bluuebunny/crossref_metadata_2025 huggingface dataset:
Induction of lambda 1-immunoglobulin is determined by a regulatory gene (r lambda 1) linked (or identical) to the structural (c lambda 1) gene.
Authors: Epstein R , Lehmann K , Cohn M
Published: June 2004

The cis-acting gene regulating specifically the inducibility of lambda 1-bearing B cells has been mapped within 2.9 cM of the structural gene. If the lambda 1lo-phenotype is due to the gly leads to val interchange in C lambda 1, then an argument can be made that (a) the lambda 1lo-phenotype is due to inefficient induction of lambda 1lo-bearing B cells and (b) B cell triggering is dependent upon a conformational change in the Ig receptor upon interaction with antigen. If the lambda 1lo-phenotype is due to a regulatory sequence linked to the structural C lambda 1-gene, then it must control the expression of the lambda 1-locus during development into adulthood, e.g., by an effect on methylation.
Impaired fc-mediated mononuclear phagocyte system clearance in HLA-DR2 and MT1-positive healthy young adults.
Authors: Kimberly R P , Gibofsky A , Salmon J E , Fotino M
Published: June 2004

Normal individuals with an HLA haplotype containing either DR2, MT1, or B8/DR3 are more likely to have abnormally prolonged Fc receptor-mediated mononuclear phagocyte system (MPS) clearance of IgG-sensitized autologous erythrocytes than their normal counterparts without such haplotypes. Although measurement of Fc receptor binding by rosette formation and saturable IgG aggregate binding revealed no differences among groups, Fc receptor-mediated phagocytosis of IgG-sensitized bovine erythrocytes by monocytes was decreased in the DR2-positive and MT1-positive individuals. The basal in vivo MPS clearance in normal individuals may be immunogenetically determined and may reflect differences in phagocytic rates.
Modulation of Fc receptors of mononuclear phagocytes by immobilized antigen-antibody complexes. Quantitative analysis of the relationship between ligand number and Fc receptor response.
Authors: Michl J , Unkeless J C , Pieczonka M M , Silverstein S C
Published: June 2004

Macrophages plated on surfaces coated with antigen-IgG complexes lose the capacity to bind and ingest IgG-coated particles via their Fc receptors (FcR). Macrophages plated on surfaces containing a similar number of IgG molecules that are not complexed to antigen show little or no decrease in FcR activity. Using a rat monoclonal antibody (2.4G2 IgG) directed against the trypsin-resistant FcR (FcRII) of mouse macrophages we show that the decrease in receptor activity induced by substrate-adherent immune complexes is caused by the physical removal of 60 and 75% of FcRII from the nonadherent membrane surfaces of resident and thioglycollate broth-induced macrophages, respectively. Macrophages maintained on antigen-IgG-coated surfaces for up to 44 h show no recovery in FcRII activity or number, while macrophages on control surfaces exhibit two and threefold increases, respectively, in these parameters. Macrophages maintained for 72 h on antigen-IgG-coated surfaces show a small recovery in FcRII activity, and in the number of FcRII that is accessible to bind 125I-2.4G2 IgG. FcRII modulation, as measured by the binding of 125I-labeled 2.4G2 IgG, is initiated when the number of IgG molecules bound to the substrate is approximately equal to the total number of FcRII on the plasma membranes of all the macrophages on the substrate. FcRII activity and number decrease linearly as the number of substrate-bound IgG molecules increases exponentially, and are maximally reduced when the number of IgG molecules on the substrate is 20-fold greater than the total number of all FcRII on the surfaces of all the macrophages in the culture. Thus there is a stoichiometric relationship between the number of IgG molecules on the substrate and the extent of FcRII modulation.
In vitro analysis of allogeneic lymphocyte interaction. VII. I-A-restricted self-reactive and alloreactive helper components of allogeneic effect factor are distinct donor T cell-derived Ia-molecules that recognize Ia determinants on antigen-presenting cells.
Authors: Delovitch T L , Kaufman K , Gorczynski R M
Published: June 2004

An allogeneic effect factor (AEF) derived from mixed lymphocyte reaction (MLR) cultures of alloactivated A.SW (H-2s) responder T cells and irradiated T cell-depleted A/WySn (H-2a) stimulator spleen cells was fractionated on the basis of molecular size and charge into two I-A-restricted helper components. The cellular origin of these components is believed to be an Lyt-1+2- -activated responder T helper (TH) cell. One alloreactive component, TIAH-1, recognizes allo-I-A determinants on an A/WySn antigen-presenting cell (APC). The other self-reactive component, TIAH-2, recognizes self-I-A determinants on an A.SW APC. The interaction of each of these components with the appropriate APC subsequently activates an in vitro primary anti-SRBC PFC response of either stimulator haplotype- or responder haplotype-derived B cells. These data demonstrate that the activity of TIAH-1 and TIAH-2 is dependent on the genotype of the APC and not the B cell, and that the target cell of action of these AEF TH components is an APC. TIAH-1 and TIAH-2 are 68,000 mol wt single polypeptide chains that have an isoelectric point (pI) of 5.8 and 5.5, respectively. Their charge difference is not attributable to altered amounts of sialylation or phosphorylation, but probably is due to other forms of altered glycosylation and/or to changes in their amino acid sequence. They share approximately 80% of their tryptic peptides and likely constitute homologous but nonidentical molecules. Papain cleaves TIAH-1 and TIAH-2 into a 40,000 mol wt fragment. TIAH-1 and TIAH-2 may represent structurally very related but nonidentical secreted forms of activated responder TH cell-derived receptors for allo-I-A and self-I-A determinants, respectively.
Enhancement of human eosinophil-mediated killing of Schistosoma mansoni larvae by mononuclear cell products in vitro.
Authors: Veith M C , Butterworth A E
Published: June 2004

