IL6 and the T-cell response

Mixing ratio optimization for functional complex extracts of Rhodiola crenulata, Panax quinquefolius, and Astragalus membranaceus using mixture design and verification of immune functional efficacy in animal models

We aimed to identify the optimum mixing ratio for various ingredients to obtain complex extracts with high extract yields and immune-enhancing activity in animals. The extract yield and amounts of nitric oxide (NO) and interleukin (IL)-6 were set to maximum for modeling predictions. The predicted optimum values for the mixing ratio were 49.5% for Rhodiola crenulata, 26.1% for Astragalus membranaceus, and 24.4% for Panax quinquefolius, and the predicted response values were 31.5% yield, 13.4% NO production, and 6.1% IL-6 production; actual values were 35.3% yield, 14.7% NO, and 6.6% IL-6. The optimum mixing ratio extract (OMRE) was used for the animal experiments. Treating mice with OMRE at 200 mg/kg produced significant increases in spleen indexes and T-cell/B-cell proliferation. OMRE treatment increased IL-10 and IL-6 production in concanavalin A- and lipopolysaccharide-induced T- and B- lymphocytes, respectively. These results provide a basis for the development of functional extracts and drinks.

Effect of Bee Venom and Its Fractions on the Release of Pro-Inflammatory Cytokines in PMA-Differentiated U937 Cells Co-Stimulated with LPS

The venom of Apis mellifera (honey bee) has been reported to play a role in immunotherapy, but existing evidence to support its immuno-modulatory claims is insufficient. Four fractions from whole bee venom (BV) were separated using medium pressure liquid chromatography. Their ability to induce the production of cytokines TNFα, IL-1β and IL-6 in phorbol-12-myristate-13-acetate (PMA)-treated U937 cells was assessed. The levels of the three cytokines produced by stimulation with the four fractions and crude BV without LPS were not significantly different from negative control values. However, co-stimulation of the cells with LPS and Fraction 4 (F-4) induced a 1.6-fold increase in TNF-α level (p < 0.05) compared to LPS alone. Likewise, LPS-induced IL-1β production was significantly synergised in the presence of F-1 (nine-fold), F-2 (six-fold), F-3 (four-fold) and F-4 (two-fold) fractions, but was only slightly enhanced with crude BV (1.5-fold) relative to LPS. Furthermore, the LPS-stimulated production of IL-6 was not significantly increased in cells co-treated with F-2 and F-3, but the organic fraction (F-4) showed an inhibitory effect (p < 0.05) on IL-6 production. The latter was elucidated by NMR spectroscopy and found to contain(Z)-9-eicosen-1-ol. The effects observed with the purified BV fractions were more marked than those obtained with the crude sample.

Immunostimulatory activity of protein hydrolysate from oviductus ranae on macrophage in vitro

Oviductus Ranae is the dry oviduct of Rana chensinensis, which is also called R. chensinensis oil. Oviductus Ranae is a valuable Chinese crude drug and is recorded in the Pharmacopoeia of the People's Republic of China. The aim of this study was to investigate the immunostimulatory activity of protein hydrolysate of Oviductus Ranae (ORPH) and to assess its possible mechanism. Immunomodulatory activity of ORPH was examined in murine macrophage RAW 264.7 cells. The effect of ORPH on the phagocytic activity of macrophages was determined by the neutral red uptake assay. After treatment with ORPH, NO production levels in the culture supernatant were investigated by Griess assay. The mRNA and protein expressions of inducible nitric oxide synthase (iNOS) were detected by RT-PCR and Western blotting. The production of TNF-α, IL-1β, and IL-6 after treatment with ORPH was measured using ELISA assay. In addition, NF-κB levels were also investigated by Western blot. The results showed that ORPH enhanced the phagocytosis of macrophage, increased productions of TNF-α, IL-1β, IL-6, and NO in RAW 264.7 cells, and upregulated the mRNA and protein expression of iNOS. Besides, NF-κB, levels in RAW 264.7 cells were elevated after ORPH treatment. These findings suggested that ORPH might stimulate macrophage activities by activating the NF-κB pathway.

