Periodic Bedrock Ridges at the ExoMars 2022 Landing Site: Evidence for a Changing Wind Regime

Wind-formed features are abundant in Oxia Planum (Mars), the landing site of the 2022 ExoMars mission, which shows geological evidence for a past wet environment. Studies of aeolian bedforms at the landing site were focused on assessing the risk for rover trafficability, however their potential in recording climatic fluctuations has not been explored. Here we show that the landing site experienced multiple climatic changes in the Amazonian, which are recorded by an intriguing set of ridges that we interpret as Periodic Bedrock Ridges (PBRs). Clues for a PBR origin result from ridge regularity, defect terminations, and the presence of preserved megaripples detaching from the PBRs. PBR orientation differs from superimposed transverse aeolian ridges pointing toward a major change in wind regime. Our results provide constrains on PBR formation mechanisms and offer indications on paleo winds that will be crucial for understanding the landing site geology.

Bridging pro-inflammatory signals, synaptic transmission and protection in spinal explants in vitro

Multiple sclerosis is characterized by tissue atrophy involving the brain and the spinal cord, where reactive inflammation contributes to the neurodegenerative processes. Recently, the presence of synapse alterations induced by the inflammatory responses was suggested by experimental and clinical observations, in experimental autoimmune encephalomyelitis mouse model and in patients, respectively. Further knowledge on the interplay between pro-inflammatory agents, neuroglia and synaptic dysfunction is crucial to the design of unconventional protective molecules. Here we report the effects, on spinal cord circuits, of a cytokine cocktail that partly mimics the signature of T lymphocytes sub population Th1. In embryonic mouse spinal organ-cultures, containing neuronal cells and neuroglia, cytokines induced inflammatory responses accompanied by a significant increase in spontaneous synaptic activity. We suggest that cytokines specifically altered signal integration in spinal networks by speeding the decay of GABA_A responses. This hypothesis is supported by the finding that synapse protection by a non-peptidic NGF mimetic molecule prevented both the changes in the time course of GABA events and in network activity that were left unchanged by the cytokine production from astrocytes and microglia present in the cultured tissue. In conclusion, we developed an important tool for the study of synaptic alterations induced by inflammation, that takes into account the role of neuronal and not neuronal resident cells.

Effects of near-infrared laser radiation on the survival and inflammatory potential of Candida spp. involved in the pathogenesis of chemotherapy-induced oral mucositis

Candida spp. usually colonize ulcerative lesions of atrophic mucosa in patients with chemotherapy-induced oral mucositis inducing severe inflammation. The spread of antifungal-resistant strains strongly encouraged the search of complementary or alternative therapeutic strategies to cure inflamed mucosa. In this paper, we studied the effects of a near-infrared (NIR) laser system with dual-wavelength emission (808 nm + 904 nm) on the survival and inflammatory potential of C. albicans, C. glabrata, and C. parapsilosis. Laser treatment was performed with a Multiwave Locked System laser. Survival and apoptosis of fungal strains were evaluated by colony-forming units (CFU) counting and annexin V staining. Cytokine production was evaluated by ImmunoPlex array. Laser treatment significantly affected the survival of Candida spp. by inducing apoptosis and induced a lower production of inflammatory cytokines by dendritic cells compared to untreated fungi. No differences in the survival and inflammatory potential were recorded in treated or untreated Saccharomyces cerevisiae cells, used as the control non-pathogenic microorganism. Laser treatment altered the survival and inflammatory potential of pathogenic Candida spp. These data provide experimental support to the use of NIR laser radiation as a co-adjuvant of antifungal therapy in patients with oral mucositis (OM) complicated by Candida infections.

Production and secretion of interleukin 1 receptor antagonist in monocytes and keratinocytes

IL-1 receptor antagonist (IL-1ra) is a newly described member of the IL-1 family, isolated from supernatants of Ig stimulated monocytes, that binds competitively to IL-1 receptors without stimulating target cells (1-3). Also epithelial cells produce IL-1ra in a form which lacks a secretory signal sequence (4).Here we have compared the biosynthesis and secretion of IL-1ra in monocytes and keratinocytes. Our data show that monocytes produce two molecular forms of IL-1ra, of 18 Kd and 23 Kd respectively, which differ in the degree of glycosylation. Both forms are secreted via the "classical" endoplasmic reticulum (ER)-Golgi secretory pathway. By contrast keratinocytes produce IL-1ra in a molecular form of 20 Kd, which is not N-glycosylated: 20 Kd IL-1ra is detectable in supernatants of keratinocytes, although in small amounts. The presence of IL-1ra in keratinocytes cultures fluids is not inhibited by Brefeldin A (BFA), suggesting a possible secretion through the leaderless secretory pathway.