Previous studies have shown that eosinophils from eosinophilic individuals differ functionally from those of normal individuals. In order to test whether agents that might induce eosinophilia could also affect eosinophil function, we have compared the capacity of culture supernatants from mononuclear cells of eosinophilic or normal individuals to enhance eosinophil activity, as reflected by an increased killing of schistosomula of Schistosoma mansoni in vitro. An enhancing activity was detected, which increased both the antibody-dependent, and to some extent the antibody-independent killing of schistosomula by eosinophils, in the absence of complement. Under similar conditions, the supernatants failed to stimulate an otherwise undetectable neutrophil-mediated killing. The activity could be removed from the assay by washing, without reversing previous eosinophil stimulation, and was not directly toxic to the schistosomula. Preliminary characterization of the activity indicated that it was relatively heat-stable at 100 degrees C for 30 min, and had an estimated molecular weight of 35,000-45,000 as judged by G-200 Sephadex fractionation. The activity was produced by a nonlymphocytic, nonspecific esterase-containing adherent mononuclear cell in the absence of either Con A or antigenic stimulation. Significant enhancing activity was detectable after 1 h of culture and continued for at least 25 h. Protein synthesis was required for its production or release. Although the activity was detectable in supernatants from both eosinophilic and normal individuals, the supernatants that demonstrated highest activity and that could be titrated out furthest were generally derived from eosinophilic individuals, suggesting that there might be some association between eosinophilia and enhanced eosinophil function.
T cell regulation of B cell activation. I-A-restricted T suppressor cells inhibit the major histocompatibility complex-restricted interactions of T helper cells with B cells and accessory cells.
Authors: Asano Y , Hodes R J
Published: June 2004

The present studies were carried out to characterize the cellular interactions involved in the activation and function of the antigen-specific and antigen-nonspecific T suppressor (Ts) cells that regulate the IgG responses of Lyb-5-B cells. The in vitro activation of both Lyt-1+2- antigen-nonspecific Ts cells and Lyt-1-2+ antigen-specific Ts cells was shown to require the interaction of accessory cells and antigen-primed T cells. It was further demonstrated that this interaction was major histocompatibility complex (MHC)-restricted in that T cell recognition of I-A-encoded determinants on accessory cells was required for Ts cell activation. The activation of antigen-primed (A X B)F1 T cells with antigen in the presence of parentA or parentB accessory cells resulted, respectively, in the generation of parentA-restricted or parentB-restricted Ts cells. ParentA-restricted F1 Ts cells suppressed the responses generated by (A X B)F1 T helper (Th) cells cooperating with parentA (B + accessory) cells but did not suppress responses by the same (A X B)F1 Th cell population cooperating with parentB (B + accessory) cells. Neither parentA-restricted Ts cells alone nor parentB-restricted Ts cells alone suppressed the responses of (A X B)F1 (B + accessory) cells, whereas a mixture of these two Ts cell populations was able to significantly suppress the responses of F1 (B + accessory) cells. In contrast, responses of (A X B)F1 leads to parentA Th cells (restricted to recognizing parentA but not parentB MHC determinants on F1 cells) and (A X B)F1 (B + accessory) cells was suppressed by parentA-restricted Ts cells but not by parentB-restricted Ts cells. Collectively these findings suggest that the Ts cell populations characterized here do not function by directly inhibiting the activity of Th cells, B cells or accessory cells of a given MHC genotype, but rather that they appear to function through a unique mechanism involving highly specific inhibition of the interaction between MHC-restricted Th cells and the (B + accessory) cells required for these responses.
Circumsporozoite proteins of malaria parasites contain a single immunodominant region with two or more identical epitopes.
Authors: Zavala F , Cochrane A H , Nardin E H , Nussenzweig R S , Nussenzweig V
Published: June 2004

We have used panels of monoclonal antibodies to circumsporozoite (CS) proteins of Plasmodium falciparium, P. vivax, and P. knowlesi to determine the number of topographically independent epitopes of these antigens. The results of competition binding assays indicated that single regions of the CS molecules were recognized by the homologous monoclonal antibodies. Competition binding assays were also used to study the specificity of antibodies contained in the sera of humans and monkeys that had developed sterile immunity after immunization with irradiated, intact sporozoites. We found that single monoclonal antibodies inhibited 70-95% of the specific binding of the polyclonal antibodies to crude extracts of sporozoites. It appears, therefore, that CS proteins are among the most immunogenic constituents of sporozoites, and that a single region of these molecules contains most of the immunogenic activity. An additional finding was that the immunodominant region of CS molecules is multivalent with regard to the expression of a single epitope. This was demonstrated by the ability of monomers of CS proteins to bind simultaneously two or more molecules of the same monoclonal antibody.
Paroxysmal nocturnal hemoglobinuria: deficiency in factor H-like functions of the abnormal erythrocytes.
Authors: Pangburn M K , Schreiber R D , Trombold J S , Müller-Eberhard H J
Published: June 2004