A comparative study on immunomodulatory activity of polysaccharides from two official species of Ganoderma (Lingzhi)

Two Ganoderma species, G. lucidum and G. sinense, are listed as Lingzhi in Chinese Pharmacopoeia and they are considered to have the same therapeutic effects. Polysaccharides were the main immunomodulatory and anticancer components in Ganoderma. In this study, the chemical characters and the effects of polysaccharides from G. lucidum (GLPS) and G. sinense (GSPS) on macrophage functions were investigated and compared. Chemical studies showed that GLPS and GSPS were different, displaying various molecular weight distribution and ratio of monosaccharide components. In vitro pharmacological studies showed that both GLPS and GSPS had potent effects on macrophage functions, such as promoting macrophage phagocytosis, increasing their release of nitric oxide and cytokines interleukin (IL)-1α, IL-6, IL-10, and tumor necrosis factor-α. Generally, GLPS was more powerful than GSPS. This study is helpful to elucidate the active components and pharmacological variation between the 2 Ganoderma species. The structure-activity relationship of polysaccharides from Ganoderma needs further study.

Epicutaneous Exposure to Anticoagulant Rodenticide Warfarin Modulates Local Skin Activity in Rats

Dermatotoxic effects of epicutaneous application of a first generation anticoagulant, warfarin (WF), were examined in rats. Selected parameters of skin activity were determined 24 hours following warfarin application by histomorphological and immunohistochemical analysis and by assessing some aspects of immunomodulatory potential of warfarin in skin. Increased number of mast cells, with degranulation at higher doses of warfarin was noted in warfarin treated skin. Mast cell presence coincided with changes in blood vessels and fibroblast appearance suggesting mast cell activity in warfarin treated skin. Signs of nuclear hypertrophy and anysonucleosys were noted by analysis of PCNA(+) cells in epidermis following warfarin application. Histomorphological changes were accompanied by immunemodulating activity in warfarin treated skin. This was judged by slightly increased numbers of CD3(+) cells in epidermis and superficial dermis and by production of organ cultured full thickness skin explants of factors with costimulatory activity in T-cell activation/proliferation assay. Presented data demonstrates the potential of warfarin to modulate local skin activity in rats.

Immunomodulatory Activities of HERBSnSENSES™Cordyceps—in Vitroandin VivoStudies

The commercially available HERBSnSENSEStrade mark Cordyceps (HSCS) belongs to a cultivated strain of Cordyceps sinensis whose immunomodulatory activities has been renowned in traditional Chinese medicine (TCM) for centuries. The present report is the first that describes its immunomodulatory features through a series of in vitro and in vivo experiments. We measured, in peripheral blood mononuclear cells the in vitro effects of HSCS on the gene expression of cytokines and cytokine receptors, cytokine release, and surface expression of cytokine receptors using cDNA expression array, cytometric bead array (CBA), and immunoflorescence staining, respectively, as well as macrophage phagocytosis and monocyte production of H2O2 using flow cytometry. Sixty female BALB/c mice were fed with either HSCS (40 mg/kg/day) or water consecutively for 14 days. Proliferation, cytokine liberation, and CD3/4/8 expression of splenic cells were measured using 5-bromo-2'-deoxyuridine proliferation ELISA, CBA, and cytometry immunoflorescence staining, respectively. In vitro results demonstrated that HSCS induced the production of interleukin(IL)-1beta, IL-6, IL-10 and tumor necrosis factor alphaalpha from PBMC, augmented surface expression of CD25 on lymphocytes, and elevated macrophage phagocytosis and monocyte production of H2O2. In vivo results showed that HSCS did not induce splenomegaly and cytokine overliberation. Our results possibly provide the biochemical basis for future clinical trials.

