Recombinant interferon-gamma (rIFN-gamma) in dermatology.

This paper gives a short review on the function, pharmacokinetics, and therapeutic application of recombinant interferon-gamma (rIFN-gamma) in dermatology. Simultaneously, our own experiences are presented for 57 patients (phase II study) suffering from genital warts (21 patients), psoriatic arthritis (10 patients), psoriasis vulgaris (three patients), malignant melanoma (six patients), bowenoid papulosis (four patients), Behcet's disease (four patients), basal cell carcinoma (six patients), as well as herpes simplex recidivans, epidermodysplasia verruciformis, and mycosis fungoides (one patient each). We conclude that there might be an indication for treatment with rIFN-gamma in genital warts, bowenoid papulosis, Behcet's disease, and microbial infections, such as leprosy and cutaneous leishmaniasis. Even though there are reports of a limited beneficial effect of rIFN-gamma on arthritis and skin lesions in psoriasis, we failed to observe any in 10 patients. The main side effects in our low-dose study (50-100 micrograms/d) were mild fever (78%), fatigue (78%), and myalgia (65%). Laboratory tests revealed an increase in the serum triglyceride level, in particular, in psoriatic patients.

The influence of structural modifications of dihydrophenazines on arachidonic acid mobilization and superoxide generation by human neutrophils.

In this study the effects of nine dihydrophenazine derivatives, relative to clofazimine (B663), on the N-formyl-L-methionyl-L-leucyl-L-phenylalanine (FMLP) stimulated release of superoxide anion and on the spontaneous generation of arachidonic acid by human neutrophils were investigated. Previous findings that the pro-oxidative activity of the agents depended largely on the substitution in position 2 of the phenazine molecule and on chlorination in the paraposition of the phenyl and anilino rings were confirmed. Only riminophenazines, but not aposafranone derivatives or the imidazophenazine B621, could enhance superoxide release from activated neutrophils. The lack of chlorination of the phenyl and anilino rings could be compensated for by chlorine substitution in position 7 of the phenazine core. The priming effect of the agents on FMLP stimulated superoxide generation was completely prevented by the phospholipase A2 inhibitor 4-p-bromophenacyl bromide. Furthermore pro-oxidative activities correlated closely with a stimulatory effect of the agents on arachidonic acid release. It was therefore concluded that dihydrophenazine derivatives with pro-oxidative properties can prime neutrophils for FMLP-stimulated superoxide release by modulation of phospholipase A2 activity.

An n.m.r. and conformational analysis of the terminal trisaccharide from the serologically active glycolipid of Mycobacterium leprae in different solvents.

The 1H- and 13C-n.m.r. spectra of allyl 2-O-[4-O-(3,6-di-O-methyl-beta-D-glucopyranosyl)-2,3-di-O-methyl-alpha-L -rhamnopyranosyl]-3-O-methyl-alpha-L-rhamnopyranoside (3), a glycoside of the terminal trisaccharide found in the phenolic glycolipid I from Mycobacterium leprae, and those of the two component disaccharides, allyl 4-O-(3,6-di-O-methyl-beta-D-glucopyranosyl)-2,3-di-O- methyl-alpha-L-rhamnopyranoside (1) and allyl 2-O-(2,3-di-O-methyl-alpha-L-rhamnopyranosyl)-3-O-methyl-alpha-L- rhamnopyranoside (2) have been assigned completely by 1D and 2D techniques. The preferred conformations, determined by chemical shift and n.O.e. studies, were different in D2O, CD3OD, and CDCl3. The preferred conformation of 3 accorded with the results of hard-sphere exo-anomeric (HSEA) calculations.

Strategies for the chemoenzymatic preparation of optically active 1-alkyn-3-ols.

A series of (R)- and (S)-1-alkyn-3-ols, chiral building units for the synthesis of leukotrienes and pheromones, were prepared via enantioselective hydrolysis of their racemic esters. While the majority of biocatalysts employed (lipases, fermenting or freeze-dried microorganisms) failed in discriminating between enantiomers, lyophilized cells of baker's yeast (Saccharomyces cerevisiae Hansen) gave (S)-1-alkyn-3-ols and their corresponding (R)-esters with greater than 90% e.e.

