Cytokine production in human periodontal ligament cells stimulated with Porphyromonas gingivalis

BACKGROUND AND OBJECTIVE

Although some functions and characterizations of human periodontal ligament (hPDL) cells have been reported, the role of hPDL cells in periodontal disease is poorly understood. We have previously reported that hPDL cells produce many kinds of inflammatory cytokines by stimulation with Prevotella intermedia. In this study, we examined the production of cytokines in hPDL cells stimulated with Porphyromonas gingivalis as compared with P. intermedia.

MATERIAL AND METHODS

hPDL cells cultured in Dulbecco's modified Eagles's medium (DMEM) containing 10% fetal bovine serum (FBS) and antibiotics. After three to four passages, hPDL cells were stimulated with P. intermedia (ATCC25601) or P. gingivalis (ATCC33277) for 24 h. Total RNA was extracted by ISOGEN and the expression of cytokine mRNA was determined using reverse transcription-polymerase chain reaction. Cytokines in the culture supernatants were assessed by enzyme-linked immunosorbent assay.

RESULTS

The expression of interleukin-1beta, interleukin-6, interleukin-8, tumor necrosis factor-alpha (TNF-alpha), receptor activator of nuclear factor-kappaB ligand (RANKL) and osteoprotegerin (OPG) mRNA was detected in hPDL cells after stimulation with P. gingivalis as well as P. intermedia. There were no significant differences in the kind of cytokines expressed in hPDL cells between P. gingivalis and P. intermedia. However, P. gingivalis induced a significantly higher production of cytokines in hPDL cells than P. intermedia (p < 0.05).

CONCLUSION

This study demonstrated that hPDL cells produce many kinds of cytokines as a result of bacterial stimulation, including stimulation with P. gingivalis and P. intermedia. These results suggest that hPDL cells may play a role in cytokine production in periodontal disease.

Mechanical stress induces expression of cytokines in human periodontal ligament cells

OBJECTIVE

Periodontal tissue has a unique structure in that the human periodontal ligament (hPDL) lies between the hard tissues of cementum and alveolar bone. Although the role of cytokines in hPDL function is not clearly understood, we investigated the effect of mechanical stress as hydrostatic pressure (HP) on cytokine expression in hPDL cells.

MATERIALS AND METHODS

The hPDL cells were obtained from a healthy maxillary third molar. After the third to fourth passage, the cells were exposed to HP ranging from 1 to 6 MPa as previously described. Total RNA was extracted and the expression of cytokine mRNA was determined by RT-PCR.

RESULTS

The exposure to 6 MPa of HP caused no morphological changes of hPDL cells, and did not affect the cellular viability. No expression of IL-1beta, IL-6, IL-8, TNF-alpha, receptor activator of NF-lambdaB (RANK), receptor activator of NF-lambdaB ligand (RANKL), or osteoprotegerin mRNA was observed in the control cells under atmospheric pressure, whereas, in hPDL cells treated with HP, a pressure-dependent enhancement of IL-6, IL-8, RANKL, and OPG mRNA expression was observed between 10 and 60 min after the exposure to HP.

CONCLUSION

These results suggest that hPDL cells may play a role in the production of cytokines in response to mechanical stress in vivo.

A role for ferritin in hematopoiesis and the immune system

Elevated serum ferritin levels have been reported in a number of pathological states. These observations indicate that cells of the immune system can participate in the prevention of potential tissue toxicity from iron accumulation, and iron and iron-binding protein have important effects on immune systems. Ferritin is generally regarded as an intracellular iron storage protein. However, small amounts of ferritin circulate in the serum of normal individuals, and the physiological role of serum ferritin remains obscure. Although the function of ferritin is inevitably linked to iron metabolism, a role for ferritin in hematopoiesis and the immune system has drawn attention for years. Ferritin has an inhibitory effect on the in vitro growth of human hematopoietic progenitor cells and on the proliferation of T lymphocytes in vitro. Recently we report that ferritin may directly suppress the differentiation of human B lymphocytes maturing into antibody producing cells in vitro. In the present review, we summarise this field of research.

Distinct effect of G-CSF on the growth and differentiation of myeloid progenitor cells from chronic idiopathic neutropenia

Chronic idiopathic neutropenia (CIN) is a disorder characterized by severe neutropenia and a maturational arrest of the neutrophil precursors in the bone marrow. We examined the effect of recombinant human granulocyte-colony stimulating factor (rhG-CSF) on the growth and maturation of the myeloid progenitor cells from a patient with CIN. The patient's marrow cells showed poor colony forming activity, but a normal differentiating capacity to the stimulation with rhG-CSF, although they displayed a normal colony forming capacity in the presence of GM-CSF. Our observation indicates the distinct effect of rhG-CSF on the growth and maturation of the myeloid progenitors from a CIN patient.

Immunomodulatory effects of three macrolides, midecamycin acetate, josamycin, and clarithromycin, on human T-lymphocyte function in vitro

The effect of three macrolide antibiotics, midecamycin acetate, josamycin, and clarithromycin, on human T-cell function was investigated in vitro. Midecamycin acetate and josamycin suppressed the proliferative response of peripheral blood mononuclear cells stimulated by polyclonal T-cell mitogens at concentrations between 1.6 and 8 micrograms/ml. At higher concentrations (40 to 200 micrograms/ml), all these drugs showed a marked inhibitory effect. At concentrations of 1.6 to 40 micrograms/ml, these drugs suppressed interleukin-2 (IL-2) production induced by mitogen-stimulated T cells, but not the expression of IL-2 receptor (CD25), in a dose-dependent manner. Therefore, the suppressive action on T-lymphocyte proliferation seems to be based on the ability of these drugs to inhibit IL-2 production by T cells. The drug also inhibited mixed lymphocyte reaction at the same concentrations. Combined treatment with these macrolides and the known immunosuppressants such as FK506 and cyclosporin A resulted in an increased inhibition of T-cell proliferation. The immunomodulatory properties of the antibiotics may have clinical relevance for modulation of the immune response in transplant patients and in patients with inflammatory diseases.

