Failure of Corynebacterium parvum to inhibit antipyrine metabolism in man

Summary In animals, Corynebacterium parvum lowers the rate of drug metabolism and enhances the pharmacologic effect of drugs requiring hepatic microsomal enzyme activity for elimination. A pilot study was conducted to assess this drug interaction in patients given clinical protocol doses of C. parvum. In individual patients, C. parvum did not reduce microsomal drug metabolism as measured by antipyrine half-life. Conversely, antipyrine elimination appeared to be enhanced in 10 of 14 patients. Results from this small heterogenous patient group are not definitive, and further studies are needed to determine the clinical significance of the effects of nonspecific immunotherapy on drug metabolism.     

Inhibition of cell-mediated cytotoxicity by Corynebacterium parvum

Summary We investigated the effect of altering dose and route of Corynebacterium parvum (C. parvum) administration on the adjuvant's inhibition of cell-mediated cytotoxicity (CMC). Primary in vivo and secondary in vitro CMC of C57B1/6 mice alloimmunized to P815 were depressed if C. parvum was administered systemically (IV or IP) but not when it was given SC. Similarly, only systemic C. parvum generated cells capable of suppressing in vitro CMC. Primary and secondary CMC in spleen was equally inhibited by 700 and 70 g, whereas suppressor cell activity was marked with 700 g and minimal with 70 g. Administration of C. parvum SC admixed with alloantigen resulted in early enhancement and late depression of primary CMC. Secondary CMC was depressed but suppressor activity was absent. Dissociation of CMC depression from suppressor cell generation indicates that these phenomena can be separated under certain conditions.     

Splenic suppressor macrophages induced in mice by injection of Corynebacterium parvum.

Spleen cells from C57BL/6N mice injected with killed Corynebacterium parvum (CP) had a marked growth inhibitory effect on the in vitro proliferation of RBL-5 murine lymphoma cells. It was most marked 12 to 14 days after injection and was usually no longer detectable later than 21 days. It could be demonstrated at effector cell to target ratios between 20:1 and 5:1 at which normal spleen cells had a growth-promoting effect. Addition of CP to an in vitro mixture of spleen cells and tumor cells augmented the inhibitory effect of spleen cells from CP-injected mice although it conferred no inhibitory potential on normal spleen cells. Growth inhibiton by CP spleen cells was not mediated by T cells and various depletion experiments suggested that the effector cells of the phenomenon were macrophages. Spleen cells of CP-injected mice also showed strongly depressed responses to the T cell mitogens PHA and Con A and suppressed the mitogen responses of syngeneic normal spleen cells. The characteristics of the suppressor cells mediating this effect appeared to be very similar to those inhibiting lymphoma cell growth. The responses to LPS were also strongly suppressed in mice injected with 2.1 mg of CP. However, after injection of one-tenth of the dose a relative sparing of the LPS response was noted, whereas the PHA response was still suppressed.     

Ribonucleotide reductase--transition enzymes from RNA metabolism to DNA metabolism]

Ribonucleotide reductases catalyze the reduction of ribonucleotides to deoxyribonucleotides, this reaction being vitally important for all organisms. The enzyme provides a link between RNA and DNA metabolisms. Several forms of the enzyme occur in nature and those differ in their structure and catalytic mechanisms. While the direct reduction of ribonucleotides via a radical mechanism is a general mode of dNTP synthesis in all organisms, the way in which this is achieved varies. The ability of the enzyme to control DNA synthesis is of considerable clinical interest. Selective inhibition of DNA synthesis is desired, for example, in clinical applications, such as restriction of tumour growth or virus replication.     

