Biomedical subjects

B M Sultzer

Publications and source records attributed to B M Sultzer.

At least 37 records · Page 2Linked to original sources

PubMed1989

Immunogenic endotoxin associated protein from a rough strain of Salmonella.

A multimolecular complex of polypeptides found associated with the lipopolysaccharide endotoxin in Salmonella, referred to as endotoxin-associated protein (EP), has been extracted from a rough strain of Salmonella typhimurium which does not synthesize 0 antigens. Since standard methods of extraction applicable to smooth strains of Salmonella were not successful for this rough strain, two modified procedures were developed. The resulting products were similar to smooth EP in terms of their biochemical, physical and mitogenic properties. When the immunogenicity of the rough EP was characterized by a protection assay in mice challenged with virulent Salmonella, it was found that the rough EP preparations were protective; however, they were not as active as the EP from a smooth strain of S. typhimurium.

Animals↗

PubMed1988

Inhibition of activated nonresponder C3H/HeJ lymphocytes by lipopolysaccharide endotoxin.

The B lymphocytes and macrophages of lipopolysaccharide (LPS) nonresponder C3H/HeJ mice were found to respond to certain R types of LPS endotoxin in a fashion resembling that ordinarily seen with the cells from normal responder mice. DNA synthesis, polyclonal antibody synthesis, and interleukin-1 activity were stimulated by Bordetella pertussis LPS and Salmonella minnesota R595 LPS, although to a lesser extent than with responder cells. Mitogenesis stimulated by both LPSs was inhibited by polymyxin B; this finding provided evidence that any trace endotoxin-associated proteins were not responsible for the activity. Of particular interest was the finding that wild-type smooth LPS actually inhibited activation of the C3H/HeJ B cells not only by the LPS but also by mitogenic proteins, including purified protein derivative of tuberculin. The nonspecific nature of this inhibition and the fact that maximal inhibition occurred some 9 to 12 h into the culture period suggested that the proliferation of the B cells was affected by smooth-type LPS in a manner heretofore unrecognized. These findings permit a new approach to the study of how LPS endotoxin affects cells of the immune system.

Animals↗

PubMed1985

The adjuvant effect of pertussis endotoxin protein in modulating the immune response to cholera toxoid in mice.

Endotoxin protein represents a group of immunobiologically active p polypeptides which are associated with the lipopolysaccharide endotoxin in the outer membrane of Gram-negative bacteria. To study the adjuvant effect of endotoxin protein, CF-1 mice were immunized intraperitoneally with graded doses of glutaraldehyde-inactivated cholera toxoid with and without endotoxin protein prepared from Bordetella pertussis, Salmonella typhi or Vibrio cholerae. Immune responsiveness was assessed by measuring resistance to intravenous challenge with cholera enterotoxin and by serum antitoxin responses. The results showed that endotoxin protein from S. typhi can enhance the 50% protective dose (PD50) of cholera toxoid five to 12-fold, the endotoxin protein from V. cholerae enhances the PD50 six to seven fold at most, but the endotoxin protein from B. pertussis can enhance the PD50 some 27-fold. Furthermore, within the variability of both the mouse protection test and the rabbit intracutaneous assay of toxin induced vascular permeability, mouse serum neutralizing antitoxin levels correlated with the greater degree of resistance of the mice to the toxin challenge. The adjuvant effect also has been demonstrated by measuring the appearance of antitoxin specific plaque forming cells derived from mouse lymphocyte cultures. After seven days of culture in the presence of endotoxin protein and cholera toxoid, the number of plaque forming cells to cholera toxin coated sheep erythrocytes was enhanced some 28 times as compared to the cultures exposed to the cholera toxoid alone.

Adjuvants, Immunologic↗

PubMed1984

Immunity to infection with Salmonella typhimurium: mouse-strain differences in vaccine- and serum-mediated protection.

