bluuebunny/crossref_metadata_2025_split huggingface dataset:
Clonal analysis of mechanisms of murine T helper cell collaboration with effector cells of macrophage lineage.
Authors: Fan S T , Edgington T S 
Published: December 2022

Abstract
The molecular basis and genetic restrictions of collaboration between Th cells and macrophages (Mo) and the numbers of types of collaboration in the Ag-specific cellular immune response were analyzed. Using the response of cloned Ag-specific T cells we examined the mechanisms of induction of the macrophage procoagulant response. Two generic types of collaboration were identified. One was mediated by the lymphokine monocyte procoagulant inducing factor (MPIF) and the second mechanism was by apparent contact collaboration. The lymphokine MPIF was produced by T cells and cloned CD4+ T cells after specific Ag stimulation. Cloned CD8+ cells, most of which also exhibited cytolytic activity, produced little MPIF. There was no evident restriction of the response of Mo of different MHC or background genes. In the second collaborative pathway a subset of CD4+ cloned Th cells were able to directly collaborate by an apparent contact mechanism with Mo for the procoagulant response. There was no correlation of this latter capacity with MPIF production. In addition abrogation of protein synthesis and lymphokine production by Ag-driven clones did not abrogate the direct cell association type of collaboration. Both forms of collaboration were equally efficient across MHC incompatibility barriers and different genetic background. We conclude that there are two independent and parallel Th:Mo collaborative pathways for Ag-driven responses in this limb of the cellular immune response, i.e., a MPIF lymphokine pathway and a contact pathway, and that there are quantitative and qualitative clonal differences in the use of these two pathways. We suggest that the existence of multiple parallel pathways for cellular collaboration may occur more widely in the Th:Mo limb of the immune response in respect to other Mo effector molecules and should be explored to understand the orchestration of this limb of the immune response.
Involvement of major histocompatibility complex products in tolerance induction in the thymus.
Authors: McDuffie M , Roehm N , Kappler J W , Marrack P 
Published: December 2022

Abstract
KJ23a+ T cell clones, which bear the determinant encoded by the V beta 17a T cell receptor gene segment, frequently recognize IE molecules of various murine H-2 haplotypes. In the presence of IE molecules, thymic maturation of KJ23a+ clones is infrequent. We investigated the basis of this phenomenon by blocking expression of IE molecules with monoclonal anti-IE antibodies in organ cultures of fetal thymus and in neonates from the C57BR/cdJ strain (H-2k, V beta 17a homozygous). Our data support the contention that this process results from deletion of clones with anti-IE reactivity, as functional blocking of the IE molecule results in maturation of IE-reactive clones and increased numbers of KJ23a+ mature cells. In addition, we noted that blocking of functional IE expression in this haplotype permitted development of both CD4+/KJ23a+ and CD8+/KJ23a+ T cells. The CD4+ clones isolated from anti-IE-treated animals were frequently reactive against IEk; we could demonstrate no alloreactivity against B cell or B lymphoma stimulators in the CD4- clones. We conclude that clonal deletion events during thymic development may be initiated by T cell precursor interactions with MHC molecules against which the mature clones display no measurable reactivity. Specifically, clones destined to be MHC Class I-reactive may be deleted during development by interactions with MHC Class II molecules.
Rapid T cell receptor modulation accompanies lack of in vitro mitogenic responsiveness of double negative T cells to anti-CD3 monoclonal antibody in MRL/Mp-lpr mice.
Authors: Davignon J L , Cohen P L , Eisenberg R A 
Published: December 2022

Abstract
The role of the CD8-, CD4- (double negative) (DN) T cells accumulating in MRL/Mp-lpr/lpr (lpr) mice is unclear. Although they bear the TCR/CD3, the lpr DN cells do not respond to Ag, and the specificity of TCR/CD3 on these cells is unknown. With the aid of monoclonal anti-murine CD3 epsilon (145-2C11), we have investigated the function of the CD3 molecule on the DN cells. 145-2C11 was not mitogenic for lpr DN lymph node cells (LNC), even in the presence of the phorbol ester 12-O-tetradecanoylphorbol 13-acetate, whereas MRL/Mp-+/+ (+/+) LNC responded strongly. Surprisingly, CD3 modulation induced by 145-2C11 was much more rapid for lpr DN than for +/+ LNC. For example, the modulation observed after 10 min in lpr DN LNC required at least 2 h in +/+ cells. This was not due solely to a property of the 145-2C11 antibody, because both TPA and the F23.1 anti-TCR mAb also provoked a faster modulation of the TCR in lpr DN LNC. Double-staining experiments showed that co-culturing +/+ and lpr DN LNC did not alter their respective rates of modulation, which suggests an intrinsic defect in the lpr DN cells. Moreover, in LNC from 6-wk-old lpr mice (before the appearance of DN cells), as well as in normal phenotype-bearing T cells (CD8+ or CD4+) from 6-mo-old lpr mice, the CD3 modulation was similar to that of +/+ LNC. After modulation, the CD3 molecule was reexpressed at the surface of both +/+ and lpr DN cells during subsequent incubation of the cells without 145-2C11. In addition, spontaneous recycling of CD3 was similar in +/+ and lpr DN LNC. The rapid modulation of the lpr DN TCR/CD3 is presumably related to the anergy of this cell population.
Expression, distribution and specificity of Fc receptors for IgM on murine B cells.
Authors: Mathur A , Lynch R G , Köhler G 
Published: December 2022