Erythrocytes from patients with paroxysmal nocturnal hemoglobinuria (PNH) contained a subpopulation that lacked membrane-associated Factor H-like activity present on normal human erythrocytes. Initial deposition of C3b on the erythrocytes was effected using a fluid phase C3 convertase. The cells were then treated with fluorescein-labeled C3 and the cell-bound C3 convertase. Analysis utilizing the fluorescence-activated cell sorter revealed two distinct cell populations, one of which was highly fluorescent, indicating a large number of C3b molecules per cell. Only this population (43%) was susceptible to lysis (44%) when exposed to acidified serum before C3b deposition. The less fluorescent population resembled normal human erythrocytes and was not affected by prior treatment with acidified serum. Since C3b deposition occurred almost exclusively on the complement-sensitive cells in the PNH erythrocyte population, these cells could be examined for the Factor H-like regulatory activities without prior isolation. These functions include enhancement of inactivation of erythrocyte-bound C3b by Factor I and acceleration of the decay of erythrocyte-bound C3 convertase, C3b,Bb. It was found that C3b on PNH erythrocytes was 100-fold less susceptible to inactivation by Factor I than C3b on normal human erythrocytes. The half-life at 22 degrees C of C3b,Bb on PNH erythrocytes was threefold greater than on normal human erythrocytes and similar to that of the enzyme bound to particles that do not possess Factor H-like activity. These observations suggest that the abnormal susceptibility of PNH erythrocytes to lysis by complement is due to a functional deficiency in one or more of the Factor H-like proteins present on normal human erythrocytes.
Activation of basophil and mast cell histamine release by eosinophil granule major basic protein.
Authors: O'Donnell M C , Ackerman S J , Gleich G J , Thomas L L
Published: June 2004

Major basic protein (MBP) is a primary constituent of eosinophil granules. In this report, we demonstrate that MBP from human eosinophil granules initiates a nonlytic histamine release from human leukocytes. A direct effect of MBP on basophils was confirmed using purified human basophils. The kinetics of release were similar to those reported for poly-L-arginine, although MBP was less potent than poly-L-arginine of similar molecular weight. Reduction and alkylation of MBP diminished both the potency and efficacy of the molecule. Native MBP also stimulated histamine secretion from purified rat peritoneal mast cells in a manner characteristic of other polycations. These results emphasize the bidirectional nature of the basophil/mast cell-eosinophil regulatory axis.
A protein anomaly in erythrocyte membranes of patients with Duchenne muscular dystrophy.
Authors: Wallach D F , Verma S P , Singer W E
Published: June 2004

Raman spectroscopic comparisons of erythrocyte membranes from 20 patients with Duchenne muscular dystrophy and 8 age-matched controls indicate a prominent and consistent protein anomaly in the patient samples. This was apparent in the following: (a) CH-stretching signals from control membranes reveal a thermotropic transition at 15.6 degrees C, attributable to a protein/lipid phase that is lacking in dystrophic membranes. (b) CH-stretching signals from control membranes also show a protein transition at 39 degrees C [pH 7.4] that is shifted to 45 degrees in dystrophic membranes. (c) A reduction in pH to 5.7 shifts this transition from 39 degrees C to 7 degrees C in normal membranes and from 45 degrees C to 24 degrees C in dystrophic membranes. (d) The Amide I/Amide III regions indicate a significant proportion of beta-structured peptide in dystrophic but not normal membranes. (e) Analysis of tyrosine signals indicates greater polar exposure of tyrosine hydroxyl groups in dystrophic vs normal membranes. All of the differences between dystrophic and normal membranes are highly significant (P less than 0.001).
Expression of C5a-like biological activities by the fifth component of human complement (C5) upon limited digestion with noncomplement enzymes without release of polypeptide fragments.
Authors: Wetsel R A , Kolb W P
Published: June 2004

Experimental conditions required for the expression of maximum C5 activation upon limited trypsin hydrolysis were determined to be 0.008 mol of trypsin/mol C5 in a reaction mixture containing 1 mg C5/ml veronal-buffered saline incubated at 37 degrees C for 30 min. Employing these optimal incubation conditions, the primary or preferred site of trypsin hydrolysis of the C5 alpha-chain resulted in the production of C5 alpha 1 (molecular weight, 90,000) and C5 alpha 5 (molecular weight, 25,000) fragments that remained disulfide bonded to the modified C5 molecule (C5'try). Detailed structural-functional analyses clearly indicated the trypsin-mediated conversion of the C5 alpha-chain to C5 alpha 1 and C5 alpha 5 was responsible for the acquisition of neutrophil lysosomal enzyme-releasing and chemotactic activities. Gel filtration column chromatography under physiological ionic strength, pH 7.4, or in the presence of 0.2% SDS further demonstrated that at least 90% of the total recoverable C5a-like biological activity was mediated by the 210,000 molecular weight forms of trypsin-modified C5. Other physiologically relevant, noncomplement protease enzymes (alpha-thrombin, plasmin, and elastase) also activated C5 to express C5a-like reactivities. Analysis of alpha-thrombin-induced, C5 alpha-chain cleavage events by SDS-polyacrylamide slab gel electrophoresis indicated that the mechanism of alpha-thrombin-activation of C5 is similar to that described for trypsin. Reconciliation of this novel mechanism of C5 activation by trypsin with previously published results, and a discussion of the biological significance of noncomplement enzyme-mediated activation of C5 as it might relate to inflammatory processes in vivo, was presented.
Fc receptor modulation in mononuclear phagocytes maintained on immobilized immune complexes occurs by diffusion of the receptor molecule.
Authors: Michl J , Pieczonka M M , Unkeless J C , Bell G I , Silverstein S C
Published: June 2004

