bluuebunny/crossref_metadata_2025 huggingface dataset:
T cell surface markers expression by immature human thymocytes in in vitro culture: role of Ia+ accessory cells.
Authors: Larocca L M , Piantelli M , Maggiano N , Musiani P
Published: December 2022

Previous studies have indicated that the human thymus is composed of several discrete compartments. Cortical thymocytes are reactive with the monoclonal antibody anti-T6, whereas most medullary cells, unreactive with anti-T6, stain brightly with anti-T3 antibody, which defines mature T cell populations. By using an indirect immune rosette method, we isolated the minor thymocyte population (1 to 2% of all thymocytes) lacking both T3 and T6 but expressing T11 antigens. These cells could be maintained in culture supplemented with recombinant IL 2 (Rec-IL 2) for several days. Under these conditions, T3-T6- cells were shown to undergo phenotypic changes. In the absence of thymic macrophage (Mo), T3+ and T8+ thymocytes appeared in culture, whereas the development of T4+ cells strictly required the presence of Mo. The expression of T4 antigen could be largely prevented by the addition of anti-HLA-DR antibody, further indicating that Ia+ accessory cells had the ability to promote in vitro development of T4+ thymocytes. In the presence of Mo, not only T4+ but also T8+ cells were obtained. Double fluorescence staining with anti-T8-FITC and anti-T4-biotin demonstrated that after 12 days of culture, T4 and T8 antigens were mutually exclusive. Furthermore, during the course of these studies, we observed that under the culture conditions utilized (e.g., presence or absence of Mo), T3-T6-thymocytes failed to express the T6 antigen. Thus, the in vitro development of T cells bearing a mature phenotype could be obtained in the absence of intermediate expression of cortical (T6+) thymocytes.
Regulation of the anti-alpha (1,3) dextran response: two populations of dextran-reactive B cells that differ in their T cell requirements for induction to antibody synthesis.
Authors: Murray P D , Kagnoff M F
Published: December 2022

The in vitro antibody response to dextran B1355S, a thymus-independent Type 2 antigen, requires T cell-derived lymphokines but is not thought to require an activation signal from an antigen-specific T helper cell. The present study demonstrates that there are two dextran-reactive B cell populations in BALB/c mice with respect to the T cell requirements for the generation of antibody-forming cells. One population found among dextran-reactive spleen B cells from 12- to 14-mo-old BALB/c mice generated anti-dextran PFC in the presence of B cell growth factor (BCGF II) and IL 2 or the combination of BCGF II, IL 2, and IFN-gamma. A second population of dextran-reactive B cells found in spleen and Peyer's patches of 2-mo-old unprimed mice did not respond to these same lymphokines, but did generate anti-dextran plaque-forming cells in the presence of Thy-1.2+, L3T4+ T cells from Peyer's patches. However, splenic B cells obtained from 2-mo-old mice that had been primed with dextran 2 to 3 days after birth were shown to be responsive to the same lymphokines as dextran-reactive B cells from 12- to 14-mo-old mice. These results suggest that previous priming with dextran B1355S induces a dextran-specific B cell population that can be activated to antibody-forming cells in the presence of antigen and T cell-derived lymphokines, whereas a second, unprimed population requires an additional activation signal from L3T4+ T cells.
Human thymic epithelial cells produce interleukin 1.
Authors: Le P T , Tuck D T , Dinarello C A , Haynes B F , Singer K H
Published: December 2022

Although the thymus plays a critical role in generation of immunocompetent T lymphocytes, the precise role of the epithelial component of the thymus in the induction of T cell proliferation and maturation remains unknown. Since interleukin 1 (IL 1) is required for mature T cell activation, we have determined whether human thymic epithelial (TE) cells produce IL 1. By using a system for longterm culture of human TE cells, we found that human TE cells produced an IL 1-like factor (TE-IL 1) that augmented the proliferation of C3H/HeJ mouse thymocytes to phytohemagglutinin. IL 1 activity (20 to 200 U/ml) was detected in supernatants of TE cultures from all individuals (2 to 13 yr old) tested. IL 1 activity was also detected in supernatants of TE cultures from a 17-wk fetus but not from a 10-wk fetus. Production of TE-IL 1 was dependent on TE cell density and time in culture with optimal TE-IL 1 activity observed at 10(6) TE cells/ml after 48 to 72 hr of culture. With the use of high performance liquid chromatography, TE-IL 1 chromatographed as a molecule of 18,000 to 20,000 relative molecular mass, and by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, TE-IL 1 migrated at 15,000 to 17,000 Mr. With the use of isoelectrofocusing gels, charge heterogeneity of TE-IL 1 was demonstrated with two major isoelectric points of 5.7 to 5.8 and 6.9 to 7.0. Polyclonal antibody to human monocyte IL 1 markedly inhibited the TE-IL 1 activity. In indirect immunofluorescence assay of frozen human thymic sections, rabbit anti-IL 1 antibody reacted with epithelial cells in human thymic cortex and medulla. Furthermore, high performance liquid chromatography-purified TE-IL 1 augmented human thymocyte proliferation to suboptimal concentrations of phytohemagglutinin. Thus, thymic epithelial cells are capable of providing an intrathymic source of IL 1-like cytokine (TE-IL 1), which affects thymocyte proliferation. We propose that TE-IL 1 may play an important role in intrathymic proliferation and differentiation of human thymocytes.
Autocrine growth function of human interleukin 1 molecules on ROHA-9, an EBV-transformed human B cell line.
Authors: Scala G , Morrone G , Tamburrini M , Alfinito F , Pastore C I , D'Alessio G , Venuta S
Published: December 2022