Immunosuppressive activity of bromocriptine on human T lymphocyte function in vitro

Bromocriptine (BRC), a dopamine type 2 agonist, prevents secretion of pituitary prolactin (PRL). BRC has been shown to impair lymphocyte responsiveness toward antigenic stimulation by decreasing serum PRL levels. Hypoprolactinaemia induced by BRC produces a similar immunosuppressive effect, as observed in hypophysectomized rats, which is restored by the administration of PRL. Therefore, the immunosuppression induced by BRC has been interpreted as the result of hypoprolactinaemia. However, the direct mechanism of BRC in immune response has never been evoked. We recently reported that BRC has an immunosuppressive activity on human B lymphocyte function in vitro. In the present study we demonstrate that BRC suppresses T cell proliferation by means of blocking IL-2 production by T cells as well as mixed lymphocyte reaction (MLR) in a dose-dependent manner. We could not detect the immunoreactive PRL activity in the conditioned medium from polyclonal T cell mitogen-stimulated T cell cultures. Then, the immunosuppressive activity of BRC on human T cell function appeared to be independent of its hypoprolactinaemic effect. Treatment with low-dose cyclosporin A (CsA) or FK506 in combination with BRC has proved more effective than either drug alone in suppression of T cell proliferation and CD25 antigen expression. Thus, the therapeutic application of BRC in combination with immunosuppressants may enhance the immunosuppressive effect, while at the same time decreasing the toxicity.

H- and L-rich ferritins suppress antibody production, but not proliferation, of human B lymphocytes in vitro

The effect of human spleen(L-rich) and heart(H-rich) ferritins on the proliferation and differentiation of human B lymphocytes was studied in comparison with that of holo- and apo-transferrins. Ferritins rich in H and L chain, as well as the transferrins, did not inhibit the proliferative response of resting and activated B cells stimulated with polyclonal B-cell mitogen, Staphylococcus aureus Cowan strain I. In contrast, the ferritins, but not the transferrins, clearly suppressed the antibody production by B blasts in T-cell-independent as well as T-cell-dependent system. Kinetic study showed that inhibitory action of ferritins on immunoglobulin (Ig) production was caused at an early stage of B-cell differentiation. The cytoplasmic Ig-containing cells decreased in proportion to the reduction of Ig secretion. The evidence that ferritin inhibited Ig synthesis of Epstein-Barr virus-transformed human B-lymphoblastoid cell line also supported the idea that the effect of ferritin was directed toward the antibody-producing B lymphocytes. The molecular analysis showed that the inhibitory effect of ferritin was regulated at the transcriptional level of the Ig generation signal. Our results suggest that H- and L-rich ferritins exert their inhibitory action on the differentiation of B cells maturing into Ig-producing cells.

Immunosuppressive activity of fosfomycin on human T-lymphocyte function in vitro

Recent investigations have shown that some antibiotics also work as immunomodulators. We have recently reported that fosfomycin (FOM) has an immunomodulatory effect on human B-cell activation. FOM is a unique antibiotic which is chemically unrelated to any other known antibacterial agent. In the present study, we examined the effect of FOM on human T-cell function. FOM inhibited the proliferation of human lymphocytes induced by polyclonal T-cell mitogens in a dose-dependent manner. FOM also strongly suppressed mixed lymphocyte reaction and interleukin-2 (IL-2) production by T cells. Moreover, FOM inhibited the expressions of IL-2 receptor (CD25) and transferrin receptor (CD71) on the activated T-cell surfaces. These data suggest that FOM may block the T-cell division during the transition from G1 to S phase of the cell cycle. Combined treatment with FOM and low-dose cyclosporin A or FK506 caused additive or synergistic suppression of T-cell proliferation, but not on IL-2 receptor expression. It seems that the mode of action of FOM on T-cell function involves a specific suppression of IL-2 production.

[Biosynthesis and secretory regulation of pituitary prolactin]

We summarized recent advancements in biosynthesis and secretory regulation of pituitary prolactin at the cellular and molecular levels from some literatures. We singled out dopamine, estrogen and thyrotropin releasing hormone (TRH) from many factors controlling the biosynthesis and the regulation, because they are important, physiologically and pathologically. Dopamine exerts some effects on the membranes of the lactotrope inhibiting activities of cAMP, phosphatidylinositols and calcium ion channels. It inhibits prolactin gene transcription by suppressing action of the promoter region. Estrogen and TRH increase prolactin biosynthesis and the secretory regulation. Estrogen coupled with the receptors in the cytoplasma goes directly to the DNA region -1713-->-1495 being upstream to the starting site of prolactin transcription and differing from the region on which dopamine acts. TRH accelerates prolactin production and release in such steps as transcription, stabilization of mRNA, accumulation of mRNA in the cytoplasma, protein synthesis and exocytosis.

G-CSF enhances the immunoglobulin generation rather than the proliferation of human B lymphocytes

The effect of granulocyte-colony stimulating factor (G-CSF) on human B-cell function was studied in in vitro cultures. G-CSF alone had no effect on the proliferative response of resting B cells, but it slightly enhanced the proliferative response of these cells in the presence of polyclonal B-cell mitogen, Staphylococcus aureus Cowan strain I (SAC) at concentrations of 0.2 to 25 micrograms/ml (1.5-fold increase in the DNA synthesis). In contrast, immunoglobulin (Ig) secretion of activated B cells was increased approximately three-fold to four-fold by adding G-CSF to the cultures. The neutralization of G-CSF bioactivity with anti-G-CSF antibody abrogated this effect. Though cytoplasmic Ig-positive cells or plasma cell marker-positive cells did not change, the expression of IgM mRNA in antibody-producing B cells increased in the presence of G-CSF in the cultures. Interestingly, human B lymphocytes are shown to express the binding to biotin-conjugated G-CSF preparation, but not to biotin-conjugated GM-CSF preparation when examined by flow cytometry. These data suggest that G-CSF may influence B-cell function in special circumstances.

Impaired G-CSF production at post-transcriptional level in a patient with chronic idiopathic neutropenia

Chronic idiopathic neutropenia (CIN) is a disorder characterized by severe neutropenia and a maturational arrest of the neutrophil precursors in the bone marrow. The pathogenesis of this disorder has been obscure. We examined the production of endogenous G-CSF and the expression of G-CSFmRNA in a patient with adult type CIN. The G-CSF production by the patient's mononuclear cells was deficient in spite of the adequate accumulation of G-CSFmRNA. Our data suggests that the defect in the endogenous G-CSF production at the post-transcriptional level is likely to be an aetiological factor in CIN.