We describe a method for synchronously assembling antigen-antibody complexes underneath macrophages adherent to an antigen-coated surface. We have used this method to study the mechanism of Fc receptor (FcR) disappearance that occurs when resident and thioglycollate-elicited mouse macrophages are cultured on immune complex-coated surfaces. Erythrocytes opsonized with IgG (E(IgG) and a monoclonal antibody (2.4G2 IgG) directed against the trypsin-resistant FcR (FcRII) were used as indicators of the presence and distribution of FcRII molecules on the macrophage plasma membrane. Inhibitors of aerobic (NaCN) and anerobic (2-deoxyglucose, NaF) glycolysis and pinocytosis, of protein biosynthesis (cycloheximide), and of cytoskeletal function (cytochalasin B and D, colchicine, podophyllotoxin, taxol) did not reduce the rate or extent of FcRII modulation. Moreover, treatment of the macrophages with 0.1-0.5% formaldehyde did not reduce the extent of FcRII modulation as measured by the disappearance of E(IgG) binding sites. FcRII modulation was markedly slowed when the temperature was decreased to 2-4 degrees C. These results prove that FcRII modulation is governed by diffusion of the receptor in the plasma membrane. From the speed of FcRII disappearance from the macrophage's upper surface we calculate that the receptor has a diffusion coefficient at 37 degrees C of 2.5 X 10(-9) cm2/s. This finding indicates that FcRII, in its unligated form, is not linked to the macrophage's cytoskeleton, and that the receptor is capable of accommodating spatially to any distribution of ligands on a particle's surface.
IgE-mediated chemotaxis of rat basophilic leukemia cells towards specific antigen.
Authors: Orida N , Feldman J D , Katz D H , Liu F T
Published: June 2004

We evaluated chemotactic properties of four sublines of rat basophilic leukemia cells using blindwell Boyden chamber assays. After sensitization with a mouse monoclonal IgE directed against dinitrophenyl (DNP), cells from sublines 2H3-C and 926a underwent chemotaxis toward DNP-bovine serum albumin (BSA) and sublines RBL-1 and 4A did not. Chemotactic responses required specific IgE and were determined by the IgE antigen specificity used for sensitization. The threshold for chemotaxis was on the order of 10(-10) M DNP-BSA. Release of incorporated [3H]-serotonin did not always parallel chemotactic responses, which suggests that chemotaxis and secretion may be two unlinked processes that occur during basophil activation. Our results predict a possible in vivo mechanism whereby specific chemotactic responses of basophils and other FcR epsilon-bearing cells are mediated via specific IgE bound to membrane FcR epsilon.
Kinetics and distribution of antigen-specific IgE-secreting cells during the primary antibody response in the rat.
Authors: Sedgwick J D , Holt P G
Published: June 2004

A new assay system is described for the enumeration of antigen-specific IgE immunoglobulin-secreting cells (ISC) based on an enzyme-linked immunoabsorbent assay. Using this technique to monitor the organ distribution of OVA-specific ISC after primary immunization of rats, approximately 12,000 specific IgE ISC were detected at the peak of the response in the draining lymph nodes compared with 117,000 IgG ISC; the splenic anti-OVA response was restricted to the IgM class. Using plates precoated with anti-rat IgE instead of antigen, total IgE ISC were enumerated in normal and helminth-parasitized rats. The assay system detected up to 5 X 10(5) IgE ISC in mesenteric lymph nodes from parasitized animals compared with less than 50 in controls.
Stimulating effect of MDP and its adjuvant-active analogues on guinea pig fibroblasts for the production of thymocyte-activating factor.
Authors: Iribe H , Koga T , Kotani S , Kusumoto S , Shiba T
Published: June 2004

Synthetic muramyl dipeptide (MDP) could stimulate skin fibroblasts of the guinea pig to produce thymocyte-activating factor, which augments the proliferative response of thymocytes to phytohemagglutinin (PHA). Adjuvant-active analogues of MDP also stimulated fibroblasts to produce the factor, whereas adjuvant-inactive analogues failed to do so. Thus a marked parallelism was found between adjuvant activity of these compounds and the stimulating effect on fibroblasts. Thymocyte-activating factor derived from MDP-stimulated fibroblasts was found in the fraction of mol wt 30,000-60,000 by gel filtration on a Sephacryl S-200 column. Furthermore, this factor did not exhibit T cell growth factor activity.
Graft-versus-host disease in cyclosporin A-treated rats after syngeneic and autologous bone marrow reconstitution.
Authors: Glazier A , Tutschka P J , Farmer E R , Santos G W
Published: June 2004

Lethally irradiated rats treated with cyclosporin A (CsA) for 20-40 d develop classic graft-versus-host disease (GVHD) when reconstituted with syngeneic or autologous bone marrow, upon discontinuation of CsA, whereas normal rats do not. Syngeneic GVHD may be transferred to irradiated but not normal syngeneic recipients. Normal spleen cells fail to prevent the development or adoptive transfer of syngeneic GVHD.
Relative efficacy of human monocytes and dendritic cells as accessory cells for T cell replication.
Authors: Van Voorhis W C , Valinsky J , Hoffman E , Luban J , Hair L S , Steinman R M
Published: June 2004

