Genetic factors and efficiency of thymosin.
Explore the source record for details and available documents.
Animals↗
Biomedical subjects
J Fachet
Publications and source records attributed to J Fachet.
Grouping of monoclonal antibodies to adenovirus hexons by their cross-reactivity.
Thirty two mouse ascitic fluids containing monoclonal antibodies (MAbs) directed against the hexon of human adenovirus type 1 were examined. The type and degree of cross-reactivity (CR) of the MAbs were determined by ELISA and hemagglutination methods with 10 heterologous hexon types. The similarity and the dissimilarity of the MAbs was also characterized by the correlation coefficient calculated from their reactivity values. On the basis of these, the 32 MAbs could be divided into five groups and fourteen individual MAbs, which altogether recognized 19 distinct epitopes. One of the recognized epitopes is the genus specific epitope of adenovirus hexons; the others are interspecies specific ones which can be found on the surface of the different hexon types in characteristic, mosaic-like combinations. The type and degree of CR of the MAbs lead to the conclusion that there exists a close antigenic relationship among the members of subgenus C of human adenoviruses and there is also a definite antigenic relationship between subgenera C and D. Hexons belonging to the oncogenic subgenera A and B display a much looser antigenic relationship with subgenus C.
Adenoviruses, Human↗
Multiple copies of identical epitopes on the adenovirus hexon.
A double monoclonal antibody (MAb) sandwich enzyme-linked immunosorbent assay (double MAb ELISA), which uses the same MAb as solid-phase immunosorbent (capture MAb) and as detector MAb (peroxidase-labeled), was developed to quantify the specific epitopes of adenovirus hexon. Four MAbs directed against crystallized adenovirus type 1 (Ad h 1) hexon were tested by this assay with homologous and different heterologous hexons. The lowest reacting concn with the homologous and heterologous hexon types both in direct and double MAb ELISA was determined and compared. At least two copies of four different epitopes were identified by the MAbs. Evidence is presented that more than one copy of identical or closely related epitopes exist on the homologous as well as on the heterologous hexon molecules. However, their presence could be detected only in higher concn of hexon preparations of subgenera A, B and D.
Adenoviruses, Human↗
Effect of lentinan on pinocytosis in mouse peritoneal macrophages and the murine macrophage cell line C4M phi in vitro.
Lentinan, an immunopotentiating polysaccharide, stimulated the pinocytosis of horseradish peroxidase (HRP) or FITC-dextran by resident or thioglycollate-elicited mouse macrophages from 10 to 50% in a dose dependent manner. Pinocytosis of HRP and FITC-dextran by C4M phi cells, a murine macrophage cell line, exhibiting a lower basic pinocytic activity than peritoneal cells, was augmented up to 310 and 120%, respectively, by lentinan. Mannan inhibited the HRP uptake by peritoneal macrophages via specific mannose receptors. This inhibitory effect was partly abolished, when lentinan was also added to the cells. Mannan was not able to inhibit pinocytosis of HRP by C4M phi macrophages, indicating little or no mannose receptor activity on these cells. Pinocytosis of FITC-dextran was not affected by mannan. Lentinan, opsonized in mouse sera inhibited the uptake of HRP by peritoneal macrophages by 30-35%. Opsonized lentinan and mannan added together caused 60% inhibition of HRP uptake in peritoneal macrophages indicating a possible functional relationship between the mannose and C3b receptors. The results demonstrate that lentinan activates the pinocytic function of macrophages predominantly via specific beta-glucan receptors. These mechanisms may contribute to the antitumor and immunopotentiating action of lentinan and other glucan-type polysaccharides.
Adjuvants, Immunologic↗
Detection of adenovirus hexon using monoclonal antibodies for antigen capture in ELISA.
The feasibility of using monoclonal antibodies to capture specific viral polypeptides in double monoclonal antibody (MAb) sandwich ELISA has been demonstrated. Ten MAbs with different reactivity patterns were used for antigen capture and four of them were labelled with horse radish peroxidase and used for the detection of specifically bound hexon antigen and for the determination of the lowest reacting hexon concentrations. Differences have been found in the effectiveness of the different MAbs used for capturing or detecting the antigen. Two assay systems (MAbs 1A3/1A3 and H12/1A3), which were the most sensitive for the hexon types studied could be useful for detection of the adenovirus hexons. Assay system MAb 2D1/2A1 and several combinations of MAb 2B2 proved to be specific for subgenus C.
Adenoviruses, Human↗
Effect of mannozym on the chemiluminescence of phagocytes.
Mannozym (zymosan) induces chemiluminescence (CL) in human neutrophils, monocytes and in the cells of C4M phi murine macrophage cell line. The CL enhancing effect of Mannozym opsonized in human serum is higher than that of non-opsonized material. This may be due to the capacity of Mannozym to bind complement components and immunoglobulins from serum and to activate the phagocytes via their C3b and Fc receptors. Besides, Mannozym can be phagocytosed both in opsonized and non-opsonized forms.
Animals↗
Differentiation of adenovirus hexon epitopes with monoclonal antibodies by gel diffusion assays.
