Yoshino, Tadashi

Using the peroxidase antiperoxidase (PAP) method, lysozyme (LZM) was shown to exist in normal, reactive and neoplastic cells belonging to the mononuclear phagocyte system (MPS), but was not detected in histiocytosis X cells. Immunostaining for cytoplasmic LZM by the PAP method is useful for identification of mononuclear phagocytes and for diagnosis of the diseases in which these cells participate.

We have attempted to clarify the characteristics of monoclonal antibodies (MAbs) detecting lymphocyte subsets in fixed materials. We examined by means of flow cytometric technique influences of fixatives and reactivity with malignant lymphomas (MLs). Specific markers for T-cells were UCHL1 and OPD4, which reacted especially with helper/inducer T-cells. MT1 recognized almost all of T-cells from peripheral blood and tonsils, but reacted with a part of B-MLs. As for B-cell markers, L26 was the most reliable marker for B-MLs. L26 and MB1 antigens could not be detected on living cells flow cytometrically. LN1 reacted with a part of T-cells as well as B-cells, but fluorescent intensity of the former was apparently stronger than that of the latter. Although LN2 antigen was located mainly in the cytoplasm close to the nuclear membrane immunohistochemically, it could be detected on living cells flow cytometrically. LN2 positive cells belonged to B-cells in peripheral blood and tonsils. When fixed for relatively short time, B5 and buffered formalin were better for examining MAbs than non-buffered formalin and ethanol.

A rare gastrointestinal tract neoplasm, primary non-Hodgkin's B-cell lymphoma in a 39-year-old, asymptomatic woman is described. The tumor was originally localized in the rectum without evidence of any other lymphoma-involved organ and treated by curative surgical procedure associated with postoperative chemotherapy.

To elucidate the latent state and reactivation of Epstein-Barr virus (EBV) in non-neoplastic lymphoid lesions, we investigated 144 non-neoplastic lymphoid lesions by in situ hybridization (ISH) to detect the expression of EBV-encoded small RNAs (EBER)-1 and BCRF-1 and by immunostaining for latent membrane protein (LMP)-1 and ZEBRA. ISH for EBER-1 detected EBER-1-positive cells (EPC) in 31 of the 144 examined lesions (22%). EPC were detected in 4 of 49 cases of nonspecific lymphoid hyperplasia, in 16 of 20 abscess-forming granulomatous lymphadenitis (AFGL), 5 of 25 Kikuchi's disease, and in 3 of 3 infectious mononucleosis. LMP-1 was expressed in 6 of 124 non-neoplastic lymphoid lesions (4.8%). LMP-1-positive cells were observed in 6 of the 31 EBER-1-positive cases (19%). EPC were detected significantly more frequently in LMP-1- and ZEBRA-positive specimens than in the LMP-1- and ZEBRA-negative specimens. BCRF-1 was expressed in 4 of 11 cases examined: 2 of 3 AFGL, 1 of 2 Kikuchi's disease, and in the 1 case of atypical lymphoid hyperplasia. This study suggests that Epstein-Barr virus is prevalent and can be reactivated in the lymph nodes effaced by destructive inflammation, such as AFGL. Such inflammation may provide a local milieu that is conducive for EBV to enter the lytic cycle.

<P>Reed-Sternberg cells (RS cells) of Hodgkin's disease (HD) are frequently infected with Epstein-Barr virus (EBV) and express EBV-encoded nonpolyadenylated RNA transcripts (EBER)-1. EBV latency has been classified into three distinct forms: Latency I, expressing only one of the latent proteins, EBV nuclear antigen (EBNA)-1, latency II, coexpressing EBNA-1 and LMPs, and latency III, expressing all latent viral proteins. RS cells express LMP-1 in addition to EBNA-1 and are considered to be EBV latency II frequently encountered in nasopharyngeal carcinoma. We examined 13 cases of EBV-infected HD by combined EBER-1 in situ hybridization and immunostaining for LMP-1. All of the RS cells expressed EBER-1, but a substantial number of EBER-1+ RS, cells were negative for LMP-1. The percentage of LMP-1+ RS cells out of EBER-1+ RS cells varied from 7% to 100% (average 69%). In this study, we showed that all EBV-infected RS cells were not restricted to latency II, and some belonged to latency I.</P>

Circulating hepatitis C virus (HCV) particles can be fractionated by means of differential flotation centrifugation. It is reported that in the bottom fraction HCV is in the form immune complexes, whereas in the top, it is free of antibodies. We evaluated the significance of circulating complex and free HCV in chronic hepatitis C, and assessed the relationship in terms of the response to interferon (IFN) therapy. We examined sera before, just after, and 1 year after administering IFN to 18 patients with chronic hepatitis C, 10 of whom responded (group CR), and 8 did not (group NR). The amounts of virus were similar between both groups before therapy. After differential flotation centrifugation with 1.063 g/ml of NaCl, the top and bottom fractions were assayed for HCV RNA. Before therapy, HCV RNA was detected in the top fraction in 1 of 10 in group CR, and in 6 of 8 in group NR (P < 0.05, chi-square test). HCV RNA was positive in the bottom fraction of all samples. In a follow-up study of group NR, HCV RNA was detected in the top fraction in 3 of 8 just after IFN therapy, and in 7 of 8 after 1 year. This study suggests that the presence of HCV in the top fraction can predict a poor response to IFN therapy.

