Taro Kuritani

Elevated levels of interleukin-6 in serum and cerebrospinal fluid of HTLV-I-associated myelopathy/tropical spastic paraparesis

A significant elevation of interleukin-6 (IL-6) level was observed both in serum (mean 0.455 +/- 0.251) and in cerebrospinal fluid (CSF) (mean 0.043 +/- 0.016) obtained from 13 patients with HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP) when compared to that of either asymptomatic carriers (mean 0.181 +/- 0.074 and 0.021 +/- 0.015, respectively) or controls (mean 0.208 +/- 0.119 and 0.021 +/- 0.015, respectively). The differences were statistically significant between HAM/TSP and asymptomatic carrier for serum (P less than 0.05) or CSF (P less than 0.01). The correlation indexes between serum IL-6 and anti-HTLV-I antibody titers in serum and CSF were 0.61 (P less than 0.06) and 0.67 (P less than 0.05), respectively. Both the cell count and protein level in CSF correlated with CSF IL-6 activity at 0.68 (P less than 0.01) and 0.56 (P less than 0.05), respectively. The results demonstrate that IL-6 may contribute to the production of anti-HTLV-I antibody, and signs of slight inflammation are present in the central nervous system in HAM/TSP.

B Cell Growth and Differentiation Factors and Mechanism of B Cell Activation

B cells, one of the best understood eukariotic cells, originate from pluripotent hematopoietic stem cells and differentiate into immunoglobulin {Ig)-secreting cells through multistep developmental stages, such as pre-pre-B cells, pre-B cells, immature B cells, mature B cells, activated B cells and Ig-secreting cells. An understanding of the stimuli which cause the activation, proliferation and differentiation of B cells is critical to the delineation of the normal regulation of the immune responses as well as proliferation and differentiation of eukariotic cells. Since the discovery of T-B collaboration in the antibody response, extensive studies on the regulatory molecules involved in B cell activation have been done. More than a decade ago, Dutton and his colleagues (1971) suggested the involvement of soluble helper factors in the T cell-dependent activation of B cells into Ig-secreting cells. Since then, hundreds of factors, antigen specific or nonspecific, have been reported and those results have supported the notion that helper or suppressor function of T cells in B cell activation can be replaced by the soluble products released from T cells. Kishimoto and Ishizaka (1975) and Kishimoto and his colleagues (1975) have shown Ig-induction in rabbit B cells by anti-Ig and T cell-derived helper factors, suggesting that 2 signals, crosslinkage of Ig-receptors and helper factors, could induce activation of B cells into Igproducing cells. This finding was confirmed by several investigators in murine or human B cells (Parker etal. 1979, Isakson etal. 1981, Yoshizaki et al. 1982)and also supported the notion that helper function of T cells was mediated by T cellderived helper factors.

Induction of IgG production in human B lymphoblastoid cell lines with normal human T cells.

THYMUS-DERIVED (T) lymphocytes play a critical part in the induction of B lymphocytes to antibody production1, especially for conversion of IgM to IgG response2. In humans, the presence of T lymphocytes is also essential for the induction of IgM or IgG production by pokeweed mitogen (PWM) stimulated B lymphocytes3,4. In many experiments it has been shown that antigen-specific5 or nonspecific6–8 soluble factors from T cells, together with antigen or other inducers, for example, anti-immunoglobulin antibody, acting on B-cell surface receptors9, can also provide the stimulus for Ig production in B cells. However, the chemical nature of a B-cell acceptor for the T–effector molecule, the biochemical events responsible for the differentiation of B cells to Ig-producing cells, and the mechanism of the switch of transcription from μ chain to γ chain genes under the influence of T cells remain largely unknown. Heterogeneity of B-cell population in spleen, lymph node and blood has hindered the molecular analysis of immune phenomena. In this situation, B lymphoblastoid cell lines may be useful models for such analysis, since they may be arrested at certain phases of their differentiative history and if influenced by T cells or T-cell factors might permit incisive analysis of induction and switching of gene action at the molecular level. We report here the induction of IgG production or enhancement of IgM secretion in several human B lymphoblastoid cell lines with the help of normal T cells.

A new highly sensitive immunoassay for cytokines by dissociation-enhanced lanthanide fluoroimmunoassay (DELFIA).

Non-isotopic immunoassays for human tumor necrosis factor alpha (TNF alpha) and human interleukin-6 (IL-6) were established by employing the dissociation-enhanced lanthanide fluoroimmunoassay (DELFIA) system based on the time-resolved fluoroimmunoassay technique with europium-labeled antibody. Compared to enzyme-linked immunosorbent assays and bioassays, the sensitivity and range of measurement were significantly increased by applying the DELFIA systems to TNF alpha and IL-6. TNF alpha was measurable from 100 fg/ml to 10 ng/ml with the TNF alpha-DELFIA and IL-6 was measurable from 100 fg/ml to 1 ng/ml with the IL-6-DELFIA.