Low molecular weight, non-peptidic agonists of TrkA receptor with NGF-mimetic activity

Exploitation of the biologic activity of neurotrophins is desirable for medical purposes, but their protein nature intrinsically bears adverse pharmacokinetic properties. Here, we report synthesis and biologic characterization of a novel class of low molecular weight, non-peptidic compounds with NGF (nerve growth factor)-mimetic properties. MT2, a representative compound, bound to Trk (tropomyosin kinase receptor)A chain on NGF-sensitive cells, as well as in cell-free assays, at nanomolar concentrations and induced TrkA autophosphorylation and receptor-mediated internalization. MT2 binding involved at least two amino-acid residues within TrkA molecule. Like NGF, MT2 increased phosphorylation of extracellular signal-regulated kinase 1/2 and Akt proteins and production of MKP-1 phosphatase (dual specificity phosphatase 1), modulated p38 mitogen-activated protein kinase activation,sustained survival of serum-starved PC12 or RDG cells, and promoted their differentiation. However, the intensity of such responses was heterogenous, as the ability of maintaining survival was equally possessed by NGF and MT2, whereas the induction of differentiation was expressed at definitely lower levels by the mimetic. Analysis of TrkA autophosphorylation patterns induced by MT2 revealed a strong tyrosine (Tyr)490 and a limited Tyr785 and Tyr674/675 activation, findings coherent with the observed functional divarication. Consistently, in an NGF-deprived rat hippocampal neuronal model of Alzheimer Disease, MT2 could correct the biochemical abnormalities and sustain cell survival. Thus, NGF mimetics may reveal interesting investigational tools in neurobiology, as well as promising drug candidates.

Low molecular weight, non-peptidic agonists of TrkA receptor with NGF-mimetic activity

Exploitation of the biologic activity of neurotrophins is desirable for medical purposes, but their protein nature intrinsically bears adverse pharmacokinetic properties. Here, we report synthesis and biologic characterization of a novel class of low molecular weight, non-peptidic compounds with NGF (nerve growth factor)-mimetic properties. MT2, a representative compound, bound to Trk (tropomyosin kinase receptor)A chain on NGF-sensitive cells, as well as in cell-free assays, at nanomolar concentrations and induced TrkA autophosphorylation and receptor-mediated internalization. MT2 binding involved at least two amino-acid residues within TrkA molecule. Like NGF, MT2 increased phosphorylation of extracellular signal-regulated kinase1/2 and Akt proteins and production of MKP-1 phosphatase (dual specificity phosphatase 1), modulated p38 mitogen-activated protein kinase activation, sustained survival of serum-starved PC12 or RDG cells, and promoted their differentiation. However, the intensity of such responses was heterogenous, as the ability of maintaining survival was equally possessed by NGF and MT2, whereas the induction of differentiation was expressed at definitely lower levels by the mimetic. Analysis of TrkA autophosphorylation patterns induced by MT2 revealed a strong tyrosine (Tyr)490 and a limited Tyr785 and Tyr674/675 activation, findings coherent with the observed functional divarication. Consistently, in an NGF-deprived rat hippocampal neuronal model of Alzheimer Disease, MT2 could correct the biochemical abnormalities and sustain cell survival. Thus, NGF mimetics may reveal interesting investigational tools in neurobiology, as well as promising drug candidates.

Biologic and clinical significance of cytokine production in B-cell malignancies

Cytokines are a group of polypeptide hormones endowed with pleiotropic biological properties. Normal B lymphocytes produce a number of these factors that subserve important regulatory functions in the combined processes of proliferation and differentiation. Also neoplastic B cells can release cytokines and, simultaneously, respond to the same factors in an autocrine circuit that supports their malignant growth. In addition, tumor cells can make use of the factors released by normal cells, either spontaneously or under the influence of inductive signals from the neoplastic cells. Inappropriate or excessive release of cytokines may have an important role in the pathophysiology of some clinical features. Thus, neutralization of cytokine biologic activity in vivo could be a therapeutic strategy for treatment of human B-cell neoplasias.