A simian cell line, Si-IIA, harboring Epstein-Barr-virus (EBV) -related herpesvirus (Si-IIA-EBV), produces malignant lymphoma in rabbits when administered by intravenous inoculation. In this study, we analyzed the Si-IIA-EBV genome and compared it with human EBV and herpesvirus macaca fascicularis 1 (HVMF 1 ), which is associated with B-cell lymphoma developing in SIV-infected immunosuppressed monkeys. DNA from Si-IIA-EBV was amplified by the polymerase chain reaction using three different primer pairs complementary to human EBV (B95-8) DNA; two of the primer pairs covered part of the long internal repeat 1 region (IR 1) and the third covered part of the BRRF 1 region. Direct sequencing of the three PCR products revealed that Si-IIA-EBV DNA had about 82% nucleotide homology to the human EBV DNA in all three regions and 92.4% homology to HVMF1 in the IR1 region. The blotting pattern by Southern blot analysis was different between Si-IIA-EBV and human EBV.

In the human lymphoreticular system, the alpha and beta subunits of S-100 protein are found in ordinary monocyte-macrophages and non-phagocytic histiocytes such as Langerhans cells and interdigitating reticulum cells, respectively. The beta subunit is also present in some CD8+ T cells. In the present study, we investigated the ontogeny of these histiocytes and lymphocytes in humans. Yolk sacs and 4 to 21-week fetuses were examined immunohistochemically for the presence of S-100 protein subunits using antisera monospecific to each subunit. S-100 alpha + macrophages were present in the yolk sacs and the hepatic sinusoids of the 4th week embryos prior to bone marrow hematopoiesis. These macrophages later appeared in other lymphoid organs when anlagen of these organs were formed. No S-100 beta + cells were found in the yolk sacs. S-100 beta+ histiocytes were first detected in the hepatic sinusoids of the 5th week embryo, and after the 8th week of gestation, they were distributed in other lymphoid organs. S-100 beta+ lymphocytes were not found in the liver. They were first detected in the thymus at the 12th week of gestation, and were subsequently distributed in other lymphoid organs. These results suggest that S-100 beta+ lymphocytes and histiocytes may belong to different cell lineages, and the former may not be the precursor of the latter.

Co-cultivation of thymus and spleen cells of Fisher and Lewis rats with lethally irradiated MT-2 cells harboring human T-cell leukemia virus type I (HTLV-I) resulted in the establishment of lymphoid cell lines, FIRT-1, FIRS-1, LERT-1, and LERS-1, respectively. Cells of these cell lines had rat T-cell characters as demonstrated by the positive reaction to monoclonal antibodies (MAbs) to rat T cell antigens (Thy 1 and pan T). They lacked surface immunoglobulins and strongly expressed rat interleukin-2 receptor antigen (Tac) and Ia antigen. Karyotypic analysis revealed that they had the normal rat karyotype in early cultures, but showed marked aneuploidy after long cultivation. None of them expressed HTLV gag proteins (p19 and p24) or virus particles, but they contained HTLV-I proviral DNA monoclonally and weakly expressed pX gene products (p40x). They were not transplantable into syngeneic newborn rats.

The sensitivity and specificity of single cell polymerase chain reaction (PCR) were studied. Its high sensitivity enabled detection of a single-copy gene, such as human T-lymphotropic virus type I genome in paraffin sections. The rate of obtaining positive signals with this method was affected by the number of copies of the gene in the target cell. Specificity was satisfactory if the procedure was properly and carefully followed. Since the single cell PCR is a time-consuming method which requires skill and experience to pick up the target cells accurately, the applicability of this method is limited. It works best when it is used to analyze a single or a few copy genes in histologically identified cells.

