Distribution of Antigens Detected with MB1, MB2 and MB3 on Non-hematopoietic Human Organs and Various Tumors

We have examined the distribution of antigens detected by MB1, MB2 and MB3 on non-hematopoietic normal human tissues and various types of benign and malignant tumors. MB1 and MB2 reacted with various organs, such as the epithelium of various glands, smooth muscle cells, vascular endothelial cells, and peripheral nerve tissue. The distributions of these two antibodies were essentially identical. Reactivity with MB3 was confined to the ductal eDithelium of salivary glands, the pancreas, and sweat glands, and the cortex of the adrenal gland. lmmunoblotting analysis demonstrated that MB1 and MB2 reacted with a few bands of an extract of myometrial cytoskeletal fraction and salivary gland cytosol fraction, whereas MB3 failed to show any bands on these materials. The reactivities of MB1 and MB2 with various neoplasms were similar to those in normal organs, with slight variations of staining pattern and preponderance in well differentiated tumors. Exceptionally, carcinoid tumor and small round cell tumors, such as small cell carcinoma or neuroblastoma, were not reactive with MB1 and MB2. MB3 reacted with several cases of well differentiated benign and malignant epithelial tumors in various organs, and exceptional cases of malignant schwannoma and glioma. These results indicate that the antigens detected by MB1 and MB2 are distributed broadly on non-hematopoietic normal organs, whereas those detected by MB3 are confined to exceptional cases of epithelial and non-epithelial tumors. Thus, although the use of MB1, MB2 and MB3 is of little value for differential diagnosis of various tumors, these three antibodies may be useful for determining of the origin of some tumor types. Acta Pathol Jpn 42: 339–346, 1992.     

Augmentation of antibody responses of mice to inhaled protein antigens by simultaneously inhaled bacterial lipopolysaccharides

Serum antibody responses of mice to repeatedly inhaled protein antigens such as bovine serum albumin and ovalbumin, plus or minus bacterial lipopolysaccharide (LPS) in the form of an aerosol were studied. Results showed that the levels of responses to inhaled protein antigens varied, depending on the mouse strain-antigen combination and that LPS inhaled simultaneously with the antigens definitely augmented the responses which were not otherwise very high. LPS extracted from Klebsiella O3 (LPS-K) but not LPS from Escherichia coli O55 (LPS-E), which was inhaled at the time of initial inhalation of antigen, significantly intensified the priming for the secondary antibody response to the antigen subsequently inhaled. Both LPS-K and LPS-E, however, definitely acted to augment the response when they were inhaled repeatedly together with the antigen. Oral administration of antigen or antigen plus LPS-K did not induce any detectable antibody response in our experiment, ruling out the possibility that the antigen and LPS stimulated the immune system via alimentary canal rather than via lung. Tissue distribution of the radioactivity soon after inhalation of 131I-labeled antigen and decay speed of the radioactivity were not significantly changed by LPS-K inhaled simultaneously. This suggested that the augmentation of responses was not mediated by the action of LPS to modulate the air-blood barrier against the entry of antigen via lung. All the results prove for the first time that inhaled LPS displays a definite adjuvant action on antibody responses to inhaled antigens.     

The appearance and role of gamma delta T cells in the peritoneal cavity and liver during primary infection with Listeria monocytogenes in rats.

We have previously reported that gamma delta T cells play important roles in protection during the early stage of infection with Listeria monocytogenes in mice. To generalize the protective roles of gamma delta T cells in listerial infection to different species, we examined the appearance of gamma delta T cells during infection with L. monocytogenes in Fisher F344 rats. The numbers of bacteria in the peritoneal cavity and liver increased to a maximum level on day 3 and then decreased to an undetectable level by day 10 after an intraperitoneal infection with a sublethal dose (1 x 10(8)) of viable L. monocytogenes in rats. CD3+ alpha beta- T cells in the peritoneal cavity and liver began to increase on day 3, reached a maximum level on day 6, and thereafter decreased gradually by day 10 after infection. Northern blot analysis confirmed that the CD3+ alpha beta- T cells expressed TCR delta and gamma gene messages. In vivo treatment with anti-TCR alpha beta mAb, which suppressed most of the alpha beta T cells in the periphery and impaired resistance during the late stage of listerial infection, did not affect the host defense by day 6 after infection. A significantly increased number of gamma delta T cells was detected in the peritoneal cavity of the TCR alpha beta-suppressed rats on day 6 after infection. These results suggest that the early appearing gamma delta T cells may contribute to the host defense at a relatively early stage during listeriosis in rats.     