Monocyte-specific monoclonal antibodies (7) were used to compare the efficacy of monocytes and dendritic cells as accessory or stimulator cells for human T cell replication. Both unfractionated and plastic-adherent mononuclear cells were first treated with a cytolytic antimonocyte antibody that kills greater than 95% of monocytes but not dendritic cells. When tested as stimulators of the mixed leukocyte reaction (MLR) and of oxidative mitogenesis (the proliferation of T cells modified with sodium periodate), the monocyte-depleted cells had normal or enhanced stimulatory capacity. Monocyte-depleted mononuclear cells also proliferated normally to soluble antigens (Candida albicans, tetanus toxoid), even under limiting conditions of cell dose, antigen dose, and culture time. Adherent blood mononuclear cells were next separated into monocyte-enriched and -depleted components using fluoresceinated antimonocyte antibody and the cell sorter. The depleted fraction (less than 2% monocytes by esterase staining and by cytology) contained the dendritic cells and exhibited at least 75% of the accessory activity. The monocyte-rich fraction (approximately 97% esterase positive) stimulated the MLR and oxidative mitogenesis weakly, and was comparable in potency to nonadherent cells. Cell-specific antibodies and complement were also used to prepare dendritic cells that were thoroughly depleted of monocytes and lymphocytes. The dendritic cells (70-80% pure) were potent stimulators of the allogeneic MLR, syngeneic MLR, and tetanus toxoid response, being active at stimulator to responder ratios of 1:100 or less. Taken together with previous studies (1, 2), these experiments indicate that the dendritic cell is the major stimulator of T cell replication in man. The contribution of class II products of the major histocompatibility complex (7) was then evaluated with a new monoclonal, 9.3F10. Accessory function was dramatically inhibited if cells bearing class II antigens were killed with 9.3F10 and complement, or if class II molecules were blocked by the addition of 9.3F10 Fab to the culture medium. The expression of 9.3F10 class II products was therefore studied on purified monocytes and dendritic cells. Most if not all cells in both populations reacted with 9.3F10, and each population exhibited approximately 150,000 125I-Fab 9.3F10 binding sites per cell. Since Ia+ dendritic cells are active accessory cells, but Ia+ monocytes are not, class II products are necessary but not sufficient for the stimulation of T cell proliferation in man.
Clonal analysis of cytotoxic T cell response against human melanoma.
Authors: Mukherji B , MacAlister T J
Published: June 2004

We investigated the feasibility of generating cytotoxic T cell clones against autologous human melanoma cells using a melanoma cell line (VIP) and a spontaneously transformed autologous fibroblast line (VIP-F:T). Cytotoxic lymphocytes (CL) generated against the VIP melanoma cells in one-way mixed lymphocyte-tumor cell interactions were expanded in interleukin 2 for 2 wk. The expanded CL were cloned in limiting dilution. Two phenotypically homogeneous clones (3:1 and E.5) were obtained bearing OKT3 phenotype. Both clones expressed cytotoxicity selectively only against the sensitizing autologous target VIP. cytotoxicity assays performed with clone E.5 against the VIP target cells in the presence of autologous unfractionated lymphocytes or serum showed no modulation of autoreactivity of clone E.5. These results indicate that analysis of cellular immune response against autologous tumor cells might be feasible using autoreactive clones generated by the currently available in vitro cloning technology.
Detection of cell surface and intracellular antigens by human monoclonal antibodies. Hybrid cell lines derived from lymphocytes of patients with malignant melanoma.
Authors: Houghton A N , Brooks H , Cote R J , Taormina M C , Oettgen H F , Old L J
Published: June 2004

This study represents an initial attempt to analyze the humoral immune reactions of patients with malignant melanoma by hybridoma methodology. Using lymphocytes from regional lymph nodes, peripheral blood and tumor infiltrates, 158 fusions were performed with SKO-007 (human myeloma line), LICR-LON-HMy2 (LICR-2), GM 4672 (human lymphoblastoid lines), or NS-1 (mouse myeloma line). Fusion of lymph node lymphocytes with NS-1 resulted in a 3-4 times higher frequency of clones than fusion with LICR-2, and a 10 times higher frequency than fusion with SKO-007 or GM 4672. In the case of peripheral blood lymphocytes, fusion with NS-1 gave greater than 25 times higher frequency of clones than fusion with LICR-2 or SKO-007. Production of human mu, gamma, or alpha heavy chains was detected in 50-80% of wells containing growing clones, and the levels of immunoglobulin ranged from 0.3 micrograms to 40 micrograms/ml. NS-1-derived clones could be easily subcultured, while LICR-2 and SKO-007 clones grew more slowly on subculturing. In this study, Ig secretion appeared to be a more stable property of LICR-2-derived clones than NS-1-derived clones. A panel of 20 human cancer cell lines was used to screen 771 Ig-secreting cultures for antibody to cell surface or intracellular antigens. Reactivity with cell surface antigens was found infrequently (6 cultures), whereas reactivity with intracellular antigens was more common (27 cultures). A new cell surface antigen with properties of a glycolipid was defined with an IgM monoclonal antibody secreted by a tetraploid cell derived from a fusion of LICR-2 with lymphocytes from the axillary lymph node of a patient with melanoma. The hybrid cell line has been subcloned four times and secretes 5 micrograms IgM/ml. The antigen detected by this IgM antibody was found on 5 of 23 melanoma cell lines and 12 of 30 epithelial cancer cell lines. No reactions were found with 11 cultures derived from normal cells. Stable cell lines secreting human antibody that detected nuclei, nucleoli, cytoskeletal elements, Golgi complex, or other cytoplasmic components were also isolated in this study. One of these antibodies detected an intracellular antigen that is restricted to cells of neuroectodermal derivation, and a second antibody reacted primarily with cells of epithelial origin. Using these methods to isolate and analyze human monoclonal antibody, it should now be possible to define the repertoire of the humoral immune response to melanoma.
Epstein-Barr virus-specific cytotoxic T lymphocytes as probes of HLA polymorphism. Heterogeneity of T cell-restricting determinants associated with the serologically defined HLA-A2 antigen.
Authors: Gaston J S , Rickinson A B , Epstein M A
Published: June 2004