Combined immunogene therapy of IL-6 and IL-15 enhances anti-tumor activity through augmented NK cytotoxicity

Many tumors evade host immunity by lowering expression of major histocompatibility complex (MHC) molecules. Theoretically, low MHC expression should activate natural killer (NK) cells and in some cases suppress tumor growth; nevertheless, some tumors also produce high concentrations of immunosuppressive cytokines, such as transforming growth factor (TGF)-beta, to inhibit the activity of NK cells. Using a canine transmissible venereal tumor (CTVT) model, we have previously demonstrated that IL-6 is a strong antagonist for TGF-beta. Herein, we found that IL-6 alone was unable to significantly promote TGF-beta-inhibited NK activities. Conversely, IL-15 alone strongly promoted NK activities; however, NK activities were inhibited to baseline levels following the addition of TGF-beta. Therefore, a new strategy using combined immunogene therapy of both IL-6 and IL-15 mediated by electroporation was used in this study. This combined IL-6 and IL-15 treatment effectively relieved the inhibitory effect of TGF-beta and activated NK cell cytotoxicity of lymphokine-activated killer (LAK) cells. Similarly, in isolated DX5+ NK cells, only IL-6 and IL-15 in combination significantly overcame the inhibitory effect of TGF-beta and promoted NK cytotoxicity. The group of BALB/c mice injected with plasmids with IL-6 and IL-15 genes (pIL-6/pIL-15) had the highest percentages of DX5+ NK cells as compared with either the pIL-6 or pIL-15 groups. Further, in SCID mice inoculated with CTVT, electroporation-mediated delivery of pIL-6/pIL-15 was significantly more efficient in suppressing both tumor establishment and tumor growth as compared with pIL-6 or pIL-15 inoculation alone. In addition, the anti-asialo GM-1 antibody abolished NK activities in SCID mice and resulted in outgrowth of the tumors. Together, these results suggest that the TGF-beta-associated inhibition of NK cytotoxicity cannot be adequately restored by simply antagonizing TGF-beta with IL-6: the co-existence of NK activating factors such as IL-15 is also important in restoring TGF-beta-inhibited cytotoxicity. This study highlights the therapeutic potential of the pIL-6/pIL-15 combination by inhibiting TGF-beta activity and enhancing NK cytotoxicity.

Dermatotoxicity of epicutaneously applied anticoagulant warfarin

Dermatotoxic effects of epicutaneous application of a first-generation anticoagulant, warfarin (WF) were examined in rats. Selected parameters of skin activity were determined 24h following warfarin application, including metabolic viability of skin explants, some aspects of oxidative activity in skin tissue homogenates and inflammatory/immune relevant activity of epidermal cells from warfarin-treated skin. No changes in skin metabolic viability (MTT reduction) were noted ex vivo following WF application, suggesting the absence of immediate toxicity for skin. In contrast, increased formation of malondialdehyde (MDA), with a decrease in protein and non-protein thiols in homogenates of warfarin-treated skin was demonstrated, pointing to prooxidant activity in warfarin-treated skin. Increased costimulatory activity of epidermal cells isolated from warfarin-exposed skin in Con-A-stimulated T-cell activation/proliferation assay was noted, reflecting proinflammatory and immune-modulating capacity of warfarin for epidermis. No evident differences in skin histology between control and warfarin-treated skin were found at that time point, while striking changes in tissue integrity, cellularity and appearance 72 h following WF application were noted. The observed histological picture probably reflects a regenerative/inflammatory program related to oxidant/inflammation-type warfarin-evoked injury to the skin. Presented data demonstrate the potential of epicutaneously applied warfarin to modulate local skin activity in rats.

Overexpression of protein kinase C-{epsilon} in the mouse epidermis leads to a spontaneous myeloproliferative-like disease

