells. Both human Mab were IgG and were cytotoxic to myeloid leukemia cells in the presence of complement. About 70% of peripheral blood cell samples from 46 AML patients contained AML-19- and CML-20-positive cells, but the reactivity pattern had no correlation to the morphologic FAB classification of the samples. The promyelocytic HL60 cell line and the K562 cell line reacted with the two antibodies. Dot blot analysis of binding of AML-19 and CML-20 to cellular extracts immobilized on nitrocellulose paper showed that both human Mab in this assay also reacted with normal bone marrow cells. This was supported by microscopic immunofluorescence because both human Mab stained intracytoplasmatic structures in normal bone marrow cells, but both intracytoplasmatic and cell surface components stained in myeloid leukemia cells. Moreover, immunoblotting demonstrated that both human Mab in leukemia cells reacted with two cellular proteins with Mr approximately 14,500 and 18,000, and in normal bone marrow cells with a molecule with Mr approximately 20,000. Immunoprecipitation of cell membrane molecules with both the AML-19 and CML-20 antibody precipitated from leukemic cells only the molecule with Mr approximately 18,000 and no components from normal bone marrow cells. It is concluded that myeloid leukemogenesis may result in generation of cell surface expression of either new or abnormally processed molecules that are immunogenic in the autochthonous host. These molecules may also be useful as markers in diagnosis of myeloid leukemia.
Idiotope antigens (Ab2 alpha and Ab2 beta) can induce in vitro B cell proliferation and antibody production.
Authors: Huang J H , Ward R E , Kohler H
Published: December 2022

We previously showed that immunization of various strains of mice with three types of antigen--PC-Hy (nominal antigen), F6-Hy (Ab2 alpha-Hy, and 4C11-Hy (Ab2 beta-Hy)--induces a differential PC-specific, T15-Id+ antibody response. In this report, the in vitro phosphorylcholine (PC)-specific B cell responses induced by these three antigens were studied. A hemocyanin-specific long-term T helper cell line was used to provide help for primary and secondary in vitro T cell-dependent B cell responses. At low doses (0.005 to 0.5 micrograms/ml) of antigen, a significant increase in the proliferation of PC-OVA-primed BALB/c B cells was observed with Ab2-Hy or PC-Hy conjugate, but not unconjugate, antigens. Similar low doses of antigen could stimulate naive B cells to secrete IgM and stimulate PC-OVA- or 4C11-Hy-primed B cells to secret IgM and IgG1 anti-PC antibodies. The percentage of T15-Id of the PC-specific antibodies produced in the in vitro T-B culture was found to be less dominant than that produced by in vivo immunization, suggesting that certain regulatory mechanisms occur in the in vivo environment that may help to maintain the T15-Id dominance. Taken together, our in vivo and in vitro results indicate that idiotope antigens can function like nominal antigens to induce antigen-specific B cell responses. The mechanisms of thymic-dependent B cell activation induced by idiotope and nominal antigen are similar in that the T-B interaction is MHC-restricted and requires cognate recognition.
Purification to homogeneity of a human hematopoietic growth factor that stimulates the growth of a murine interleukin 3-dependent cell line.
Authors: Watson J D , Crosier P S , March C J , Conlon P J , Mochizuki D Y , Gillis S , Urdal D L
Published: December 2022

A human lymphokine derived from the 5637 bladder carcinoma has been purified to homogeneity by using sequential reverse-phase high pressure liquid chromatography. A high recovery of biological activity is obtained by using this purification. The NH2-terminal amino acid sequence shows no homology to human interleukin 1 (IL 1), human IL 2, murine IL 3, or human granulocyte-macrophage colony-stimulating factor. The growth-promoting properties of the 5637-derived factor can be rapidly assayed by using the murine IL 3-dependent 32D c1-23 cell line. The amino acid sequence described is identical to that recently described for a human granulocyte colony-stimulating factor.
The choice between two distinct T cell determinants within a 23-amino acid region of lysozyme depends on their structural context.
Authors: Shastri N , Gammon G , Horvath S , Miller A , Sercarz E E
Published: December 2022