Immunosuppressive property of bromocriptine on human B lymphocyte function in vitro

Bromocriptine (BRC), a dopamine ergot alkaloid, inhibits the release of pituitary prolactin (PRL). Hypoprolactinaemia induced in rat by treatment with BRC produces a similar immunosuppressive effect as observed in hypophysectomized rats. The effect of immunosuppression by the administration of BRC has been interpreted as the result of hypoprolactinaemia produced by BRC. However, the direct effect of BRC on lymphocyte function has never been evaluated. The purpose of this study was to investigate the in vitro effect of BRC on human B cell functions. Highly purified B cells from tonsil samples were isolated by Percoll density gradient from non-rosetted cells, and were used as target cells. BRC significantly suppressed the proliferative response of resting and activated B cells in vitro. It suppressed immunoglobulin generation of activated B cells. The inhibition of BRC was manifested in the early stage of the proliferation and differentiation of B cells. The conditioned medium from the polyclonal B cell mitogen-stimulated B cell cultures did not contain PRL as detected by immunoradiometric assay. Treatment with low-dose cyclosporin A or FK506 in conjunction with BRC has proved more effective than either drug alone in suppression of B cell proliferation. Thus, the combined therapy of BRC and immunosuppressants may be effective with decreased toxicity for clinical use.

Induction of CD5 antigen on human CD5- B cells by stimulation with Staphylococcus aureus Cowan strain I

We have examined whether the CD5 phenotype could be induced on human B cell surfaces by the polyclonal B cell stimulator, Staphylococcus aureus Cowan strain I (SAC). Fresh tonsillar B cells were prepared by Percoll density gradient from E- cells. The proportion of CD5+ B cells in the 50/60% and 60/70% interface high-density fractions varied between 1.2 and 10.2% depending on the tonsil preparations when they were placed on the in vitro culture 12-60 h prior to flow cytometric analysis. The expression of CD5 antigen obviously increased in the presence of SAC (1:10(5) v/v). The percentage of CD5+ B cells varied from tonsil to tonsil, from 25.1 to 65.9% in a series of experiments. The CD5+ B cells were found both among CD23+CD25+CD71+ and CD23-CD25-CD71- B cells. The level of CD5 expression was related to the cell size enlargement. The addition of anti-CD5 antibody in the culture blocked the CD5 induction by SAC without interfering with the expression of other activation markers. A time-course study showed that CD5 antigen appeared to be induced on the cell surface during the G0 to G1 phase transition in the cell cycle. When CD5+ and CD5- B cells were separated by magnetic isolation, the CD5- B cells showed DNA synthesis to the stimulation by SAC and expressed CD5 antigen on their cell surface. These results suggest that human CD5- B cells can express the CD5 phenotype by stimulation with the polyclonal B cell stimulator, SAC.

Recombinant human IL-5 augments immunoglobulin generation by human B lymphocytes in the presence of IL-2

The biological activity of interleukin-5 (IL-5) on human B lymphocytes was examined by using a newly purified recombinant human IL-5 preparation. Different densities of B cells from human tonsil samples were isolated by Percoll density gradient from nonrosetted cells. The IL-5 preparation did not act as a B cell growth factor on the large (in vivo-activated) or small (resting) B cells after activation with polyclonal B cell activators. The IL-5 augmented the immunoglobulin (Ig) generation of Staphylococcus aureus Cowan strain I (SAC)-activated B blasts in the presence of interleukin-2 (IL-2). The effect of IL-5 on Ig generation was greater in pokeweed mitogen (PWM)-driven B blasts than that in SAC-induced B blasts when assessed by enzyme-linked immunosorbent assay. The amounts of mu RNA isolated from IL-5/PWM-treated cells were also larger than those from IL-5/IL-2-treated B blasts. These results suggest that the human IL-5 can increase Ig generation of B cells in the presence of IL-2 by working at the level of mRNA coding for Ig.

Immunomodulatory effect of fosfomycin on human B-lymphocyte function

Fosfomycin (FOM) is an unique antibiotic which is chemically unrelated to any other known antimicrobial agent. Recent investigations have demonstrated that FOM inhibits histamine release from basophils. In this study, we examined the effect of FOM on human B-cell functions. FOM inhibited the proliferative response of resting B cells induced by Staphylococcus aureus Cowan 1 in a dose-dependent manner. FOM interfered with the transition from the G0 to the G1 phase of the cell cycle, leading to cell arrest. The proliferative response of in vivo-activated B cells and lymphokine-induced B-cell proliferation were also affected by FOM. In addition, FOM suppressed immunoglobulin secretion by antibody-producing B cells. Interestingly, FOM did not affect the expression of activation antigens such as the CD25 (interleukin-2 receptor) and CD71 (transferrin receptor) antigens. Moreover, FOM sustained the increased Ia expression on B-cell membranes induced by S. aureus Cowan 1 stimulation, which suggests that FOM may not block the role of B cells in antigen presentation in T-cell-B-cell interaction.

Bromocriptine effects on plasma luteinizing hormone and its responses to gonadotropin-releasing hormone in normal men

Secretory changes in plasma pituitary luteinizing hormone (LH) after administration of a dopaminergic drug were studied in five normal men. Each subject received orally 5 mg of bromocriptine (Brc) daily for 8 weeks. Each received gonadotropin-releasing hormone (GnRH) stimulation tests at the beginning (control), and at 2, 4, 6, and 8 weeks after initiation of Brc treatment. We referred the basal plasma LH and a ratio of maximally GnRH-responded plasma LH to its basal level (R-Max) as indicators of secretory alterations of the LH. Mean basal levels of plasma LH in the five subjects at the beginning and those of R-Max were 3.4 +/- 2.3 (SD) mIU/mL and 8.5 +/- 2.9 units, respectively. Statistically, both the mean values of plasma LH and R-Max during the control period did not differ significantly from those obtained after Brc treatment, although mean basal levels of plasma prolactin during the control period (15.6 +/- 4.6 ng/mL) decreased significantly (p < 0.05) after initiation of treatment. A low dose of Brc administered to normal men for 8 weeks does not significantly influence pituitary secretion of LH.