In this study we report that the ROHA-9 cell line, an IL 1-secreting EBV-transformed human B cell line, exhibits an autocrine pathway of growth. In fact, ROHA-9 cells spontaneously secreted an autoregulatory growth factor that co-purified with the constitutively secreted IL 1-like molecules. Accordingly, monocyte-derived human IL 1, free of other known biological activities, also stimulated the growth of ROHA-9 cells in a dose-dependent way. Human recombinant interleukin 2, recombinant IFN-alpha or IFN-gamma and purified IFN-beta were ineffective when used at concentrations up to 1 X 10(3) U/ml. Furthermore, mouse recombinant IL 1, HPLC-purified multi-colony stimulating factor and partially purified preparations of BCGF were ineffective when assayed for growth-promoting activity on ROHA-9 cells. Moreover, a rabbit polyclonal antibody and a mouse monoclonal antibody to human IL 1 molecules blocked the growth of ROHA-9 cells induced by the autologous growth factor and by human IL 1. Lastly, purified human IL 1 increased the clonal efficiency of ROHA-9 cells seeded at a low cell concentration, allowing the isolation of the ROHA-9MC3 subclone, which showed similar growth response specificity and was particularly sensitive to the mitogenic activity of human IL 1.
Differential effects of interferon-alpha and interferon-gamma on interleukin 1 secretion by monocytes.
Authors: Gerrard T L , Siegel J P , Dyer D R , Zoon K C
Published: December 2022

We examined the effect of interferon (IFN)-alpha and IFN-gamma on the ability of human monocytes to secrete interleukin 1 (IL 1). IFN-alpha directly induced IL 1 secretion by monocytes. IFN-gamma did not induce any IL 1. IFN-gamma-stimulated monocyte supernatants were also negative for pyrogenic activity. However, IFN-gamma greatly enhanced the amount of IL 1 secreted when monocytes were stimulated by lipopolysaccharide or Staphylococcus aureus, even at concentrations which by themselves did not induce IL 1. IFN-alpha did not enhance IL 1 secretion induced by other stimuli. IFN-gamma enhanced IL 1 secretion by priming monocytes to be more sensitive to an IL 1-inducing stimulus. However, IFN-gamma does not enhance IL 1 induced by all stimuli, because there was no enhancement of IL 1 induced by PMA. Thus, IFN-alpha and IFN-gamma have very distinct roles in the induction and enhancement of IL 1 by monocytes.
Evidence that recombinant IL 1 alpha exhibits lectin-like specificity and binds to homogeneous uromodulin via N-linked oligosaccharides.
Authors: Muchmore A V , Decker J M
Published: December 2022

Uromodulin, a recently described immunosuppressive glycoprotein isolated from human pregnancy urine, has been shown to inhibit T cell proliferative assays dependent upon interleukin 1 (IL 1). We have also recently demonstrated that uromodulin binds specifically to IL 1. We now show that not only the biologic activity but also the binding affinity of uromodulin for recombinant IL 1 is dependent upon intact glycosylation. Furthermore, oligosaccharides isolated from pronase-digested uromodulin are immunosuppressive by themselves and are able to compete with native uromodulin for binding to IL 1. We conclude that recombinant IL 1 exhibits lectin-like specificity, and uromodulin is a biologically functional glycoprotein target of the lectin-like specificity of IL 1.
B cell surface glycoprotein induced during growth response: molecular structure and expression pattern.
Authors: Southern S O , Swain S L , Dutton R W
Published: December 2022

We present the molecular characterization of a cell surface antigen, B 7.2, that is expressed on activated B lymphocytes. The BCL1 and CH12 B lymphoma cells express the B 7.2 antigen constitutively. In small resting B cells from spleen, the B 7.2 expression is induced during polyclonal growth in response to mitogenic stimulation. B 7.2 expression also occurs with a significant frequency in cells from fresh lymphoid tissues. The endogenous expression of the B 7.2 antigen is high in spleen and lymph nodes, and is undetectable in the thymus. The B 7.2 antigen is a microheterogeneous 45,000 to 50,000 dalton glycoprotein with a single polypeptide chain, intramolecular S--S bonds, and N-linked glycan moieties. The folded structure of the B 7.2 antigen appears to contain a domain with hydrophilic properties exposed on the cell surface and a hydrophobic segment that may comprise a transmembrane portion. Considering the observed expression pattern and the molecular structure, we speculate that the B 7.2 antigen has a specific function in regulation of B cell activation, perhaps as a receptor for a regulatory ligand or as a ligand recognized by other B or T cells.
Blood clearance of Streptococcus pneumoniae by C-reactive protein.
Authors: Horowitz J , Volanakis J E , Briles D E
Published: December 2022

C-reactive protein (CRP) has long been known to be an acute phase protein associated with infection and various forms of tissue damage. Recent studies have shown that human CRP can be used to passively protect mice from lethal infection with Streptococci pneumoniae. In this study we have undertaken a detailed examination of the ability of human CRP and rabbit CRP (CxRP) to mediate the blood clearance of pneumococci in mice. We have shown that the optimal activity of these acute-phase proteins requires a functioning complement system, and it can take place even in the xid mouse, which has virtually no naturally occurring anti-pneumococcal antibody in its serum. These studies provide additional evidence that CRP may play a protective role in pneumococcal infections, and it may help postpone the development of fatal levels of pneumococci in the blood, long enough for an effective anti-pneumococcal antibody response to be generated.
Immune response to intermediate filament-associated, Epstein-Barr virus-induced early antigen.
Authors: Sairenji T , Nguyen Q V , Woda B , Humphreys R E
Published: December 2022

