bluuebunny/crossref_metadata_2025_split huggingface dataset:
Participation of C1q and its receptor in adherence of human diploid fibroblast.
Authors: Bordin S , Ghebrehiwet B , Page R C 
Published: December 2022

Abstract
C1q binds through its collagen-like domain to specific surface receptors of fibroblasts and to adhesive elements of extracellular matrix including fibronectin, collagens, proteoglycans, and laminin. To determine whether C1q participates in fibroblast adhesion, cells in serum-free medium were plated on surfaces coated with purified C1q at physiologic ionic strength and pH. Surfaces coated with fibronectin or collagen type I served as positive controls, and those coated with BSA were negative controls. Substratum-adsorbed C1q promoted fibroblast adhesion to a maximum of 73% of available cells within 90 min at 37 degrees C. Adhesion was C1q concentration dependent, saturable, specific, and dependent on the collagen-like domain of the molecule. De novo protein synthesis plays a role in adhesion: pretreatment of fibroblasts with cycloheximide reduced adherence about 50% of controls. Addition of exogenous fibronectin, collagen type I, or C1q as soluble mediators did not affect adhesion of the cycloheximide-treated cells to C1q substrate. Adhesion could be accounted for primarily, although not completely, by the C1q receptors. Antibodies raised against the Raji cell C1q receptors (alpha C1qR Ab) specifically inhibited fibroblast adhesion to C1q substrates about 60% of controls. The binding of fibroblasts to C1q substrates could be inhibited about 24% of controls with the GRGDTP cell recognition peptide. GRGDTP and alpha C1q Ab had an additive effect on adhesion that was inhibited 77 to 80% of controls. We conclude from these data that aggregated rather than monomeric C1q may be the natural ligand of the fibroblast C1q receptor, and the biologic function of the receptor in cells of the connective tissue may be cell adhesion.
Monoclonal antibodies against an HLA-B27-derived peptide react with an epitope present on bacterial proteins.
Authors: Raybourne R B , Williams K M 
Published: December 2022

Abstract
The role of molecular mimicry in the spondyloarthropathies was investigated with respect to the epitopes involved. mAb were produced against a synthetic peptide whose sequence was derived from a polymorphic region of the HLA-B27 molecule (amino acids 63-83). Two antibodies (J7F2 and H2B6) were selected for study on the basis of their ability to react with bacterial envelope proteins (ELISA) and B27-positive cells (immunofluorescence). J7F2 reacted preferentially with B27-positive cells and neither antibody reacted with MHC class I negative cells. Based on SDS-PAGE blot analysis of bacterial envelope proteins, the pattern of reactivity for both antibodies (against 36- and 19-kDa proteins) was the same as that for a third monoclonal produced against bacterial envelope and reactive with B27-positive cells. This apparent epitope similarity was investigated by using synthetic peptides to inhibit binding of the monoclonals. The B27 synthetic peptide and a smaller peptide derived from it were efficient inhibitors of antipeptide and antibacterial antibody binding to bacterial Ag and B27-positive cells. These studies provide insight into the molecular basis of cross-reactivity between bacterial proteins and MHC class I molecules.
Degree of platelet activating factor-induced neutrophil migration is dependent upon the molecular species.
Authors: Carolan E J , Casale T B 
Published: December 2022

Abstract
Multiple molecular species of platelet activating factor (PAF) are produced as a result of inflammatory processes. PAF-induced neutrophil migration across endothelium is intrinsic to inflammatory responses. We therefore compared the ability of three naturally occurring PAF species (C16:0, C18:0, and C18:1), which only varied at carbon 1, to induce 51Cr-labeled human neutrophil migration across a naked 3-microns pore filter and human umbilical vein endothelial (HUVE) monolayers cultured on these filters. Time-course experiments indicated that all species of PAF tested induced significant neutrophil migration between 15 and 45 min. PAF-induced neutrophil migration through both filters alone and HUVE monolayers occurred at lower doses with C16:0 PAF. The rank order of chemotactic potency for the PAF species was C16:0 greater than C18:0 greater than C18:1 with both filters and endothelium coated filters as barriers. Intrinsic differences in the potency of these PAF molecular species to induce neutrophil chemotaxis were greater when HUVE cells were the barriers vs when filters alone were the barriers. Regardless of the molecular species used, at optimal PAF doses the degree of neutrophil migration through HUVE cells was often greater than that through filters alone. The specific PAF antagonist WEB 2086 inhibited neutrophil migration induced by all three PAF species equally. WEB 2086 pretreatment of the neutrophil or WEB 2086 coincubation with PAF, but not WEB 2086 pretreatment of the HUVE cell monolayers, significantly inhibited (65 to 80%) neutrophil migration. We conclude that the degree of PAF-induced neutrophil migration is dependent upon the molecular species of PAF. Moreover, the barrier through which the neutrophil must migrate appears to be important in influencing the overall chemotactic response to the various PAF species.
Induction of the respiratory burst in HL-60 cells. Correlation of function and protein expression.
Authors: Levy R , Rotrosen D , Nagauker O , Leto T L , Malech H L 
Published: December 2022