The distinct effects of FK506 on the activation, proliferation, and differentiation of human B lymphocytes

We examined the effect of FK506 on the activation, proliferation and differentiation of human B lymphocytes in vitro. FK506 inhibited the proliferative response of resting B cells induced by Staphylococcus aureus Cowan strain I (SAC) and phorbol myristate acetate (PMA) in a dose-dependent manner. Inhibition of cell proliferation by FK506 was caused by a selective block of G0 to G1 phase transition leading to cell arrest. In addition, the proliferative response of in vivo-activated B cells and lymphokine-driven B cell proliferation were also found to be sensitive to FK506. Interestingly, FK506 did not affect the expression of activation antigens such as CD23, IL-2 receptor (CD25), and transferrin receptor (CD71). Finally, FK506 had little effect on B cell antibody generation in a T cell-independent system. Conversely, FK506 suppressed neither proliferation nor immunoglobulin secretion in a human B lymphoblastoid cell line. These results indicate that FK506 has discrete effects on the different stages of the B cell maturation.

The suppressive effect of deoxyspergualin on the differentiation of human B lymphocytes maturing into immunoglobulin-producing cells

Deoxyspergualin, an analog of spergualin, has been known as a novel immunosuppressive agent with strong immunosuppressive activity in in vivo experimental systems. In the present study, we examined the effect of deoxyspergualin (DSG) and methyldeoxyspergualin (MeDSG) on the proliferation and differentiation of human B lymphocytes in vitro. Highly purified B cells from human tonsil samples were isolated by Percoll density gradient from nonrosetted cells and were used as target cells. Both agents had little effect on the proliferative response of resting or activated B lymphocytes. However, they suppressed the immunoglobulin synthesis of B lymphocytes not only in a T cell-dependent, but also in a T cell-independent system. The inhibition of antibody synthesis was manifested in the early stage of B cell differentiation. Both drugs also suppressed Ig secretion, but not proliferation, of an EBV-transformed human B lymphoblastoid cell line. These results indicate that DSG and MeDSG have a selective immunosuppressive effect on the differentiation pathway of B lymphocytes.

Inhibition of proliferation and differentiation of human B-lymphocytes by a biscoclaurine alkaloid

A biscoclaurine alkaloid, cepharanthine, is known to be a potent inhibitor of snake venom-induced hemolysis by interaction with the lipid bilayer of the membrane. The drug also interferes with the ion channel intracellularly. In this study, we examined the effect of cepharanthine on human B-cell functions. Small dense B-cells from tonsil samples were isolated using a Percoll density gradient from non-rosetted cells and were used as the target cells. Cepharanthine inhibited the proliferation of the lymphocytes and antibody production of human B-lymphocytes. The inhibitory effect of cepharanthine on the proliferation was caused by the arrest of the late G1 to S phase transition in the cell cycle. However, the mechanism of suppression of antibody formation remains unknown. These results suggest that cepharanthine acts on human B-cells as an immunomodulating agent.

The role of CD45 in the activation, proliferation and differentiation of human B lymphocytes

We examined the role of CD45 antigen in human B cell function, using the anti-CD45 antibody, T29/33. The addition of T29/33 to B cells inhibited the proliferative response induced by various polyclonal B cell activators in a dose-dependent manner at concentrations of 0.01 to 10 micrograms/ml. Kinetic analysis indicated that T29/33 exerted its inhibitory effect when added within the first 24 h of culture initiation during a 72-h culture period, but had little effect when added at 48 h. Pre-treatment of high-density B cells with T29/33 antibody for 48 h showed a marked inhibitory effect on the proliferative response of these B cells when they were subsequently stimulated with SAC. Antibody to CD45 appeared to block the G0(G1) to S phase transition in the cell cycle analysis by propidium iodide staining. T29/33 antibody suppressed the RNA and DNA synthesis induced by SAC stimulation in B cells. These data suggested that small resting B cells were sensitive to anti-CD45-induced suppression. T29/33 antibody also suppressed immunoglobulin synthesis in B cells, independently of its suppressive effect on proliferation. These results indicated that CD45 antigen defined by T29/33 is involved in the activation, proliferation, and differentiation signals of human B lymphocytes.

Regulation of lymphocyte blastogenesis and antibody production by soluble factor released by a human B-lymphoblastoid cell line

Yam 1B, a human B lymphoblastoid cell line, spontaneously produced an immunoregulatory factor, which suppresses blastogenesis and antibody formation by human lymphocytes. The Yam 1B cells, which were derived from the peripheral blood of an adult T-cell leukemia patient, have been established and maintained in our laboratory since 1985. This cell line expressed mature B-cell surface antigens including surface immunoglobulin M (IgM), CD23, and HLA-DR; had cytoplasmic IgM; and secreted small amounts of IgM in the culture supernatants. Yam 1B was positive for Epstein-Barr virus-associated antigen (EBNA) but negative for adult T-cell-associated antigen (ATLA). The serum-free Yam 1B culture supernatants (SN) inhibited the expression of transferrin R, but neither the expression of interleukin 2 (IL-2) R(CD25) nor the production of IL-2 in the lymphocytes stimulated with phytohemagglutin. Yam 1B SN also inhibited DNA synthesis by human T and B lymphocytes and immunoglobulin generation by normal B cells as well as by Epstein-Barr virus-transformed human B lymphoblastoid cell lines. The inhibitory activity of Yam 1B SN was inactivated at 56 degrees C and at pH 10 but was relatively stable at pH 2. It was abrogated by digestion with pronase and was partially stable by digestion with trypsin. Fractions collected from a Sephacryl S-300 gel filtration column (Pharmacia Fine Chemicals, Uppsala, Sweden) were found to have a peak of inhibitory activity of cell proliferation associated with molecules of apparent MWr of 43,000 to 67,000. The inhibitory activity of Yam 1B SN was not blocked by the anti-transforming growth factor beta antibody.(ABSTRACT TRUNCATED AT 250 WORDS)