The specificity of C57BL/6 T cells reactive to peptide aa 74-96 of hen egg-white lysozyme (HEL) was analyzed by using a panel of synthetic peptides of varying lengths from this region. It was found that peptide 74-96-reactive T cells induced by native HEL (aa 1-129) or its denatured fragment L2 (aa 13-105) recognized two distinct but overlapping determinants contained within aa 74-90 or aa 81-96, respectively. Peptide 74-96 itself induced both peptide 74-90-and peptide 81-96-specific T cells. Thus, a choice was made between these two potential T cell determinants on peptide 74-96, depending on which immunogen was used. Interestingly, the ability of both peptide determinants aa 74-90 and aa 81-96 to stimulate peptide 74-96-reactive T cells was partly dependent on the presence of residues within the overlap region (aa 81-90), suggesting that this region may play an important role in Iab-restricted T cell activation. This was further supported by the poor immunogenicity of shorter peptides 74-86 or 85-96, lacking residues from the overlap region in B6 mice. These two short peptides were nevertheless capable of eliciting T cell responses in B10.A mice, suggesting that the importance of this overlap region in obtaining a response to peptide 74-96 is related to the MHC haplotype.
Only one DQ-beta restriction fragment pattern of each DR specificity is associated with insulin-dependent diabetes.
Authors: Böhme J , Carlsson B , Wallin J , Möller E , Persson B , Peterson P A , Rask L
Published: December 2022

Insulin-dependent diabetes is generally associated with the serologic HLA-DR specificities 3 and 4, in particular with DR-3,4 heterozygosity. The disease is negatively associated with DR-2. To investigate these associations further at the genomic level, DNA from 13 families with a proband having insulin-dependent diabetes, from 11 other individuals with the same disease, and from HLA-DR-matched control individuals was subjected to restriction fragment analysis. Three different enzymes (Bam HI, Eco RI, and Pvu II) and cDNA clones for three HLA-D region class II antigen alpha- and beta-chains (DR-beta, DQ-beta, and DQ-alpha) were used. In six families, a total of 11 siblings HLA-DR-identical to the proband were examined. There was no discrepancy between the hybridization patterns of the proband and those of the DR-identical siblings. Two different DQ-B fragment patterns were detected with each one of the serologic specificities DR-2 and DR-4. In both cases, only one of the patterns correlated significantly with diabetes. Thus, DQ-beta genomic hybridization may be used in conjunction with HLA-DR typing to identify individuals with higher relative risk to acquire insulin-dependent diabetes. These results may suggest that insulin-dependent diabetes is associated with the DQ rather than with the DR locus.
Origin of autoreactive T helper cells. I. Characterization of Thy-1+, Lyt-, L3T4- precursors in the spleen of normal mice.
Authors: de Talance A , Regnier D , Spinella S , Morisset J , Seman M
Published: December 2022

A new population of dull Thy-1+, Ly-1-, Lyt-2-, L3T4- PNA- cells, resistant to a double cytotoxic treatment by monoclonal antibodies to these T cell markers plus complement, has been isolated from the spleen of normal adult BALB/c and DBA/2 mice (Tkr cells). These cells exhibit no spontaneous autoreactivity or alloreactivity but can be activated with concanavalin A (Con A). Once activated, they differentiate into bright Thy-1+, Ly-1+, Lyt-2-, L3T4+ PNA- T lymphocytes. Con A-activated Tkr cells also strongly proliferate in the presence of allogeneic or syngeneic dendritic cells in secondary cultures. Moreover, contrary to other Con A-stimulated T cell populations, they induce B lymphocytes to proliferate and to differentiate into Ig-secreting cells at a very high level. Con A-activated Tkr cells are therefore very potent polyclonal B cell activators. Restimulated of Tkr cells by syngeneic dendritic cells can be inhibited by anti-L3T4 or anti-class II monoclonal antibodies. The results suggest that Tkr cells are the precursors of class II-specific autoreactive T helper cells. Tkr cells are absent in the spleen of B6 animals. This indicates that their expression might be genetically controlled. It also suggests that Tkr cells may not be the unique splenic precursors of autoreactive T cells. Con A activation of Tkr cells in Click's medium is 2-mercaptoethanol dependent and highly sensitive to pCO2, like the response of thymocytes. Tkr cells are also absent in the spleen of nude mice. We conclude that Tkr cells represent splenic precursors of autoreactive T helper cells equivalent to Thy-1+, Ly-2-, L3T4- PNA- cortical thymocytes.
The cells responsible for murine natural cytotoxic (NC) activity: a multi-lineage system.
Authors: Bykowsky M J , Stutman O
Published: December 2022