A murine monoclonal antibody (MAb) (15TD3) was found to recognize a unique filamentous structure in Epstein-Barr virus (EBV)-producing lymphoblastoid cell lines. By immunofluorescent morphology, in comparison with a control MAb to vimentin, the 15TD3 filamentous structure was judged to be associated with intermediate filaments of the cytoskeleton. Expression of the 15TD3 antigen and vimentin was induced simultaneously in some EBV genome-positive cell lines either by EBV superinfection or by 12-0-tetradecanoyl-1-phorbol-13-acetate (TPA) and n-butyrate treatment. The 15TD3 antigen was considered to be a restricted component of the EBV-induced early antigen (EA) complex. The 15TD3 antigen was expressed only in EBV genome-activated cells after either spontaneous EBV genome activation, EBV superinfection, or TPA and n-butyrate treatment. The expression of 15TD3 antigen paralleled the induction of EA in several models of induction of EBV antigens, and was detected only in EA+ cells which were stained with anti-EA+ human sera. The reactivity of 15TD3 MAb was blocked with anti-EA+ human serum, but not with anti-EA- serum. The synthesis of 15TD3 antigen was not inhibited with phosphonoacetic acid, was resistant to acetone fixation, and was sensitive to ethanol (or methanol) fixation. Human lymphoblastoid cells from patients with acute infectious mononucleosis were cloned for the production of antibodies which detected EBV-specific or -nonspecific epitopes on filamentous structures. Two human MAb were defined by two-color immunofluorescence to react to the 15TD3 determinants on intermediate filaments of EBV+ cells. This study supports the following views: that EBV genome activation induces a structure associated with intermediate filaments, and that antibodies against both the EBV-specific, intermediate filament-associated epitope and native intermediate filament epitopes are produced by some EBV-transformed lymphoblastoid cell lines from patients with infectious mononucleosis.
Polyclonal activation of the murine immune system by a goat antibody to mouse IgD. IX. Induction of a polyclonal IgE response.
Authors: Finkelman F D , Snapper C M , Mountz J D , Katona I M
Published: December 2022

The possibility that injection of mice with an affinity-purified goat antibody to mouse IgD (GaM delta) that stimulates polyclonal IgG1 secretion might also stimulate differentiation of B cells into IgE-secreting cells was suggested by the observation that such treatment induces T cells from those mice to secrete a lymphokine, B cell stimulatory factor 1 (BSF-1), that can stimulate both IgG1 and IgE secretion in vitro. Studies described in this paper show that injection of BALB/c mice with 200 to 3200 micrograms of GaM delta greatly increased the quantity of splenic epsilon chain-encoding mRNA, the number of spleen cells with cytoplasmic IgE, and the concentration of serum IgE 7 days after injection. Serum IgE levels obtained in these mice were approximately 100 times baseline levels and were comparable with those found in mice infected with the nematode parasite Nippostrongylus brasiliensis, but were approximately 2000-fold less than the peak serum IgG1 levels induced by GaM delta injection. Both IgE and IgG1 secretion in GaM delta injected mice were T dependent (blocked by anti-L3T4 antibody). These observations are consistent with the hypothesis that BSF-1 may play a role in the in vivo stimulation of IgE secretion and provide an easy to apply model for the investigation of in vivo regulation of IgE responses.
M241 (CD1) expression on B lymphocytes.
Authors: Small T N , Knowles R W , Keever C , Kernan N A , Collins N , O'Reilly R J , Dupont B , Flomenberg N
Published: December 2022

The human thymus leukemia-like antigens (CD1a-c) consist of three similar glycoproteins found on subpopulations of normal thymocytes, T cell acute leukemias, and cutaneous dendritic cells. The CD1c antigen recognized by the M241 monoclonal antibody was detected on the circulating mononuclear cells of three children with severe combined immunodeficiency disease (SCID). Two-color immunofluorescence analysis demonstrated that M241 expression (43 to 95%) was limited to cells expressing the B cell-restricted antigens B4 (CD19), B1 (CD20), and surface immunoglobulin. To confirm M241 expression on normal cells of the B lineage rather than aberrant expression limited to SCID B cells, its expression was demonstrated serologically and biochemically on purified B cells from spleen, tonsil, and peripheral blood. Parallel analyses with monoclonal antibodies NA1/34 and 4A76 demonstrated that the CD1a and CD1b molecules were negative on all B cells that were studied. It has been hypothesized that the CD1 molecules represent the human counterpart of the murine thymus leukemia antigens due to their similar size, limited tissue distribution, and association with beta 2-microglobulin. This study suggests that a subset of CD1 antigens detected by M241 (CD1c) may represent a human analog of a murine Qa antigen due to its extended distribution on normal peripheral B cells.
Establishment of a human T cell hybridoma cell line producing suppressor factor specific for anti-thyroglobulin antibody production.
Authors: Noma T , Yata J
Published: December 2022

Thyroglobulin (Tg)-binding peripheral blood T cells from a normal individual were fused with a T cell leukemia cell line (Jurkat-AG9) treated by emetine and actinomycin D. Several cell lines were established from thus-prepared human T cell hybridomas. The culture supernatant from one of these lines (Tg-Ts47) whose phenotype was OKT3- 11+ 4+ 8- suppressed the generation of Tg-specific antibody-forming cells from the lymphocytes of patients with Hashimotos' chronic thyroiditis, but not anti-SRBC and anti-ovalbumin antibody production from both autologous and patient lymphocytes. Tg-Ts47-derived factors also bore Tg antigen-binding sites. The suppressive activity of the supernatants was shown in almost all patients lymphocytes tested. This indicated that the supernatants of Tg-Ts47 line contain a suppressive factor specific for Tg antigen and capable of acting across allogeneic barriers.
The production of tumor necrosis factor by mouse bone marrow-derived macrophages in response to bacterial lipopolysaccharide and a chemically synthesized monosaccharide precursor.
Authors: Sayers T J , Macher I , Chung J , Kugler E
Published: December 2022