The role of CD45RA on human B-cell function: anti-CD45RA antibody (anti-2H4) inhibits the activation of resting B cells and antibody production of activated B cells independently in humans

Anti-CD45RA antibody defined by anti-2H4 monoclonal antibody has been reported to split CD4+T cells into two distinct subpopulations. CD45RA antigen is present on the surface of virtually more than 95% B lymphocytes in the purified tonsillar B-cell preparations. We examined the role of CD45RA antigen on human B-cell function using this antibody. The addition to anti-2H4 to tonsillar B cells inhibited the proliferative response induced by Staphylococcus aureus Cowan strain I(SAC) in a dose-dependent manner. Kinetic analysis indicated that anti-2H4 exerted its inhibitory effect when added within the first 24 h of culture initiation during a 72-h culture period. Anti-2H4 inhibited the transferrin receptor expression without interfering with the expression of the IL-2 receptor on SAC-stimulated B cells in a short-term culture. Anti-2H4 blocked the progress of SAC-stimulated B cells from the G1 to S phase of the cell cycle. These events suggested that anti-CD45RA MoAb inhibited the proliferative response by directly acting on B cells in the G1 phase. In addition, anti-CD45RA antibody also had a suppressive effect on early phase of B-cell differentiation. This effect appeared to be independent of its suppressive effect on proliferation, because anti-CD45RA did not inhibit the proliferative response of preactivated B cells with lymphokines. These studies suggested that the restricted epitope recognized by anti-2H4 antibody may be directly involved in regulatory function on B cells.

Effects of chronic bromocriptine-induced hypoprolactinemia on plasma testosterone responses to human chorionic gonadotropin stimulation in normal men

To study the role played by normal levels of plasma prolactin (PRL) in the secretion of testosterone (T) in the testes, we induced hypoprolactinemia with a daily dose of 5 mg bromocriptine administered orally in five normal men 20 to 35 years of age for 8 weeks. The basal PRL, T, luteinizing hormone, follicle-stimulating hormone, and maximum responses of plasma T to human chorionic gonadotropin (hCG) stimulation were measured every 2 weeks. Basal levels of plasma T were reduced in the 1st 2-week-long period of hypoprolactinemia. In the 4-week-long period of hypoprolactinemia, the maximal response of plasma T to hCG stimulation was significantly reduced. The findings suggest that normal levels of plasma PRL may play an important role in the secretion of T in the human testes in vivo.

Establishment of a novel cell line with T-lineage phenotype (HPB-MLp-W) from a non-Hodgkin's lymphoma patient

We report the characterization of a novel human T-cell line, HPB-MLp-W, which was established from blastic cells of a lymph node specimen from a patient with non-Hodgkin's lymphoma. They demonstrated the T-cell association antigens, CD2 and CD4, but no CD3, CD8, CD1, CD5, CD7 nor T-cell antigen receptor on their cell surfaces. They were also positive for Ia and Ki-1 antigen, and negative for CD25 (Tac-1). The cell line HPB-MLp-W had the same pattern of antigen expression as the patient's cells. Southern-blot analysis of DNA showed a rearrangement of the T-cell receptor-alpha and beta genes. To our knowledge, this is a novel cell line with unique T-lineage marker, to be established from a case of non-Hodgkin's lymphoma.

Functional analysis of clonally expanded CD8, TCR gamma delta T cells in a patient with chronic T-gamma lymphoproliferative disease

Leukemic cells from a patient with T-gamma lymphocytosis were found to have the surface phenotype, CD3+, CD4-, CD8+, Leu19+, TCR delta 1+, WT31-. The clonal nature of the TCR gamma delta T cell proliferation was documented by flow cytometry and Southern blot analysis. Morphologically, they were large to medium-sized mature lymphocytes with cytoplasmic granules. Functionally, the cells revealed strong cytotoxic activities against NK-sensitive target cells, but had neither killer T cell activity nor suppressive activity on PWM-driven immunoglobulin synthesis by B cells. Interestingly, both suppressive and cytotoxic T cell activities were recovered with the depletion of CD8+ T cells. These studies may suggest some functions of the CD8+ population of human TCR gamma delta T cells in a normal immune system.

High cytotoxic cell activity in the marrow from patients with aplastic anemia

The mechanism which produces marrow failure in idiopathic aplastic anemia is still unknown. Recent investigations have suggested the crucial role of NK cells in the regulation of normal hematopoiesis. In this study, the cytotoxic activity of mononuclear cells from human bone marrow and peripheral blood was examined against three NK-sensitive target cell lines in 15 patients with aplastic anemia as well as 21 normal subjects. Marrow mononuclear cells from aplastic anemia demonstrated a high cytotoxicity comparable to peripheral blood NK cells to these target cells. Neither large granular lymphocytes nor the cells expressing known NK cell surface phenotypes increased in aplastic marrow cell elements. The aplastic marrow cells showed strong killing activity rather than binding at single cell assay. They consisted of non-adherent and adherent cell population in plastic adherence and were unresponsive to IFN treatment. The existence of cytotoxic cells with high NK-like activity may be responsible for the mechanism of marrow failure in aplastic anemia.

Natural killer (NK) cell activity in patients with various malignancy against a variety of target cell lines: re-evaluation of clinical significance of natural killer cell activity

Sixty-eight patients with various malignancy was examined for their natural killer (NK) cell activity against 14 target cell lines. The group consisted of 10 patients with gastric cancer, 10 patients with lung cancer, 8 patients with hepatoma, 11 patients with cancer of female genital organs, 14 patients with malignant lymphoma and 15 patients with acute myelogenous leukemia (AML). The target cells from a variety of lineage were selected to examine the disease-related specificity in NK cell activity. The peripheral mononuclear cells from patients with gastric cancer did not show a decrease in NK activity against 14 targets including gastric cancer cell lines. Other patients except for AML demonstrated low NK activity against one or two target cells out of 14 targets. Whereas, NK activity in patients with AML was remarkably depressed against 10 target cells out of 14. At single cell assay, killing ability rather than binding activity to target was markedly impaired in AML. Comprehensively, the data demonstrated the marked difference in the NK level between the patients with solid tumor and the patients with hematopoietic malignancy. There existed neither disease-related specificity in NK cytolysis, nor correlation in NK levels and clinical severity in the patients with malignancy. These results suggested that it was very difficult to evaluate the anti-cancer capacity in patients with malignancy by NK activity alone.