Abstract
Differentiation of myeloid cells is associated with the gradual acquisition of functional capacity to produce a respiratory burst. In our study HL-60 cells were differentiated to the monocyte phenotype with IFN-gamma or 1,25-dihydroxyvitamin D3, or to the neutrophil phenotype with retinoic acid or DMSO to compare the time-course of expression of membrane and cytosolic oxidase components, and to correlate this with the appearance of a functional oxidase. Over a 6-day period of induction the rank order of the ability of these agents to induce expression of PMA-stimulated superoxide production was: IFN-gamma greater than 1,25(OH)2D3 greater than retinoic acid greater than DMSO. Immunoblot analysis of HL-60 membranes and cytosol was used to assess the amount of specific phagocyte oxidase factors (91 and 22 kDa subunits of membrane cytochrome b558 (gp91 and p22), and 47 and 67 kDa cytosol oxidase factors (p47 and p67)). HL-60 cell membranes or cytosol were tested in a cell-free assay of superoxide production by mixing with normal neutrophil cytosol or membranes, respectively. p47 was first detected at 16 h of differentiation, increasing similarly thereafter with all induction regimens and reaching a maximum by 3 to 4 days. The earliest detection of p67 varied from 2 to 6 days depending on the inducing agent and appeared to be the limiting cytosol component. Small amounts of both subunits of cytochrome b558 were detected in uninduced HL-60 membranes, but were sufficient to support substantial superoxide production when combined with normal neutrophil cytosol. Both cytochrome b558 subunit proteins and membrane oxidase activity increased during differentiation in parallel. We conclude that membrane and cytosol components of the NADPH oxidase complex appear at different times and increase differently during HL-60 differentiation. The production of p67 is the major factor limiting the respiratory burst during HL-60 differentiation.
A soluble factor produced by inoculation of human monocytes with Leishmania donovani promastigotes suppresses IFN-gamma-dependent monocyte activation.
Authors: Engelhorn S , Bruckner A , Remold H G 
Published: December 2022

Abstract
Whereas human cultured monocytes preactivated with IFN-gamma increase their antileishmanial capacity, monocytes inoculated with Leishmania donovani before IFN-gamma treatment fail to respond with an increase of antileishmanial capacity. Cell surface expression of class II MHC products also fails to be increased by IFN-gamma in the infected monocytes, although the accumulation of HLA-DR alpha-chain mRNA is increased to the same extent in infected and noninfected activated monocytes. This inhibition of monocyte activation is caused in a dose-dependent manner by a soluble substance elaborated into the cell supernatant after inoculation of monocytes with L. donovani and is referred to as activation suppressing factor (ASF). ASF activity can be abrogated by dialysis and by treatment with a proteinase, indicating that ASF is a small peptide.
Induction of T helper cell unresponsiveness to antigen by macrophages from schistosomal egg granulomas. A basis for immunomodulation in schistosomiasis?
Authors: Stadecker M J , Kamisato J K , Chikunguwo S M 
Published: December 2022

Abstract
The present studies were undertaken in an effort to understand the role of mononuclear phagocytes in the regulation of the T cell-mediated granulomatous inflammatory response in experimental murine schistosomiasis mansoni. We report that macrophages from schistosomal egg granulomas did not efficiently stimulate, but rather induced marked proliferative unresponsiveness to Ag in an IL-2-producing, I-Ek-restricted, CD4+ Th cell clone specific for pigeon cytochrome c. The unresponsive state of the T cells was achieved after incubation with granuloma macrophages in the presence of the specific Ag fragment 81-104, but not with either of them independently, and was, similarly, restricted by the I-Ek molecule. Equivalent amounts of peritoneal macrophages from schistosome-infected, but not from normal mice, were also effective in inducing T cell unresponsiveness. We postulate that granuloma macrophages, and potentially other accessory cells in schistosome-infected individuals, are similarly capable of inducing anergy in egg Ag-specific Th cells, and that the resulting inhibited T cell reactivity, which translates into failure of lymphokine secretion and of clonal expansion, represents a major basis of the immunologic down-regulation (immunomodulation) of granulomatous hypersensitivity, characteristically seen in this disease.
Characterization of new mouse V kappa groups.
Authors: D'Hoostelaere L A , Klinman D 
Published: December 2022