Nine monoclonal antibodies (MAbs) directed against crystallized human adenovirus type 1 (Ad h 1) hexon were tested with purified homologous and heterologous hexon preparations by gel diffusion. Six MAbs formed a single line with the homologous hexon in a 2-well pattern, and 3 MAbs formed lines only in biclonal combinations with an appropriate MAb. All of the 6 precipitating MAbs formed a continuous line of complete identity when tested simultaneously against homologous and different heterologous hexons. With Ad h 1 hexon a line of double partial identity (double spur) was formed when some pair combinations of 2 MAbs were placed in 2 juxtaposed wells. Other MAbs in the adjacent wells formed a line of identity. The MAbs could be divided into 2 antibody groups (groups A and B) based on this phenomenon. Members of antibody groups A and B apparently identified 2 sterically distinct epitopes: one of them is presumably the genus-specific epitope of the hexons (group A) and the other(s) should be intertype-specific epitope(s). Thus, the gel diffusion method can be used for selecting pairs of MAbs for their specificity to sterically independent epitopes. Mixtures of 2 MAbs belonging to the different antibody groups formed double lines with Ad h 1 hexons. Members of group A showed some helper effect to the members of group B for their precipitin line formation.
Adenoviruses, Human↗
Effect of lentinan on the chemiluminescence produced by human neutrophils and the murine macrophage cell line C4M phi.
Lentinan, an immunopotentiating polysaccharide, stimulates the production of chemiluminescence (CL) by human neutrophils and the murine macrophage cell line C4M phi. The CL enhancing effect of lentinan opsonized in human serum is greater than that of lentinan itself. Lentinan's stimulation of neutrophil CL was increased by 1/2 when opsonized in human serum inactivated at 56 degrees C to remove complement, while the CL was increased two fold by lentinan opsonized in whole serum. This indicates that C3b and immunoglobulin contribute separate signals in the activation process mediated by opsonized lentinan. The distinct roles of the C3b and Fc receptors was further illuminated by the finding that an Fc receptor-negative cell line was unresponsive to lentinan opsonized in heat inactivated serum (56 degrees C), whereas it exhibited a five fold increase in CL in response to lentinan opsonized in serum containing complement. Lentinan in an opsonized form can stimulate the production of CL via C3b and Fc receptors. This mechanism may be considered as one mode of action of lentinan and other similar immunopotentiating and antitumour glucan-type polysaccharides.
Animals↗
Delineation of antigenic determinants of adenovirus hexons by means of monoclonal antibodies.
60 hexon-specific mouse hybridoma clones were selected by using crystallized hexon capsomers of human adenovirus type 1 as immunizing and selecting antigen. The reactivities of the monoclonal antibodies were tested with purified hexon preparations from 10 human adenovirus types by enzyme-linked immunosorbent assay and passive hemagglutination techniques. The reactivity patterns delineated a total of 41 adenovirus-type-1-related determinants present on a number of heterologous hexons in different interspecies combinations. The pattern of interspecies specificities did not coincide with the current grouping of adenoviruses into subgenera.
Adenoviruses, Human↗
Reactivity of mouse ascitic fluids containing monoclonal antibodies directed against adenovirus hexon.
Thirty-two mouse hybridoma ascites were produced, containing hexon specific monoclonal antibodies, using crystallized hexons of human adenovirus type 1 as immunizing and selecting antigen. The reactivity of the ascitic fluids was tested with hexon preparations of 11 different human adenovirus species (serological types) belonging to 4 different subgenera by ELISA and passive haemagglutination (HA) methods. By these methods the 32 hybridoma antibodies showed 4 and 12 distinct reactivity patterns (type of cross-reactions) respectively. In the positive cases significant differences could be detected in the titres of the hybridoma antibodies in both ELISA and HA. It can be assumed that adenovirus type 1 hexon-related epitopes are present on a number of heterologous hexons in characteristic (interspecies) combinations for the given heterologous hexon and that a gradient of relationship may exist among the antigenic structures of hexons of the different adenovirus species.
Adenoviruses, Human↗
A sensitive method for detection of polyclonal and monoclonal antibodies against the adenovirus hexon.
Chromic chloride and tannic acid methods were elaborated to bind purified adenovirus hexons to sheep red blood cells (SRBC). Either method gave very sensitive haemagglutination (HA) with adenovirus antisera, but treatment with tannic acid was more sensitive. Using this method, specific antibodies present in polyclonal immune sera against adenoviruses and adenovirus hexons, and the reactivity of monoclonal antibodies directed against adenovirus hexon type 1 were tested to 11 adenovirus types. With certain types, the high haemagglutination titres exceeded those obtained with ELISA, while with other types they remained slightly below the ELISA titres. The elaborated passive HA method with tannic acid is easily accomplished and may serve as an effective and useful tool in the study of both polyclonal and monoclonal antihexon antibodies.
Adenoviruses, Human↗
The effect of thrombin activated factor XIII, thrombin and plasmin on the chemiluminescence produced by human neutrophils stimulated by opsonized zymosan (Mannozym).