Depressed natural killer (NK) function in blood and marrow is related to the decrease in CD 11+ cells in acute leukemia

The natural killer (NK) cell activity of the blood and marrow was studied in patients with acute myelogenous leukemia (AML). NK activity of the cells from blood and marrow was significantly decreased in AML to three target cell lines. Both binding and killing capacities of the effector cells were deeply depressed in the blood as well as in the marrow at single cell assay. Surface phenotypic analysis showed a significant decrease in CD 11+ cell subsets, but not in CD 16+ or Leu-7+ cells, in both blood and marrow cells from AML. A significant decrease of large granular lymphocytes (LGL) was also displayed in these samples at morphological examination. The effector cells from AML patients poorly responded to interferon stimulation in NK cytolysis. Taken together, a decrease in CD 11+ cell population with LGL morphology appeared to be responsible for the impaired NK activity in patients with AML.

Enhanced natural killer cell activity in patients with pulmonary tuberculosis

The natural killer (NK) cell activity of patients with pulmonary tuberculosis (TB) was studied using blood samples. The patients with pulmonary TB showed higher NK activity to 10 out of 12 NK-sensitive target cell lines than healthy subjects did. When NK activity was compared between active and inactive stages of the disease, the patients with active TB demonstrated higher NK activity than did patients with inactive TB. Furthermore, active patient displayed cytolysis to one out of 4 NK-resistant target cell lines. In study of NK cell cyotoxicity at single cell level, higher killing activity than binding activity to target cells was observed in patients at an active stage. Morphological and surface marker analysis of peripheral mononuclear cells showed an increase in CD16+ cells in patients with pulmonary TB. These results suggested that NK cell activity is augmented qualitatively and quantitatively in patients with pulmonary TB.

Bestatin, an inhibitor of aminopeptidase B, suppresses the proliferation and differentiation of human B-cells in vitro

Bestatin, an inhibitor of aminopeptidase B, was examined for its effect on B-cell activation. Small, dense B-cells from human tonsil samples were isolated by Percoll density gradients from non-rosetted (E-) cells and were used as target cells. Although bestatin was not cytotoxic towards B-cells, it inhibited the proliferative response of B-cells induced by SAC- or PMA-stimulation. The inhibition of cell proliferation by bestatin was manifested as cell arrest caused by the selective block of G1b to S phase transition. This inhibitory effect was prevented by the addition of B-cell growth factor (BCGF) or interleukin-2 (IL-2). The presence of BCGF or IL-2 at the initiation of the culture prevented the bestatin-mediated suppressive effect on B-cell proliferation. Bestatin also has a direct inhibitory effect on the differentiation of B-cells independent of its suppressive effect on B-cell proliferation, which was not relieved by T-cell help. Conversely, bestatin suppressed neither proliferation nor Ig secretion of human B lymphoblastoid cell lines, although aminopeptidase activities on the membrane of these cell lines were strongly inhibited by bestatin. These results indicated that bestatin selectively suppressed normal B-cell proliferation and differentiation. Although several studies have demonstrated that bestatin has immunopotentiating effects in tumor-bearing subjects, the above results indicated that the mechanism of immunopotentiation by bestatin is not a direct stimulatory effect on B-cells.

Effects of chronic sulpiride-induced hyperprolactinemia on menstrual cycles of normal women

We investigated the influence of chronic (27-65 days) sulpiride-induced hyperprolactinemia on the menstrual cycles of four normal women. The hyperprolactinemia (206.4 ng/mL, the average of the mean values of each subject obtained by sulpiride treatment) suppressed the LH surge and the secretion of plasma estradiol-17 beta and progesterone to their basal levels. The results suggest that the endocrine changes in normal women with sulpiride-induced hyperprolactinemia are similar to those in women with spontaneous hyperprolactinemia. Sulpiride-induced hyperprolactinemia may be useful as a model for studying spontaneous hyperprolactinemia.

Effects of chronic sulpiride-induced hyperprolactinemia on plasma testosterone and its responses to hCG in normal men

To elucidate the effects of sulpiride-induced (300 mg daily) long-term (64 days) hyperprolactinemia on basal and hCG-stimulated plasma testosterone (T), hCG was given to five normal men five times at 2-week intervals (before sulpiride administration and at 2, 4, 6 and 8 weeks). Mean integrated hCG responses of plasma T did not change significantly as compared with baseline. However, mean (+/- SEM) basal plasma levels of T decreased significantly (P less than 0.05) from 1011 +/- 148 ng/dl to 852 +/- 13 at 2 weeks, 520 +/- 53 at 4 weeks, 572 +/- 137 at 6 weeks and 554 +/- 140 at 8 weeks. These results suggest that sulpiride-induced hyperprolactinemia (73.8 ng/ml, the average of mean values obtained at 2, 4, 6 and 8 weeks) for 64 days does not suppress secretion of T in response to hCG in spite of a decrease in basal plasma T concentrations. It is unlikely that the low concentrations of plasma T are due to direct effects of hyperprolactinemia on the testis.

Parathyroid hormone-induced lipolysis in human adipose tissue

Relative lipolytic activity of human parathyroid hormone-(1-34) (hPTH-(1-34], hPTH-(3-34), desamino-Ser1-hPTH-(1-34), and rat PTH-(1-34) was compared in human subcutaneous adipose tissues in vitro. Human PTH-(1-34), rat PTH-(1-34), and desamino-Ser1-hPTH-(1-34) stimulated in vitro lipolysis significantly above basal level at the concentration of 10(-6) M. Average increments of lipolytic rate were 2.39, 1.82, and 0.87 mumol/g per 2 hr, respectively, being significantly different among the three groups. On the other hand, hPTH-(3-34)-induced lipolytic rate was 0.83 +/- 0.18 mumol/g per 2 hr, not significantly different from the basal level (0.71 +/- 0.20 mumol/g per 2 hr). The effect of hPTH-(3-34) on glycerol release stimulated by hPTH-(1-34), isoproterenol, or forskolin was subsequently investigated. Human PTH-(3-34) produced a dose-dependent inhibition of hPTH-(1-34)-stimulated lipolysis. In contrast, isoproterenol- and forskolin-induced lipolytic rates were not influenced by hPTH-(3-34). The effect of propranolol on hPTH-(1-34)- or isoproterenol-induced lipolysis was also studied. Propranolol dose-dependently inhibited isoproterenol-induced lipolysis but had no effect on lipolysis stimulated by hPTH-(1-34). These results suggest that the amino acids at positions 1 (serine) and 2 (valine) of PTH are critical for the stimulation of lipolysis in human adipose tissue. Human PTH-(1-34) causes lipolysis after binding to receptors distinct from beta-adrenergic receptors of fat cells and possibly hPTH-(3-34) inhibits hPTH-(1-34)-stimulated lipolysis by competing at the level of PTH receptor.

