Activity of acid phosphatase in target binding cells expressing NK cytotoxic potential

Versatile Prostate Cancer Treatment with Inducible Caspase and Interleukin-12

To establish optimized conditions for immunity against prostate cancer, we compared the efficacy of multiple approaches in autochthonous and s.c. transgenic adenocarcinoma of the mouse prostate (TRAMP)-based models. Mice immunized with interleukin (IL)-12-containing apoptotic, but not necrotic TRAMP-C2 cell-based, vaccines were resistant to TRAMP-C2 tumor challenge and re-challenge, independently of the route of vaccination (s.c. or i.p.). Administration of gamma-irradiated TRAMP-C2 cells preinfected with adenovirus containing both B7-1 and IL-12 genes, unlike adenovirus containing B7-1 alone, considerably protected C57BL/6 mice from TRAMP-C2 tumor growth and extended the life span of TRAMP mice. Vaccines that included dendritic cells, instead of IL-12, were equally efficient. Whereas injections of ligand-inducible caspase-1- and IL-12-containing adenoviruses cured small s.c. TRAMP-C2 tumors, nanopump-regulated delivery of viruses led to elimination of much larger tumors. The antitumor immune responses involved CD4+-, CD8+-, and natural killer cells and were strengthened by increasing the number of vaccinations. Intraprostatic administration of inducible caspase-1- and IL-12-containing adenoviruses resulted in local cell death and improved survival of adenocarcinoma-bearing TRAMP mice. Thus, tumor cell apoptosis induced by caspase in situ and accompanied by IL-12 is efficient against prostate cancer in a preclinical model.

Purification and characterization of Kurloff cell sialoglycoproteins with acid phosphatase activity

The major alpha 2-6 sialoglycoproteins in detergent-extracts of Kurloff cells were purified by anion-exchange and Sambucus nigra agglutinin-affinity chromatographies. The similar ultrastructural localisations of (1) S. nigra agglutinin-gold conjugates and (2) acid phosphatase activities on the Kurloff body and particularly on its myelin figures indicated that the major alpha 2-6 sialoglycoproteins of the Kurloff cell had acid phosphatase activity. Two-dimensional electrophoresis showed that these tartrate-sensitive phosphatases corresponded to 2 acidic (pI 3.4-3.7) polypeptides of 36 and 34 kDa. Hydrolysis with peptide-N-glycosidases F gave a 33 kDa apoprotein rich in alanine, glutamic acid, tyrosine and lysin. A lectin-affinity study demonstrated that they contained hybrid type bisected and fucosylated N-linked oligosaccharides. Cytotoxic properties were previously attributed to Kurloff cells and other studies suggested that not only acid phosphatases but also alpha 2-6-linked sialic acid residues themselves may participate in natural killer activity.

Arylsulfatase B in Kurloff cells: increased activity of anionic isoforms in guinea pig acute lymphoblastic leukemia

We examined the in vivo role of Kurloff cells (KC), guinea pig natural killer cells, during the development of L2C leukemia, by analysing changes in the arylsulfatases (Asases) in the lysosomal Kurloff body. The Kurloff body is rich in acid phosphatase, esterase and proteoglycans, as are large granular lymphocyte granules. Moreover, the Kurloff body contains lysosomal Asase B, with unusual anionic isoforms. Injection of L2C cells elicited a three-fold increase in KC Asase activity on day 6. The increase in KC Asase activity was correlated with the number of circulating L2C cells. The basic Asase form (pl 8) was lost, and a concomitant increase in anionic isoforms (pl 5-6) was observed on day 6. The role of the latter in cytolysis was investigated by examining their capacity to lyse L2C target cells. We conclude that Asase participates in cytolysis when lysis is mediated by the complete assembly of cytolytic proteins. Changing and increasing KC Asase activity during leukemia development may be a marker for activated KC in vivo. These findings suggest that the cytolytic activation of KC occurs during the preleukemic period.

Coexistence of reduced function of natural killer cells and osteoclasts in two distinct osteopetrotic mutations in the rat

Recent evidence suggesting that immune cells and their products (cytokines) play an important role in the regulation of skeletal development and function, particularly of the osteoclast, implies that immune cell dysfunction may be involved in the pathogenesis of certain skeletal disorders. The mammalian osteopetroses are a pathogenetically heterogeneous group of skeletal disorders characterized by skeletal sclerosis resulting from reduced osteoclast-mediated bone resorption. Using a 51Cr-release microcytotoxicity assay we demonstrated that splenic natural killer (NK) cell activity was significantly reduced in two distinctly different osteopetrotic mutations in the rat, osteopetrosis (op) and toothless (tl). To determine whether this reduction in NK cell-mediated cytotoxicity is caused by decreased cell number and/or function in these osteopetrotic mutants, we quantitated NK cells by analyzing mononuclear cell suspensions labeled for two-color fluorescence with OX8 and OX19 monoclonal antibodies in a fluorescence-activated cell sorter. Flow cytometry of these double-labeled cells revealed that the percentage of NK cells (OX8+/OX19- subset) in op and tl spleens was not significantly different from that of normal spleens. These results suggest that NK cells in these osteopetrotic mutants are functionally defective. Thus aberrations in osteoclast and NK cell function coexist in these mutations, and their developmental relationships deserve further study.

Ultrastructural evidence of large granular lymphocyte (LGL) activity in lesions of chronic adult periodontitis

The purpose of this investigation was to determine, on the basis of ultrastructural evidence, whether large granular lymphocyte (LGL)-mediated cytotoxic activity could be identified in lesions of chronic adult periodontitis. 18 gingival papilla biopsies were obtained from 8 adult patients, each satisfying the clinical criteria for chronic adult periodontitis. One-half of each biopsy was processed for examination by transmission electron microscopy (TEM). B-lymphocyte, T-lymphocyte, and NK-cell contributions to the inflammatory cell infiltrate were determined by subjecting the remaining one-half to the 3-layer avidin-biotin affinity immunoperoxidase technique. Immunohistochemistry using the anti-human leu-11b monoclonal antibody (representative of NK-cells which are known to comprise approximately 80% of the LGL population) showed that the Leu-11b+ population comprised 3-7% of the total monocytic infiltrate. The Leu-11b+ cells tended to occur as single cells or in small clusters of 3-12 cells. Generally, the Leu-11b+ cells exhibited perivascular locations situated subjacent to the epithelial basal lamina. TEM observations showed LGLs in intimate contact with fibroblasts that exhibited morphologic changes consistent with cellular damage or degeneration. In addition, LGLs were observed to exhibit apparent non-cytotoxic contacts with plasma cells, macrophages and other monocytic cells.