Genetic and stimulatory cell type requirements for inducing class I major histocompatibility complex alloantigen-specific in vivo cytotoxic T cell immunity

Current interpretation based on analytical in vitro works that actions of Ia antigens and accessory cells such as macrophages and dendritic cells are crucial for inducing cytotoxic T cell responses to class I major histocompatibility complex (MHC) alloantigens has been challenged by experiments performed in a newly developed system handling in vivo cytotoxic T cell immunity. We first characterized the transplantation immunity for second-set rejection of ascitic tumor allografts as principally induced by allogeneic stimulator cells via direct pathway, and as exclusively mediated by class I MHC alloantigen-specific in vivo cytotoxic T cell activity. By comparison of activities of limiting effective doses (10(4)-10(5) cells per mouse) of various stimulator cells in this defined system, we could demonstrate that genetic disparity at the D region of H-2 to the recipient is just enough for inducing the immunity, and presence of allogeneic or syngeneic Ia antigens in addition to H-2D alloantigens on stimulator cells does not give any premium effect. Further study revealed that allogeneic peritoneal cells rich in macrophages or glass-adherent spleen cells enriched for dendritic cells are not stronger stimulators than allogeneic adherent cell-depleted spleen cells and semi-allogeneic thymocytes. These results fit with the alternative concept that the physiological pathway inducing in vivo cytotoxic T cell immunity for graft rejection entirely depends on class I MHC antigens on live lymphocytes as self-supported stimulators, and does not crucially involve additional stimulator activities of Ia antigens and special accessory cell types, which must be in vivo concerned with induction of other types of transplantation immunity.     

Expression of E-cadherin in bone and soft tissue sarcomas: a possible role in epithelial differentiation

The cadherin-mediated cell-cell adhesion system is now known to play a critical role in both the morphogenesis of cancer cells and suppression of their invasion. However, the pattern of expression of E-cadherin, the major cadherin of epithelial cells in bone and soft tissue sarcomas, remains unclear. This prompted us to study E-cadherin expression in a variety of bone and soft tissue sarcomas. Using the monoclonal antibody HECD-1, raised against the extracellular domain of E-cadherin, we observed immunoreactivity in 1 pleomorphic rhabdomyosarcoma, 2 of 5 diffuse mesotheliomas, 4 of 5 clear cell sarcomas, 1 of 5 epithelioid sarcomas, and 10 synovial sarcomas. Other types of bone and soft tissue sarcoma (4 osteosarcomas, 4 chondrosarcomas, 3 primitive neuroectodermal tumors, 1 fibrosarcoma, 4 malignant fibrous histiocytomas, 5 liposarcomas, 4 leiomyosarcomas, 6 alveolar and 5 embryonal rhabdomyosarcomas, 4 angiosarcomas, 4 malignant peripheral nerve sheath tumors, 2 extraskeletal myxoid chondrosarcomas, 2 extraskeletal osteosarcomas, and 3 alveolar soft part sarcomas) were completely negative for E-cadherin. Our findings indicate that E-cadherin is expressed in certain kinds of soft tissue sarcomas, especially those with epithelioid features, suggesting that E-cadherin plays a role in the constitution of their architecture.     

Cytoskeletal properties of alveolar soft part sarcoma

The immunohistochemical expression of cytoskeletal proteins in alveolar soft part sarcoma (ASPS) was studied by light and electron microscopy. Of the five cases examined by the avidinbiotin-peroxidase complex method, variable numbers of immunoreactive cells for desmin were found in three, for vimentin in two, for muscle-specific actins in three, and for alpha-smooth muscle actin in four. Immunoelectron microscopic study demonstrated that desmin and vimentin were localized on whorled bundles of intermediate filaments in the perinuclear cytoplasm. In addition, a few dispersed intermediate filaments became evident in specimens treated with saponin and fixed with tannic acid. These immunohistochemical results indicate that a few tumor cells of ASPS may express some properties of the cytoskeleton of smooth muscle cells in addition to those of skeletal muscle cells. Considering the discrepancies reported in the actin isoforms demonstrated in myogenic tumors, we conclude that ASPS is probably a peculiar, primitive myogenic tumor that does not show any distinctive features of rhabdomyogenic or leiomyogenic differentiation.     

Atypical Glomus Tumor in the Mediastinum: A Case Report with Immunohistochemical and Ultrastructural Studies

A case is reported of atypical glomus tumor occurring in the posterior inferior mediastinum of a 26-year-old woman complaining of severe back pain. The tumor was composed of atypical small, round tumor cells with scattered mitotic figures. In addition to sheet-like, diffuse proliferation of the tumor cells, some areas of the tumor contained small “glo-moid” cells arranged in organoid and hemangiopericytoma-like patterns. Immunohistochemically, many tumor cells were positive for muscle-type actins and a few cells were focally positive for desmin. Ultrastructural studies revealed smooth muscle features of tumor cells, that is, pinocytotic vesicles, external laminas, dense plaques, and occasional thin filaments with dense bodies. The patient remained well for 5 years and 4 months after the operation without additional radiation and chemotherapy. The tumor was diagnosed as an atypical, or low-grade malignant, glomus tumor morphologically. It seems important to recognize the presence of this type of tumor in sites other than extremities and to differentiate it from other malignant small, round cell tumors.