Synthesis of galactofuranose disaccharides of biological significance.

Methyl beta-D-galactofuranoside was readily obtained by tin(IV) chloride-catalyzed glycosylation of penta-O-benzoyl-alpha,beta-D-galactofuranose, followed by debenzoylation with sodium methoxide. Glycosylation of 1 with 2,3,5-tri-O-benzoyl-D-galactono-1,4-lactone or with the 6-O-trityl-lactone derivative 5 gave the benzoylated beta-D-galactofuranosyl-(1----6)-D-galactono-1,4-lactone 6 in excellent yield. The structure of disaccharide 6 was confirmed by borohydride reduction to the glycosyl-alditol 7. A byproduct of the condensation reaction of 1 with 4 or 5 was identified as the benzoylated (1----1)-beta,beta'-D-galactofuranosyl disaccharide 8. Compound 8 was readily prepared (88% yield) by controlled addition of water to 1, in the presence of stannic chloride. O-Debenzoylation of 8 afforded crystalline beta'-D-galactofuranosyl-(1----1)-beta-D-galactofuranoside. The glycosyl-lactone 6 constitutes a key intermediate for the synthesis of a disaccharide derivative having both units in the furanoid form. Thus, diisoamylborane reduction of the lactone function of 6 led to the disaccharide derivative 10, from which the methyl glycoside 12 was prepared. O-Debenzoylation of 12 gave the corresponding methyl beta-D-galactofuranosyl-(1----6)-beta-D-galactofuranoside. The free disaccharide beta-D-Galf-(1----6)-D-Galp and its acetylated derivative were also synthesized from 10.

Chemical synthesis of an artificial antigen containing the trisaccharide hapten of Mycobacterium leprae.

The trisaccharide allyl O-(3,4-di-O-methyl-beta-D-glucopyranosyl)-(1----4)-O-(2,3-di-O-methyl-al pha-L- rhamnopyranosyl)-(1----2)-3-O-methyl-alpha-L-rhamnopyranoside was synthesized from partially methylated monosaccharide derivatives. Condensation of 1,4-di-O-acetyl-2,3-di-O-methyl-alpha-L-rhamnopyranose promoted by boron trifluoride etherate with the appropriate alcohol proceeded stereoselectively and with very high yields. Selective deacetylation and glycosylation with 2,4-di-O-acetyl-3,6-di-O-methyl-alpha-D-glucopyranosyl bromide led to a trisaccharide. The acrylamide copolymers of mono-, di-, and tri-saccharide were compared in their ability to specifically bind antibodies from leprosy patients.

Synthesis and immunoreactivity of neoglycoproteins containing the trisaccharide unit of phenolic glycolipid I of Mycobacterium leprae.

The trisaccharide segment, O-(3,6-di-O-methyl-beta-D-glucopyranosyl)-(1----4)-O-(2,3-di-O-methyl- alpha-L-rhamnopyranosyl)-(1----2)-3-O-methyl-L-rhamnopyranose, of the Mycobacterium leprae-specific phenolic glycolipid I has been synthesized as its 8-(methoxycarbonyl)octyl glycoside and coupled to a carrier protein, to produce a leprosy-specific neoglycoprotein, the so-called natural trisaccharide-octyl-bovine serum albumin (NT-O-BSA). Special features of the synthetic strategy were the use of silver trifluoromethanesulfonate (triflate) to promote glycosylation, resulting in the rhamnobiose in high yield and absolute stereospecificity. The terminal 3,6-di-O-methyl-D-glucopyranosyl group was introduced after O-deallylation of the rhamnobiose. Removal of protecting groups yielded the trisaccharide hapten suitable for coupling to carrier protein. Poly(acrylamide)-gel electrophoresis of the neoglycoprotein demonstrated its purity, and subsequent immunoblotting with a monoclonal antibody directed to the terminal 3,6-di-O-methyl-beta-D-glucopyranosyl epitope of the native glycolipid demonstrated its antigenicity. Comparative serological testing in enzyme-linked immunosorbent assays of NT-O-BSA, the corresponding disaccharide-containing products, and another trisaccharide-containing neoglycoprotein, O-(3,6-di-O-methyl-beta-D-glucopyranosyl)-(1----4)-O-(2,3-di-O- methyl-alpha-L-rhamnopyranosyl)-(1----2)-(3-O-methyl-alpha-L-rhamnopy ran osyl)- (1----4')-oxy-(3-phenylpropanoyl)-BSA (NT-P-BSA) [Fujiwara et al., Agric. Biol. Chem., 51 (1987) 2539-2547] against sera from leprosy patients and control populations showed concordance; the presence of the innermost sugar did not contribute significantly to sensitivity or specificity. The di- and tri-saccharide-containing neoantigens, on account of ready availability and solubility, provide greater flexibility than the native glycolipid for the serodiagnosis of leprosy.