No substrate specificity of converting enzyme for N-terminal substituted angiotensin I in man

In 5 normal men sarcosine1-angiotensin II (Sar1-ANG II) (Exp. 1) and sarcosine1-angiotensin I (Sar1-ANG I) (Exp. 2) infused iv at a rate of 5 pmol/kg X min from 0900 h to 0930 h caused the same degree of rise in blood pressure (BP). But 100 mg of captopril given orally at 0800 h (Exp. 3) completely abolished the BP rise by Sar1-ANG I. In Exps. 1 and 2 plasma renin activity (PRA) decreased and plasma aldosterone (PA) increased after the infusions. In Exp. 3 PRA increased markedly and PA decreased 60 min after captopril, and at 30 min of Sar1-ANG I infusion PRA decreased to the pre-captopril level despite no BP change but PA was kept at the pre-infusion level. Hence, substrate specificity of converting enzyme previously demonstrated for N-terminal deleted ANG I was not shown for N-terminal substituted ANG I in man because the conversion of Sar1-ANG I to Sar1-ANG II was 100%. Sar1-ANG I may possibly inhibit renin release in normal men.

Biological activities of sarcosine1-angiotensin I in man

In order to examine whether substrate specificity of angiotensin-converting enzyme (ACE) exists or not for N-terminal substituted angiotensin I (ANG I) in man, biological activities of sarcosine1-angiotensin I (Sar1-ANG I) and the effects of an ACE inhibitor, captopril, on the Sar1-ANG I activities were studied in 5 normal men. The following 3 experiments were done at 1 week intervals. Sarcosine1-angiotensin II (Sar1-ANG II) was infused iv at a rate of 5 pmol/kg X min from 0900 h to 0930 h in 5 normal men in a recumbent position. Blood pressure rose remarkably and the average increment was 38/31 mmHg at 30 min (p less than 0.001). Average duration of the pressor action after the cessation of the infusion (T) was 40 min for systolic and 50 min for diastolic and much longer than T of isoleucine5-angiotensin II. Plasma renin activity (PRA) decreased (p less than 0.01) and plasma aldosterone (PA) increased significantly (p less than 0.01). Sar1-ANG I was infused iv at a rate of 5 pmol/kg X min from 0900 h to 0930 h. Blood pressure rose to the same extent as in (1) (p less than 0.001). T was 40 min for both systolic and diastolic and much longer than T of ANG I in man. PRA decreased (p less than 0.01) and PA increased (p less than 0.01) significantly. Oral 100 mg captopril was given at 08:00 h and Sar1-ANG I was infused iv at a rate of 5 pmol/kg X min from 09:00 h to 09:30 h.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of chronic hyperprolactinemia induced by sulpiride on plasma dehydroepiandrosterone (DHA) in normal men

In order to elucidate the relationship between plasma dehydroepiandrosterone (DHA) and sulpiride-induced hyperprolactinemia (of 60 day duration) in normal men, five normal men (aged 27-46) were administered daily 300 mg of sulpiride orally for 60 days to induce hyperprolactinemia. Plasma levels of prolactin, DHA and cortisol were measured by radioimmunoassay before sulpiride treatment, at day 14 and day 60 after initiation of the treatment. Plasma levels of prolactin after the administration rose significantly (P less than 0.001) to 71.6-95.3 ng/ml in four out of the five subjects compared with those of the controls. In the same four subjects the mean DHA values in plasma were elevated significantly (P less than 0.05) to 877 +/- 160 ng/dl from the mean baseline values (669 +/- 91 ng/dl). The elevated values remained during sulpiride treatment. Plasma levels of cortisol did not change significantly during sulpiride administration in all subjects. Our results suggest that sulpiride-induced hyperprolactinemia sustained at least 14-60 days in normal men stimulates the adrenal cortex to secrete DHA.

Neutral glyceride synthesis from glucose in human adipose tissue: comparison between growing and mature subjects

Basal and insulin-stimulated neutral glyceride syntheses from glucose were studied in fat cells of different size (fat cell volume, 0.07-0.20, 0.20-0.60, 0.60-1.00, 1.00-1.50 micron3 X 10(6)) obtained from subcutaneous adipose tissues in 20 subjects aged 3 months to 67 years. In 0.07-0.20 or 0.20-0.60 micron3 X 10(6) fat cells, the basal rate of glucose conversion to neutral glyceride was significantly lower in mature (36 to 67 years old) than in growing (0 to 12 years old) subjects. In 0.60-1.00 or 1.00-1.50 micron3 X 10(6) fat cells, however, basal rate was not significantly different between the two groups. The stimulating effect of insulin on conversion of glucose to neutral glyceride was not significantly different from the basal rate in fat cells of each size taken from the mature subjects, whereas in fat cells from growing subjects, it was significantly different from the basal rate in each fat cell size category. These results indicate that when fat cell size is taken into account, not only is the rate of basal glucose conversion to neutral glyceride higher in growing subjects but also its responsiveness to exogenous insulin, and that insulin insensitivity of large fat cells, reported previously, may be influenced by age.