Lipid X, a monosaccharide biosynthetic precursor of lipid A, has been chemically synthesized and was shown to induce bone marrow-derived macrophages to release tumor necrosis factor (TNF) in vitro. However, relatively high amounts of lipid X were necessary for induction, and the levels of TNF were much less than those induced by small amounts of lipid A itself or LPS. Lipid X prepared by extraction of Escherichia coli mutants induced higher levels of TNF than the chemically synthesized material, but this is probably partially due to amounts of impurities in the extracted material. Pretreatment of macrophages with IFN-gamma resulted in the release of higher amounts of TNF on subsequent induction with either LPS or lipid X. In contrast, pretreatment of macrophages with LPS induced hyporesponsiveness for TNF production on subsequent rechallenge with LPS. Lipid X, on the other hand, was incapable of making macrophages hyporesponsive for TNF production.
Epitopes associated with the MHC restriction site of T cells. I. Selective expression of Iat epitopes on H-2-restricted helper T cells.
Authors: Abe R , Yagi J , Asano Y , Tada T
Published: December 2022

We previously established monoclonal antibodies (mAb) that are putatively directed to the I region of H-2k but are reactive only with T cells. Because of their specificity to the unique epitopes different from class II antigens, they are designated as anti-Iat reagents. The present study demonstrated that these anti-Iat inhibit the H-2k-restricted helper T (Th) cell function by acting on the very H-2 restriction site of both H-2k and H-2kxb F1 T cells. This was determined by both the cytotoxic treatment and blocking of antigen-primed Th cells. In the F1 Th population, only those restricted to H-2k were eliminated, leaving the H-2b-restricted Th cells uninhibited. The inhibition of the response was not due to the induction of suppressor T cells, but to the elimination of the function of radioresistant Lyt-1+,2- Th cells. Iatk epitopes were also found on an H-2k-restricted but not on H-2b-restricted Th cell clone established from the same H-2kxb F1 animal. None of the anti-Iatk were reactive with class II antigens on B cells. These results indicate that Iat epitopes are not directly encoded by the I region genes, but are associated with the H-2 restriction site of T cells, which see the self class II polymorphism. Thus, Iat epitopes are expressed clonally in high frequency on H-2k-restricted Th cells of F1, being excluded from the H-2b-restricted Th population. The relationship between Iat and T cell receptor molecules is unknown.
Auranofin increases the affinity of phorbol dibutyrate receptors in chronic lymphocytic leukemia cells (B cells).
Authors: Zalewski P D , Forbes I J , Valente L , Hurst N P
Published: December 2022

Previous studies have shown that auranofin (AF), a lipophilic gold I complex, modulates metabolic events in leukocytes stimulated by phorbol esters, whose major cellular binding site is now known to be the Ca++/phospholipid-dependent protein kinase (protein kinase C). In these experiments we have investigated the effect of AF on the binding of phorbol dibutyrate (PDBu) to human chronic lymphocytic leukemia (CLL) B cells. AF enhanced binding of PDBu to its receptor in CLL cells by a) causing an increase in the affinity of PDBu receptors from Kd 20.3 nM to 7.3 nM, and b) enhancing translocation of PDBu receptors to the cell membrane. The increase in PDBu binding induced by AF in whole cells was only partially reversible by EGTA or the intracellular Ca++ antagonist TMB-8. Studies performed with quin-2-labeled cells showed that 100 microM AF caused a mean (+/- SD) rise in cytosolic Ca++ levels from 0.41 (0.12) to 0.85 (0.33) (n = 5). Thus the mechanism by which AF increases binding of PDBu to its receptor appears to be partially dependent on Ca++. These effects of AF occurred at cellular levels achieved in mononuclear cells during chrysotherapy of patients with rheumatoid arthritis.
Pathogenesis of trachoma: the stimulus for inflammation.
Authors: Taylor H R , Johnson S L , Schachter J , Caldwell H D , Prendergast R A
Published: December 2022

Active trachoma is characterized by chronic inflammation of the conjunctiva, and repeated episodes of reinfection are thought to be necessary to sustain this inflammation. It is currently believed that much of the tissue damage is immunologically mediated. To identify which antigens might be responsible for stimulating this continued inflammation, cynomolgus monkeys that had recovered from a previous ocular infection with Chlamydia trachomatis were challenged with various antigen preparations. Purified preparations of formalin- or UV-inactivated elementary bodies did not elicit any inflammation even with daily inoculation. In addition, neither purified chlamydial major outer membrane protein nor lipopolysaccharide, including recombinant organisms expressing the lipopolysaccharide group antigen, elicit inflammation. A soluble triton extract of the organism rapidly induced marked inflammation when inoculated in the eyes of immune monkeys but had no effect in naive animals. These studies suggest that the continual inflammation in trachoma may not be due to repeated exposure to chlamydial surface antigen(s) but rather to a labile product released by the living organisms.
Identification and partial characterization of a parasite antigen in sera from humans infected with Wuchereria bancrofti.
Authors: Weil G J , Liftis F
Published: December 2022