Nerve growth factor inhibits apoptosis in memory B lymphocytes via inactivation of p38 MAPK, prevention of Bcl-2 phosphorylation, and cytochrome c release

Survival of memory B lymphocytes is tightly linked to the integrity of the Bcl-2 protein and is regulated by a nerve growth factor (NGF) autocrine circuit. In factor-starved memory B cells, the addition of exogenous NGF promptly induced p38 mitogen-activated protein kinase (MAPK), but not c-Jun N-terminal kinase (JNK), dephosphorylation. Conversely, withdrawal of endogenous NGF was followed by p38 MAPK activation and translocation onto mitochondria, whereby it combined with and phosphorylated Bcl-2, as assessed by co-immunoprecipitation and kinase assays in vivo and in vitro. Mitochondria isolated from human memory B cells, then exposed to recombinant p38 MAPK, released cytochrome c, as did mitochondria from Bcl-2-negative MDCK cells loaded with recombinant Bcl-2. Apoptosis induced by NGF neutralization could be blocked by the specific p38 MAPK inhibitor SB203580 or by Bcl-2 mutations in Ser-87 or Thr-56. These data demonstrate that the molecular mechanisms underlying the survival factor function of NGF critically rely upon the continuous inactivation of p38 MAPK, a Bcl-2-modifying enzyme.

NGF-withdrawal induces apoptosis in pancreatic beta cells in vitro

AIMS/HYPOTHESIS

Using primary cultures of human pancreatic islets, purified human pancreatic beta cells and the mouse beta TC6-F7 cell line, we analysed the expression of nerve growth factor, (NGF/NGF) receptors in beta cells. To investigate whether NGF could sub-serve an autocrine antiapoptotic role in beta cells, we studied the effects of NGF withdrawal using a neutralizing monoclonal anti-NGF antibody.

METHODS

The expression of NGF and NGF receptors (gp140(Trk-A) and p75(NTR)) were analysed by RT-PCR and immunofluorescence. Pulse-chase experiments and beta cell/PC12 co-cultures were used to investigate NGF production and secretion from beta cells. Possible apoptosis induced by NGF withdrawal was monitored by phosphatidylserine translocation, nucleosomal formation, DNA laddering and FACS analysis. Involvement of transcription/translation mechanisms were investigated as well as the gp140(Trk-A) required. Finally, signal transduction pathways typically involved in apoptotic mechanisms were analysed by western blot analysis.

RESULTS

We show that NGF and both NGF receptors, gp140(Trk-A) and p75(NTR) are expressed in beta cells where NGF is produced and secreted in a biologically active form. NGF-withdrawal induces beta-cell transcription/translation independent apoptosis but mediated by gp140(Trk-A). Analysis of signal transduction pathways revealed that NGF withdrawal inhibits the PI3-K, protein kinase B (AKT), Bad survival pathway and activates c-Jun kinase (JNK) whereas ERKs and p38 mitogen-activated protein kinase (MAPK) are not affected. Moreover, Bcl-XL, but not Bcl-2 protein expression are reduced.

CONCLUSION/INTERPRETATION

We suggest that the integrity of the NGF/NGF receptor system and NGF bioavailability participate in controlling beta-cell survival in culture which represents a key issue for improving possibilities for transplantations in the treatment of diabetes.

NGF withdrawal induces apoptosis in CESS B cell line through p38 MAPK activation and Bcl-2 phosphorylation

The sIgG(+) lymphoblastoid B cell line CESS spontaneously produces a high amount of NGF and expresses both high affinity (p140(Trk-A)) and low affinity (p75(NTR)) NGF receptors. Blocking NGF signals with neutralizing antibodies or specific Trk-A inhibitors induces a rapid phosphorylation of antiapoptotic Bcl-2 protein, followed by caspase activation, and apoptotic death of CESS cells. Bcl-2 phosphorylation in several sites within a approximately 60 aa "loop" domain of protein is known to regulate its antiapoptotic function. Accordingly, CESS cells expressing the loop deletional mutant cDNA constructs Bcl-2 Delta40-91 were completely resistant to apoptosis induced by NGF withdrawal, indicating that Bcl-2 phosphorylation is a critical event. NGF withdrawal induces p38 MAPK, but not JNK, activation in CESS cells, and SB203580, a specific inhibitor of p38 MAPK, is able to prevent both Bcl-2 phosphorylation and apoptosis, indicating that p38 MAPK is the enzyme responsible for these events.

