bluuebunny/crossref_metadata_2025 huggingface dataset:
T cell receptor-CD3 complex during early T cell differentiation. Analysis of immature T cell acute lymphoblastic leukemias (T-ALL) at DNA, RNA, and cell membrane level.
Authors: van Dongen J J , Quertermous T , Bartram C R , Gold D P , Wolvers-Tettero I L , Comans-Bitter W M , Hooijkaas H , Adriaansen H J , de Klein A , Raghavachar A
Published: December 2022

T cell acute lymphoblastic leukemias (T-ALL) can be regarded as the malignant counterparts of cells in various T cell differentiation stages. To study the expression of the human T cell receptor (TcR)-CD3 complex during the early stages of T cell differentiation, we have analyzed 22 T-ALL at the cell membrane level and the DNA level and 12 of them at the RNA level. According to their immunologic phenotype, the T-ALL could be divided into three main groups: 10 immature T-ALL (CD1-/CD3-), seven common thymocytic T-ALL (CD1+/CD3-or+), and five mature T-ALL (CD1-/CD3+). Among the 10 immature T-ALL three appeared to express the immunologic phenotype of the putative prothymocyte (TdT+/HLA-DR+/CD7+/CD2+/CD5-/CD1-/CD3-), whereas the other seven T-ALL appeared to be immature thymocytic (TdT+/HLA-DR-/CD7+/CD2+/CD5+/CD1-/CD3-). Transcripts of the CD3-delta and CD3-epsilon genes were present in all CD3- and CD3+ T-ALL tested, including prothymocytic T-ALL. However, prothymocytic T-ALL had germline TcR-beta genes and were not rearranged to the characterized TcR-gamma joining regions. The presence of CD3 transcripts and absence of TcR gene rearrangements in prothymocytic T-ALL supports their immature T cell character. Two immature thymocytic T-ALL also had germline TcR-gamma genes and one of them had germline TcR-beta genes. In all other T-ALL the TcR-gamma and TcR-beta genes were rearranged. The presumptive functional 1.3-kilobase TcR-beta transcripts were detected in the majority of T-ALL with rearranged TcR-beta genes. Distinct levels of TcR-gamma transcripts appeared to be present only in some thymocytic T-ALL, i.e., some immature thymocytic T-ALL and common thymocytic T-ALL. TcR-alpha mRNA could only be detected in CD3+ mature T-ALL, but was absent in all CD3+ common thymocytic T-ALL tested. Our data indicate that CD3 gene transcription is one of the earliest events during T cell differentiation and already occurs in prothymocytes. The TcR-gamma and TcR-beta genes rearrange early during thymocytic differentiation and can subsequently be transcribed. High levels of TcR-gamma gene transcription may only occur in a part of the T cells during thymic differentiation, while TcR-beta gene transcription continues during further differentiation. TcR-alpha gene transcription may be the final step in the production of the complete set of TcR and CD3 proteins, resulting in the expression of the TcR alpha beta-CD3 complex at the cell surface of mature T cells.(ABSTRACT TRUNCATED AT 400 WORDS)
Idiotype vaccination against murine B cell lymphoma. Inhibition of tumor immunity by free idiotype protein.
Authors: Kaminski M S , Kitamura K , Maloney D G , Levy R
Published: December 2022

A murine B cell lymphoma (38C13) was used as a model to study the induction of idiotype (Id)-specific tumor immunity. Immunization of syngeneic mice with Id protein derived from the tumor resulted in the production of anti-Id antibodies by the host and in the induction of a state of resistance to tumor growth. Tumor immunity could be established only if the Id protein was conjugated to a strongly immunogenic carrier protein such as keyhole limpet hemocyanin or thyroglobulin, and if the conjugate was administered at least 1 week prior to tumor challenge. Free Id protein, such as that present in tumor bearing animals, was found to inhibit tumor immunity in a dose-dependent manner. Although tumor immunity could be induced in animals with pre-existent serum Id protein, the expression of the immune state was inhibited by the presence of the soluble protein.
Immunochemical and functional analysis of HLA class II antigens induced by recombinant immune interferon on normal epidermal melanocytes.
Authors: Tsujisaki M , Igarashi M , Sakaguchi K , Eisinger M , Herlyn M , Ferrone S
Published: December 2022

The effect of recombinant immune interferon (IFN-gamma) on the expression and shedding of HLA antigens and of melanoma-associated antigens (MAA) by epidermal melanocytes was investigated by using serologic and immunochemical techniques. IFN-gamma enhances the expression and/or shedding of HLA class I antigens and of the cytoplasmic MAA defined by monoclonal antibody (MoAb) 465.12S and induces a slight reduction in the expression of the high m.w. melanoma-associated antigen (HMW-MAA). In agreement with the data in the literature, melanocytes incubated with IFN-gamma acquire HLA-DR, -DQ, and -DP antigens. Contrary to previous information in the literature, the effect is not restricted to HLA class II antigens, since IFN-gamma also induces the expression of the 96-kDa MAA recognized by MoAb CL203. The effect of IFN-gamma on HLA class II antigens and 96-kDa MAA is dose and time dependent and is specific, because recombinant leukocyte interferon affects the expression of neither type of antigen. In spite of the expression of HLA class II antigens, IFN-gamma-treated melanocytes do not acquire the ability to stimulate the proliferation of allogeneic lymphocytes. HLA-DR antigens are more susceptible to induction by IFN-gamma than HLA-DQ and -DP antigens, since the percentage of melanocytes acquiring HLA-DQ and -DP antigens is lower than that acquiring HLA-DR antigens. Furthermore, the dose of IFN-gamma is higher and the time of incubation is longer to induce HLA-DQ and -DP antigens than to induce HLA-DR antigens. The differential susceptibility of HLA-DR, -DQ, and -DP antigens as well as of melanocytes from various donors to the modulating effect of IFN-gamma may provide an explanation for the more frequent detection of HLA-DR than of HLA-DQ and -DP antigens in melanoma lesions and for the expression of HLA class II antigens by some, but not all, melanoma lesions.
Graft-vs-host reaction limited to a class II MHC difference results in a selective deficiency in L3T4+ but not in Lyt-2+ T helper cell function.
Authors: Moser M , Mizuochi T , Sharrow S O , Singer A , Shearer G M
Published: December 2022