Recent advances in the understanding of the biochemistry and clinical pharmacology of interleukin-2.

This review covers significant developments in the understanding of the biochemistry and clinical pharmacology of Interleukin-2 (IL-2) that were achieved from 1984 through September 1986. These include developments in the molecular biology of IL-2 and its receptors. Human IL-2 was cloned and sequenced by Taniguchi et al. in 1983. The gene for human IL-2 is located on the long arm of chromosome 4. The secondary structure of the gene is predominantly alpha helix. The mature gene product is a 133 amino acid glycoprotein with a molecular weight of 15,420 Daltons. The IL-2 receptor was revealed to be a glycoprotein of 272 amino acids. The mature receptor has a molecular weight of 55,000 Daltons. A more precise understanding of the mechanism of action IL-2, in particular its role in the induction of the IL-2 receptor, and aspects of the control of IL-2 production was also achieved. Metabolic and morphologic studies have revealed that activation of the T-cell antigen receptor renders the cells responsive to IL-2, but does not move them through the cell cycle. Rather, it appears that IL-2 stimulates G1 progression to S phase ie. blastic transformation. During this progression the cellular proto-oncogene c-myb is induced transiently to 6 to 7 times basal levels. The role of IL-2 as a growth factor for several subsets of T cells has been confirmed, and a new role as a growth factor for B cells was defined. Most importantly, IL-2 was shown to be directly mitogenic for and to expand subpopulations of peripheral blood cells, termed lymphokine-activated killer (LAK) cells and tumor-infiltrating lymphocytes (TIL). A number of pathologies of IL-2 production or activity have been defined, including Hodgkin's disease, graft versus host disease, systemic lupus erythematosus, lepromatous leprosy, acquired immune deficiency syndrome, and adult T cell leukemia. Murine and human in vivo studies reviewed here have revealed significant parameters of the therapeutic potential as well as the toxicity of this growth factor. Finally, the modulation of IL-2 receptors on human PBL's by thymosin fraction 5 and thymosin alpha 1 suggests that it might be possible to up-regulate IL-2 receptor expression in certain disease states and thus increase the efficacy of IL-2.

Detection of trehalose monomycolate in Mycobacterium leprae grown in armadillo tissues.

Trehalose-6-monomycolate (TMM) was isolated from the lipids of armadillo-derived Mycobacterium leprae. Only meagre amounts of this glycolipid were recovered, but its structure was unequivocally established. Only alpha-mycolates were detected in the TMM by 252Cf plasma desorption mass spectrometry. Electron impact mass spectrometry showed the alpha branch to be principally C20. Trehalose dimycolate (cord factor) was not detectable. Since we have also found TMM in M. lepraemurium and in every Mycobacterium species so far examined, we suggest that this glycolipid is truly ubiquitous amongst mycobacteria.

Use of an artificial antigen containing the 3,6-di-O-methyl-beta-D-glucopyranosyl epitope for the serodiagnosis of leprosy.