Interferon-alpha-induced inhibition of B16 melanoma cell proliferation: interference with the bFGF autocrine growth circuit

The molecular mechanisms underlying the growth inhibition induced by interferon-alpha (IFN-alpha) in B16 murine melanoma cells were investigated. IFN-alpha did not induce cell apoptosis, but strongly interfered with the synthesis of basic fibroblast growth factor (bFGF), which acts as an autocrine growth factor in this system. Inhibition of bFGF synthesis was observed at the same concentrations (50-500 pM, 10-100 U/ml) of IFN-alpha able to induce growth arrest of B16 melanoma cells. Although the synthesis of acidic (a)FGF was only slightly affected by IFN-alpha, the cytokine induced release of an aFGF-related low-molecular-weight peptide, which was able to interfere with bFGF binding to surface receptors. Thus, the molecular mechanisms of IFN-alpha activity on melanoma cells include a specific modulation of the bFGF autocrine circuit.

Stevens-Johnson syndrome. Description of an unusual clinical case due to glucocorticoid therapy for oral lichen planus

Erythema multiforme (EM) is an acute inflammatory disease with an autoimmune pathogenesis clinically expressing in a wide variety of mucocutaneous illnesses. It is usually described in a minor form (Von Hebra) characterized by classical cutaneous lesions, and in major form (Stevens-Johnson), involving mucosal damage, while a clinical type restricted to the oral mucosa is described in oral pathology. A considerable number of factors of different nature have been reported as etiologic agents of EM, but most of them are not well documented; however, a certain relationship with EM is recognized for different classes of systemic drugs. This paper describes a case of Stevens-Johnson syndrome with initial oral involvement, in which the precipitating factor was due to the administration of systemic glucocorticoids, prescribed for the therapeutic treatment of an erosive form of oral lichen planus.

Recent advances on the pathogenesis of oral lichen planus (OLP). The adhesion molecules

Oral Lichen Planus is a chronic inflammatory pathology with not well defined etiology, characterized by an immunoreactivity directed against the keratinocytes of basal layer and mediated by a cellular infiltrate of T-lymphocytes. This immunoreactivity is caused by a modification of basal keratinocytes surface antigens, with activation of antigen-presenting cells allowing the recognition on non-self antigens by CD4 lymphocytes. The migration of T-cells at the sites of the damage and their interactions with leucocytes and keratinocytes represent a key effect of pathogenesis of OLP, and are mediated by specific cell surface adhesion molecules. Recent studies in molecular biology, with the discovery and the definition of cell adhesion receptors, have greatly contributed to clarify the pathogenic mechanism of OLP; these molecules regulate immune functions such as adhesion to endothelial cells, lymphocytes migration into extravasal tissues at the site of immune response and T-cell interactions with target cell antigens. The adhesion molecules have been classified into various families, differing on the basis of their molecular structure: the Immunoglobulin Superfamily (ICAM 1-3, PECAM-1, VCAM-1), the Selectins (ELAM-1, LECAM-1, GMP-140), the Integrins (LEA-1) and others. In this paper, the principal classes of adhesion molecules which are involved in the immune response are described and their importance in the pathogenesis of Lichen Planus is underlined.

Modulation of osteoclast-activating factor activity of multiple myeloma bone marrow cells by different interleukin-1 inhibitors