Three mouse strains in the C3H lineage--C3H/HeJ, C3HeB/FeJ, and C3H/HeNCr1BR--were tested for their ability to be protected against infection with Salmonella typhimurium by a panel of nonviable vaccines and by passive transfer of hyperimmune serum. These strains differ in their innate susceptibilities to infection with S. typhimurium, but all are histocompatible. The same vaccines showed a widely different ability to protect different mouse strains. Ability to protect was not closely related to the capacity of the mice to make either agglutinating or anti-O antibody (as shown by ELISA) in response to a particular vaccine. Passive transfer of antibody was shown to protect inherently resistant mice but not inherently susceptible strains. These observations suggest that reported discrepancies in vaccine efficacy among laboratories may be attributable to differences in the mouse strains used and raise the question as to what might be an appropriate mouse model for human infections with Salmonella species.

Animals↗

PubMed1984

Cellular immunity induced by avirulent Salmonella in LPS-defective C3H/HeJ mice.

An avirulent strain of Salmonella, SL3235, has been shown to confer high levels of immunity on lipopolysaccharide (LPS)-hyporesponsive C3H/HeJ mice. Immunized mice were also protected against challenge with Listeria monocytogenes, indicating that the Salmonella vaccine activates macrophages. It was shown that protection and macrophage activation occurred without correction of the LPS defect, as assessed by in vivo endotoxin toxicity, in vitro spleen cell mitogenicity, and the ability of in vivo treatment with LPS to enhance in vitro macrophage ingestion of C3b-coated erythrocytes. It is concluded that LPS responsiveness is neither a necessary nor a sufficient condition for Salmonella immunity, and that macrophage activation can apparently occur in C3H/HeJ mice in the face of a sustained LPS defect.

Animals↗

PubMed1983

Immunity to Salmonella infection.

The foregoing literature review and data presentation have been set forth in the hope of clarifying some complex and confusing issues in regard to Salmonella infection. From a practical point of view, the information presented has implications for the direction to take with regard to improving the current typhoid vaccine, as the presently used acetone-killed cell preparation has considerable toxicity. The issues are important from a theoretical standpoint, because they have bearing on the nature of the concepts researchers and clinicians carry as working hypothesis with regard to the mechanisms of immunity to Salmonella infection. An incomplete appreciation of the literature seems to have led many scientists to believe that only cellular immunity can protect a mouse, and by analogy a human, against Salmonella. The logical deduction from such a premise is that only live vaccines will be effective in humans againsT S. typhi. Such a conclusion would appear unfounded, as documented in this review, for killed vaccines have been shown to be highly effective in vaccinating many mouse strains, as well as humans, against enteric fever.

Animals↗

PubMed1983

The inhibition of the mitogenic stimulation of B lymphocytes by a serine protease inhibitor: commitment to proliferation correlates with an enhanced expression of a cell-associated arginine-specific serine enzyme.

By the use of diisopropylfluorophosphate (DFP) we have been able to show that the mitogenic stimulation of murine B lymphocytes can be maximally inhibited a few hours before commitment of the cells to DNA synthesis. This inhibition was shown to be specific for a serine enzyme(s). The results of experiments designed to determine the location of this enzyme indicated that the mitogens-linked serine enzyme is not a secreted extracellular factor but is cell-associated. Fluorographic analysis of electrophoretic gels of cell homogenates labeled with [3H]DFP revealed the presence of one major and three minor bands which were arginine-specific serine enzymes. In stimulated cells, there was a clear quantitative difference in the amount of [3H]DFP bound to the major band (approx. 23,000 m.w.) suggesting that this protein may be critical to the progression of the cells through the cell cycle into the S phase of DNA synthesis.

Animals↗

PubMed1982

Dissociation of innate susceptibility to Salmonella infection and endotoxin responsiveness in C3HeB/FeJ mice and other strains in the C3H lineage.

Studies of various mouse strains in the C3H lineage have shown that there is no correlation between innate susceptibility to Salmonella infection and sensitivity to the toxic or mitogenic effects of lipopolysaccharide (LPS). C3H/HeNCrlBR mice were Salmonella resistant, but sensitive to the toxic and mitogenic effects of LPS, whereas C3HeB/FeJ mice were Salmonella susceptible as the C3H/HeJ mice, yet were mitogenically responsive to LPS and sensitive to its lethal effects. Furthermore, other mouse strains (C3H/HeTex and C3H/HeDub) displayed intermediate susceptibility to Salmonella infection and were responders to the mitogenic and toxic effects of LPS. These results are interpreted to mean that endotoxemia cannot be a major factor in the pathogenesis of Salmonella infection and provide evidence for the involvement of multiple factors in the control of innate resistance to Salmonella infection in mice of the C3H lineage.