Abstract
Subpopulations of normal adult murine splenic B cells and a panel of murine B cell tumors were examined for their ability to bind murine IgM specifically. By using two-color flow cytometric analyses, we have demonstrated that 90 to 95% of surface (s)IgD+ B cells express surface membrane receptors for IgM (Fc mu R). The binding of pentameric murine IgM to splenocyte Fc mu R was IgM-specific since it was totally inhibited by other polymeric IgM proteins, but not by Ig of other H chain classes or by mAb specific for the murine IgG or IgE FcR. Binding of IgM to splenic cells was saturable. Fc mu R were co-expressed with the Fc gamma R as well as the Fc epsilon R on the majority of splenic B cells. Minor populations of splenic mononuclear cells expressed only an Fc mu R, Fc gamma R or Fc epsilon R. In a survey of B tumor cell lines representing different stages of B cell development, we observed that the Fc mu R was expressed on pre-B cell lines and that Fc mu R detection was maximal on immature B cell lines that expressed sIgM and low amounts of sIgD and Ia. Fc mu R were not detected on cell lines that had switched from sIgM to the expression of another sIg, or on plasmacytomas and hybridomas. The studies with normal splenocytes establish that the majority of sIgD+ B lymphocytes in adult BALB/c mice express surface membrane receptors that specifically bind IgM. The studies with B lineage tumor cells suggest that the expression of Fc mu R on B cells is developmentally regulated and that the pattern of expression exhibited by Fc mu R during B cell ontogeny differs from the patterns that have been previously found for IgG and IgE FcR. These observations raise the possibility that Fc mu R might have a functional significance in some aspect of B cell maturation and activation. By using a family of IgM H chain constant region domain deletional mutants, we have further demonstrated that, like the T cell Fc mu R, the B cell Fc mu R also requires a C mu 3 domain for binding to occur, raising the possibility that the T and B cell Fc mu R in mice may be structurally related molecules.
Age-related changes in the capability of the bone marrow to generate B cells.
Authors: Zharhary D 
Published: December 2022

Abstract
The capability of the bone marrow (BM) to generate new B cells in aging was studied in vitro. BM cells from old (26 to 30 mo) or young (3 mo) BALB/c and (C3H/eB x C57BL/6)F1 mice were depleted of mature B cells and these surface Ig (sIg) BM cells were incubated in culture for 3 days. The frequency of newly generated B cells in these cultures was determined by assessing the frequency of slg+ cells and of B cells forming colonies in agar and by assaying the proliferative capacity of these newly generated B cells after stimulation by LPS. We found that BM cells from aged mice are significantly inferior to young ones in their capability to generate new B cells in culture. By mixing old and young slg- BM cells, we found that, in general, this reduction was not caused by a suppressive effect of T cells or of any other cells, but rather to lack of some sort of supportive cell or factor in the aged BM. In addition, we found that the frequency of cells expressing the B220 surface molecule, a B lineage-specific marker, is significantly reduced in aged BM. These results indicate that a quantitative decrease in B cell progenitors combined with changes in cell populations that are important in supporting B cell generation contribute to the age-related decrease in the capacity to generate B cells.
Identification of a human endothelial cell antigen with monoclonal antibody 44G4 produced against a pre-B leukemic cell line.
Authors: Gougos A , Letarte M 
Published: December 2022