We have studied the effects of several interleukin-1 (IL-1) inhibitors--IL-1 receptor antagonist (IL-1ra), soluble IL-1 receptor (sIL-1R) types I and II, and neutralizing monoclonal antibody (mAb) specific for IL-1 receptor type I--on the osteoclast-activating factor (OAF) activity of recombinant IL-1beta and of culture supernatants of unfractionated bone marrow mononuclear cells from multiple myeloma (MM) patients. The latter activity sharply correlated with the IL-1 content of culture supernatants (r = 0.949; p < 0.001). IL-1ra and sIL-1R types I and II had a clear-cut modulating effect on the OAF activity of IL-1beta at saturating doses (2-10 ng/mL); their effect was evident at 2 ng/mL and was dose-dependent over a large range of concentrations. Similarly, the three reagents neutralized the OAF activities of all MM cell supernatants in a dose-dependent fashion and completely abolished them when tested at the fixed concentration of 5 nM. The bone-resorbing activity of tumor necrosis factor-alpha (TNF-alpha) or lymphotoxin (LT), tested alone or added to MM cell supernatants, was affected not at all by IL-1ra and only minimally by sIL-1R types I and II, suggesting that little or no endogenous IL-1 was produced by the rat cells in the assay under TNF-alpha or LT stimulation. Consistent with these findings, PGE2 production elicited by IL-1beta or IL-1-rich supernatants in the rat long-bone assay was abolished by each reagent. Also, mAbs to the IL-1R p80 (type I) chains could modulate the effects of IL-1--recombinant or plasma cell-derived--in the OAF assay, but their activity was markedly less pronounced when compared with the IL-1 inhibitors, since they could never completely abolish bone resorption. Taken together, these findings demonstrate that inhibition of IL-1 interaction with cognate surface receptors on bone cells effectively counteracts its biologic activity. The findings also strongly indicate that OAF activity in conditioned medium of unfractionated myeloma bone marrow cells is predominantly, if not solely, related to IL-1beta.

Nerve growth factor is an autocrine survival factor for memory B lymphocytes

Production of nerve growth factor (NGF) was assessed in cultures of human T and B lymphocytes and macrophages. NGF was constitutively produced by B cells only, which also expressed surface p140trk-A and p75NGFR molecules and hence efficiently bound and internalized the cytokine. Neutralization of endogenous NGF caused disappearance of Bcl-2 protein and apoptotic death of resting lymphocytes bearing surface IgG or IgA, a population comprising memory cells, while surface IgM/IgD "virgin" B lymphocytes were not affected. In vivo administration of neutralizing anti-NGF antibodies caused strong reduction in the titer of specific IgG in mice immunized with tetanus toxoid, nitrophenol, or arsonate and reduced numbers of surface IgG or IgA B lymphocytes. Thus, NGF is an autocrine survival factor for memory B lymphocytes.

Familial AL-amyloidosis in three Italian siblings

BACKGROUND AND METHODS

Familial occurrence of immunoglobulin-related (AL) amyloidosis has occasionally been reported. In this work we describe the concomitance of systemic amyloidosis and monoclonal gammopathy (one case of Waldenström's macroglobulinemia and two cases without multiple myeloma or related diseases) in three Italian siblings, two males and one female.

RESULTS AND CONCLUSIONS

All of them showed a common pattern of polyneuropathy to different degrees; two presented a sicca syndrome and one also suffered from nephropathy. Two of them showed the same HLA typing with the same light chain type (k), but had different presenting symptoms. Polyneuropathy and a history of peptic disease in two cases was suggestive of type III familial amyloidotic polyneuropathy (FAP) occurring in the setting of a familial monoclonal component. However, immunohistochemical studies on different tissue specimens using anti-apolipoprotein A1 and anti-transthyretin antibodies were negative. Further screening of DNA samples for transthyretin (TTR) gene mutations was also negative. Clinical and laboratory investigations ruled out reactive or senile amyloidosis and immunohistochemical studies with anti-light chain antibodies on amyloidotic tissue specimens were positive. As a consequence, this family represents a new case of familial AL-amyloidosis.

Modulation of cell proliferation and cytokine production in AML by recombinant interleukin-1 receptor antagonist

In Acute Myelogenous Leukemia (AML), Interleukin 1 (IL-1) might sustain autocrine and paracrine loops of leukemic growth. An IL-1 inhibitor has been recently purified and cloned. This molecule binds to the IL-1 receptors but has no IL-1 like activity fulfilling the characteristics of a pure Interleukin-1 receptor antagonist (IL-1ra). We studied the in vitro effect of human recombinant IL-1ra on proliferation of AML blasts. Spontaneous as well as IL-1 stimulated AML proliferation was significantly inhibited by the addition of 50 ng/ml of recombinant IL-1ra in a dose dependent manner. The inhibitory effect of IL-1ra was measurable after 12 hours of culture and reached a plateau at 60 hrs. We found that IL-1ra could compete with IL-1 in binding to specific IL-1 receptors on AML cells. As expected, culture supernatants of unstimulated leukemic samples contained IL-1 beta and GM-CSF activity. The incubation of the same leukemic blasts with IL-1 ra was followed by reduction or disappearance of GM-CSF in culture supernatants whereas the IL-1 beta production was only partially modulated. By Northern blot experiments performed on freshly isolated, uncultured leukemic blasts, we found a constitutive expression of the IL-1 beta gene in 19 of 23 AML cases analyzed. On the contrary, only three of these patients express the IL-1 RA mRNA. All together these results suggest that imbalanced secretion of IL-1 and its natural receptor antagonist could contribute to the unrestricted growth of AML cells.