In Vitro Immune Response of Human Peripheral Lymphocytes

Con A‐stimulation of human peripheral T lymphocytes induced both suppressor and helper T cells. Con A‐generated suppressor T cells inhibited PWM‐indueed IgG and IgM production in PBL. Lower concentrations of Con A (0.5 μg/ml) or shorter incubation periods (6 to 24 hr) induced mainly helper T cells, while higher concentrations of Con A (10 μg/ml) or longer incubation periods (at least 48 hr) induced suppressor T cells. Con A‐generated suppressor T cells were sensitive to mitomycin treatment and exerted their suppressor function on the early phase of differentiation and/or proliferation of B cells but not on the final differentiation of B cells to Ig‐producing cells. The identity of the MHC was not required for the expression of suppressor function. Suppressor T cells competed with helper T cells in PWM‐induced Ig‐production of PBL. This experimental system can be applied to estimate the regulatory function of T cells in several disease states.

High Sensitivity to Peripheral Blood Lymphocytes and Low HLA‐class I Antigen Expression of Small Cell Lung Cancer Cell Lines with Diverse Chemo‐radiosensitivity

Three cell lines of small cell lung cancer (SCLC), which were established from specimens of untreated primary tumors biopsied by diagnostic bronchofiberscopy, were analyzed for immunological characteristics. These cell lines showed considerable heterogeneity in chemo‐radiosensitivity, which was well correlated with clinical responses of the respective tumors, but their HLA‐class I antigen expressions were equally depressed and they were susceptible to peripheral blood lymphocytes (PBL) and lymphokine‐activated killer (LAK) cells, irrespective of their diverse chemo‐radiosensitivity. Treatment of the cell lines with recombinant immune interferon (rIFN‐γ) increased their HLA‐class I antigen expression and conversely depressed PBL sensitivity but not LAK sensitivity. This inverse relationship between HLA‐class I expression and PBL susceptibility was also demonstrated using other pairs of autologous PBL and SCLC cell lines. rIFN‐γ changed neither HLA‐class H antigen nor SCLC‐spccilic antigen expression under the same experimental conditions. In vitro immunization of allogeneic peripheral blood lymphocytes with rIFN‐γ ‐treated SCLC cells induced allo‐specific killer cells which lysed rIFN‐7‐treated more strongly than non‐treated SCLC cells. These results suggest that reduced HLA‐class I antigen expression of SCLC could protect the cancer from attack of killer T cells in spite of the higher sensitivity to PBL or LAK cells.

A case report of a patient with rheumatoid arthritis complicated withMycobacterium aviumduring tocilizumab treatment

Abstract A female patient with rheumatoid arthritis (RA) suffered from Mycobacterium avium (M. avium) infection during tocilizumab treatment. Tocilizumab was discontinued and she was treated with a recommended chemotherapy, resulting in improvement of M. avium. Tocilizumab retreatment did not aggravate M. avium infection, and radiographic abnormalities improved over 1 year after cessation of the recommended therapy. Tocilizumab may be one candidate for intractable RA patients with M. avium if any biologic is required.

Psychological state is related to the remission of the Boolean-based definition of patient global assessment in patients with rheumatoid arthritis

Abstract Objectives. To evaluate whether the psychological state is related to the Boolean-based definition of patient global assessment (PGA) remission in patients with rheumatoid arthritis (RA). Methods. Patients with RA who met the criteria of swollen joint count (SJC) ≤ 1, tender joint count (TJC) ≤ 1 and C-reactive protein (CRP) ≤ 1 were divided into two groups, PGA remission group (PGA ≤ 1 cm) and non-remission group (PGA > 1 cm). Anxiety was evaluated utilizing the Hospital Anxiety and Depression Scale-Anxiety (HADS-A), while depression was evaluated with HADS-Depression (HADS-D) and the Center for Epidemiologic Studies Depression Scale (CES-D). Comparison analyses were done between the PGA remission and non-remission groups in HADS-A, HADS-D and CES-D. Results. Seventy-eight patients met the criteria for SJC ≤ 1, TJC ≤ 1 and CRP ≤ 1. There were no significant differences between the PGA remission group (n = 45) and the non-remission group (n = 33) in age, sex, disease duration and Steinbrockers class and stage. HADS-A, HADS-D and CES-D scores were significantly lower in the PGA remission group. Conclusions. Patients with RA who did not meet the PGA remission criteria despite good disease condition were in a poorer psychological state than those who satisfied the Boolean-based definition of clinical remission. Psychological support might be effective for improvement of PGA, resulting in the attainment of true remission.

Establishment of highly sensitive and wide-ranged immunoassay for TNF.ALPHA. by DELFIA.

Non-isotopic immunoassay for the human tumor necrosis factor α (TNFα) was established by employing the dissociated enhanced lanthanide fluoroimmunoassay (DELFIA) system, based on the timeresolved fluoroimmunoassay (TR-FIA) technique utilizing the europium-labeled antibody. In comparison with enzyme-linked immunosorbent assay and bioassay, the sensitivity and range of measurement could be significantly increased by applying the DELFIA system to TNFα.Biological samples, including serum, may affect some of the immunoassays. We overcome the serum influence to the measurement of TNFα by DELFIA, Percent recovery of additional TNFα in each diluted serum was determined, then the sliding standard curve of each serum sample was mathematically calculated from the recovery. Finally corrected TNFα amount was detected by using the sliding standard curve. We suggest that more accurate, sensitive and wide ranged TNFα immunoassay has been established by DELFIA with some revising calculation.