Response of the central metabolism of Corynebacterium glutamicum to different flux burdens

To evaluate the importance of reactions within the central metabolism under different flux burdens the fluxes within the pentose phosphate pathway (PPP), as well as the other reactions of the central metabolism, were intensively analyzed and quantitated. For this purpose, Corynebacterium glutamicum was grown with [1-(13)C]glucose to metabolic and isotopic steady state and the fractional enrichments in precursor metabolites (e.g., pentose 5-phosphate) were quantified. Matrix calculus was used to express these data together with metabolite mass data. The detailed analysis of the dependence of (13)C enrichments on exchange fluxes enabled the transketolase-catalyzed exchange rate (2 pentose 5-phosphate <--> sedoheptulose 7-phosphate + glyceraldehyde 3-phosphate) to be quantified as 74.3% (molar metabolite flux) at a net flux of 10.3% and the exchange rate (pentose 5-phosphate + erythrose 4-phosphate <--> fructose 6-phosphate + glyceraldehyde 3-phosphate) to be quantified as 5.6% at a net flux of 8.1%. The flux entering the tricarboxylic acid cycle was 93.3%. The same comprehensive flux analysis as performed for the nonexcreting condition was done with the identical strain that had been forced to excrete L-glutamate. Because we had already quantified the fluxes for L-lysine excretion with an isogenic strain, three directly comparable flux situations are thus available. Consequently, this comparison permits a direct cause-and-effect relationship to be specified. In response to the different flux burdens of the cell, the PPP flux decreased from a maximum of 67% to 26%, with the glycolytic flux increasing accordingly. The carbon flux through isocitrate dehydrogenase increased from 20% to 36%. The bidirectional carbon flux between pyruvate and oxaloacetate decreased from 36% to 9%. Since the cause of the three different flux states was the allelic exchange in the final L-lysine assembling pathway or the glutamate export activity, respectively, the flexible response is the effect. This shows conclusively the enormous flexibility within the central metabolism of C. glutamicum to supply precursors upon their withdrawal for the synthesis of amino acids. (c) 1997 John Wiley & Sons, Inc. Biotechnol Bioeng 56: 168-180, 1997.     

Inhibition of cell-mediated cytotoxicity to tumor alloantigens by systemic administration of Corynebacterium parvum

Summary Intravenous administration of C. parvum following SC immunization with a tumor allograft markedly impaired the generation and expression of primary cell-mediated cytotoxicity to the immunizing alloantigens. For the inhibition to become manifest, a minimum of 4 days of in vivo exposure to C. parvum was necessary, and the effect was seen only when C. parvum was injected during the developing immune response; injection prior to or simultaneously with alloimmunization resulted in no impairment. The inhibition of cell-mediated cytotoxicity was selective. While spleen cell populations exhibited decreased cytotoxic activity, lymphoid cell populations from lymph nodes and blood were unaffected. The inhibitory effect was restricted to the cellular component of the immune response. Complement-dependent cytotoxic antibodies developed normally and their titer was comparable to that of control alloimmunized mice.     

Inhibition of memory cell-mediated cytotoxic response by systemic administration of Corynebacterium parvum.

Intravenous administration of Corynebacterium parvum to mice during a developing immune response to alloantigens resulted in the marked inhibition of the generation and expression of memory cell-mediated cytotoxic response in the spleen. The inhibition was observed following rechallenge in vivo or by in vitro culturing with the same alloantigen. The impairment in vitro was due, in part, to the generation of regulatory cells which were non-T phagocytic cells, probably macrophages activated by C. parvum administration. These suppressor macrophages appear to act by inhibiting proliferation and clonal expansion of memory cytotoxic cells.     

Treatment of malignant ascitic and pleural effusion with Corynebacterium parvum.

Six patients with malignant effusions, five from adenocarcinomas and one from a melanoma, were treated by intrapleural or intraperitoneal Corynebacterium parvum. In each case there was a definite reduction in the effusions with a significant decrease in the number of malignant cells; in most cases the effusions stopped completely. Although none of the patients lived for more than a year after treatment, they were undoubtedly more comfortable, as they no longer required frequent paracentesis. In some cases the patients lived for longer than originally expected in a state in which the quality of life was acceptable.     