Hybrid mice of the (B6 X bm12)F1 combination were inoculated i.v. with parental B6 spleen cells to induce a class II graft-vs-host disease (GVH). Such mice failed to generate in vitro cytotoxic T lymphocyte (CTL) responses that were dependent upon L3T4+ T helper cell (Th) function (e.g., anti-B6-TNP) but were capable of generating in vitro CTL responses that could be mediated by Lyt-2+ Th cells (anti-allo class I). When Th function was assayed directly by interleukin 2 (IL 2) secretion, class II GVH animals were found to be deficient in L3T4+ but not Lyt-2+ IL 2-secreting Th cells. This selective deficiency in L3T4+ Th function correlates with a selective decrease in class II GVH mice of host-derived derived L3T4+ T cells. In addition, it was found that the spleens of class II GVH mice contained cells capable of selectively suppressing L3T4+ Th function. In contrast, mice in which a class I + II GVH occurred were depleted of both L3T4+ and Lyt-2+ Th function as assessed by IL 2 production. The findings that class II GVH selectively depletes L3T4+ T cells and T cell functions are discussed with respect to the immune function of distinct T cell subsets in normal and diseased states.
Synergistic interactions between interleukin 1, tumor necrosis factor, and lymphotoxin in bone resorption.
Authors: Stashenko P , Dewhirst F E , Peros W J , Kent R L , Ago J M
Published: December 2022

Cytokines with bone-resorbing activity include IL 1 beta (pI 7), IL 1 alpha (pI 5), tumor necrosis factor (TNF), and lymphotoxin (LT). Possible interaction between IL 1 beta, the major mediator with osteoclast-activating factor (OAF) activity, and other cytokines was studied. By itself, IL 1 beta was 13-fold more potent than IL 1 alpha and 1000-fold more potent than either TNF or LT in stimulating bone resorption. Suboptimal concentrations of IL 1 beta or IL 1 alpha in combination with suboptimal concentrations of TNF or LT resulted in synergistic bone-resorptive responses (1.5 to 10 times the expected responses if their effects were additive). Synergy between either form of IL 1 and TNF or LT resulted in a twofold increase in activity of IL 1, and a 100-fold increase in activity of TNF or LT. However, even with optimal synergy, IL 1 beta remained 20-fold more potent in inducing bone resorption than TNF or LT. Because IL 1 beta is considerably more potent than TNF and LT in stimulating bone resorption either alone or under synergistic conditions, it is unlikely that TNF and LT are responsible for more than a minor proportion of the total bone-resorbing activity formerly referred to as OAF.
Evidence that a protective membrane epitope is involved in early but not late phase immunity in Schistosoma mansoni.
Authors: Harn D A , Quinn J J , Cianci C M , Ko A I
Published: December 2022

An anti-egg monoclonal antibody E.1, which is partially protective in passive transfer experiments, is shown in this study to recognize a membrane epitope on cercariae, schistosomula, and the ciliary plates of miracidia. E.1 did not bind to the surface membranes of lung or adult worms, or recognize secreted egg antigen in infected liver tissue. The E.1 epitope was present in the glycocalyx of cercariae, as well as on the syncytial membrane as determined by electron microscopy. Immunoprecipitation of iodinated surfaces of cercariae and schistosomula demonstrated E.1 binding to a high m.w. moiety in cercariae, which corresponds to the glycocalyx because it was not immunoprecipitated from schistosomula. In addition, a band at 38,000 daltons was immunoprecipitated from both cercariae and schistosomula. When compared with in vitro cultured parasites, schistosomula that were obtained from mice 1 to 24 hr after tail vein injection showed significant loss of E.1 binding. Consistent with the rapid loss of antigen in vivo, E.1 antibody was unable to passively transfer protection to naive mice when administered 5 days after cercarial challenge.
Identification of specific and cross-reactive antigens of Leishmania donovani chagasi by human infection sera.
Authors: Reed S G , Badaro R , Lloyd R M
Published: December 2022

Cloned Leishmania donovani chagasi (Ldc) promastigotes were analyzed by SDS-PAGE separation and immunoblotting with human infection sera. The patterns of antigen reactivity were compared by using sera from individuals with Ldc, Leishmania mexicana amazonensis (Lma), Trypanosoma cruzi, Mycobacterium tuberculosis, or Mycobacterium leprae infections. Sera from individuals with these infections recognized Ldc antigens in several m.w. ranges. Reactivity was due to recognition of Ldc molecules and not to Ldc culture medium components, as shown by comparing Ldc promastigotes grown in the presence or absence of fetal bovine serum (FBS), by immunoblotting of FBS, and by [35S]methionine labeling. The major findings of the study were as follows. Immunoblots with Ldc promastigotes could be used to distinguish individuals with Ldc infections from those with Lma infections. Persons with Ldc infections had antibodies to a Ldc antigen of approximately 32 to 35 kd not recognized by persons with Lma infections. Individuals cured of acute Ldc infection did not develop antibodies that differed in specificity to those present during their acute phase of infection. Ldc antigens in the 62 to 66 kd region were recognized by all individuals with Ldc or Lma infections but were not recognized by individuals in the other disease groups or by control sera. This region was found to contain at least four distinct bands, one of which appeared to be glycosylated as indicated by periodic acid-Schiff staining and concanavalin A labeling; an apparently nonglycosylated protein of 62 to 63 kd was eluted from SDS-PAGE gels and was used to diagnose Ldc infection by the ELISA. Whereas crude Ldc antigen gave false positive results with T. cruzi and mycobacteria infection sera, the eluted 62 to 63 kd protein was 100% specific and sensitive in the diagnosis of Ldc infection.
Highly preferential VH-VL pairing in normal B cells results in antigen-independent selection of the available repertoire.
Authors: Primi D , Drapier A M , Cazenave P A
Published: December 2022