Abstract
Staining of a variety of human tissue sections (lymph node, tonsil, spleen, thymus, kidney, lung, and liver) by the indirect immunoperoxidase method indicated that mAb 44G4, produced against a human pre-B leukemic cell line, was strongly reactive with vascular endothelium. All other cell types observed in these tissues were unreactive. Immunofluorescence staining of endothelial cells isolated from umbilical cord vein and grown in culture confirmed that mAb 44G4 recognized a surface membrane component of vascular endothelium. Granulocytes, monocytes, B and T lymphocytes, and T lymphocytes cultured in the presence of PHA for 72 h did not express the 44G4 Ag. mAb 44G4 reacted weakly with leukemic cells from 28 of 41 patients with non-T cell acute lymphocytic leukemia and 4 of 7 patients with acute myelocytic leukemia, whereas 8 of 10 cases of T cell acute lymphocytic leukemia were negative. Moderate reactivity with leukemic cell lines of pre-B and myelomonocytic origin was also observed. The level of 44G4 Ag on umbilical endothelial cells was three to five times that of leukemic cell lines and 25 times the average levels observed on leukemic cells isolated from patients. Immunoprecipitation of lysates prepared from surface-iodinated endothelial cells and the immunizing pre-B leukemic cell line revealed that the 44G4 Ag from both cell types was composed of two subunits of apparent m.w. 95,000 linked by disulfide bond(s). Comparison of the cellular localization and subunit structure of 44G4 to that of known Ag suggests that it represents a previously undescribed marker of endothelial cells.
Biochemical characterization of the 44G4 antigen from the HOON pre-B leukemic cell line.
Authors: Gougos A , Letarte M 
Published: December 2022

Abstract
The 44G4 antigen is expressed in high amounts on human endothelial cells and at low levels on leukemic cells of pre-B and myelomonocytic origin. Its level of expression on the pre-B leukemic HOON cell line used for derivation of the corresponding mAb is intermediate but sufficient to permit the purification of the Ag. The molecule isolated by immunoaffinity from HOON is a glycoprotein since it bound to Ricinus communis agglutinin, wheat germ agglutinin, and peanut agglutinin lectins. The Ag was purified 2400-fold from a soluble taurocholate extract of HOON cells by affinity to wheat germ agglutinin-agarose and 44G4-IgG-Sepharose. The purified glycoprotein is likely a homodimer as it migrated on SDS-PAGE with an apparent m.w. of 170,000, nonreduced, and 95,000, reduced. Removal of N-linked oligosaccharides by endoglycosidase F led to a decrease in m.w. of 25,000; if neuraminidase and O-glycanase were also present, the total decrease in m.w. was 33,000 suggesting a polypeptide chain of 62,000 and 8,000 in O-linked substitutions. The glycoprotein digested with N-glycanase, neuraminidase, or O-glycanase could still be immunoprecipitated with the 44G4 mAb indicating that the antigenic epitope resides in the polypeptide. By Western blot analysis, the dissociated but nonreduced protein was reactive with 44G4, whereas the reduced and alkylated protein was not. Therefore, the epitope is dependent on the presence of intact disulfide bond(s). Sequential immunoprecipitation with OKT9 and 44G4 antibodies indicated that these epitopes are present on two distinct molecules and that 44G4 is distinct from the transferrin receptor despite a similar subunit structure.
Autoreactive T cells in MRL/Mpr-lpr/lpr mice. Characterization of the lymphokines produced and analysis of antigen-presenting cells required.
Authors: Weston K M , Ju S T , Lu C Y , Sy M S 
Published: December 2022

Abstract
Lymph node cells from 4-wk-old MRL/Mp-lpr/lpr mice, but not from MRL/Mp-+/+ mice, when cultured in vitro for 5 to 7 days, will spontaneously proliferate and produce IL-2. We examined the expression of several cell surface Ag on lymph node cells from MRL/Mp-lpr/lpr mice before and after in vitro culture. There is an increase in the expression of Thy-1, L3T4, IL-2R, T cell activating protein, T cell receptor, and T3 complex on the surface of cultured cells. Cultured cells produced IL-3, IFN-gamma, and small but detectable amounts of IL-1 in addition to IL-2. Gamma irradiation of APC from young MRL/Mp-lpr/lpr mice or treatment of APC with a mAb (J11D) and C, completely abrogated their stimulatory capacity. These experiments suggest that B cells are the predominant APC responsible in the activation of autoreactive T cells in MRL/Mp-lpr/lpr mice. Lymph node cells from C57BL/6-lpr/lpr or C3H-lpr/lpr mice were unable to spontaneously proliferate or produce IL-2. Lymph node cells from (MRL/Mp-lpr/lpr x C57BL/6-lpr/lpr) F1 mice or (C3H-lpr/lpr x MRL/Mp-lpr/lpr) F1 mice did proliferate and produced IL-2 after in vitro culture. Using T cells from these F1 animals and APC from each parental haplotype, we found that APC from MRL/Mp-lpr/lpr mice induced more proliferation and greater amounts of IL-2, when compared to APC from F1 animals. APC from C57BL6-lpr/lpr mice or C3H-lpr/lpr were unable to induce spontaneous proliferation and IL-2 production. Therefore, B cells from MRL/Mp-lpr/lpr mice appear to possess unique features that enable them to activate autoreactive T cells more effectively than B cells from other mice bearing the lpr/lpr gene.
Immune recognition of AIDS virus antigens by human and murine cytotoxic T lymphocytes.
Authors: Langlade-Demoyen P , Michel F , Hoffenbach A , Vilmer E , Dadaglio G , Garicia-Pons F , Mayaud C , Autran B , Wain-Hobson S , Plata F 
Published: December 2022