The purpose of this study was to identify and characterize soluble parasite antigens present in sera from humans infected with the filarial nematode Wuchereria bancrofti. Affinity chromatography and immunoblot methods were used to demonstrate a 200,000 m.w. circulating parasite antigen in sera from infected humans which corresponded to an antigen released by adult W. bancrofti during in vitro culture. Two monoclonal antibodies were produced to this antigen by immunizing mice with antigens from Dirofilaria immitis, a filarial parasite that is closely related to W. bancrofti, and screening cell fusion supernatants by enzyme immunoassay and counterimmunoelectrophoresis inhibition. The antibodies bound to a single repeated epitope (not phosphorylcholine) that was resistant to heat, acid, and protease treatments but sensitive to periodate oxidation. Immunoperoxidase studies showed that the epitope was concentrated in the cuticle and reproductive organs in D. immitis, and it was released in relatively large amounts by adult female D. immitis in vitro. The epitope is also present in antigens of other species of filarial and nonfilarial nematodes, but on the basis of preliminary studies, its presence in human serum appears to be specific for W. bancrofti infection.
Quantitation of cell surface molecules on a differentiating, Ly-1+ B cell lymphoma.
Authors: Ovnic M , Corley R B
Published: December 2022

The number of molecules expressed on the B cell membrane is known to influence the level of immune responses. However, a careful study of the changes in numbers of cell surface molecules during B cell differentiation has not been undertaken. We have addressed this question by using an inducible B cell lymphoma, CH12. Scatchard analysis was used to quantitate the levels of expression of surface immunoglobulin, major histocompatibility complex-encoded class I and class II molecules, and Ly-1 molecules on these cells during their differentiation in response to lipopolysaccharide (LPS). We found that the density of most molecules on the initial population of CH12 cells was comparable to their densities on small splenic B cells. Upon culture, we could classify the molecules into two groups based on their change in expression. One group, represented by surface immunoglobulin and class II molecules, decreased (surface immunoglobulin) or did not change (class II) in number after LPS stimulation, but increased during culture in the absence of LPS. The second set, represented by class I and Ly-1 molecules, increased after LPS stimulation, but did not change as a result of culture. Although the characteristic behavior of class I and class II molecules was different, concomitant changes were observed in both class I (K and D) molecules, and in both class II (I-A and I-E) molecules.
B cell stimulatory factor-1 (interleukin 4) prepares resting murine B cells to secrete IgG1 upon subsequent stimulation with bacterial lipopolysaccharide.
Authors: Snapper C M , Paul W E
Published: December 2022

B cell stimulatory factor-1 (BSF-1)/interleukin 4 markedly enhances IgG1 and IgE secretion by B cells stimulated with bacterial lipopolysaccharide (LPS). We show that preincubation of resting B cells with BSF-1 alone prepares them to secrete IgG1, but not IgE, on subsequent stimulation with LPS. The ability of BSF-1 preincubation to increase overall viable cell yield on the subsequent addition of LPS only partially accounts for this enhancement. The degree of enhancement is dependent on the duration of preincubation, up to at least 48 hr. BSF-1 exerts this effect on resting B cells which have been selected for absence of surface IgG and in the presence of the reversible DNA synthesis inhibitor, hydroxyurea. BSF-1 can act to significantly enhance the IgG1 response when added for 48-hr periods before, at the same time as, or after the addition of LPS. These results suggest strongly that the mode of action of BSF-1 in preparing for the secretion of IgG1 is independent of that of LPS.
Alpha-melanocyte-stimulating hormone exhibits target cell selectivity in its capacity to affect interleukin 1-inducible responses in vivo and in vitro.
Authors: Daynes R A , Robertson B A , Cho B H , Burnham D K , Newton R
Published: December 2022

The ability of i.v.-administered recombinant human interleukin 1 (IL 1 beta) to increase core body temperature, stimulate an increased production of serum amyloid P substance, and augment blood levels of circulating neutrophils in mice was inhibited in a dosage-dependent manner by administration of the neuropeptide alpha-melanocyte-stimulating hormone (alpha-MSH). alpha-MSH administration was also capable of inhibiting the capacity of i.v.-administered IL 1 beta to enhance plasma levels of corticosterone and to depress the generation and/or elicitation of contact hypersensitivity responses to skin-reactive chemicals. An analog of alpha-MSH (Nle4, D-Phe7 alpha-MSH), known to be more potent than native alpha-MSH in a number of melanotropin-sensitive systems, was determined to be more active than alpha-MSH in the modification of these same in vivo responses. Neither alpha-MSH nor its analog were capable of altering the capacity of IL 1 to stimulate increased plasma levels in prostaglandin E2 (PGE2). In vitro, neither alpha-MSH nor its analog were capable of reducing the capacity of IL 1 to stimulate fibroblast production of PGE2 or to augment the proliferation of murine thymocytes exposed to phytohemagglutinin. The apparent selectivity associated with the regulatory influences of alpha-MSH on IL 1-induced responses in vivo suggests that this neuropeptide may function as an endogenous inhibitor of certain immunomodulatory and inflammatory activities of the cytokine IL 1.
Inhibition of IL 2-driven proliferation of murine T lymphocyte clones by supraoptimal levels of immobilized anti-T cell receptor monoclonal antibody.
Authors: Nau G J , Moldwin R L , Lancki D W , Kim D K , Fitch F W
Published: December 2022