Protein kinase C (PKC)-epsilon, a Ca(2+)-independent, phospholipid-dependent serine/threonine kinase, is among the PKC isoforms expressed in mouse epidermis. We reported that FVB/N transgenic mouse lines that overexpress (8- or 18-fold) PKC-epsilon protein in basal epidermal cells and cells of the hair follicle develop papilloma-independent squamous cell carcinoma (SCC) elicited by 7,12-dimethylbenz(a)anthracene initiation and 12-O-tetradecanoylphorbol-13-acetate-promotion or by repeated ultraviolet radiation exposures. The susceptibility to the development of SCC was proportional to the level of expression of the PKC-epsilon transgene. We now report that PKC-epsilon FVB/N transgenic mice (line 215) that overexpress in epidermis approximately 18-fold PKC-epsilon protein more than their wild-type littermates spontaneously develop a myeloproliferative-like disease (MPD) in 100% of PKC-epsilon transgenic mice. The MPD was characterized by an excess of neutrophils and eosinophils, resulting in invasion of almost all vital organs of the mouse by 6 months of age. On gross examination these mice present with splenomegaly, hepatomegaly, and severe lymphadenopathy. Examination of the bone marrow revealed almost complete effacement by neutrophils, eosinophils, and their precursors. Furthermore, the spleen and lymph nodes were enlarged and exhibited marked extramedullary hematopoiesis. Complete pathological analysis of the second PKC-epsilon transgenic mouse (line 224) that expresses approximately eightfold PKC-epsilon protein more than their wild-type littermates revealed no remarkable findings in any of the affected organs as seen in line 215. However, peripheral blood analyses of PKC-epsilon transgenic mice indicated significant increases of neutrophils in the circulating blood in both PKC-epsilon transgenic lines. To determine whether there was an imbalance of cytokines in PKC-epsilon transgenic mice (line 215), resulting in aberrant myelopoiesis, we analyzed 17 cytokines in the peripheral blood. This analysis indicated that interleukin-5, interleukin-6, and granulocyte-colony stimulating factor were up-regulated as a function of age. The transgene PKC-epsilon was not detected in any of the affected organs (bone marrow, liver, spleen, lung) We suggest that overexpression of PKC-epsilon in the epidermis may lead to the induction of specific cytokines that may, in a paracrine mechanism, perturb normal hematopoiesis in bone marrow resulting in a granulocytic skew toward that of neutrophils and eosinophils. The susceptibility of PKC-epsilon transgenic mice to the induction of SCC and the spontaneous development of MPD are unrelated.

The immunomodulating properties of human respiratory syncytial virus and immunostimulating complexes containingQuillajasaponin components QH-A, QH-C and ISCOPREPTM703

A successful vaccine against human RSV (HRSV) is likely to induce a Th1 or a balanced Th1/TH2 cytokine response. We tested a panel of HRSV immunostimulating complexes (ISCOMs) containing different Quillaja saponin fractions (QH-A, QH-C, and 703: a mixture of 70% QH-A and 30% QH-C) with different immunological properties for their capacity of inducing innate and acquired immune responses. The HRSV 703 ISCOMs induced the strongest innate and acquired immune responses, followed by RSV QH-C and QH-A ISCOMs. All three formulations induced various degrees of Th1 bias response with prominent production of IFN-gamma being 10-50 times higher than that of IL-4 and IL-5. The HRSV specific IgG isotype profile correlated with the predominant secretion of Th1 cytokines, with strong induction of IgG2a antibodies. The 703 ISCOMs induced the most pronounced Th1 profile followed by QH-C and QH-A ISCOMs. The high incorporation of F protein in these ISCOMs compared to G protein combined with the Th1 biased nature of ISCOM are likely to be the causes to promote a Th1 type of profile. The prospect to formulate an RSV ISCOM formulation with an optimal Th1/Th2 balance is in reach particularly in view of the versatile properties of the ISCOM concept.

Augmentation of macrophage phagocytosis by modified arabinoxylan rice bran (MGN-3/biobran)

MGN-3/Biobran, modified arabinoxylan rice bran, has been shown to be a potent biological response modifier (BRM) as manifested by stimulation of different arms of the immune system such as NK, T and B cells; however, its effect on macrophages has not yet been studied. The effects of MGN-3 on macrophage function was examined in vitro using 3 models: human macrophage cell line U937, murine macrophage cell line RAW264.7, and murine peritoneal macrophages (P-M phi). Treatment with MGN-3 resulted in an increase in the percentages of attachment and phagocytosis of yeast by macrophages. The effect depends on the type of macrophage and the dose of MGN-3 applied. Macrophages also demonstrated enhancement in their spreading ability, post treatment with MGN-3. Results also showed that MGN-3, in a dose dependent manner (1, 10,100 microg/ml), significantly induced high levels of production of cytokines: TNF-alpha; and IL-6. In addition, MGN-3 significantly increased nitric oxide (NO) production. This data demonstrates that MGN-3 is a potent inducer of phagocytic function by macrophage, and suggests that MGN-3 is a useful agent for fighting microbial infection.