Abstract
A lambda gt10 BXSB spleen cDNA library was screened with a DNA probe for the C kappa region. Forty individual C kappa+ phages were tested for hybridization with DNA probes representing 11 V kappa region groups. Of the phage inserts large enough to contain V kappa region sequences, 3 were negative for hybridization with all 11 V kappa region probes. The inserts from those three were subcloned, sequenced, and compared with V kappa region sequences in the gene bank. One was identical to 87.92.6 for the region sequenced (a member of V kappa RF). The second showed 93.8% sequence similarity with AN04 and called V kappa 32. The third called V kappa 33 showed 76% sequence similarity with the human sequence V52 and 73.2% sequence similarity with the mouse sequence L6. An insert from V kappa 32 containing the 5' untranslated regions through the codon for Cys 88 of the V kappa region was used as a probe in Southern blot analysis of genomic DNA from inbred and congenic strains of mice. V kappa 32 is a four to eight member group and some of the members are retained in the B6.PL-Ly2a congenic and missing from the B6.PL (85NS) congenic consistent with a map location near V kappa 28. The same filters were hybridized with the insert from V kappa 33 containing 5' untranslated region through the codon for Ser 93 of the V kappa region. V kappa 33 is a one to three member group and using the B6.PL congenics maps with the polymorphic fragments of V kappa 32 and V kappa 28.
Identification of rabbit genomic Ig-VH pseudogenes that could serve as donor sequences for latent allotype expression.
Authors: Fitts M G , Metzger D W 
Published: December 2022

Abstract
Synthetic DNA oligomers specific for the VHa allotypes of rabbit Ig genes have been used to identify latent allotypic sequences in homozygous a1 and a2 rabbits. Two Ig VH pseudogenes containing latent a3 regions have been cloned from the genome of a homozygous a2 rabbit. Analysis of the regions associated with allotype expression indicates that these two pseudogenes contain VHa- sequences in framework region 1 (FR1) and VHa3 sequences in FR3. One gene has undergone an unusual rearrangement with a third VH gene, deleting their intervening sequences and recombining in FR3 with sequences 5' to the leader exon. Our results demonstrate the presence of latent VH sequences in the genomic DNA of normal rabbits and suggest that a mechanism such as gene conversion is responsible for expression of genetically-unexpected Ig VH genes.
A V kappa-J kappa junctional change in an antidigoxin recombinant antibody destroys digoxin-binding activity.
Authors: Hudson N W , Bruccoleri R E , Steinrauf L K , Hamilton J A , Mudgett-Hunter M , Margolies M N 
Published: December 2022

Abstract
A set of high affinity antidigoxin antibodies were previously identified with high homologous V kappa 1A L chain sequences but were associated with two entirely different VH regions and two dramatically different specificities for digoxin analogs. Antibodies 40-20, 40-60, 40-90, and 40-100 displayed similar binding specificities but differed from that of antibody 26-10. In a previous study using somatic cell fusion for Ig chain recombination we demonstrated that a recombinant antibody consisting of the H chain of antibody 26-10 and the L chain of antibody 40-20 retained digoxin binding and the 26-10 Id, but displayed a binding specificity pattern dominated by the 26-10 H chain donor. In the present study we produced three additional chain recombinant antibodies that contain the 26-10 H chain recombined with each of the L chains of antibodies 40-60, 40-90, and 40-100. All four recombinants expressed the 26-10 Id indistinguishably from the 26-10 antibody. Two of the recombinants (using the 40-60 and 40-90 L chains) bind digoxin; however, the recombinant using the 40-100 L chain failed to bind digoxin. Complete sequence analyses of the 40-20, 40-60, 40-90, and 40-100 VH and VL regions were performed. Antibodies 40-90 and 40-100 have identical VH region sequences but differed only in their L chains at position 96 (proline/leucine). This single difference at the VK-JK junction abolished digoxin binding in the context of one H chain (26-10), but does not cause a significant change in binding in association with the "normal" parental chains 40-90 and 40-100. Thus, structurally closely related VL regions can recombine with different VH regions to form digoxin binding sites of different specificity; in one binding site the identity of a L chain junctional residue is critical whereas in the second binding site that residue is unimportant. Molecular modeling studies revealed major differences between calculated binding site structures for 26-10 when leucine is substituted for proline at position 96 in the 26-10 VL region.
IL-2-PE40 prevents the development of tumors in mice injected with IL-2 receptor expressing EL4 transfectant tumor cells.
Authors: Kozak R W , Lorberboum-Galski H , Jones L , Puri R K , Willingham M C , Malek T , Fitzgerald D J , Waldmann T A , Pastan I 
Published: December 2022