Cellular suppression of murine ADCC and NK activities induced by Corynebacterium parvum

Summary Administration of a single dose of C. parvum (CP) induces depression of splenic NK activity in mice after a lag period of 3–5 days and this depression lasts about 2 weeks. The depressed levels of NK activity noted in this study depended on time of CP administration and were associated with the induction of suppressor cell activity. Neonatally thymectomized or sublethally irradiated mice had unimpaired ability to generate suppressor cells following CP treatment. Depletion of adherent/phagocytic cells by carbonyl iron plus magnetism, Sephadex G-10 filtration, or both neither enriched NK activity nor removed suppressor activity from the spleens of CP-treated mice. Antibody-dependent cellular cytotoxicity (ADCC) against lymphoma targets was also depressed in CP-treated mice, accompanied by a concomitant appearance of suppressor cells that interfere with ADCC at the effector level.     

Production of an antiviral factor by murine spleen cells after treatment with Corynebacterium parvum.

We have previously shown that injection of Corynebacterium parvum (CP) in mice protected them against lethal encephalitis induced by herpes simplex virus, (HSV). It is shown here that spleen cells of CP-injected mice in vitro produce a factor capable of inhibiting the replication of HSV in mouse embryo fibroblasts (MEF). A similar activity was produced after in vitro exposure of spleen cells from untreated mice to CP. CP was only slightly mitogenic in contrast to phytohemagglutinin (PHA), concanavalin A (Con A), and bacterial lipopolysaccharide (LPS) which were strongly mitogenic but did not induce antiviral activity high enough to be detected in the HSV-MEF system. The activity produced by CP-treated spleen cells appeared to be interferon since it was trypsin sensitive and species specific and not virus specific, and since preincubation of the cells was required to demonstrate an antiviral effect. However, the identity of CP-induced interferon with any of the previously described subclasses of interferon remains to be determined.     

Specific folding and contraction of DNA by histones H3 and H4.

We demonstrate that the arginine-rich histones H3 and H4 can introduce torsional constraints on closed circular DNA with a concomitant compaction of the nucleic acid. SV40 DNA I complexed with H3 and H4 appears relaxed in electron micrographs and contains particles of 75 +/- 10 A in diameter along the DNA. SV40 DNA I is contracted 2.75 +/- 0.25 fold by all the four smaller histones and 2.6 +/- 0.4 fold by H3 and H4 alone. The arginine-rich histones can cause the topological equivalent of unwinding the DNA close to one Watson-Crick turn per particle formed. Spherical nucleoprotein complexes morphologically similar to isolated nu bodies or nucleosomes are obtained by association of H3 and H4 with 140 base pair length DNA isolated from chromatin core particles. These reconstituted particles sediment at 9.8S, as compared to 10.8S for native core particles, and contain a tetramer of the arginine-rich histones. None of these specific alterations in DNA structure is seen om complexing the slightly lysine rich-histones H2A and H2B to DNA. Our data provide further evidence indicating that the arginine-rich histones are the major determinants of the architecture of DNA within the chromatin core particle.     

Splenocytes from tumor-bearing Corynebacterium parvum treated mice maintain interleukin-2 and -3 activity

Summary Systemic and local administration of the bacterium Corynebacterium parvum (more accurately known as Propionibacterium acnes) is reported to exert antitumor action via activated macrophages or short-lived cytotoxic T lymphocytes (CTL), respectively. This study examined the effect of C. parvum treatment on resulting in vitro interleukin levels, which are components in the sequence of events leading to the development of effective CTL. C. parvum administration prevented palpable fibrosarcoma development. This was concomitant with restoration and maintenance of normal interleukin-2 (IL-2) and interleukin-3 (IL-3) levels and prevention of suppressor cell development in mice injected with both tumor cells and vaccine. Our finding of C. parvum-induced maintenance of IL-2 and IL-3 levels and apparent lack of suppressor cell formation lends support to the idea of local C. parvum antitumor action possibly being mediated by CTL arising via the interleukin cascade.