In vitro cytokine production and proliferation of T cells from patients with anti-proteinase 3- and antimyeloperoxidase-associated vasculitis, in response to proteinase 3 and myeloperoxidase

OBJECTIVE

To investigate in vitro proliferative responses of CD4+ T cells and generation of specific cytokines induced by stimulation of peripheral blood mononuclear cells (PBMCs) from patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis with the autoantigens proteinase 3 (PR3) and myeloperoxidase (MPO).

METHODS

PBMCs from vasculitis patients with PR3 ANCA or MPO ANCA and from healthy controls were stimulated for 7 days with PR3, MPO, or control stimuli. Proliferation of CD4+ T cells was assessed by flow cytometry, using the proliferation marker Ki-67. Levels of the pro-proliferative cytokines interleukin-2 (IL-2) and IL-6 and of the Th1 and Th2 cytokines interferon-gamma (IFN gamma) and IL-10 in culture supernatants were determined.

RESULTS

PR3 and MPO induced proliferative responses in CD4+ T cells from individual patients with ANCA-associated vasculitides and healthy controls in vitro. Neither PR3 nor MPO elicited significant IL-2 production. Levels of IL-6 were highest after stimulation with PR3 but low after stimulation with MPO, independent of study group. Stimulation with PR3, and to a lesser extent with MPO, induced a Th2 cytokine milieu, characterized by high production of IL-6 and IL-10 and low production of IFN gamma in patients and controls.

CONCLUSION

PR3 and MPO promote proliferation of CD4+ T cells from patients with ANCA-associated vasculitides, but also cross-stimulate T cells from healthy individuals. Strong IL-10 production elicited by PR3 in vitro may act as an inhibitory signal for T cell proliferation and may have an important immunoregulatory function in vivo.

Augmentation of macrophage functions by an aqueous extract isolated from Platycodon grandiflorum

Platycodon grandiflorum has been claimed to have a wide range of health benefits, which include immunostimulation and antitumor activity. The associated biological mechanisms are unclear; however, of the wide diversity of effects, it is believed that their activities may be exerted through several potent effector cells such as macrophages. Therefore, the effects of an aqueous extract from the root of P. grandiflorum (Changkil: CK) on mouse peritoneal macrophage function were investigated. It was found that CK stimulated macrophage proliferation, spreading ability, phagocytosis, cytostatic activity, and nitric oxide production in a dose-dependent manner, and that the production of cytokines such as TNF-alpha, IL-1beta and IL-6 were similarly increased. CK significantly affected secretion at concentrations greater than 10 microg/ml; its maximal effects were at the concentration of 100 microg/ml. Reverse transcription-polymerase chain reaction showed that CK increased the appropriate cytokine mRNAs. These results suggest that CK is a potent enhancer of macrophage function.

Overexpression of interleukin-6 in human basal cell carcinoma cell lines increases anti-apoptotic activity and tumorigenic potency