Previous studies on the surface phenotype of natural cytotoxic (NC) cells defined by negative selection with antibodies and complement showed that most if not all NC activity is the property of "null" cells that did not express a variety of lymphoid markers, including some expressed by natural killer (NK) cells. In the present study we show that when murine C57BL/6 spleen cells were sorted by flow cytometry into fractions positive or negative for Qa-5, Ly-2.2, Thy-1.2, L3T4, or surface immunoglobulin (sIg) and for high or low expression of H-2Kb, the pattern of NC activities was quite different from the negative selection experiments with antibody and complement. Enrichment of NC activity tested against WEHI-164 targets was observed in the H-2Kb high, Qa-5+, Thy-1.2+, and Ly-2.2- fractions, and to a lesser extent in the L3T4+ and sIg- fractions. However, significant NC activity, although lower than in the unseparated cells, was also found in the H-2Kb low, Qa-5-, Thy-1.2-, L3T4-, Ly-2.2+, and sIg+. With the exception of the anti-Ig, all the reagents were monoclonal antibodies. By comparison, NK activity tested against YAC-1 targets was clearly enriched in the H-2Kb high, Ly-2.2-, sIg-, and to a lesser extent, Thy-1.2+ sorted fractions, whereas most of the NK activity was in the L3T4- fractions. These results indicate that NC activity against WEHI-164 targets is mediated by an heterogeneous population of effector cells, which includes cells with markers of both the T and the B lineages, as well as of NK cells. These studies also show that negative selection with antibodies and complement is not always a reliable method for defining the surface phenotype of effector cells.
Immunoregulatory activity of human bone marrow. Identification of suppressor cells possessing OKM1, SSEA-1, and HNK-1 antigens.
Authors: Mortari F , Bains M A , Singhal S K
Published: December 2022

Human bone marrow contains natural regulatory cells capable of suppressing the in vitro primary IgM response of normal tonsillar cells. The suppression is mediated by non-T cells possessing Fc receptors, OKM1, SSEA-1, and HNK-1 antigens on their surface. The suppression was abrogated by treatment of bone marrow cells (BMC) with anti-HNK-1 or anti-SSEA-1 antisera and complement. Furthermore, BMC depleted of HNK-1+ cells could respond in a primary in vitro antibody response when provided with accessory T cells and macrophages from tonsillar cells. Our findings support the idea that HNK-1+ and HNK-1- BMC populations act antagonistically in the regulation of antibody synthesis. Further, the finding of HNK-1+, SSEA-1+, and OKM1+ suppressor cells in human bone marrow may represent a precursor phenotype of mature natural killer cells with potent immunoregulatory activity.
Identification of an early activation antigen (Bac-1) on human B cells.
Authors: Suzuki T , Sanders S K , Butler J L , Gartland G L , Komiyama K , Cooper M D
Published: December 2022

We have produced a monoclonal antibody, Bac-1, that appears to identify a novel antigen on activated human B cells. The Bac-1 antigen can be detected between 8 to 16 hr, as well as transferrin receptors (T9), after activation of small resting B cells with phorbol myristic acetate, anti-IgM antibody, Staphylococcus aureus Cowan I, or Epstein-Barr virus. The expression of the Bac-1 antigen precedes that of IL 2 receptors (Tac-1). Peak expression of the Bac-1 antigen was observed on day 3 after activation, and decreased thereafter. The Bac-1 antigen was present on a minor subpopulation of relatively large B cells isolated from blood samples, and on "preactivated" B cells of heterogeneous size isolated from spleens and tonsils. It was not detected on bone marrow pre-B cells, blood small B cells, or plasma cells, nor was it expressed by resting or activated T cells or nonlymphoid cells. Certain B cell neoplasms and B lymphoblastoid cell lines were Bac-1+, but neoplastic cells of non-B lineage were Bac-1-. With immunoperoxidase staining, Bac-1+ cells were detected predominantly in the germinal centers of tonsil sections. The Bac-1 antigen on activated B cells was destroyed by protease treatment and was enhanced by neuraminidase treatment, suggesting that the Bac-1 antibody detects a cell surface molecule via an antigenic determinant which is partially obscured by neighboring sialic acid residues. The reactivity pattern of Bac-1 differs from the patterns of cellular reactivity reported for other monoclonal antibodies with specificity for activated human B cells.