Previously, we reported that interleukin-2 (IL-2)-stimulated helper T cells produced an unknown soluble factor which induced dendritic cell-like differentiation in primary cultures of monocytic leukemia cells and we referred to this factor as dendritic cell differentiation factor (DCDF). In this study, we attempted to purify and characterize DCDF and investigated its biological effect on normal human monocytes. Gel filtration chromatography indicated that the molecular weight of DCDF is approximately 30-35 kDa. Chromatofocusing indicated that the isoelectric point of DCDF is approximately 5.0. DCDF, partially purified by subsequent gel filtration, chromatofocusing, and hydrophobic chromatography, significantly enhanced the HLA-DR expression of normal human monocytes and a human monocytic leukemia cell line, THP-1. This biological activity was not neutralized by any known antibodies to human cytokines. DCDF significantly amplified the T-cell stimulatory activity of monocytes in the allogeneic mixed leukocyte reaction (MLR). Moreover, DCDF significantly enhanced IL-1 beta and IL-6 production by monocytes in a dose-dependent manner. These results suggest that DCDF is a novel human cytokine which stimulates the accessory cell function of monocytes.

Endoscopical segmental piecemeal tumorectomy (ESPT) for nodular elevation of colorectal tumor is advantageous in terms of minimizing both surgical invasion and postoperative burden to the patients. Nodular elevation of colorectal tumors is said to occur when the body of the tumor is adenomatous and the surface of the focal cancer grows more horizontally into the lumen than vertically. We report here four cases of nodular elevation of colorectal tumors which were each treated by different surgical procedures.

Lymphocyte adhesion molecules defined by anti-CD44 antibody (Hermes-3) may be involved in lymphocyte binding to high endothelial venules at sites where lymphocytes exist the blood. CD44 expression was immunohistochemically examined in 167 well characterized cases of malignant lymphomas (MLs). None of 12 nodal follicular lymphomas (FLs) were CD44+, whereas 3 of 4 extranodal ones showed distinct CD44 expression. In contrast to nodal FLs, 28 of the 38 (74%) nodal diffuse B-cell lymphomas were CD44+ (p < 0.0001). T-cell lymphomas showed a significantly higher expression of CD44 antigen than diffuse B-cell lymphomas in the nodal cases (p < 0.04), but not in the extranodal ones. In nodal diffuse lymphomas, 3 of 5 stage I lymphomas (60%) were CD44+ in contrast to 53 of 63 stage II-IV lymphomas (84%), but the difference was not statistically significant. Of 14 Hodgkin's diseases, 9 cases were CD44+ with no significant correlation with clinical stage. The data of flow cytometric analysis confirmed the results of immunohistochemical analysis. In conclusion, CD44 expression is relevant to primary sites of distinctive MLs originating in the mucosal regions (MALToma) and some histological subtypes, but the relation with clinical stage was not defined. Some other adhesion molecules or different mechanisms must also be taken into account concerning the genesis and the expansion of MLs.

The distribution of lectin receptors in the human tonsil was studied using 16 biotinylated lectins. The avidin-biotin-peroxidase complex (ABC) method was used on frozen and paraffin-embedded tissue sections. Cell suspensions were also analysed by dual flow cytometry using respective fluorescein isothiocyanate-conjugated lectins and phycoerythrin-labeled anti-CD3 and anti-human immunoglobulin. Frozen sections fixed with acetone and paraffin-embedded materials fixed in three solutions were compared for lectin affinity; ethanol-fixed sections gave best results followed by frozen and buffered formalin-fixed ones, then nonbuffered formalin. Con-A, RCA-1, LcH, WGA, MPA, PHA, PSA, PNA, SJA and GSA-1 reacted with all tissue components of the tonsil in immunohistochemical studies, but binding intensity was fixative dependent. Binding of Lotus and BPA to lymphocytes was limited to germinal center lymphocytes. Other tissue components were also reactive but staining intensity was weaker in Lotus compared with BPA. SBA and DBA did not react with lymphocytes, but reacted with macrophages/histiocytes, vascular endothelia, and epithelial cells. LBA and LPA were constantly negative with all tissue components irrespective of fixatives. Flow cytometric analyses showed that all but three (DBA, LBA and LPA) partially or totally stained lymphocyte surfaces. Lotus receptors were expressed exclusively on B-lymphocytes.

Corticoids are well known for their immunosuppressive properties. Interleukin-10 (IL-10) is an intrinsic antiinflammatory peptide in immune diseases, originally identified as cytokine synthesis inhibitory factor. We examined the effect of hydrocortisone sodium succinate (HSS) on the production of IL-10 by human peripheral blood mononuclear cells (PBMCs). PBMCs from healthy volunteers and cancer-burden patients were preincubated separately with or without HSS for 1 h, then stimulated with 5 microg/ml lipopolysaccharide (LPS). Production of IL-10 by human PBMCs was detected with LPS stimulation and its production was higher in cancer-burden patients than in normal volunteers, although this was not statistically significant. HSS suppressed production of IL-10 by LPS-stimulated PBMCs in a dose-dependent manner both in normal volunteers and in cancer-burden patients. These results indicate that, in addition to their antiinflammatory properties, corticoids act to restore the immunosuppressive states even in cancer-burden states