Both cloned murine helper T lymphocytes (HTL) and cytolytic T lymphocytes (CTL) proliferated and secreted lymphokines when stimulated with immobilized anti-T cell receptor monoclonal antibody (anti-TCR mAb). However, although proliferation of CTL increased and reached plateau levels as concentrations of anti-TCR mAb were increased, the proliferation of HTL decreased with high concentrations of anti-TCR mAb. A reduction of IL 2-dependent proliferation by CTL was observed when IL 2 was added to cultures of CTL in the presence of high concentrations of anti-TCR mAb, whereas IL 2-independent proliferation appeared to be unaffected by these concentrations of anti-TCR mAb. Inhibition of IL 2-driven proliferation caused by high concentrations of immobilized anti-TCR mAb did not seem to be mediated by soluble factors. Cells continued to express cell surface receptors for IL 2 and transferrin after treatment with immobilized anti-TCR mAb. Inhibition of IL 2-driven proliferation by high concentrations of immobilized anti-TCR mAb may represent a mechanism for regulating the proliferation of T lymphocytes. This inhibitory mechanism is initiated by stimulation of the T cell receptor, in this case by immobilized anti-TCR mAb, and is independent of other cells and factors.
Biosynthesis of paf-acether. IX. Role for a phosphorylation-dependent activation of acetyltransferase in antigen-stimulated mouse mast cells.
Authors: Ninio E , Joly F , Hieblot C , Bessou G , Mencia-Huerta J M , Benveniste J
Published: December 2022

Mouse bone marrow-derived mast cells passively sensitized with monoclonal IgE released paf-acether (platelet-activating factor) and beta-hexosaminidase when challenged with the specific antigen. The formation and the release of paf-acether followed an early increase in the activity of the acetyltransferase, the main enzyme in paf-acether biosynthesis. The antigen-induced activation of the acetyltransferase was dependent on physiologic temperature and on the presence of Ca2+. By using microsomal fractions from unchallenged and challenged mast cells, the Vmax values were 3.5 and 12.0 nmol/min/mg of protein, respectively, whereas in both cases a Km value for acetyl-coenzyme A of 172 microM was measured. The stimulation of acetyltransferase could be mimicked in vitro under experimental conditions which favor phosphorylation, i.e. adding ATP and Mg2+ to lysates from unchallenged mast cells. In contrast, ATP and Mg2+ were uneffective on lysates from challenged cells that exhibited high level of acetyltransferase activity, suggesting that phosphorylation of the enzyme already took place at the time of cell stimulation. Moreover, addition of alkaline phosphatase to microsomal fraction obtained from either antigen-challenged mouse bone marrow-derived mast cells or unchallenged cells, resulted in 52% and 43% loss of acetyltransferase activity, respectively. Phorbol myristate acetate treatment of cells doubled the enzyme activity supporting the phosphorylation hypothesis. Thus, we report on the immunologic activation of a key enzyme for paf-acether synthesis and on the mechanism of this activation in a pure mast cell population. A link between bridging of IgE receptors and the activation of an enzyme critical to the formation of a lipid mediator is thereby evidenced.
The effect of pertussis toxin on mediator release from human basophils.
Authors: Warner J A , Yancey K B , MacGlashan D W
Published: December 2022

We have found that basophils (n = 9) treated with pertussis toxin (1.0 microgram/ml) fail to respond to a subsequent challenge with either 1.0 microM f-Met peptide (p less than 0.0005) or 0.24 microgram/ml of C5a (p less than 0.0005) although their responses to anti-IgE (0.1 microgram/ml) and A23187 (1.0 microgram/ml) were unaltered. These results were confirmed in purified (average purity = 89 +/- 3%) basophils (n = 4). Leukotriene C4 release was also reduced to 15 +/- 5% of control (p less than 0.005) when pertussis toxin-treated basophils were exposed to 1.0 microM f-Met peptide, although no inhibition was noted when anti-IgE or A23187 were used as the stimuli. The effect of pertussis toxin on basophils appears to be independent of the presence of contaminating mononuclear cells. We found that pertussis toxin inhibited f-Met peptide-induced histamine release regardless of the magnitude of the stimulus (0.01 microM to 1.0 microM f-Met peptide), although anti-IgE-induced release was unaffected over a dose-response curve. The effect of pertussis toxin was found to be both time- and concentration-dependent. The maximum effects were obtained after a 3-hr incubation with 1 microgram/ml of toxin. Lower (0.01 to 0.05 microgram/ml) concentrations of toxin or shorter (30 to 60 min) incubation periods did not significantly (p greater than 0.05) inhibit mediator release.
IgM binding protein expressed by activated B cells.
Authors: Sanders S K , Kubagawa H , Suzuki T , Butler J L , Cooper M D
Published: December 2022

We have identified an IgM binding protein, a single chain polypeptide of Mr 60,000, that is expressed on the surface of B lymphocytes within 18 hr following their activation with phorbol myristate acetate. The IgM binding protein was also detected on fresh leukemic B cells from individuals with chronic lymphocytic leukemia, and the level of its expression was increased after phorbol myristate acetate activation. Resting and phorbol myristate acetate-activated T cells, monocytes, and polymorphonuclear leucocytes did not express detectable amounts of the IgM binding protein. The 60-kDa protein on activated human B cells could bind secreted IgM molecules of both mouse and human origin, as well as endogenous membrane-bound IgM molecules following their cross-linkage with anti-mu antibodies. The binding of soluble IgM molecules to the surface of activated B cells was also demonstrated by indirect immunofluorescence analysis.
Stimulation of S-adenosylmethionine synthetase in human lymphocytes by streptococcal M protein.
Authors: Kotb M , Dale J B , Beachey E H
Published: December 2022