Epstein-Barr (EB) virus-specific effector T cell lines were established from nine virus-immune donors positive for the serologically defined HLA-A2 antigen; of these, four lines contained a demonstrable A2-restricted cytotoxic component. When these four effector populations were each tested on the same panel of EB virus-transformed lines from 20 HLA-A2-positive individuals, 16 of the target cell lines were consistently killed at levels above 25% of the relevant autologous cell lysis. Cytotoxicity appeared to be mediated through a restricting determinant associated with the 'common A2' antigen that these lines shared; indeed the lysis could be specifically blocked by high concentrations of an HLA-A2-specific monoclonal antibody. In contrast, 4 out of 20 target cell lines were not killed by HLA-A2-restricted effector cells, even though they did express the serologically defined A2 antigen and were found in other tests to be susceptible to EB virus-specific cytolysis restricted through other HLA-A or -B antigens on their surface. These results suggest that EB virus-specific cytotoxic T cells can distinguish between serologically identical HLA-A2 molecules via the heterogeneity of their T cell-restricting determinants. Data from one of the effector cell populations further suggested that a serologically defined cross-reaction between the otherwise distinct HLA-A2 and -Bw57 antigens might also be reflected in a cross-reactivity of T cell-restricting determinants.
Influenza virus site recognized by a murine helper T cell specific for H1 strains. Localization to a nine amino acid sequence in the hemagglutinin molecule.
Authors: Hackett C J , Dietzschold B , Gerhard W , Ghrist B , Knorr R , Gillessen D , Melchers F
Published: June 2004

The functional helper T cell line Vir-2, derived from a PR8 (H1N1) influenza virus-immunized BALB/c mouse, proliferates in response to syngeneic antigen-presenting cells and naturally occurring strains of subtype H1 human influenza virus from 1934-1957 and 1977-1980 isolates. A conserved region of the hemagglutinin molecule around amino acid position 115 in the heavy chain (HA1) was implicated as being important in this recognition by the lack of stimulatory activity associated with a glutamic acid to lysine substitution at position 115 in the laboratory mutant RV6, derived from wild-type PR8. Characterization of the stimulatory determinant on the wild-type hemagglutinin molecule was then undertaken using cleavage products and synthetic peptides. Vir-2 cells recognized the reduced and alkylated purified HA1 of PR8 virus, and this reactivity was retained after cleavage at methionine and tryptophan residues. High-pressure liquid chromatography separation of cleavage fragments indicated that a short sequence of the HA1 containing residue 115 was being recognized. This recognition was localized to a nine amino acid segment (positions 111-119) by assaying stimulation with synthetic peptide homologues of different lengths from that region. As with native hemagglutinin, Vir-2 cells responded to active peptides when presented by H-2d but not H-2k antigen-presenting cells.
Genes affecting mink cell focus-inducing (MCF) murine leukemia virus infection and spontaneous lymphoma in AKR F1 hybrids.
Authors: Rowe W P , Hartley J W
Published: June 2004

An assessment of the importance of mink cell focus-inducing (MCF)-type recombinant murine leukemia viruses in spontaneous thymic lymphomagenesis and of the genetic factors affecting its occurrence was carried out with F1 hybrids between AKR and various other inbred strains. There was generally close agreement between the frequency of detection of MCF virus, of thymocyte antigenic amplification in the preleukemic period, and of spontaneous lymphoma. Also, hybrid combinations with moderate to high spontaneous lymphoma were uniformly susceptible to lymphoma induction by neonatal inoculation of MCF 247 virus, while lower leukemic hybrids were at least partially resistant to the induced disease. At least four resistance genes can be identified as affecting the disease in the various hybrids: Fv-1, Rmcf, an unidentified gene carried by the C57 series of mice and SJL, and an unidentified minor gene carried by several other strains.
Serum transfer of collagen-induced arthritis in mice.
Authors: Stuart J M , Dixon F J
Published: June 2004

Immunization of DBA/1 mice with native chick type II collagen resulted in development of polyarthritis 4-5 wk later. Sera of these mice contained high levels of anticollagen antibodies, and immunoglobulin concentrates of their sera transferred arthritis to unimmunized recipients. Histopathologically, this passively transferred arthritis resembled the early disease of immunized donors. Immunofluorescence studies demonstrated the deposition of IgG and C3 on the articular surface but not in synovial tissue of arthritic joints. Transferred, isotopically labeled anticollagen antibodies rapidly localized to the limbs and to other cartilage-containing tissues. When transfer concentrate was administered to arthritis-resistant strains, they also developed arthritis. Indeed, immunoglobulin concentrates from rats with collagen-induced arthritis transferred arthritis to naive mice. The amount of concentrate required for transfer to B10.D2 resistant mice was reduced by immunizing them with collagen 4 wk before transfer. Although susceptibility to arthritis from immunization is H-2 linked, these studies clearly demonstrate that passive transfer of arthritis depends upon injection of specific antibody and not on other host factors.
Arachidonic acid metabolism by human monocytes. Studies with platelet-depleted cultures.
Authors: Pawlowski N A , Kaplan G , Hamill A L , Cohn Z A , Scott W A
Published: June 2004