The aim of this work was to analyze the probabilities of combined expression of the various polymorphic forms of two well-defined VH and VK segments. The availability of two monoclonal antibodies specific, respectively, for the VHT15 and VK21 D-E gene products allowed us to study, both in the selected and in the preimmune repertoire, the expression of VHT15-VK21 D-E pairs in several mouse strains. Our data establish, first, that even before antigen encounters B cells, clones utilize a highly biased repertoire of VH-VL combinations and, secondly, that the level of productive VH-VL pairing depends primarily on the "allelic" form of the relevant VH and VK genes. Furthermore, clonal analysis revealed that this asymmetry in Ig gene expression affects a large proportion of newly arising B cells. Together, these studies demand reconsideration of the current estimates of the available antibody repertoire size, and provide new insights for our understanding of the phenomenon of clonal dominance.
Idiotype regulation of the anti-bovine serum albumin response. I. Generation of an idiotype-specific Lyt-1-2+ suppressor T cell.
Authors: Eddy N K , Apple R J , Michael J G
Published: December 2022

A monoclonal antibody (3C-7) specific for a determinant localized on the carboxy-terminus of the BSA molecule (P505-582) has been shown to cause suppression of the multispecific BSA antibody response if given i.v. before immunization. The fine binding specificity and the isotype subclass are not responsible for the suppression generated. Administration of 3C-7 i.v. results in the generation of a suppressor T cell that, when transferred into reconstituted irradiated mice, results in a diminished anti-BSA response. Suppression can be eliminated by panning T cells on idiotype (3C-7) coated plates, but not by panning on BSA, polyclonal anti-BSA antibodies, or MOPC 21. The action of the cell is antigen (BSA) specific. Idiotype-binding T cells reconstitute suppression and appear to be Lyt-1-2+. These observations demonstrate that a limited set of monoclonal antibodies directed against a single determinant on a protein molecule have the capacity to regulate the immune response to a multiplicity of determinants present on the same protein. These data support the concept of antibody-induced regulation by the induction of suppressor cells through idiotype recognition.
Isotype restriction during infection of mice with the cestode Mesocestoides corti: role of immune suppression.
Authors: Abraham K M , Teale J M
Published: December 2022

Mice infected with the parasite Mesocestoides corti produce a vigorous antibody response that is restricted to the IgM and IgG1 heavy chain classes. The isotypic restriction observed is apparently associated with active infection and is not a unique characteristic of responses to M. corti antigens. Thus, animals immunized with intact but nonviable parasites respond with the production of a variety of antibody isotypes in addition to IgM and IgG1. To delineate immunoregulatory mechanisms involved in the isotypic restriction of antibody responses to M. corti, an in vitro lymphocyte suspension culture was established. The data indicate that there are two cell subsets in the spleens of infected mice that contribute to an overall suppression of the in vitro antibody response. Thus, both Lyt-2+ cells and G-10-adherent cells must be removed to maximize antibody production. However, the anti-parasite response obtained in vitro after depletion of Lyt-2+ cells and G-10-adherent cells is restricted to the IgM and IgG1 isotypes as observed in vivo, indicating that suppression is not actively involved in the IgM, IgG1 dominance of the response. The cellular regulation associated with this restriction was then studied by using isolated helper T cells derived from parasite-infected animals to stimulate B cells from uninfected animals. The antibody produced was again restricted to IgM and IgG1, indicating that the helper T cells were regulating the preferential expression of the IgM and IgG1 antibody classes.
Human monocyte adherence: a primary effect of chemotactic factors on the monocyte to stimulate adherence to human endothelium.
Authors: Doherty D E , Haslett C , Tonnesen M G , Henson P M
Published: December 2022

