Acid mucopolysaccharide and one of its glomerular degrading enzymes beta-glucuronidase in experimental and human glomerulonephritis

In 1962, when the immune complex in nephritic glomerular basement membrane (GBM) was clarified as being a type of GBM thickening, Amon and Gayer reported a different type of thickening in the rabbit administered hyaluronidase (an enzyme to degrade hyaluronic acid) and named it 'herniation' of the GBM. As we have been interested for a long time in the disappearance of normally present nonsulfated AMPS, presumably hyaluronic acid (HA), from the glomeruli in humans and experimental animals with chronic glomerulonephritis, we wanted to observe the activity of the enzyme in these conditions. Since a suitable histochemical method for the precise evaluation of hyaluronidase is unavailable, we instead chose beta-glucuronidase(beta-Gase), which is also an enzyme which degrades HA. The principal study was performed by means of light- and electron-microscopic histochemistry of chronic glomerulonephritis produced experimentally in rats and compared the obtained results to those in human chronic glomerulonephritis. The high activity of beta-Gase with a coincidental decrease of AMPS in the glomeruli was observed both in experimental and human chronic glomerulonephritis. The herniation type GBM thickening in the rat was coincidental with the enzyme localization with the disappearance of AMPS from foot processes of epithelial cells overlaying the lesion. The results might suggest the key role of beta-Gase in the deformation of GBM in chronic glomerulonephritis in general.

Acid-fast properties and pyridine extraction of M. leprae

The reportedly unique pyridine extractability of acid-fastness as an identifying characteristic for M. leprae was examined in the leprosy bacilli and in eight other strains of mycobacteria. The initial findings were, in general, in accord with previous reports except that M. smegmatis and M. phlei likewise demonstrated two hour pyridine extractability of acid-fastness. Perhaps, more significantly, it was found that this characteristic in M. leprae is related to aged, probably nonviable bacilli. Some other strains of mycobacteria when tested in aged cultures showed the same phenomenon while M. leprae cultivated in vitro in a recently developed medium resisted pyridine extraction up to three weeks of growth, but thereafter as the culture aged pyridine extractability became characteristic. It is concluded that this pyridine extractability of acid-fastness is a characteristic of aging or nonviable bacilli. As such it is not definitive in the determination of whether or not in vitro cultivation of M. leprae has been achieved.

Specific direct fluorescent antibody identification of Mycobacterium leprae

In vitro cultivation of M. leprae requires a rapid, specific identification procedure for monitoring the cultures. A method utilizing direct FITC-coupled lepromatous, specific serum globulin is described in detail with suggestions for improvement. After various purification and adsorption procedures, notably against human liver powder and M. tuberculosis, a fluorescent serum preparation is obtained which specifically reacts with M. leprae and not with other mycobacteria.

In vitro cultivation of leprosy bacilli on hyaluronic acid based medium. 1. Preliminary report

In vitro cultivation is reported of Mycobacterium leprae on a medium (designated LA-3) based on hyaluronic acid with additional ingredients of yeast extract, bovine albumin and glycerin together with phosphate buffer. The medium is also incorporated with agar or agarose (designated LA-3P) to serve as culture plates. Initial growth in LA-3 in test tubes required about six weeks but subsequently this was speeded up to about two weeks utilizing large quantities of media with aeration by shaking twice a day. Growth on LA-3P yields numerous small orange-yellow colonies in two to three weeks. Facets of the emerging aspects of the life cycle of M. leprae under cultivation are given preliminary report. The bases for the allegation of M. leprae identity of the cultured bacilli are essentially the following six determinations. 1. Pathologic and experimental determined rationale for the essential M. leprae nutrient requirement. 2. Several cultures having the same characteristics have been isolated from LL patients widely separate in time and by geography. 3. Failure of culture isolates to subculture on the usual media employed in the cultivation of mycobacteria at both 37 degrees C and room temperature. 4. 1 degree cultures in liquid medium successfully transferred to 2 degrees liquid medium and to 2 degrees agar medium plates. 5. Bacillary isolates and bacilli of 1 degree and 2 degrees liquid medium cultures all stain with pooled LL serum, FITC coupled, M. leprae specific antibody with which a broad range of other mycobacteria do not react. 6. M. lepraemurium also presents good growth on this medium.

Acid mucopolysaccharide metabolism in leprosy. 3. Hyaluronic acid mycobacterial growth enhancement, and growth suppression by saccharic acid and vitamin C as inhibitors of beta-glucuronidase

A series of pilot studies are presented utilizing mouse and human infections with M. leprae and mouse infections with M. lepraemurium relating to the previously reported finding that hyaluronic acid seems to be a major nutrient substrate for these bacilli. The "feeding" of hyaluronic acid to the bacilli enhanced the growth of M. leprae in mouse abdominal walls and increased the Morphologic Index of M. lepraemurium infection. Saccharic acid, an inhibitor of beta-glucuronidase previously reported as present in these leprosy bacilli, caused marked regression of advanced M. lepraemurium infection, inhii. Ascorbic acid (vitamin C), also an inhibitor of beta-glucuronidase, given at a level of 1.5 gm/day for 4.5 months to one lepromatous patient without other treatment and for up to 24 months to four other lepromatous patients receiving DDS, was accompanied by lesion regression and changes in bacillary morphology similar to those seen in the inhibitor treated mice. If these observations are confirmed the possible use of beta-glucuronidase inhibitors as a useful adjunct to other leprosy therapy is raised as is also the likelihood of developing new therapies.

Acid mucopolysaccharide metabolism in leprosy. 2. Subcellular localization of hyaluronic acid and beta-glucuronidase in leprous infiltrates suggestive of a host-Mycobacterium leprae metabolic relationship

Electron- and light microscopic analyses were conducted on leprosy skin biopsies relative to the origin of hyaluronic acid, which has previously been observed to be distributed inversely in ratio to the degree of cell- mediated immunity. The present study investigated the subcellular localization of hyaluronic acid and its degrading enzyme in various types of leprosy. Hyaluronic acid in some lepromatous leprosy cases was shown to be accumulated in the limiting membranes of the phagosomes of lepra cells and Myco-bacteria leprae have beta-glucuronidase which plays a role in the degradation of hyaluronic acid. Contrariwise, in tuberculoid leprosy, beta-glucuronidase was detected in the lysosomes of epithelioid cells and giant cells. This result suggests that the origin of hyaluronic acid is in histiocytes and at the same time it might suggest that M. leprae is in competition with enzymes of epithelioid cells for hyaluronic acid, whereas reduced or absent beta-glucuronidase in lepra cells enable bacilli to utilize the AMPS as a nutrient.

Acid mucopolysaccharide metabolism in leprosy. 1. Storage of hyaluronic acid and its possible significance in the pathogenesis of leprosy

A histochemical analysis of 102 skin biopsies from a variety of leprosy types revealed the persistent presence of hyaluronic acid in lepra cells of lepromas. In contrast, the hyaluronic acid content of tuberculoid epithelioid cells showed a minimum amount of hyaluronic acid and hyaluronic acid tended to disappear from these granulomas as they aged. The macrophages of dimorphous leprosy occupied an intermediate position with respect to hyaluronic acid content and distribution, resembling the tuberculoid in BT cases and the lepromatous expression in BL cases. It is suggested that hyaluronic acid, in a manner similar to M. leprae and lipid, has a quantitatively varied distribution reflecting the immunopathologic spectrum of leprosy. This finding suggests that acid mucopolysaccharide may be significantly involved in that host/parasite interaction in leprosy.