Coagulation factor XIII formed by thrombin activation from zymogen factor XIII decreases the chemiluminescence (CL) of human neutrophils stimulated by opsonized zymosan (Mannozym). At high concentrations, thrombin and plasmin also decreased the CL induced by opsonized zymosan. The inhibitory effect of all the three enzymes was due to their influence on the cell membrane receptors (C3b and Fe) and not to their direct effect on opsonized Mannozym. The potential clinical role of factor XIII, thrombin and plasma in the regulation of neutrophil functions is assumed.
Cells, Cultured↗
Superoxide anion, superoxide dismutase and lipid peroxidation in the murine macrophage cell line C4M phi.
A remarkable increase in the production of superoxide radicals and SOD activity was measured in suspension of the murine macrophage cell line C4M phi treated with Lentinan (4-10 X 10(3) micrograms/5 X 10(6) cells). In activated macrophages the decrease of lipid peroxidation could be interpreted as a consequence of enhanced SOD activity.
Animals↗
Superoxide dismutase, catalase and lipid peroxidation in liver of young mice of different ages.
The lipid peroxidation and activities of main enzymes involved in the peroxide metabolism were measured at resting conditions and after completion of a 2-month treatment with H2O2. At the start of the experiments 1- and 3-month-old female BALB/c mice received either a high dose of H2O2 (0.5% H2O2 in drinking water; intake 12.5 x 10(-3) g/day/mouse) or a low dose of H2O2 (0.5 ml of 0.5% H2O2 by esophageal canula on every alternate day; intake 1.0 x 10(-3) g/day/mouse). The following conclusions can be drawn: a relative higher increase in activity of catalase could be induced at the age of 3 months than at the age of 5 months by a high dose of H2O2. The activity of superoxide dismutase (SOD) was not changed by a high dose of H2O2. A moderate increase in the activity of catalase and a remarkable decrease in SOD-activity resulted from a low-dose H2O2 treatment at the age of 5 months. The level of lipid peroxidation was increased by the low-dose and not influenced by the high-dose H2O2 treatment in 5-month-old-mice.
Aging↗
Characterization of adenovirus hexon epitopes by monoclonal antibodies.
Three-thousand hybridoma clones were produced using crystallized hexon of human adenovirus type 1 for immunization. ELISA revealed 69 homospecific antibody producing clones. The monoclonals were reactive with both crystallized and non-crystallized purified soluble hexon preparations, as well as with the hexons derived from purified virions. Hexon preparations of 10 different human adenovirus species (members of 4 different subgenera) were used for the characterization of 33 monoclonal antibodies. ELISA and passive haemagglutination (HA) tests revealed 6 and 15 distinct reactivity patterns (RP) i.e. intertype cross-reaction of a given antibody with the panel of test-antigens, respectively. Four of these RP-s were identical by both techniques. Significant quantitative differences existed between extinction values in ELISA and HA-titres. The results indicate the presence of identical epitopes as well as epitypic relationships among the hexons. The common epitopes and the epitypic relationship seem to be characterized by 16 different interspecies specificities under the experimental conditions, which are independent of subgenus boundaries and are demonstrable in different combinations on the hexons of adenovirus species belonging either to the same or to different subgenera.
Adenoviruses, Human↗
Correlations between the titres of natural and immune antibodies to sheep erythrocytes in inbred mouse strains.
Explore the source record for details and available documents.
Agglutinins↗
Mechanism of the A/Ph.MC.S1 tumor graft rejection in syngeneic mice.
A considerable number of normal mice injected with a low dose of A/Ph.MC.S1 syngeneic methylcholanthrene-induced tumor cells showed regression of the tumor after a transient period of growth. The regressor mice eliminated a challenge inoculum in an accelerated fashion. Splenic lymphocytes from such regressor mice inhibited the growth of the same tumor in the local adoptive transfer assay. This capacity required the presence of thymus-derived cells. The regressor animals developed a delayed-type hypersensitivity response against the tumor In vivo and their lymph-node cells produced macrophage migration inhibitory factor in the presence of tumor cells in vitro. The growth of this tumor was facilitated by treating the primary recipients with carrageenan, and the strong tumor-inhibitory capacity of regressors was also depressed by this agent. Early macrophage infiltration of the tumor in regressor mice was demonstrable histochemically, preceding the inhibition of tumor growth. A lymphokine-producing T cell-mediated, macrophage-dependent delayed-type hypersensitivity-like mechanism is proposed to be the dominant mechanism of the resistance in this tumor-host model.
Animals↗
Alterations of the connective tissue in nude mice.
The epiphyseal cartilage of nude mice was studied by light and electron microscopy. The resting and maturation zones become narrow and mineralization of the ground substance starts already in the zone of proliferation. Electron microscopy reveals signs of degeneration in the chondrocytes of this latter zone. An increased osteoclast activity can be observed in the metaphysis. The alterations may be due to a decrease in T-cell-mediated immunoreactivity of nude mice, as well as to an increased production of the osteoclast-activating factor, which might be attributed, among other things, to the B lymphocytes or macrophages.
Animals↗