Abstract
A number of different immunotherapeutic reagents are currently being developed to target IL-2R for the treatment of leukemia, graft rejection, and certain autoimmune diseases. Previously, we have shown that IL-2-PE40, a chimeric protein composed of human IL-2 linked to the N-terminus of a truncated form of Pseudomonas exotoxin (PE), could effectively kill a variety of cell lines in vitro expressing either low, intermediate, or high affinity IL-2R. Here, we demonstrate that IL-2-PE40 can successfully retard or prevent the growth of a lethal ascites tumor or a solid tumor composed of EL4J murine thymoma cells transfected with the p55 murine IL-2R. The transfected line, EL4J-3.4, expresses 1,000 to 3,000 high affinity IL-2R. Survival extension in the ascites model was achieved by initiating treatment either after 4 to 6 h or within 5 days post-tumor injection in both athymic nude and C57BL/6 mice. Similarly, the growth of an aggressive s.c. solid tumor could also be inhibited. Extension of survival was not achieved either by using the truncated toxin alone not attached to IL-2 or by using an IL-2-PE40Asp553 mutant lacking a functional toxin. Survival extension was not caused by IL-2 activated NK or other host effector mechanisms as IL-2-PE40 was unable to prevent the receptor-negative EL4J parental line from forming a lethal ascites or a solid tumor. Thus, IL-2-PE40 is a potent, specific cytolytic reagent that may prove useful in the arsenal of anti-IL-2R immunotherapeutics.
Freshly isolated spleen dendritic cells and epidermal Langerhans cells undergo similar phenotypic and functional changes during short-term culture.
Authors: Girolomoni G , Simon J C , Bergstresser P R , Cruz P D 
Published: December 2022

Abstract
Spleen dendritic cells (DC) and epidermal Langerhans cells (LC) belong to the same family of dendritic leukocytes and are considered to be prototypes of lymphoid DC and nonlymphoid DC, respectively. These cells are active APC in vitro and play a key role in the induction of primary T cell dependent immune responses in vivo. Two functional states of LC have been characterized in vitro, freshly isolated LC and cultured LC (cLC). That cLC closely resemble spleen DC in phenotype and function, has led to the hypothesis that LC undergo maturation toward DC while in culture, an event that has been correlated with the emigration of LC from skin into lymphoid organs. To date, however, DC have been studied only after overnight culture. To better understand the relationship between LC and DC, we examined DC shortly after their isolation from spleen, and after 24 h of culture. Freshly isolated DC (fDC) express high levels of MHC molecules and low levels of Fc gamma RII and C3biR; fDC also uniformly express the Ag recognized by the mAb 33D1, NLDC-145, and J11d. After culture, DC display a marked increase in the expression of MHC molecules, and they are induced to express the low affinity receptor for IL-2. By contrast, the expression of Fc gamma RII and F4/80 decreases with culture. With respect to function, fDC can efficiently present keyhole limpet hemocyanin to Ag-specific T cells, whereas cultured DC exhibit a marked reduction in this capacity. Finally, both fDC and cultured DC are capable of endocytosing surface Ia molecules, but only fDC are able to deliver them into acidic compartments. Our data indicate that fDC from spleen resemble freshly isolated LC from epidermis and that both cells undergo parallel changes during culture. These results suggest that LC and DC possess analogous attributes in vivo and respond similarly to external influences.
Human severe combined immunodeficiency disease: phenotypic and functional characteristics of peripheral B lymphocytes.
Authors: Gougeon M L , Drean G , Le Deist F , Dousseau M , Fevrier M , Diu A , Theze J , Griscelli C , Fischer A 
Published: December 2022