The effects of the specific antigen M5 protein of group A streptococci on AdoMet synthetase activity and AdoMet levels in peripheral blood (PB) lymphocytes were studied and were compared with the effects of the nonspecific polyclonal T cell mitogen PHA. M5 protein stimulated AdoMet synthetase activity, whereas PHA had a biphasic effect with an early inhibitory effect and a later stimulatory effect on AdoMet synthetase activity. S-Carbamyl-L-cysteine (SCC), an inhibitor of human lymphocyte AdoMet synthetase, reduced AdoMet levels and inhibited the blastogenic response of PB lymphocytes to both M5 protein and PHA. Inhibition of the response to M5 protein was stronger than that to PHA. However, the inhibitory effects of SCC were totally reversible by washing the cells. It is our hypothesis that such differences in the biochemical events triggered by specific antigen as opposed to a polyclonal mitogen may determine the direction of the functional differentiation of T lymphocytes.
Induction of macrophage Ia antigen expression by rIFN-gamma and down-regulation by IFN-alpha/beta and dexamethasone are mediated by changes in steady-state levels of Ia mRNA.
Authors: Fertsch D , Schoenberg D R , Germain R N , Tou J Y , Vogel S N
Published: December 2022

In previous studies, the induction of Ia antigens on murine peritoneal exudate macrophages by recombinant IFN-gamma (rIFN-gamma) and the antagonism of rIFN-gamma-induced Ia expression by the inhibitors IFN-alpha/beta and glucocorticoids have been examined. In this report, these findings have been extended to an analysis of total or cytoplasmic mRNA from macrophage cultures treated with rIFN-gamma in the absence or presence of these two inhibitors. Recombinant IFN-gamma induced a 5.7- to 6.5-fold increase in steady-state levels of Ia (A alpha-specific) mRNA. Coordinate increases in steady-state mRNA for A beta, and E alpha were observed in response to rIFN-gamma. Maximum induction occurred 24 hr post-treatment and required the continued presence of rIFN-gamma. Induction of A alpha-specific mRNA was sensitive to the protein synthesis inhibitor cycloheximide. Simultaneous treatment of macrophage cultures with rIFN-gamma and IFN-alpha/beta or the glucocorticoid dexamethasone (DEX) resulted in a significant decrease in steady-state, A alpha-specific mRNA levels compared with treatment with rIFN-gamma alone. This analysis suggests that both the induction of Ia expression by rIFN-gamma, and the antagonism of rIFN-gamma-induced Ia gene expression by IFN-alpha/beta and DEX, are regulated by cognate changes in Ia mRNA.
Identification of a family of high molecular weight tumor-associated glycoproteins.
Authors: Abe M , Kufe D W
Published: December 2022

The monoclonal antibody (MAb) designated DF3 was prepared against a human breast carcinoma metastatic to liver. This MAb reacts with a high molecular weight glycoprotein detectable in human breast carcinomas and human milk. In contrast, MAb F36/22 was prepared against the MCF-7 breast carcinoma cell line, MAb 115-D8 against human milk fat globule membrane (HMFGM) and MAb Ca1 against the HEp-2 human laryngeal carcinoma cell line. These MAb have similar patterns of reactivity with normal tissues and tumors based upon immunoperoxidase staining. In the present study we have monitored reactivity of these MAb against DF3 antigen purified from human breast carcinoma cell lines (MCF-7, BT-20) and HMFGM. Solid phase immunoassays and immunoblotting demonstrate that MAb DF3, F36/22, 115-D8, and Ca1 all react with the same purified DF3 antigen. Furthermore, immunoblot analysis indicates that the DF3 antigen reactive with these MAb differs structurally in preparations from breast carcinoma cells and HMFGM. We also demonstrate that MAb F36/22 completely inhibits MAb DF3 binding in competitive blocking assays. In contrast, the results indicate that MAb 115-D8 and Ca1 only partially block MAb DF3 reactivity and the extent of this inhibition varies with DF3 antigen purified from breast carcinoma cells and HMFGM. Taken together, these findings with multiple MAb prepared against a variety of immunogens suggest that existence of a family of related but not identical high molecular weight tumor-associated glycoproteins.
Tumor-specific idiotype vaccines. II. Analysis of the tumor-related network response induced by the tumor and by internal image antigens (Ab2 beta).
Authors: Raychaudhuri S , Saeki Y , Chen J J , Iribe H , Fuji H , Kohler H
Published: December 2022

In this study the tumor-specific immuneresponse induced by irradiated tumor cells (L1210/GZL) and by anti-idiotype antibodies was analyzed. The anti-idiotype antibodies (Ab2) were made against the paratope of a monoclonal antitumor antibody (11C1) that recognizes a tumor-associated antigen which cross-reacts with the mouse mammary tumor virus-encoded envelope glycoprotein 52. Two Ab2, 2F10 and 3A4, induced idiotypes expressed by the monoclonal antitumor antibodies 11C1 and 2B2. Cytotoxic T cells, generated by immunization with irradiated tumor cells, lyse 2F10 and 3A4 hybridoma cells. Furthermore, immunization with Ab2 induces tumor-specific cytotoxic T lymphocytes. The frequency of tumor-reactive cytotoxic T lymphocyte was found to be similar in mice immunized with Ab2 or irradiated tumor cells when examined at the precursor level. However, only 2F10 induces protective immunity against the growth of L1210/GZL tumor cells. The depletion of a L3T4+ T cell population from 2F10 immune mice was found to increase the effectiveness of transferred T cells to induce inhibition of tumor growth. The inability of 3A4 to induce antitumor immunity could be correlated with the presence of a population of Lyt2+ regulatory T cells. Collectively, these results demonstrate the existence of a regulatory network controlling the expression of effective tumor immunity. Our results demonstrate that selection of binding site-related Ab2 may not be a sufficient criteria for the development of an idiotype vaccine. A better understanding of the regulatory interactions induced by anti-idiotypes is needed for the design of effective antitumor immunotherapy.
Generation of NK cell activity from human bone marrow.
Authors: Lotzová E , Savary C A
Published: December 2022