Monocyte emigration into areas of inflammation is initiated by monocyte adherence to the microvascular endothelium which may be induced by the local production of chemotactic factors at the inflammatory site. However, it is not clear whether such stimuli act on the monocyte and/or the endothelial cell to promote this effect. Accordingly, the effect of the chemotactic peptides C5a des arg and formyl-methionyl-leucyl-phenylalanine (FMLP) on human monocyte adherence to human microvascular endothelial cell monolayers was investigated in vitro. Monocytes (92 to 98% pure) were isolated by discontinuous plasma-Percoll density gradients and cell elutriation, methods designed to minimize monocyte exposure to endotoxin. Mean spontaneous (unstimulated) adherence of 111Indium-tropolonate-radiolabeled monocytes to microvascular endothelial cell monolayers was 19.7% +/- 1.3. Monocyte adherence to microvascular endothelial cell monolayers was stimulated in a dose-response fashion in the presence of C5a des arg or FMLP to a maximum mean adherence of 47.2% +/- 2.9 or 43.8% +/- 2.2, respectively. C5a des arg or FMLP stimulated monocytes to adhere to monolayers of human vascular smooth muscle cells, human dermal fibroblasts, or serum-coated plastic wells in a comparable fashion as to endothelial cells. The simultaneous presence of both chemotactic peptides C5a des arg and FMLP in the assay system stimulated monocyte adherence to the same degree as either stimulus alone. This finding suggested that those monocytes stimulated to adhere by C5a des arg were the same subpopulation responding to FMLP. Spontaneous monocyte adherence (in the absence of chemotactic peptides) to both endothelial cell monolayers and serum-coated plastic wells was reduced in the presence of plasma, but chemotactic peptides induced a significant, albeit reduced, adhesion of monocytes in this circumstance. The pretreatment of monocytes with either C5a des arg or FMLP prior to the adherence assay induced stimulus-specific desensitization of monocyte adherence. Neither a desensitization nor stimulated monocyte adherence occurred when endothelial cell monolayers or serum-coated plastic wells were pretreated with either of the chemotactic peptides. The fixation of endothelial cell monolayers prior to the adherence assay did not alter the degree of spontaneous, C5a des arg-stimulated, or FMLP-stimulated monocyte adherence. These data suggest that the stimulated adhesion of monocytes to endothelial cells by C5a des arg or FMLP represents primarily an effect of these chemotactic peptides on the monocyte.
Interleukin 1 stimulates endothelial cells to release multilineage human colony-stimulating activity.
Authors: Segal G M , McCall E , Stueve T , Bagby G C
Published: December 2022

Cultured human umbilical vein endothelial cells, when exposed to soluble products of peripheral blood monocytes, elaborate granulocyte-macrophage colony-stimulating activity (GM-CSA) and erythroid burst-promoting activity (BPA). We have performed studies to determine if the monokine IL 1 can stimulate endothelial cells to release hematopoietic growth factors and whether such factors can also support human megakaryocyte (Meg) and mixed-cell colony growth. Various concentrations of recombinant human IL 1 beta (rIL 1) and media conditioned by monocytes (MCM), endothelial cells (ECM), and endothelial cells cultured for 3 days in 50% MCM (ECMM) or rIL 1 (ECMrIL 1) were added to marrow mononuclear cells cultured in methylcellulose. ECMM and ECMrIL 1 stimulated, in a dose-dependent fashion, the growth of Meg, mixed-cell, and GM colonies and erythroid bursts. In contrast, ECM, MCM, and rIL 1 displayed little or no activity in the colony-forming assays. Preincubation with specific antisera to native human IL 1 or rIL 1 reduced by 75 to 100% the activity of MCM in stimulating endothelial cell release of BPA, GM-CSA, Meg-CSA, and mixed-cell CSA. Meg-CSA, although readily detectable at ECMM and ECMrIL 1 concentrations in culture of 1 to 5%, was partially masked by lineage-specific inhibitors of Meg colony growth. When ECMM was analyzed by gel filtration chromatography, the megakaryocytopoietic inhibitory activity eluted in the high Mr fractions (greater than 75 kD). Meg-CSA co-eluted with GM-CSA and BPA in a single peak of 30 kD. We conclude that endothelial cells, in response to IL 1, produce one or more growth factors that probably act on multiple classes of progenitor cells.
Role of T cell-replacing factor (TRF) in the murine B cell differentiation: induction of increased levels of expression of secreted type IgM mRNA.
Authors: Matsumoto M , Tominaga A , Harada N , Takatsu K
Published: December 2022

T cell-replacing factor (TRF) is known to play a critical role in the regulation of B cell growth and differentiation. In this study, the role of TRF in the expression of mRNA for both IgM and IgG1 class was investigated. The TRF was purified from cellfree supernatants from a T cell hybridoma, B151K12. RNA was isolated from chronic B cell leukemia (BCL1) cells, DNP-KLH-primed B cells, or normal B cells cultured with or without LPS, and LPS plus TRF or LPS plus BSF-1. The steady state level of isotype-specific mRNA was assessed by Northern blot analysis with a mu-specific or a gamma 1-specific probe. It was demonstrated that BCL1 and purified B cells cocultured with TRF expresses increased levels (twofold and fourfold, respectively) of secreted forms of mu mRNA. Purified B cells from DNP-KLH-primed mice also expressed increased levels (twofold to fourfold) of mu as well as gamma 1 mRNA for secreted form by stimulation with TRF. Total expression of mu mRNA, however, was approximately threefold higher than that of gamma 1 mRNA. The stimulation of normal B cells with LPS plus TRF induced an increase in the levels of mu mRNA and gamma 1 mRNA expression, fourfold and threefold, respectively. However, the levels of gamma 1 mRNA expression was one-third of that induced in B cells stimulated with LPS plus BSF-1. These results indicate that TRF preferentially induces increased levels of secreted type of mu mRNA and induces less gamma 1 mRNA than BSF-1. The differential role of TRF from BSF-1 in the expression of Ig mRNA will be discussed.
Methylxanthine bronchodilators potentiate multiple human neutrophil functions.
Authors: Schmeichel C J , Thomas L L
Published: December 2022