Biological activities of angiotensin II-(1-6)-hexapeptide and angiotensin II-(1-7)-heptapeptide in man

Biological activities of angiotensin II-(1-6)-hexapeptide [ANG-(1-6)] and angiotensin II-(1-7)-heptapeptide [ANG-(1-7)] were studied in 5 normal men and 3 patients with Bartter's syndrome. The angiotensins were infused iv in each subject from 0900 h to 0915 h at a rate of 21 nmol(16.8 micrograms)/kg X min and 18 nmol(16.2 micrograms)/kg X min for ANG-(1-6) and ANG-(1-7), respectively. In the normal men a significant rise in blood pressure was observed by the infusions of both peptides. Average increments of blood pressure for ANG-(1-6) were 17/14, 23/18, 22/15 and 17/14 mmHg at 2, 5, 10 and 15 min, respectively, and those for ANG-(1-7) were 19/15, 20/17, 13/13 and 15/13 mmHg at 2, 5, 10 and 15 min, respectively. The duration of pressor actions after the cessation of the infusions (T) was 10 min for ANG-(1-6) and 20 (for systolic) and 30 (for diastolic) min for ANG-(1-7). T for ANG-(1-6) was shorter than and T for ANG-(1-7) was similar to T for Ile5-angiotensin II (Ile5-ANG II) reported previously in 7 normal men 5 of whom were the same as examined in the present study. On the other hand, both peptides did not cause a rise in blood pressure in the 3 patients with Bartter's syndrome. Both angiotensins did not cause an increase in plasma aldosterone but did cause a significant decrease in plasma renin activity both in the normal men and in the patients. From these results and our previous observations of inactivity of angiotensin II-(5-8)-tetrapeptide, a pressor action of angiotensin II-(4-8)-pentapeptide, and pressor, renin-suppressing and steroidogenic actions of angiotensin II-(3-8)-hexapeptide in normal men, it is thought that ANG-(1-6) and ANG-(1-7) are bound to angiotensin II (ANG II) receptor in the peripheral arterioles and show pressor actions (less than 0.024% and less than 0.028% of Ile5-ANG II, respectively) and suppress renin mainly via short loop feedback and that the shortest biologically active ANG II molecules for pressor, renin-suppressing and steroidogenic actions are Tyr-Ile-His, Val-Tyr-Ile-His and Val-Tyr-Ile-His-Pro-Phe, respectively, in man. It is also evident that ANG-(1-6) is more rapidly metabolized than ANG-(1-7) or Ile5-ANG II in man.

Natural killer cell activity against a variety of target cell lines in normal persons: NK-target sensitivity and effect of age and sex on NK levels

Natural killer (NK) cells have been implicated as first line of defence mechanism for carcinogenesis in humans. A lot of studies of depressed NK activity in patients with malignancies have supported this. Two major problems, however, in these studies are the choice of normal controls and target cells. To study this problem, peripheral mononuclear cells (PBMC) of sixty-six normal subjects from young and elderly, males and females were tested for NK function against twenty target cell lines with a microcytotoxicity assay. The result was shown that no sex or age difference existed with respect to NK function, except for a slight but significant decreased in NK activity of young female to K562 target cells. Target cells were divided into four groups by their NK sensitivity, namely, high, moderate, low and refractory sensitive. In general, NK activity of healthy persons is considered to remain stable and polyspecific in our results.

A case of adiposis dolorosa: lipid metabolism and hormone secretion

The present report describes a 53-year-old non-obese man with adiposis dolorosa whose pain was dramatically relieved by the intravenous injection of lidocaine. The patient showed a paradoxical response of growth hormone to thyrotropin-releasing hormone. In addition, in-vitro studies on adipose tissue metabolism revealed the reduced glucose conversion to neutral glycerides in painful adipose tissue. These abnormalities may be related in some ways to the pathogenesis of this disorder.

Pressor activity of angiotensin II-(2-7)-hexapeptide in man

Pressor activity and speed of metabolic degradation of angiotensin II-(2-7)-hexapeptide [ANG-(2-7)] were studied in 5 normal men. When infused iv at a rate of 72 nmol/kg X min for 7 min, ANG-(2-7) caused a very slight but statistically significant increase in blood pressure. Average blood pressure increases at 2, 5 and 7 min were 5/4, 8/10 and 8/9 mmHg, respectively, and the duration of the pressor action after the cessation of the infusion (T) was 5 min on the average. The pressor activity and T of this peptide were much less than or shorter than those of angiotensin II-(1-7)-heptapeptide [ANG-(1-7)] infused previously in the same 5 normal men at a rate of 18 nmol/kg X min, indicating that the pressor activity ratio of both the peptides in man is 1: greater than 7.2 which is similar to that of angiotensin II-(2-8)-heptapeptide (angiotensin III) and Ile5-angiotensin II (Ile5-ANG II) (1: greater than 5) and that the removal of N-terminal aspartic acid from ANG-(1-7) hastens the speed of metabolic degradation of the peptide as from Ile5-ANG II.

Agonistic activities of isoleucine8-angiotensin II in man

In order to clarify the importance of C-terminal phenylalanine in angiotensin II (ANG II) molecule, agonistic activities of a C-terminal substituted peptide, isoleucine8-angiotensin II (Ile8-ANG II), were studied in comparison with those of sarcosine1-, isoleucine8-angiotensin II (Sar1-, Ile8-ANG II) and isoleucine5-angiotensin II (Ile5-ANG II) in 5 normal men. When infused iv at a rate of 600 pmol/kg X min for 30 min, Ile8-ANG II and Sar1-, Ile8-ANG II raised the blood pressure to the same extent (15/15 mmHg on the average), while the average blood pressure increase was 21/21 mmHg after an iv infusion of Ile5-ANG II at a rate of 5 pmol/kg X min for 30 min. Duration of the pressor action after the cessation of each infusion was 50-90, 90-120 and 10-25 min, respectively. In each case plasma renin activity (PRA) decreased and plasma aldosterone (PA) increased. When infused iv at a rate of 10 pmol/kg X min (maximum non-pressor dose) for 120 min, both Ile8-ANG II and Sar1-, Ile8-ANG II lowered PRA and increased PA gradually, but 100 mg oral captopril given immediately before these infusions caused no significant increase in PRA or no significant decrease in PA but again a decrease in PRA and an increase in PA.(ABSTRACT TRUNCATED AT 250 WORDS)