This study was designed to examine the effect of interleukin 2 (IL 2) on cytotoxic activity of human bone marrow cells and to characterize the IL 2-dependent killer cells and the cell population required for their induction. We have demonstrated that the most aggressive IL 2-dependent killer cells (directed against leukemic and solid cancer targets) exhibited LGL morphology and expressed NK cell-associated antigens NKH1 and CD16, but not T cell-associated antigens CD3, CD4, CD5, or CD8. Similarly, the bone marrow cell population necessary for induction of killer cells with highest cytotoxic activity displayed NK cell surface characteristics, as exemplified by CD16 and Leu-7 antigens. On the contrary, very low or no lytic activity was generated from the bone marrow cell population expressing T cell markers CD3 and CD5. These data indicate that the IL 2-dependent bone marrow-derived killer cells with antitumor activity were activated NK cells. If T cells are involved at all in IL 2-dependent bone marrow killing, their potency is inferior to that of activated NK cells. The clinical applications of these studies are discussed.
Identification of a subset of normal B cells with a Burkitt's lymphoma (BL)-like phenotype.
Authors: Gregory C D , Tursz T , Edwards C F , Tetaud C , Talbot M , Caillou B , Rickinson A B , Lipinski M
Published: December 2022

Fresh biopsy cells from cases of Burkitt's lymphoma (BL) display a homogeneous cell surface phenotype. The cells were found to be reactive with the pan B cell marker B1, and consistently co-expressed the BL-associated glycolipid antigen, BLA, and the common acute lymphoblastic leukemia antigen, CALLA, but lacked the B cell "activation" antigens characteristically expressed on EB virus-transformed normal B cells. Microscopic and cell sorter analysis of cells isolated from a series of fresh normal tonsils have identified a subpopulation of normal B cells carrying the same cell surface markers. That BLA and CALLA could be co-expressed on individual B cells was demonstrated by two-color immunofluorescence (IF) of tonsils in suspension, and immunoperoxidase (IP) staining of serial tonsil sections. These BLA+, CALLA+, "activation" antigen- cells were further characterized as B1+, sIgM+, sIgD-, C3d/EB virus receptor+ and were susceptible to virus-induced transformation in vitro. IF studies on Percoll-fractionated tonsillar cell populations and direct examination of IP-stained tonsil semi-thin sections indicated that the BLA+, CALLA+ cells were localized in germinal centers. Their morphological characteristics matched those of BL cells, and their location within germinal centers was consistent both with the known phenotype of germinal center tonsillar B cells and with the description of BL as a proliferation of centroblasts. We suggest that this population of tonsillar germinal center B cells provides the normal counterpart of BL tumor cells.
Characteristics of calmodulin binding to purified human lymphocyte plasma membranes.
Authors: Lee T P , Venuti J , Macara I , Kawauchi R , Davis P J , Mookerjee B K
Published: December 2022

We have explored the role of calmodulin in plasma membrane-related phenomena in lymphocyte activation by measurement of [125I]calmodulin binding to highly purified plasma membrane of human peripheral blood lymphocytes. Calcium-dependent calmodulin binding to lymphocyte membrane was found to reach equilibrium within 5 min of incubation at 37 degrees C and to be saturable and specific. A single class of high affinity-binding sites was identified, with a dissociation constant (Kd) of 1 to 3 X 10(-8) M and a total binding capacity (Bt) of 1 to 2 pmol/mg membrane protein. The free calcium concentration necessary for half-maximal binding was 100 to 300 nM. This was strikingly similar to the cytoplasmic-free calcium activity [Ca2+]i measured by the Quin-2 fluorescence technique, particularly after stimulation with phytomitogens. Calmodulin binding was inhibitable by trifluoperazine (TFP), W-7, and chloropramazine, all of which are calmodulin antagonists. The concentration of TFP that caused 50% inhibition of lymphocyte proliferative responses to phytomitogens was found to be identical to the concentration of TFP which causes 50% inhibition of calmodulin binding to lymphocyte plasma membrane. SDS-polyacrylamide gel electrophoresis followed by gel overlay and autoradiography with iodinated calmodulin revealed five calcium-dependent, TFP-inhibitable, calmodulin-binding polypeptides.
Large granular lymphocytes from SCID horses develop potent cytotoxic activity after treatment with human recombinant interleukin 2.
Authors: Magnuson N S , Perryman L E , Wyatt C R , Mason P H , Talmadge J E
Published: December 2022

Peripheral blood mononuclear cells from foals with hereditary severe combined immunodeficiency (SCID) have morphologic characteristics of large granular lymphocytes (LGL). Attempts to demonstrate cytotoxic activity were without success unless the LGL were incubated with 100 U of human recombinant interleukin 2 (rIL 2)/ml for 24 hr. With rIL 2 incubation, low effector to target ratios (10:1) consistently yielded high levels of cytotoxic activity (30 to 50%) in a standard 4-hr 51Cr-release assay using YAC-1 lymphoma or K562 erythroleukemia cell lines as targets. Monoclonal antibody EqT12 reacted with a large percentage of these cells, and the level of cytotoxic activity was directly correlated to the percentage of EqT12+ cells in the preparation. In normal horses, the percentage of circulating EqT12+ cells is low (5%), while at the same time, cytotoxic activity is not usually detectable even with rIL 2 incubation. In contrast, the percentage of EqT12+ cells in blood of SCID horses is high (up to 40%), as is the IL 2-inducible cytotoxic activity. These results indicate that cytotoxic cells with morphologic and functional characteristics of natural killer cells are produced by horses with SCID.