RESUMEN

Five monoclonal antibodies (MAbs) directed against antigens of Mycobacterium leprae were tested for their ability to bind to components of tissue sections prepared from biopsies taken from patients with various forms of leprosy. Immunoperoxidase was the most successful marker system used, although immunofluorescence and alkaline phosphatase were also successful in certain cases. Positivity was high with all five antibodies successfully staining those sections containing a bacterial index of 3+ or more; sections with 0 bacterial counts also had areas staining positively with two of the MAbs. The positive staining in the tissues was confined to areas infiltrated by inflammatory cells; however it was not identifiable as being associated with individual bacteria. These findings suggest that immunostaining with specific monoclonal antibodies can help to identify leprosy in diagnostic samples in which acid-fast bacilli are not identifiable by standard histochemical means. Immunohistochemical techniques are likely to be valuable in studies of the distribution of M. leprae antigens and their association with individual tissue elements.

Asunto(s)

RESUMEN

Monoclonal antibodies directed to six separate antigen molecules of Mycobacterium leprae have been tested in an antigen-capture assay based on combined use of polyclonal ("capture") and monoclonal ("detector") antibody reagents. This approach provides a potentially versatile, sensitive and specific assay for detection and relative quantitation of M. leprae antigens. Characterisation of monoclonal antibodies to mycobacterial lipoarabinomannan (LAM-B) by the antigen-capture assay indicates that some of the antigenic determinants present on LAM-B from M. leprae may be either absent altogether or present at much lower concentrations on the corresponding LAM-B structure form M. tuberculosis.

Asunto(s)

Asunto(s)

RESUMEN

A panel of nine monoclonal antibodies to Mycobacterium leprae were used to characterize a protein antigen of the bacillus. Two monoclonal antibodies (IVD8 and IIIE9) were specific for M. leprae and reacted with an epitope (CWPa) present on a protein molecule associated with the cell wall fraction of M. leprae. This protein, designated cell wall-associated protein (CWP), lost its immunoreactivity upon treatment with trypsin and had an apparent molecular weight of 65,000, though additional lower-molecular-weight forms of the protein were observed by immunoblotting. Four other cross-reactive epitopes (CWPb, CWPc, CWPd, and CWPe) were defined on the same molecule using seven independent monoclonal antibodies. Therefore, M. leprae possesses a trypsin-sensitive, heat-stable protein associated with the cell wall which contains at least one species-specific and four cross-reactive antigenic determinants.

Asunto(s)

RESUMEN

Monoclonal antibodies (MoAb) have been used to analyse a protein antigen from Mycobacterium leprae with a subunit mol. wt of 28,000 daltons. Three different patterns of species specificity were observed with two antibodies being specific for M. leprae, two partially specific, and one broadly cross-reactive amongst all mycobacteria. Competitive binding and sandwich assays demonstrated that the specific and partially specific antibodies recognized closely related regions of the molecule while the cross-reactive antibody recognized a spatially separate epitope on the same polypeptide chain. Identification of specific and cross-reactive epitopes on a single antigenic molecule may be of considerable importance for understanding the functioning of the cell-mediated immune system during leprosy infection and the use of MoAb for such analyses is discussed.

Asunto(s)

RESUMEN

The immunoglobulin classes of the antibody response to the species-specific phenolic glycolipid antigen of Mycobacterium leprae have been characterized for serum specimens from 78 patients with leprosy. These patients included the entire clinical spectrum from paucibacillary to multibacillary disease, including polar tuberculoid (TT; 11 patients), borderline tuberculoid (BT; 15), borderline (BB; 17), borderline lepromatous (BL; 13), and lepromatous (LL; 22)--clinical classifications according to Ridley-Jopling criteria. In each patient group, the levels of IgM antibody to phenolic glycolipid were significantly higher than levels of IgG or IgA. Inhibition experiments with purified antigen showed that antibodies to the phenolic glycolipid dominated the human IgM antibody response to the surface of M. leprae.

Asunto(s)

RESUMEN

Nine cloned cell lines producing antibodies to the unique phenolic glycolipid of Mycobacterium leprae have been established as a result of fusions with spleens from mice immunized with the glycolipid complexed with methylated bovine serum albumin. One of the antibodies was relatively nonspecific, binding to a related glycolipid from Mycobacterium kansasii, but the remaining antibodies were specific for the M. leprae lipid. Some of the antibodies required the intact (trisaccharide) carbohydrate portion for recognition of the glycolipid antigen, whereas others recognized partially hydrolyzed forms lacking one or two sugar residues. Monoclonal antibodies directed at the terminal saccharide of the glycolipid showed the greatest specificity for M. leprae in enzyme-linked immunoassays. These antibodies brightly labeled whole mycobacteria in indirect immunofluorescence experiments, demonstrating the surface location of M. leprae-specific determinants of the glycolipid antigen. In addition to their use in providing information about the antigenic properties of the phenolic glycolipid, these antibodies have potential applications for elucidating the roles of glycolipid in the pathogenesis of leprosy.

Asunto(s)

Asunto(s)

RESUMEN

Mycobacterium leprae isolated from armadillo tissue incorporated radioactivity from D-(14C)glucose and (14C)protein hydrolysate. In the presence of glucose, the rate of incorporation of (14C)protein hydrolysate was increased. Uptake of glucose was inhibited by 2-deoxy-D-glucose and sodium azide; that of the amino acids was inhibited by puromycin and chloramphenicol and, weakly, by cycloheximide.

Asunto(s)

RESUMEN

Mycobacterium leprae isolated from armadillo tissue incorporated radioactivity from D-(14C)glucose and (14C)protein hydrolysate. In the presence of glucose, the rate of incorporation of (14C)protein hydrolysate was increased. Uptake of glucose was inhibited by 2-deoxy-D-glucose and sodium azide; that of the amino acids was inhibited by puromycin and chloramphenicol and, weakly, by cycloheximide.

Asunto(s)

RESUMEN

Mycobacterium leprae separated from armadillo tissues stored at -80 degrees C is similar to that from human sources in its ability to take up 3H-labelled 3,4-dihydroxyphenylalanine (DOPA). Several inhibitors were studied which showed complete or partial inhibition of [3H]DOPA uptake. These findings suggest that M. leprae isolated from frozen tissue possesses an active uptake system for [3H]DOPA.

Asunto(s)

Asunto(s)

Asunto(s)

Asunto(s)

RESUMEN

The percentage of T & B lymphocytes were estimated in 52 leprosy patients by 'E' and 'EAC' rosette techniques. The mean % values for 'T' lymphocytes were significantly lower in lepromatous group as compared with that of tuberculoid and borderline groups. Also, a significant difference was observed in the mean % values of T & B lymphocytes of the borderline and tuberculoid patients and of the normal control group. These findings were correlated with skin smears and lepromin testing.

Asunto(s)

Asunto(s)

Asunto(s)

Asunto(s)

Asunto(s)