Methylxanthines, including the bronchodilators theophylline and aminophylline, in high concentrations (greater than 10(-4) M) inhibit cyclic nucleotide phosphodiesterase activity and in low, clinically relevant concentrations (10(-5) to 10(-4) M) are antagonists of extracellular adenosine receptors. The effect of therapeutic concentrations of methylxanthines on human neutrophil functions stimulated by N-formyl-methionyl-leucyl-phenylalanine (FMLP) was examined. Preincubation of cytochalasin B-treated neutrophils with 10(-5) M to 3 X 10(-3) M methylxanthine resulted in a biphasic, concentration-dependent effect on neutrophil aggregation, lysosomal enzyme release, and superoxide anion formation. At 10(-5) to 10(-4) M, theophylline and aminophylline potentiated neutrophil aggregation, lysosomal enzyme release (30 to 50%, p less than 0.005), and superoxide anion formation (30 to 60%, p less than 0.005). 1-Methyl-3-isobutylxanthine at these same concentrations potentiated only neutrophil aggregation and lysosomal enzyme release (30 to 40%, p less than 0.005). The three methylxanthines inhibited each response up to 90% at concentrations greater than 10(-4) M. 8-Phenyltheophylline, which does not inhibit phosphodiesterase activity, produced only potentiation. Preincubation of neutrophils with adenosine deaminase mimicked the methylxanthine potentiation, whereas addition of adenosine (3 X 10(-8) to 3 X 10(-7) M) reversed the methylxanthine-induced potentiation in a concentration-dependent manner. These results indicate that therapeutic concentrations of methylxanthines may potentiate neutrophil activation in vivo by competing with circulating adenosine for neutrophil adenosine receptors.
Dexamethasone inhibits receptor-activated phosphoinositide breakdown in rat basophilic leukemia (RBL-2H3) cells.
Authors: Berenstein E H , Garcia-Gil M , Siraganian R P
Published: December 2022

The activation of rat basophilic leukemia cells for histamine release is accompanied by Ca2+ influx and arachidonic acid release. IgE receptor but not A23187 ionophore stimulation of these cells also resulted in phosphoinositide breakdown. In these experiments, the culture of these cells with dexamethasone inhibited IgE- and ionophore-mediated histamine release. The concentration for 50% of maximal inhibition was 12 nM, and prolonged exposure to the drug was required, with maximal effect observed in 8 to 15 hr. The inhibitory effect of dexamethasone was reversible (t1/2 for recovery was 16 hr). Dexamethasone blocked the IgE-mediated 45Ca2+ influx and the release of [14C]-arachidonic acid (IC50 of 1 nM and 10 nM respectively). Dexamethasone inhibited the IgE receptor-mediated phosphoinositide breakdown (IC50 of 5 nM). It also decreased arachidonic acid release after A23187 stimulation demonstrating an effect on phospholipase A2. Therefore, exposure of the cells to dexamethasone results in the inhibition of both phospholipase A2 and phospholipase C pathways of arachidonic acid generation.
Parasite-accessory cell interactions in murine leishmaniasis. II. Leishmania donovani suppresses macrophage expression of class I and class II major histocompatibility complex gene products.
Authors: Reiner N E , Ng W , McMaster W R
Published: December 2022

In the present study, we examined the modulation of MHC class II and class I gene products on BALB/c macrophages infected with the obligate intracellular protozoan Leishmania donovani. Our findings indicated that this organism suppressed macrophage expression of both classes of MHC antigens. These effects varied somewhat, depending on whether cells were in the basal state or were stimulated with interferon-gamma. Thus, class II density on interferon-gamma-treated infected macrophages was suppressed by as much as 90%, relative to lymphokine-stimulated control cells. Induction of H-2K and H-2D by lymphokine treatment of infected macrophages was also markedly reduced. In the basal (non-lymphokine-treated) state, infected cells also showed reduced expression of H-2K and H-2D, but not I-A or I-E. The latter result was related to minimal levels of class II molecules on normal, in vitro cultured macrophages. Suppression of MHC gene products correlated with both the duration and intensity of leishmania infection and could not be overcome by increasing doses of interferon-gamma. Culture of cells under conditions of cyclooxygenase inhibition completely abolished elevated synthesis of prostaglandin E2 by infected macrophages and augmented their responsiveness to lymphokine induction of class II antigens by 60 to 80%. These results indicate that L. donovani is capable of subverting a critical macrophage accessory function required for the induction of T lymphocyte immunity. This mechanism could account, at least in part, for defective parasite-specific cell-mediated immunity seen during infections with this protozoan.
Human allospecific cytolytic T lymphocyte lysis of a murine cell transfected with HLA-A2.
Authors: Koller T D , Clayberger C , Maryanski J L , Krensky A M
Published: December 2022

A variety of molecules are involved in the interaction of human allospecific cytolytic T lymphocytes (CTL) with target cells. Monoclonal antibodies specific for these molecules inhibit CTL-target conjugate formation and/or lysis. To further study recognition and lysis of targets by human CTL, we used a murine mastocytoma cell line transfected with the histocompatibility leukocyte antigen (HLA)-A2 gene (P815-A2+) as a target for human HLA-A2-specific CTL. We find that only a subset of human HLA-A2-specific CTL can lyse murine P815-A2+ cells, suggesting that the murine cells may lack one or more accessory molecules needed for CTL recognition and lysis.
Idiotype-specific Ly-1 B cell-mediated helper activity: hybridomas that produce anti-idiotype antibody and nonimmunoglobulin lymphokine(s)1.
Authors: Sherr D H , Braun J , Dorf M E
Published: December 2022