Abstract
The CTL response to HIV was analyzed in humans and in mice. By using a novel and strictly autologous lymphocyte culture system, human CTL lines were established with PBL from seropositive asymptomatic donors and from patients suffering from AIDS or presenting AIDS-related complex. CTL from HLA-A2 donors recognize and kill murine P815 mastocytoma cells doubly transfected with the human HLA-A2 gene and the HIV env gene; they also kill HLA-compatible human macrophages infected with HIV. CTL specific for the HIV env Ag were also generated in BALB/c mice by immunization with syngeneic murine cells transfected with the HIV env gene. Human and murine HIV-immune CTL populations belong to the CD8 subset of T lymphocytes and are restricted by class I HLA or H-2 transplantation Ag, respectively, in the recognition of HIV env Ag. The two different experimental systems presented here can be used to study CD8 lymphocyte immunity against HIV. The murine model of CTL immunity offers the additional advantage of avoiding the manipulation of infectious virus isolates.
Initial characterization of a lymphokine pathway for the immunologic induction of tumor necrosis factor-alpha release from human peripheral blood mononuclear cells.
Authors: Kornbluth R S , Gregory S A , Edgington T S 
Published: December 2022

Abstract
Under endotoxin-free conditions, unstimulated human PBMC do not release TNF-alpha, as measured in a sensitive assay with 51Cr release in 6 h from actinomycin D-treated WEHI 164 cells. IFN-gamma alone at less than or equal to 10,000 U/ml is insufficient to elicit TNF-alpha release. Similarly, the lymphokine-rich supernatant of PBMC stimulated by allogeneic cells is also insufficient to induce TNF-alpha release in a short term assay. However, when PBMC are first primed with IFN-gamma for 48 h and then exposed to lymphokine supernatant for 6 h, effector cells within the PBMC population are triggered to express TNF-alpha-mediated cytotoxicity. All of the measured cytotoxicity is attributable to TNF-alpha because it could be abolished by a specific anti-TNF-alpha neutralizing mAb. Although IFN-gamma serves to prime PBMC in this assay system, it fails to trigger the release of TNF-alpha. Instead, a second lymphokine (provisionally termed "cytotoxicity triggering factor" (CTF) is required to induce TNF-alpha release from IFN-gamma-primed human PBMC. In kinetic studies, IFN-gamma priming was optimal when PBMC were exposed to IFN-gamma (150 U/ml) for 48 h. In contrast to the prolonged interval for priming, CTF need be present for 6 h or less for maximal induction of TNF-alpha-mediated cytotoxicity. In dose-response studies, IFN-gamma priming (48 h) required at least 4 U/ml and was complete with 20 to 100 U/ml. By using fully primed PBMC, the response to CTF followed a sigmoidal dose-response curve, which allowed the quantitation of CTF in half-maximal units. Activated Th lymphocytes constitute one cellular source for CTF. CTF is produced by cloned allorective T3+T4+T8-M1- Th cells after alloantigen stimulation, and also by nylon wool-purified T cells after stimulation with PMA and A23187 calcium ionophore. Unstimulated T cells do not release CTF. In physicochemical studies, CTF activity elutes from Sephadex G-100 as a major discrete peak of Mr 55 kDa and minor peaks of 14 kDa and greater than 150 kDa. On the basis of multiple criteria, CTF is distinguishable from several other cytokines: IFN-gamma, IL-1, IL-2, GM-CSF, MIF, CSF-1, TNF-alpha, and lymphotoxin (TNF-beta). We conclude that, by acting together, IFN-gamma and CTF provide a lymphokine pathway whereby Ag-responsive human Th cells induce the immunologic release of TNF-alpha from effector cells present in PBMC.
Bone marrow stromal cell regulation of B-lymphopoiesis. I. The role of macrophages, IL-1, and IL-4 in pre-B cell maturation.
Authors: King A G , Wierda D , Landreth K S 
Published: December 2022