Purified human monocytes release and metabolize endogenous arachidonic acid (20:4) from phospholipid stores when challenged with particulate inflammatory stimuli or the calcium ionophore A23187. Using radiolabeled cultures, the percentage of total [3H]20:4 released was similar with each type of stimulus. However, the spectrum of 20:4 metabolites differed. With opsonized zymosan (OpZ) or Sephadex beads coated with IgG immune complexes (Ig-beads), the predominant product was thromboxane (25% of the total) together with smaller amounts of other cyclo-oxygenase products and lipoxygenase metabolites. Levels of thromboxane synthesis by monocytes were comparable to those by platelets, as measured by radioimmunoassay. In contrast, exposure to the nonspecific agent A23187 led to mainly lipoxygenase products (70% of the total). Monocytes isolated from mononuclear cell fractions of peripheral blood contain platelets specifically rosetted to their surfaces. These platelet contaminants were removed by sequential incubations of monocytes in serum and EDTA followed by adherence and detachment from tissue culture vessels. The presence of platelets in routinely isolated monocytes presented a major difficulty in the study of human monocyte 20:4 metabolism since platelets also synthesize thromboxane. Loss of 12-HETE synthesis (16-fold reduction relative to 5-HETE) in A23187-stimulated cultures provided a convenient measure of platelet depletion. This together with the response to monocyte-specific stimuli (OpZ and Ig-beads) allowed for the distinction between monocyte and platelet 20:4 metabolism.
Radiolabeled fragments of monoclonal antibodies against carcinoembryonic antigen for localization of human colon carcinoma grafted into nude mice.
Authors: Buchegger F , Haskell C M , Schreyer M , Scazziga B R , Randin S , Carrel S , Mach J P
Published: June 2004

Four monoclonal antibodies against carcinoembryonic antigen (CEA) have been selected from 32 hybrids that produce antibodies against this antigen, by the criteria of high affinity for CEA and low cross-reactivity with granulocyte glycoprotein(s). The specificity of tumor localization in vivo of the four MAb, and their F(ab')2 and Fab fragments was compared in nude mice bearing grafts of a serially transplanted, CEA-producing, human colon carcinoma. The distribution of radiolabeled MAb and their fragments after intravenous injection was analyzed by direct measurement of radioactivity in tumor and normal organs, as well as by whole-body scanning and by autoradiography of tumor sections. Paired labeling experiments, in which 131I-labeled antibody or fragments and 125I-labeled control IgG are injected simultaneously, were undertaken to determine the relative tumor uptakes of each labeled protein. The tumor antibody uptake divided by that of control IgG defines the specificity index of localization. Tumor antibody uptakes (as compared with the whole mouse), ranging between 7 and 15, and specificity indices ranging between 3.4 and 6.8, were obtained with the four intact MAb at day 4-5 after injection. With F(ab')2 fragments of the four MAb, at day 3, the tumor antibody uptakes ranged between 12 and 24 and the specificity indices between 5.3 and 8.2. With the Fab fragments prepared from the two most promising MAb, the antibody uptakes reached values of 34 and 82 at day 2-3 and the specificity indices were as high as 12 and 19. The scanning results paralleled those obtained by direct measurement of radioactivity. With intact MAb, tumor grafts of 0.5-1 g gave very contrasted positive scans 3 d after injection. Using MAb fragments, tumors of smaller size were detectable earlier. The best results were obtained with Fab fragments of MAb 35, which gave clear detections of tumors weighing only 0.1 g as early as 48 h after injection. Autoradiographs of tumor sections from mice injected with 125I-labeled MAb demonstrated that the radioactivity was localized in the tumor tissues and not in the stromal connective tissue of mouse origin. The highest radioactivity concentration was localized in areas known to contain CEA such as the pseudolumen of glands and the apical side of carcinoma cells. The penetration of radioactivity in the central part of tumor nodules and the pseudolumen appeared to be increased with the use of MAb fragments.
T cell hybrids that express a VH idiotope-related determinant on a glycoprotein distinct from H-2, Thy-1, and Lyt-1 molecules.
Authors: Chanh T C , Cooper M D
Published: June 2004

Two mouse monoclonal antibodies to chicken immunoglobulin VH-associated idiotypes (Id), CId-1 and CId-2, were used as probes for Id determinants on mouse T cells. CId-1, which recognized chicken antibodies to N-acetyl glucosamine (NAGA), and approximately 0.4% of chicken T lymphocytes also reacted with approximately 0.2% of BALB/c splenic Thy-1.2+ cells. When enriched CId-1+ splenic T cells from NAGA-immune BALB/c mice were fused with the AKR thymoma BW 5147 cell line, 2 of 72 resulting hybrids, termed CId-1A and CId-1B, were reactive by indirect immunofluorescence with the CId-1 antibody. CId-1 determinants were expressed both in the cytoplasm and on the cell surface. Immunofluorescence studies revealed that both CId-1+ T cell hybrids were phenotypically identical: CId-2-/Ig-/Lyt-1+2-/Thy-1.2+/II-2d+/I-Ad-/I-Ak-/I-Jd+/I-Jk+. Incubation of CId-1B hybrid cells with concanavalin A or lentil lectin resulted in capping of the CId-1 determinant, whereas incubation with pokeweed mitogen, lipopolysaccharide, phytohemagglutinin, and wheat germ agglutinin had no effect on the cell surface distribution of the CId-1 molecule. Trypsin or pronase treatment resulted in the loss of detectable CId-1 determinant on the cell surface. Treatment of CId-1B cells with tunicamycin also reduced the immunofluorescence intensity of the surface CId-1 determinant, but had no effect on its cytoplasmic expression. CId-1 antibody-induced capping of the CId-1 marker did not affect the surface distribution of Lyt-1, Thy-1.2, H-2d, I-Jd, or I-Jk molecules. Conversely, capping of I-Jd and I-Jk determinants did not alter the surface distribution of CId-1. These results suggest that the CId-1 determinant is on a glycoprotein that is not physically linked to the Lyt-1, Thy-1.2, H-2d, I-Jd, and I-Jk molecules. The clonal restriction of CId-1 expression by T cells suggests that the CId-1+ molecule could be a T cell antigen receptor.
Suppression of endogenous murine leukemia virus by maternal resistance factor.
Authors: Melamedoff M , Lilly F , Duran-Reynals M L
Published: June 2004