Interleukin-6 (IL-6) is a pleiotropic cytokine that is capable of modulating the diverse functions of cells such as acute phase responses and inflammation. Excessive or insufficient production of IL-6 may contribute to certain diseases of the skin. The aim of this study was to investigate the possible role of IL-6 in the tumorigenesis of basal cell carcinoma (BCC). Initially, we transfected IL-6 expression vector, under the control of a CMV promoter, into human BCC cells and successfully obtained IL-6-overexpressing clones (BCC/IL-6-c1 and BCC/IL-6-c2) and a mixture (BCC/IL-6). DNA synthesis assay determined using (3)H-thymidine pulse incorporation revealed that IL-6-expressing BCC cells exhibited a much higher DNA synthesis rate than the neo control or parental BCC cells. We also detected a greater abundance of IL-6-expressing cell colonies formed in soft agar than in the vector control cells. Furthermore, BCC/IL-6 cells, but not vector control cells, were resistant to UV and photodynamic therapy (PDT)-induced apoptosis, as confirmed using DNA fragmentation and morphologic change analyses. Immunoblot analysis showed that Mcl-1, an anti-apoptotic protein, was specifically up-regulated IL-6 transfectants but not in the control cells. Transient transfection of IL-6 transfectants with antisense mcl-1 greatly enhanced their apoptosis frequency by UV treatment. In tumorigenesis assay, IL-6 transfected clones formed tumors in nude mice more rapidly than the control cells. These tumors appeared to be highly vascularized using pathological examination. Supportive of this finding, we found that IL-6 transfected cells expressed elevated levels of two angiogenic factors, cyclooxygenase (Cox)-2 and vascular endothelial growth factor (VEGF). These results suggest that overexpression of IL-6 enhances the tumorigenic activity of BCC cells by both suppressing apoptosis and actively promoting angiogenesis.

Quillaja saponin formulations that stimulate proinflammatory cytokines elicit a potent acquired cell-mediated immunity

We examined the ability of various Quillaja saponins in iscom-matrix formulations to induce proinflammatory cytokines, such as interleukin (IL)-1alpha and IL-6, and to stimulate acquired immune responses to influenza virus envelope proteins. The A-fraction of Quillaja saponins (QH-A) was shown to stimulate antigen-presenting cells (APC) to produce proinflammatory cytokines, and elicited a high primary antigen-specific antibody response and potent cell-mediated responses, as measured by T-cell proliferation, production of cytokines and cytotoxic T-lymphocyte (CTL) activity. The C-fraction of Quillaja saponins (QH-C) was shown to have a low capacity to stimulate proinflammatory cytokines and elicited low primary antibody and T-cell responses. However, the QH-C iscom-matrix mediated a potent booster effect, resulting in a high secondary antibody response. The ability of APC to discriminate and to respond to QH-A formulations more efficiently than to QH-C with release of proinflammatory cytokines, which precedes a potent acquired immune response, identifies an important mechanism through which some adjuvants may exert their immunoenhancing activities.

TNF-alpha increases expression of IL-6 and ICAM-1 genes through activation of NF-kappaB in osteoblast-like ROS17/2.8 cells

Tumor necrosis factor-alpha (TNF-alpha) plays a key role in inflammatory diseases such as rheumatoid arthritis and in postmenopausal osteoporosis. In various tissues, TNF-alpha action is mediated by a transcription factor, nuclear factor-kappa B (NF-kappaB). However, little is known about how TNF-alpha exerts its action in osteoblasts. We thus examined the effect of TNF-alpha on the activation of NF-kappaB in rat osteoblast-like osteosarcoma cells (ROS17/2.8). Electrophoretic mobility shift assay revealed that the activation of the p50-p65 heterodimer NF-kappaB was induced by TNF-alpha as early as 15 minutes followed by a persistent activation for 48 h. When the binding activity of NF-kappaB in cytosol was examined using detergents that dissociate NF-kappaB from an inhibitory protein IkappaB, it decreased during the initial 30 minutes and then increased to the unstimulated level. Northern blot analysis revealed a marked increase in the mRNA levels of p105, a precursor of p50, 6 h after TNF-alpha and a gradual increase in p65 mRNA levels during the initial 1 h. Significant increase in both mRNA levels continued until 24 h after TNF-alpha. These results suggest that the rapid activation of NF-kappaB by TNF-alpha is mainly due to the nuclear translocation of NF-kappaB pre-existing in cytosol, and that the subsequent increase in the expression of p50 and p65 may result in the persistent activation of NF-kappaB during TNF-alpha stimulation. TNF-alpha also increased the mRNA levels of interleukin-6 (IL-6) and intercellular adhesion molecule-1 (ICAM-1). An antioxidant, N-acetyl-L-cysteine, significantly attenuated the TNF-alpha-dependent increase in these mRNAs, and simultaneously reduced the activation of NF-kappaB by TNF-alpha, indicating that NF-kappaB mediates the TNF-alpha-dependent expression of IL-6 and ICAM-1 in ROS17/2.8 cells. These results suggest that the activation of NF-kappaB by TNF-alpha may play an important role in the production of cytokines and cell adhesion molecules from osteoblasts, leading to the promotion of bone resorption and inflammation.