Animals↗

PubMed1981

Time-dependent inhibition of tuberculin-induced lymphocyte DNA synthesis by a serine protease inhibitor.

Diisopropylfluorophosphate (DFP), a group-specific irreversible inhibitor of serine proteases, has been shown to exert time-dependent inhibition of DNA synthesis of lymphocytes stimulated by three different B lymphocyte mitogens: purified protein derivative of tuberculin (PPD), endotoxin protein (EP), and lipopolysaccharide (LPS). The time-dependent inhibition profile found in B lymphocytes is absent in concanavalin A (Con A)-stimulated T lymphocytes. Structural analogs of DFP, which have lost the phosphorylating ability, are not inhibitory. Inhibition of DNA synthesis by DFP is reversible in the first 8 hr of mitogenic stimulation. Maximal and irreversible inhibition by DFP occurs around the 16th hour of stimulation. These data support the postulate that a mitogenesis-linked protease, or proteases, in B lymphocytes is absent in the resting cells but is made available several hours before the initiation of DNA synthesis in the late G1 phase of the cell cycle.

Animals↗

PubMed1979

Endotoxin protein is a mitogen and polyclonal activator of human B lymphocytes.

Endotoxin protein (EP) has been shown to be a mitogen and polyclonal activator of human peripheral blood lymphocytes. EP stimulates proliferation of B lymphoyctes in the absence of T cells, and this activation is nonspecific by a number of parameters. Additionally, EP mitogenesis, but not polyclonal activation, is inhibited in the presence of human serum, suggesting that these events are dissociable. In these studies, EP appears to be equivalent to or better than pokeweed mitogen in stimulating nonspecific antibody production in vitro.

Antibody Formation↗

PubMed1979

Characterization of the chemical and physical properties of a novel B-lymphocyte activator, endotoxin protein.

Endotoxin protein, a novel mouse B-lymphocyte mitogen, is a hydrophobic acidic compound composed of approximately 85% protein and 2.2% glucosamine, but no 2-keto-3-deoxyoctonate. Endotoxin protein also contains lipid, and analysis of the fatty acids in this material demonstrated the presence of beta-hydroxymyristate, a marker for lipid A. In addition, analysis of endotoxin protein by polyacrylamide gel electrophoresis showed that it is heterogeneous, containing four or five major polypeptides, depending upon the bacterial species from which it was isolated. The mitogenicity of endotoxin protein was diminished by alkaline hydrolysis, but not by treatment with hydrochloric or acetic acid. Furthermore, its activity was resistant to digestion with trypsin, chymotrypsin, and pronase and was only partially degraded by papain.

Animals↗

PubMed1979

Inhibition by human serum of lymphocyte proliferation stimulated by purified protein derivative of tuberculin and bacillus Calmette-Guérin.

The addition of normal human serum to murine lymphocyte cultures consistently depressed mitogen-induced transformation, as measured by deoxyribonucleic acid synthesis. Stimulation by the B-cell mitogens purified protein derivative-tuberculin, bacillus Calmette-Guérin, and lipopolysaccharide was consistently affected, but there was no inhibition of T-cells when human serum was added to concanavalin A-stimulated cultures. The inhibitory effects were not due to cytotoxic factors for B-lymphocytes or to specific antibodies in serum directed against the mitogens. Analogous results were found with guinea pig serum. Contact of the lymphocytes with the serum within the first 24 h of culture was necessary for inhibition.

B-Lymphocytes↗

PubMed1979

Further studies on the activation of lymphocytes by endotoxin protein.