Females of the RF and SJL inbred mouse strains transmit to their progeny of both sexes a nonmendelian maternal resistance factor (MRF) able to suppress the expression of endogenous ecotropic murine leukemia virus (E-MuLV). This MRF is demonstrable in crosses with AKR mice by comparing E-MuLV expression in the spleens and thymuses of reciprocal F1 generations. DBA/2 and ST/b mice are MRF negative by these criteria. Neonatal inoculation of E-MuLV-containing spleen extracts gives rise to persistent expression of infectious virus in mice of the MRF- but not the MRF+ strains. However, inoculation of the virus in 30-d-old females of the MRF- strains no longer leads to a state of persistent infection; instead, these females become MRF+ and transmit protection against E-MuLV expression to their progeny by AKR and RF males. The MRF appears to be transmitted to the progeny mainly through the milk, since foster-nursing AKR neonates on RF (but not DBA/2) mothers greatly reduces E-MuLV expression in the progeny. These RF-fostered AKR mice also show a reduced and delayed lymphoma incidence, a finding consistent with the idea that maternally transmitted resistance to E-MuLV expression is the basis for the classic maternal resistance to lymphomagenesis seen in the progeny of RF mothers.
Idiotype-antiidiotype regulation. IV. Expression of common regulatory idiotopes on fructosan-binding and non-fructosan-binding monoclonal immunoglobulin.
Authors: Goldberg B , Paul W E , Bona C A
Published: June 2004

The ABPC-48 Id (A48 Id) is normally not expressed in detectable amounts in the serum of BALB/c mice that have been immunized with bacterial levan (BL). However, A48 Id-bearing anti-BL clones can be activated in BL-immunized mice by three distinct prior treatments: (a) administration of A48 Id-bearing monoclonal proteins to newborn mice; (b) administration of minute amounts of anti-Id antibodies to newborn mice; and (c) production of anti-(anti-A48 Id) antibodies (Ab3), in adult mice. From these three groups of mice, eighteen monoclonal antibodies (MAb) expressing A48 Id were obtained. Regarding the binding specificity, these MAb can be divided into three groups: one that binds only BL, the second that binds BL and displays low cross-reactivity for inulin, and the third that lacks BL- and inulin-binding activity. This latter group was obtained only from adult mice immunized with anti-A48 Id-KLH conjugate. Immuno-chemical analysis of these MAb has shown that the A48 Id is made up of several idiotopes, some of them associated with the combining site and others nonantigen inhibitable. Comparisons of the amino acid sequence of the UPC-10 and A48 VH regions, and the distribution of the A48 Id family on A48, UPC-10, and three MAb, suggested that A48 regulatory idiotypes can be located on the framework segment of VH region. Furthermore, we screened 198 mouse and 80 human myeloma proteins for their ability to express A48 Id. Of these, only MOPC-167, an IgAk phosphocholine (PC)-binding myeloma protein, gave a significant inhibition of binding of labeled A48 to anti-A48 Id antibodies by radioimmunoassay and enzyme-linked immunosorbent assay. In addition, the binding of labeled MOPC-167 to anti-A48 Id antibodies was not inhibited by PC but was inhibited by A48 and 3-76-42 MAb bearing A48, UPC-10 non-antigen-inhibitable idiotopes. These results extend our prediction that the regulatory idiotopes can be expressed not only on antibodies specific for a family of antigens or members of the same network pathway, but also can be shared by antibodies with different antigenic specificity.
Identification of a variant of gross leukemia virus that induces disease in mice inoculated as adults.
Authors: Wolfe J H , Blank K J
Published: June 2004

Gross murine leukemia virus normally induces leukemia (thymic lymphoma) in mice inoculated as neonates, but not as adults. We have isolated an apparent variant of this virus which induces thymomas when inoculated i.p. into susceptible adult mice. Using H-2 congenic BALB and C57BL mice, susceptibility to virus-induced thymomagenesis was found to be linked to the H-2 complex. In addition, a radioresistant immune mechanism leading to inhibition of tumor growth was observed in mice with a C57BL but not a BALB background.
Idiotype-specific T lymphocytes. II. capability of generation of idiotype-specific T lymphocytes is determined by corresponding VH gene.
Authors: Yamamoto H , Bitoh S , Fujimoto S
Published: June 2004

MOPC-104E (M104E) idiotype-specific and major histocompatibility complex-restricted T lymphocyte activities were investigated in BALB/c (Igh-1a) and its Igh-1-congenic strains of mice, such as C.AL-20 (Igh-1d), BAB-14 (Igh-1b), and CB-20 (Igh-1b). Idiotype-specific T lymphocytes could be induced in BALB/c and BAB-14 by immunization of viable M104E tumor cells followed by surgical removal and in vitro restimulation with the homologous tumor cells. On the other hand, C.AL-20 and CB-20 mice did not show the idiotype-recognizing capacity even though they could mount comparable cytotoxic T lymphocyte activities against M104E to BALB/c and BAB-14. The results strongly suggest that the inducibility of M104E cross-reactive idiotypy closely paralleled the producibility of corresponding idiotype-specific T lymphocytes. Genetically defined VH gene products might act as internal images that construct idiotype network systems.