Renal cell carcinomas produce IL-6, IL-10, IL-11, and TGF-beta 1 in primary cultures and modulate T lymphocyte blast transformation

We investigated the immunomodulatory capacity of primary cultures of renal cell carcinomas (RCC) by assessing production of cytokines and modulation of mitogen-induced T lymphocyte blast transformation. The results clearly show that immunomodulatory capacity is a common feature of RCC and that in vitro these tumors can produce interleukin-10 (IL-10) up to 20 ng/ml, IL-6 up to 35 micrograms/ml (> 250 kU/ml in the B9 system), IL-11 up to 15 micrograms/ml, and transforming growth factor-beta 1 (TGF-beta 1) up to 22 ng/ml. Furthermore, these tumors have the capacity to modulate T cell blast transformation over two orders of magnitude in each direction. The correlations of the immunologic properties of tumor cell cultures with the conventional classification of tumors (histology, cytology, staging, grading, presence of metastases, and secondary tumors) are analyzed. The significance of these findings for modulation of local immunity by RCC as well as for patient outcome is discussed.

Recombinant human interleukin 6 in metastatic renal cell cancer: a phase II trial

A phase II trial investigating the anti-tumour effects of recombinant human interleukin 6 (rhIL-6) in patients with metastatic renal cell cancer was carried out. RhIL-6 (150 microgram) was administered as a daily subcutaneous injection for 42 consecutive days on an outpatient basis. Forty-nine patients were studied, 12 with and 37 without previous immunotherapy. Forty patients were evaluable for response. A partial remission was noted in two patients, stable disease in 17 and progressive disease in 21. Toxicity was moderate and reversible and consisted mainly of fever, flu-like symptoms, nausea, weight loss and hepatotoxicity. Anaemia, leucocytosis and thrombocytosis and induction of acute phase protein synthesis were noted in most patients. In 15% of the patients anti-IL-6 antibodies developed, and were neutralising in only one patient. Baseline plasma IL-6 concentrations did not correlate with tumour behaviour before or after rhIL-6 treatment. In conclusion, rhIL-6 can be safely administered on an outpatient basis for prolonged period of time and has moderate, reversible toxicity. Its administration induces IL-6-antibody production in only a minority of patients. Antitmour effects of rhIL-6 in metastatic renal cancer are limited.

Increased interleukin-6 mRNA expression in blood and cerebrospinal fluid mononuclear cells in multiple sclerosis

The increased intrathecal production of immunoglobulins within the cerebrospinal fluid (CSF) compartment commonly observed in multiple sclerosis (MS) implicates participation of B cell activating factors. One effect of the cytokine interleukin (IL)-6 is induction of immunoglobulin production by activated B cells. Employing in situ hybridization (ISH) with synthetic oligonucleotide probes, we measured numbers of IL-6 mRNA-expressing mononuclear cells (MNC) in blood and CSF from patients with MS, aseptic meningo-encephalitis (AM), and in blood from patients with other neurological diseases (OND) and healthy subjects. Numbers of IL-6 mRNA-expressing MNC were elevated in blood (mean frequency 1 per 33,000 MNC) and even further enriched in the CSF (1 per 10,000 MNC) of MS patients, and to a similar extent in AM patients' blood. Cultivation in the presence of myelin basic protein and proteolipid protein revealed strong augmentation of IL-6 mRNA-positive cells in MS but not in OND. The results suggest that IL-6 is one of several cytokines which are upregulated in MS, in particular locally in the CSF. A role of IL-6 in MS, whether disease- promoting or protective, remains unclear.