Abstract
Human severe combined immunodeficiency disease (SCID) includes an X-chromosome-linked type characterized by a complete absence of mature T cells, hypogammaglobulinemia but normal or elevated number of B cells, suggesting that the disease results from a block in early T cell differentiation. It has been shown that B cells from obligate carrier women of this disorder exhibit the preferential use of the nonmutant X chromosome as the active X (as shown for T cells), suggesting that the SCID gene product has a direct effect on B cells as well as on T cells. To examine this question, we analyzed the phenotypic and functional characteristics of peripheral B cells from nine infants with SCID. We found a constant absence of spontaneously expressed activation Ag on B cell membrane from all SCID patients tested which contrasts with the phenotypic pattern exhibited by age-matched infants whom all cells bearing surface Ig express the 4F2 Ag and to a lesser extent the transferrin receptor. Concurrently, B cells from SCID patients have a profound impairment in their responses to stimuli that induce in vitro B cell proliferation and differentiation. Although rIL-2 and low-Mr B cell growth factor are potent inducers of proliferation on age-matched infants' B cells, they are poorly efficient in inducing proliferation of anti-mu-activated SCID B cells. This impairment is not related to the resting B cell phenotype of SCID B cells as shown by comparison with normal resting B cells. Furthermore, we observed an apparent block in B cell differentiation inasmuch as neither rIL-2 nor rIL-6 could support SAC-activated SCID B cell differentiation, both lymphokines being very efficient in inducing SAC-activated age-matched infants' B cell or purified resting B cell differentiation. These results suggest that the SCID gene defect has a direct effect on B cells and is required during B cell maturation.
Synergistic interactions between tumor necrosis factor and inhibitors of DNA topoisomerase I and II.
Authors: Baloch Z , Cohen S , Coffman F D 
Published: December 2022

Abstract
TNF is a pleiotropic cytokine that mediates diverse cellular responses, including cytotoxicity, cytostasis, proliferation, differentiation, and the expression of specific genes. Many of these processes require the activity of DNA topoisomerases I and II. We have investigated the interactions of TNF with inhibitors of both topoisomerases in 16-h assays using the murine L929 and human ME-180 cell lines, which undergo a cytotoxic TNF response. Camptothecin, a specific inhibitor of topoisomerase I, enhanced TNF cytotoxicity 150-fold against both cell lines. The topoisomerase II inhibitors VM-26 and VP-16, which stabilize covalent DNA-topoisomerase intermediates, greatly enhance TNF cytotoxicity against both cell lines. The most effective, VM-26, can lower the TNF LD50 to femtomolar levels. In contrast, the topoisomerase II inhibitors novobiocin and coumermycin, which bind to the enzyme ATPase site, protect L929 cells from TNF cytotoxicity but enhance TNF cytotoxicity in ME-180 cells. The large changes in TNF sensitivity induced by drug concentrations that by themselves show no effect, and the opposing synergistic effects of inhibitors with different inhibitory mechanisms (in L929 cells), suggest the active involvement of topoisomerases in TNF-mediated cytotoxicity. The correlation of cytotoxic synergy with the stabilization of DNA strand breaks indicates that DNA damage may play a significant role in TNF-mediated cytotoxicity.
Immunologic responsiveness in American cutaneous leishmaniasis lesions.
Authors: Pirmez C , Cooper C , Paes-Oliveira M , Schubach A , Torigian V K , Modlin R L 
Published: December 2022

Abstract
American cutaneous leishmaniasis is a disease of skin and mucous membranes in which T lymphocytes reactive to Leishmania (Viannia) braziliensis are thought to contribute to protective immunity. To characterize the nature of the T cell inflammatory infiltrate in American cutaneous leishmaniasis lesions, immunohistochemistry with mAb that define T cell subpopulations and in situ hybridization to detect mRNA coding for IFN-gamma were performed. In both localized cutaneous (LCL) and mucocutaneous (MCL) lesions, we observed a predominance of T memory (CD4+CD45RO+) as compared to T naive cells (CD+CD45RA+). The percentages of cells containing IFN-gamma mRNA were equivalent in both LCL and MCL lesions. T cells were extracted from LCL and MCL lesions and analysis indicated that T cells from both lesions had been stimulated by L. (V.) braziliensis in vivo and gave equivalent proliferative responses in vitro. The present data suggest that T memory cells, which are likely to elaborate IFN-gamma, are components of DTH response to L. (V.) braziliensis and participate in the pathogenesis of both LCL and MCL lesions.