Previous work has shown that the expression of a predominant family of idiotypic determinants (NPb) in the in vitro response to the 4-hydroxy-3-nitrophenyl acetyl (NP) hapten is dependent on helper activity provided by Ly-1- and Ig-bearing B cells called BH. The ability of these BH cells to perform this idiotype-specific, genetically controlled helper function is related to the NPb idiotype specificity of their cell surface receptors. However, the means by which BH cells communicate with and stimulate NPb idiotypic B cell subsets is unknown. In this paper, an Ly-1- and immunoglobulin-bearing B helper cell hybridoma is described. Supernatants from the hybridoma or its subclones were shown to specifically help the response of NPb idiotypic PFC to NP-Ficoll when added to responder cell cultures depleted of Thy-1 and Ly-1 regulatory cell populations. Under these experimental conditions hybridoma supernatants functioned in much the same fashion as populations of Ly-1- and Ig-bearing BH helper populations described previously. NPb idiotype-specific helper activity was mediated by two separable activities elaborated by the hybridoma, an anti-NPb idiotype antibody and a non-Ig (lymphokine) activity. It was shown that both the Ig and the lymphokine components were required for helper activity. Kinetics experiments showed that the anti-idiotype antibody must be added early in the response to NP-Ficoll, whereas the lymphokine fraction could be added at least as late as day 3 of a 4-day culture in order to observe NPb idiotype-specific help. The data suggest that Ly-1 B cell hybridomas may affect the responsiveness of B cell subsets initially by interaction of anti-idiotype antibody with NPb idiotypic B cell surface receptors, followed by growth or maturation signals mediated by non-Ig lymphokine(s). The possibility that the helper activity of these Ly-1 B cell hybridomas represents the combined effects of an idiotype-specific network system and nonspecific growth or maturation factor activity in direct B cell-B cell interactions is discussed.
Modified responses to recipient and donor B cells by genetically donor T cells from human haploidentical bone marrow chimeras.
Authors: Schiff S E , Buckley R H
Published: December 2022

After administration of haploidentical stem cells to infants with severe combined immunodeficiency disease (SCID), mature T cells of donor karyotype appear later in the recipient without causing graft-vs-host disease (GVHD). To investigate the effect of the host microenvironment on these genetically donor T cells, mixed leukocyte cultures were carried out. Unfractionated mononuclear cells (MNC) from eight infants with SCID immunologically reconstituted by haploidentical bone marrow stem cells responded in the same pattern as MNC from non-chimeric individuals to autologous and allogeneic irradiated MNC, even though they contained all genetically donor T cells and all genetically patient B cells and monocytes. This included surprisingly vigorous proliferative responses of the patients' MNC to the original donors' irradiated MNC. This autoreactivity could be detected as soon as T cell function appeared post-transplantation and appeared to increase with time. It could be blocked by the addition of monoclonal antibodies to HLA Class II antigens. Responses of most patients' MNC were similar whether stimulated by irradiated MNC from the donor or non-donor parent or by those from unrelated normal controls. Purified genetically donor T cells that had matured from stem cells in the patient's microenvironment responded vigorously to purified donor B cells. These same cells responded much less to patient B cells. In six cases, such genetically donor T cells responded less to patient B cells than fresh donor T cells did to donor B cells in the autologous mixed leukocyte response. By contrast, T cells of donor karyotype from three of the patients responded more vigorously to donor B cells than fresh donor T cells did. Thus, genetically donor T lymphocytes that had matured from stem cells in the recipient microenvironment behaved differently from those that had matured in the donor. The hyporesponsiveness of genetically donor T cells from the patient to patient B cells does not appear to be due to T suppressor cells.
IL 1 induction by murine T cell clones: detection of an IL 1-inducing lymphokine.
Authors: Takacs L , Berzofsky J A , York-Jolley J , Akahoshi T , Blasi E , Durum S K
Published: December 2022

T cell activation is widely believed to depend on interleukin 1 (IL 1) provided by antigen (Ag)-presenting cells (APC). Because IL 1 is not a constitutive product of APC, we examined the features of its production during the interaction of murine T cell clones and APC. We observed that IL 1 was detectable in supernatants of most myoglobin-specific T cell clones grown with APC and Ag. Two of these T cell clones induced exceptionally high levels of IL 1 in their supernatants, and these same clones demonstrated the unusual restriction to I-Ek, which is a low responder type for sperm whale myoglobin. One of these clones was characterized additionally as to the mechanism of IL 1 induction. This clone rapidly stimulated IL 1 production in the APC population (detectable at 4 hr of co-culture) or in macrophages (M phi) or a M phi-like cell line. IL 1 induction was Ag dependent and H-2 restricted. Induction was radioresistant, both on the part of the T cell and of the IL 1 producer. The IL 1-induction process was attributable to a lymphokine produced by the T cell clone. This lymphokine was distinct from IFN-gamma, TNF and CSF-1 and may account for a principal mechanism of T----APC signalling. The induced IL 1 was the same in size, co-mitogenicity, and pyrogenicity as lipopolysaccharide-induced IL 1.
IL 1 expression in a clone of human T cells.
Authors: Acres R B , Larsen A , Conlon P J
Published: December 2022

Three human T cell clones, all of which are T3+, T4+, T8-, and T11+, were examined for IL 1 production. Two clones were found to express readily detectable, membrane-bound IL 1 activity upon stimulation with OKT3 antibody, rIL 2, and PMA. Northern blot analysis of RNA from one of the clones shows that cells can be induced to express the genes for both IL 1 alpha and IL 1 beta. Furthermore, the pattern of expression in response to different stimuli suggests that the genes for IL 1 alpha and IL 1 beta are regulated independently.
Evaluation of human peripheral blood leukocytes for mast cell tryptase.
Authors: Castells M C , Irani A M , Schwartz L B
Published: December 2022