Endotoxin protein, an outer membrane protein of Gram-negative bacteria associated with lipopolysaccharide endotoxin, has been found to be a potent activator of lymphocytes. In the absence of T lymphocytes and macrophages, endotoxin protein can stimulate murine B lymphocytes to synthesize DNA and produce antibodies of diverse specificities. This stimulation is greater than that obtained with two well known murine B cell activators, lipopolysaccharide endotoxin or PPD-tuberculin. Splenic lymphocytes from other species, such as rats, rabbits, and guinea pigs also proliferate when cultured with endotoxin protein. Of particular significance is the finding that endotoxin protein is an activator of human peripheral blood lymphocytes.

Animals↗

PubMed1978

Infection with Bacillus Calmette-Guérin activates murine thymus-independent (B) lymphocytes.

Thymus-independent (B) lymphocytes from BCG-infected mice respond with enhanced or depressed levels of proliferation relative to the nonspecific levels of stimulation induced by tuberculin. The type of response obtained depends on how BCG was administered and the source of the lymphocytes. The proliferation of splenic B lymphocytes was depressed when BCG was given i.v. and unchanged when BCG was given subcutaneously, whereas the lymph node B cell response was enhanced regardless of the route of injecting BCG. BCG was found also to be a mitogen for normal B cells in vitro and to stimulate polyclonal activation of B cells in vivo. Finally, evidence is presented which indicates that the depressed splenic B cell response to tuberculin may be due to the activation of suppressor T cells.

Animals↗

PubMed1977

Nonspecific stimulation of lymphocytes by tuberculin.

Lymphocytes from uninfected, nonimmune mice can be stimulated to proliferate and produce antibody to diverse antigens in culture when exposed to the purified protein derivative of tuberculin or unheated tuberculin culture filtrate. Lymphocytes from numerous inbred strains of mice respond to tuberculin, but no true low responder strain has been found as yet. The evidence presented suggests that a subpopulation of B cells, which are distinct from those activated by lipopolysaccharide endotoxin, respond to tuberculin. The results of digestion experiments with insolubilized enzymes suggest that the nonspecific activating principles in tuberculin are protein.

Animals↗

PubMed1977

Mild alkaline hydrolysis of lipopolysaccharide endotoxin enhances its mitogencity for murine B cells.

Mild alkaline hydrolysis was found to enhance the mitogenicity of lipopolysaccharide endotoxin for murine B lymphocytes. Alkaline treated lipopolysaccharide also retained its property as a polyclonal activator. Whereas this treatment reduced the lethality of endotoxin for mice, its toxicity for lymphocytes cultured in the absence of fetal calf serum was increased. Lipid analysis indicated that there were no significant changes in the fatty acids of lipid A, but particle size was significantly reduced and the material was more homogeneous and soluble than untreated lipopolysaccharide. The relationship of these effect on the structure of lipopolysaccharide endotoxin to the mechanism of B-lymphocyte activation is discussed.

Animals↗

PubMed1976

Endotoxin protein: a B-cell mitogen and polyclonal activator of C3H/HeJ lymphocytes.

A cell wall protein that is ordinarily complexed to the lipopolysaccharide endotoxin in gram-negative bacteria has been separated by the use of aqueous phenol. The protein is active as a B-cell mitogen and polyclonal activator of murine lymphocytes including the C3H/HeJ strain which is a nonresponder to lipoplysaccharide or lipid A.

Animals↗

PubMed1976

Genetic analysis of lymphocyte activation by lipopolysaccharide Endotoxin.

A genetic study of in vitro lymphocyte blastogenesis by the B-cell mitogen lipopolysaccharide endotoxin has been performed, using both low-responder C3H/HeJ mice and high-responder CBA/J mice. The crossbreeding of these strains produced F1 progeny that were intermediate in responsiveness. Responder types from the backcross of the F1 to the C3H/HeJ strain segregated into intermediate- and low-responder phenotypes, whereas intermediate- and high-responder phenotypes were produced from the backcross of the F1 to the CBA/J strain. The F2 generation consisted of all three responder phenotypes in frequencies that fit the classical Mendelian ratio of 1:2:1, indicating that the mitogenic response to lipopolysaccharide endotoxin in mice is most likely governed by a pair of autosomal co-dominant genes.

Animals↗