Abstract
Our experiments have addressed regulation of B lymphocyte formation by bone marrow stromal cells. Stromal cells appear to produce a regulatory factor that acts at the pre-B cell stage to induce the expression of Ig L chains and surface Ig. Bone marrow stromal cell conditioned medium was found to contain this factor and the active component was partially purified by HPLC. This stromal cell-derived factor had a m.w. between 16,000 and 20,000, was specifically neutralized by anti-IL-4 mAb, 11B11, and enhanced the proliferation of anti-mu-stimulated B cells. We also found that rIL-4 induced B cell formation in culture. In our studies, IL-1 had no direct effect on pre-B cell maturation, however, IL-1 was found to stimulate the production of IL-4 by both heterogeneous bone marrow stromal cells and a cloned stromal cell line, SCL-160. These effects of IL-1 on factor production by stromal cells were duplicated by the addition of bone marrow-derived macrophages to SCL-160 cells. We conclude that stromal cell-derived IL-4 is a physiologic stimulator for B cell generation. In addition, macrophages appear to play a role in B cell formation by regulating the production of IL-4 by stromal cells via the secretion of IL-1.
Down-regulation of IL-1 beta biosynthesis by inducers of the heat-shock response.
Authors: Schmidt J A , Abdulla E 
Published: December 2022

Abstract
The effect of heat on IL-1 beta biosynthesis was investigated in both THP-1 cells, a myelomonocytic cell line which can be induced to make IL-1 alpha and beta, and human peripheral blood adherent monocytes (PBMC). Induction of THP-1 cells with LPS at 39 to 41 degrees C for 2 to 4 h resulted in the expected increased synthesis of the heat-shock proteins hsp 70 and hsp 90 but decreased synthesis of the IL-1 beta precursor protein, p35 (and its mRNA), compared with control cells at 37 degrees C. This appeared to be a direct effect on p35 synthesis rather than a block in LPS induction because heat also acted on preinduced cells. PBMC similarly incubated for 4 h with LPS required a temperature of 41 to 42 degrees C to induce hsp and show a decrease in p35 synthesis. Chemical inducers of the heat-shock response (heavy metals, sulphydryl reagents) were also effective inhibitors of IL-1 beta biosynthesis. A correlation was seen between the extent of IL-1 beta reduction and the level of hsp induction by chemical inducers in both THP-1 cells and PBMC which suggests that the two responses are linked. In addition, a gold salt currently used for therapy of chronic inflammation, auranofin, induced hsp and inhibited IL-1 beta biosynthesis, whereas a second salt, sodium aurothiomalate, did neither. These results support the hypothesis that elevated temperature is one of the physiologic signals for down-regulation of IL-1 beta biosynthesis through a mechanism related to the induction of hsp.
Spontaneous IFN-beta production. A common feature of natural suppressor systems.
Authors: Cleveland M G , Lane R G , Klimpel G R 
Published: December 2022

Abstract
Natural suppression has been described in several immunologic systems in which splenocytes are not only incapable of generating an immune response, but are also able to non-specifically suppress normal splenocyte reactivity. Natural suppressor cells exist in such transitory immune deficiency states as graft vs host disease, irradiation recovery, and during neonatal development. We have found that when splenocytes from each of these three systems were placed in culture, IFN was produced spontaneously without stimulus. This spontaneous IFN production was augmented by the addition of IL-2 or granulocyte-macrophage-CSF to cell cultures. However, these lymphokines induced little or no IFN from normal splenocytes. This unusual IFN production is especially interesting since all samples have been typed to be IFN-beta. Additionally, greater IFN-beta was produced by these spleen cells during active suppression of the MLR of normal spleen cells. In fact, antibody to IFN-beta was shown to partially reverse the natural suppression mediated by graft vs host disease splenocytes in the MLR. Thus, IFN-beta production correlates extremely well with natural suppressor states. As mice begin to recover normal immune responses in all three systems, IFN-beta ceases to be produced spontaneously in culture. These findings establish a previously undescribed IFN-beta-producing splenic phenotype and suggest that IFN-beta may contribute to the immunoregulation of natural suppressor systems.