Murine monoclonal and goat polyclonal antibodies against tryptase, the dominant neutral protease and protein component in secretory granules of human mast cells, were used to assess the presence of tryptase in peripheral leukocytes. Carnoy's fluid-fixed cytocentrifuge preparations of enriched populations of lymphocytes, monocytes, eosinophils, and neutrophils showed no reactivity with anti-tryptase antibodies by a sensitive indirect immunoperoxidase procedure. Dispersed human lung mast cells showed strong granular cytoplasmic staining with both antibodies, whereas only approximately 50% of the peripheral blood basophils detectable with Wright's stain were detected with anti-tryptase antibodies, and these showed a staining pattern that was faint, granular, and cytoplasmic at high concentrations of antibody. At lower antibody concentrations mast cell staining was still intense, whereas basophils were not stained. Extracts of neutrophils and lymphocytes of up to 90% purity had undetectable amounts of tryptase by an ELISA sandwich immunoassay, as well as undetectable enzymatic activity with tosyl-L-gly-pro-lys-p-nitroanilide (a sensitive substrate for tryptase) in the presence of soybean trypsin inhibitor. Extracts of basophil-enriched (6 to 50% purity) preparations contained 0.046 +/- 0.013 pg of tryptase per basophil by the immunoassay along with 2 X 10(-9) +/- 0.8 X 10(-9) U of tryptase-like enzyme activity per basophil, compared with corresponding values of 12 pg, 480 X 10(-9) U of tryptase per human lung mast cell. Thus very small amounts of tryptase are present in human basophils (approximately 0.4% of that found in mast cells), but not in other peripheral leukocytes.
Creation of an HLA-A2/HLA-Aw69 alloantigenic determinant on an HLA-A3 molecule by site-directed mutagenesis.
Authors: Layet C , Kahn-Perles B , Pontarotti P , Ferrier P , Sire J , Lemonnier F A
Published: December 2022

The HLA-A2 and HLA-Aw69 molecules share an antigenic determinant not expressed by HLA-Aw68 and HLA-A3. Comparison of the amino acid (aa) sequences of these molecules and previous studies of the antigenic determinant expressed by different HLA-A2 X HLA-A3 hybrid molecules had established that three aa at positions 95, 97, and 107 were possibly involved in the formation of this determinant. The HLA-A3 gene was therefore mutagenized to replace successively at these positions the HLA-A3-specific aa by the HLA-A2 residues. A single substitution at position 107 of a glycine by a tryptophan residue is sufficient for full expression by HLA-A3 molecules of the HLA-A2/Aw69 shared antigenic determinant without modification of the other serological reactivities characteristic of the HLA-A3 molecules. Previous studies of ethyl methanesulfonate mutants having shown the involvement of aa 161 in this determinant, we assume that the two aa residues 107 and 161 are close to each other.
Prediction of immunodominant helper T cell antigenic sites from the primary sequence.
Authors: Margalit H , Spouge J L , Cornette J L , Cease K B , Delisi C , Berzofsky J A
Published: December 2022

We have used a data base of 23 known immunodominant helper T cell antigenic sites located on 12 proteins to systematically develop an optimized algorithm for predicting T cell antigenic sites. The algorithm is based on the amphipathic helix model in which antigenic sites are postulated to be helices with one face predominantly polar and the opposite face predominantly apolar. Such amphipathic structures can form when the polarity of residues along the sequence varies with a more or less regular period. Hence they can be identified by methods (so called power spectrum procedures) that detect periodic variations in properties of a sequence. The choice of power spectrum procedure, hydrophobicity scale, and model parameters are examined. An algorithm is tested by comparing the predicted amphipathic segments with the locations of the known T cell sites, counting the number of matches, and calculating the probability of getting this number by chance alone. The optimum algorithm, which predicts the largest number of sites with the lowest chance probability, uses the Fauchere-Pliska hydrophobicity scale and a least squares fit of a sinusoid as its power spectrum procedure. By applying this algorithm, 18 of the 23 known sites are identified (75% sensitivity) with a high degree of significance (p less than 0.001). The success of the algorithm supports the hypothesis that stable amphipathic helices are fundamentally important in determining immunodominance. This approach may be of practical value in designing synthetic vaccines aimed at T cell immunity.
Idiotype-specific T lymphocytes responsible for the selection of somatic variants of a B cell hybrid.
Authors: Ghosh S K , Wong J , Bankert R B
Published: December 2022

A B cell hybrid (2C3E1), which when cultivated in vitro stably expresses a serologically defined private idiotype on the cell surface, undergoes a somatic variation which culminates in the generation of idiotype-negative variants when propagated as a tumor in syngeneic BALB/c mice. Lyt-1+ and Lyt-2- BALB/c T cells derived from appropriately primed spleen cells when co-cultured with 2C3E1 tumor cells in vitro are responsible for the generation or selection of the idiotype-negative tumor variants. The idiotype-specific effector T cells responsible for the variant production in vitro and in vivo are triggered either by viable or irradiated 2C3E1 tumor cells, but not by soluble idiotype-positive monoclonal antibody secreted by the tumor. The idiotype-positive antibody did stimulate the production of the effector T cells when the soluble protein was covalently linked to the plasma membrane of BALB/c spleen cells, but not when the idiotype-positive protein was presented on allogeneic C57BL/6 spleen cells. A single exposure of spleen cells to 2C3E1 cells in vivo was sufficient to prime the idiotype-specific T cells, but the frequency and reproducibility of variant selection increased when the in vivo primed effector T cells were restimulated by irradiated 2C3E1 cells in vitro prior to co-cultivation with the wild-type 2C3E1 cells. The initial variant B cell lines could be segregated into several different phenotypes. However, after extensive cultivation either in vitro or after repeated transfer in vivo, all of the variant cell lines acquired a single stable phenotype that was characterized by the loss of both the surface and secreted idiotype marker and antigen-binding activity associated with the wild-type 2C3E1 cells.
Apparent sensitivity of human K lymphocytes to the spatial orientation and organization of target cell-bound antibodies as measured by the efficiency of antibody-dependent cellular cytotoxicity (ADCC).
Authors: Christiaansen J E , Burnside S S , Sears D W
Published: December 2022