The coupling of synthetic 3,6-di-O-methyl-beta-D-glucopyranosyl-(1----4)-2,3-di-O-methyl-alpha-L -rhamnopyranose, the hapten determinant of phenolic glycolipid I from Mycobacterium leprae, to bovine serum albumin (BSA) by reductive amination produced the antigen epsilon-N-1-[1-deoxy-2,3-di-O-methyl-4-O-(3',6'-di-O-methyl-beta -D-glucopyranosyl)-rhamnitol]-lysyl-BSA, which proved highly sensitive in ELISA and showed good concordance with the native glycolipid in analysis of serum samples from 223 leprosy patients. Conjugates prepared from 6-O-methyl-beta-D-glucopyranosyl- or beta-D-glucopyranosyl-containing disaccharides were inactive and those containing noncyclic 3,6-di-O-methyl-glucitol showed little activity. Thus 3,6-di-O-methyl-beta-D-glucopyranose in its cyclic hemiacetal form is necessary for binding anti-glycolipid IgM from leprosy patients. Analysis of serum samples from healthy subjects showed a false-positive rate of 2.4% (four of 169) against the glycolipid and 3.6% (six of 169) against the glycoconjugate. Comparable figures for samples of sera of tuberculosis patients were 3.0% (two of 66) and 9.0% (six of 66), respectively. Alternative synthesizing strategies may diminish this cross-reactivity. The prospects of a fully synthetic specific antigen for the worldwide serodiagnosis of leprosy look promising.

[Lipid composition of cultivable Mycobacteria isolated from livers of armadillos infected by Mycobacterium leprae]. / Etude de la composition lipidique de mycobactéries cultivables isolées de foies de tatous infectés par Mycobacterium leprae.

Four bacterial strains isolated from two livers of armadillos experimentally infected with Mycobacterium leprae were studied. Lipids obtained after saponification and methylation and complex lipids obtained by solvent extraction were examined. The presence of mycolates showed that the four strains belonged to the genus Mycobacterium, but the mycolate patterns, identical for the four strains, were different from those of all strains studied so far. Three of these strains contained phthioceranic acids, which were not found in the fourth one. Only the last strain contained mycosides of the C type, while the three others contained a new type of glycolipid. Their content in mycolates and in glycolipids demonstrated a clear-cut difference between these strains, on the one hand, and M. leprae on the other.

[Specific lipids from Mycobacterium ulcerans]. / Lipides spécifiques de Mycobacterium ulcerans.

The main lipids synthesized by Mycobacterium ulcerans are specific for the species. Three products were isolated by chromatography. Their structures were determined by means of spectrographic methods performed on the natural substances or on their split products. The most abundant products were phthiodiolone diphthioceranate and phenolphthiodiolone diphthioceranate . These structures have some analogies with those of phthiocerol dimycocerosate synthesized by M. tuberculosis and M. bovis, and with those of phenolphthiocerol mycocerosate synthesized by M. bovis. The reverse configuration of the polymethyl-branched-chain fatty acids isolated from the substances, according to their origin, remains to be pointed out. Little attention has generally been paid to the stereochemistry of such molecules. We verified that the branched-chain fatty acids found in diacyl phthiocerol and in the mycoside of M. leprae have the same configuration as in the analogous molecules isolated from M. tuberculosis or M. bovis, contrary to M. ulcerans. Another peculiarity of phenolphthiodiolone isolated from M. ulcerans is the occurrence of the phenol group in free form.

[Should thalidomide be rehabilitated?]. / Faut-il réhabiliter la thalidomide?

Thalidomide (alpha-N-phtalimido-glutarimide) was withdrawn from sale in 1961 since it was held responsible for the birth of hundreds of phocomelus children. Despite this teratogenic potential, thalidomide remains a useful tool in the treatment of erythema nodosum leprosum, as well as in discoid lupus erythematosus when antimalarial drugs are ineffective or contraindicated. In addition, good results have been reported in several diseases such as actinic prurigo, polymorphous light eruption, Behçet syndrome, Weber-Christian disease, prurigo nodularis, pyoderma gangrenosum and ulcerative colitis. The mechanism of action is under debate but it is likely that thalidomide has immunomodulating properties by controlling T-suppressor lymphocytes, and anti-inflammatory effects, particularly an inhibition of neutrophil chemotaxis. Several attempts at synthesis of effective thalidomide derivatives devoid of teratogenic effects are ongoing.