Although monoclonal antibodies (mAb) can elicit potent ADCC by human K lymphocytes, different mAb, even of the same antibody subclass or even of the same target antigen specificity, vary considerably as to their efficiency in eliciting ADCC. The extensive variability in ADCC efficiencies of murine IgG2a mAb is analyzed here. In cold-target inhibition experiments it was found that only cells coated with "ADCC-efficient" IgG2a mAb, and not "ADCC-inefficient" IgG2a mAb, inhibit K effector cell lysis of radiolabeled target cells by ADCC. This result indicates that the spatial orientation of the antibodies on the target cell membrane influences the net efficiency of ADCC reactions by affecting the efficiency of interaction between antibody and the Fc receptors (FcR) of K cells. It is proposed that a "favorable" orientation of antibodies on the target cell membrane is required for efficient ADCC reactions. This proposal is directly supported by the observation that one IgG2a mAb (20.8.4), which cross-reacts with several different H-2 alloantigens, was found to elicit efficient ADCC only when bound to certain of its possible target cell antigens. It was also observed in these studies that the organization of antibodies on a target cell membrane influences the net efficiency of ADCC reactions. It is proposed that a "favorable" antibody organization on the target cell membrane is also required for efficient ADCC reactions. This proposal is supported by the observation that certain antihuman beta 2m (anti-Hu beta 2m) IgG2a mAb, which elicit efficient ADCC lysis of human target cells, fail to elicit the lysis of murine cells having Hu beta 2m molecules coupled randomly to their external membrane surfaces. The differences in the way the Hu beta 2m was organized on the surfaces of the human cells and the murine-Hu beta 2m cell conjugates presumably caused differences in the way the bound antibodies were organized on the cell surfaces, which in turn resulted in the ADCC efficiency differences observed for the same mAb with the different target cell types. Because ADCC reactions appear to be sensitive to both the orientation and the organization of cell surface-bound antibodies, certain types of structural alterations or variations in the membrane molecules (relative to other neighboring structures on the target cell membrane) are potentially detectable by quantitative differences or variations in ADCC reactions.
Molecular events involved in regulating human interferon-gamma gene expression during T cell activation.
Authors: Hardy K J , Manger B , Newton M , Stobo J D
Published: December 2022

The human T cell line Jurkat is a useful model of regulated T cell activation. After in vitro treatment of Jurkat with phytohemagglutinin (PHA) and phorbol ester (PMA), RNA transcripts of both interleukin 2 (IL 2) and interferon-gamma (IFN-gamma) appear, followed by secretion of both biologically active lymphokines. Employing the nuclear run-on technology, we first confirmed that the expression of both lymphokines after T cell activation is regulated at the transcriptional level. By using the recombinant approach of DNase I hypersensitivity mapping, we had previously localized a structurally unique, lymphocyte-specific genomic domain in the first intron of the human IFN-gamma gene that correlated with the transcriptional potential of that gene. By using several T cell lines that differ in their inducible expression of IFN-gamma, we have now localized several additional structural domains within the human IFN-gamma gene that appear to be coordinately involved in regulating expression. These include: a distal 5' flanking region site also seen only in T lymphocytes that can express the gene, a proximal, promoter-associated site that appears only after PHA/PMA-mediated IFN-gamma induction, and a second intronic site seen only in T cells whose IFN-gamma gene is selectively inactive. Collectively, our data suggest that T cell activation is accompanied by transcriptional level induction of lymphokine gene expression. In the case of IFN-gamma, T cell nuclei possess specific structural domains within the gene itself that seem to participate both positively and negatively in activation-mediated regulatory events.
Chemotactic factor and P15E-related chemotaxis inhibitor in human melanoma cell lines with different macrophage content and tumorigenicity in nude mice.
Authors: Benomar A , Ming W J , Taraboletti G , Ghezzi P , Balotta C , Cianciolo G J , Snyderman R , Doré J F , Mantovani A
Published: December 2022

The present study was designed to characterize the production of chemoattractants by human melanoma lines with high (M4Be, M3Da, NTerDa) or low tumorigenic (Doc8, M1Do) potential when heterotransplanted in nude mice. Supernatants from the Doc8 and M1Do cell lines were strongly chemotactic in vitro for mononuclear phagocytes. Chemotactic activity was destroyed by proteolytic enzymes, and upon gel filtration on Sephadex G75, it eluted in the cytochrome c region corresponding to an apparent m.w. of 12,000. Upon chromatofocusing, the Sephadex-separated tumor-derived chemotactic factor (TDCF) showed an isoelectric point of 5.5 to 6. Cell lines with high tumorigenic potential contained low or no detectable chemotactic activity. When culture supernatants of cell lines with modest (M3Da) or no (M4Be) chemotactic activity were exposed to immobilized monoclonal antibodies directed against the retroviral transmembrane protein P15E, appreciable chemotactic activity was detectable (M4Be) or preexisting levels increased (M3Da). The material eluted from Sepharose-bound anti-P15E antibodies inhibited the migration of monocytes in response to chemoattractants. These findings demonstrate the coexistence in some human melanoma cell line supernatants of factors (TDCF and P15E-related inhibitor) with opposite influence on monocyte chemotaxis. That tumor cell products play a pivotal role in regulating the extravasation of monocytes into neoplastic tissues is suggested by the close correlation observed between macrophage levels in melanomas grown in nude mice and levels of chemotactic activity detectable in culture supernatants.