Interferon-alpha and interleukin 2 synergistically enhance basic fibroblast growth factor synthesis and induce release, promoting endothelial cell growth

To elucidate mechanisms underlying neovascularization that accompanies certain chronic immune/inflammatory disorders, the effects of interferon-alpha (IFN-alpha) and interleukin 2 (IL-2) on endothelial cell (EC) growth in vitro and angiogenesis in vivo were studied. Preincubation of cultured human ECs with IFN-alpha, followed by exposure to IL-2, resulted in effective stimulation of cell growth, whereas either cytokine alone had only a slight effect. The combination of IFN-alpha/IL-2 induced an angiogenic response in the rabbit cornea. IL-2 receptor expression was enhanced on IFN-alpha-treated ECs: p55 was increased and p70 was induced. 125I-IL-2 binding to ECs treated with IFN-alpha was enhanced (Kd from approximately 7 nM to approximately 260 pM with IFN-alpha), and anti-p55 IgG blocked 125I-IL-2/EC interaction as well as IL-2-mediated EC proliferation. Consistent with these findings in cell culture, immunohistologic studies demonstrated p55 and p70 antigen in the vasculature of rheumatoid joints, but not in normal joint tissue. Exposure of cultured ECs to IFN-alpha increased levels of intracellular EC basic fibroblast growth factor (bFGF), and subsequent addition of IL-2 led to bFGF release into the medium. The observation that anti-bFGF IgG largely blocked EC proliferation in response to IFN-alpha/IL-2 suggested that bFGF was a critical agent in this setting. These data suggest a mechanism rendering ECs responsive to IL-2 which may be relevant in immune/inflammatory disorders: IFN-alpha-mediated induction of functional EC receptors for IL-2, which drives cell proliferation by a mechanism dependent on increased synthesis and release of bFGF.

Post-translational regulation of interleukin 1 beta secretion

In view of the key role played by interleukin 1 (IL-1) beta in inflammation, its production is likely to be precisely regulated. Previous studies have shown that IL-1 beta biosynthesis is controlled at the transcriptional and translational levels. We have investigated whether post-translational events also play a role in regulating the production of bioactive IL-1 beta. IL-1 beta, which lacks a signal sequence, is released by activated monocytes through a novel pathway of secretion, alternative to the classical endoplasmic reticulum-Golgi route. Secretion of mature 17 kDA IL-1 beta is increased when pulse-labelled activated monocytes are chased in the presence of heat-aggregated immunoglobulins or of various drugs. Febrile temperatures inhibit secretion of mature IL-1 beta, but only reduce its synthesis: treatment with cycloheximide restores secretion. Processing of the 33 kDa precursor to the 17 kDa mature molecule is inhibited when the external pH is 8 or higher: under these conditions, release of unprocessed, biologically inactive 33 kDa IL-1 beta is observed. Thus, secretion of IL-1 beta is regulated by post-translational mechanisms which operate at the level of both proteolytic processing and extracellular export.

Modulation of cell proliferation and cytokine production in acute myeloblastic leukemia by interleukin-1 receptor antagonist and lack of its expression by leukemic cells

Interleukin-1 (IL-1) is spontaneously produced by acute myeloblastic leukemia (AML) cells. IL-1 also induces synthesis of colony-stimulating factors (CSFs) and sustains leukemic growth. An IL-1-specific inhibitor has been recently purified and cloned; this molecule binds to IL-1 receptors but has no IL-1 activity, fulfilling the characteristics of an IL-1 receptor antagonist (IL-1ra). Because high-affinity binding sites for IL-1ra were shown on AML cells by radioligand binding studies, we studied the effect of IL-1ra on the proliferative activity of blast cells isolated from 16 cases of AML. In each case, spontaneous proliferation was inhibited by addition of the IL-1ra in a dose-dependent manner (1 to 100 ng/mL). Culture supernatants of unstimulated leukemic cells contained IL-1 beta and granulocyte-macrophage CSF (GM-CSF), but when incubated with the IL-1ra, a reduction or disappearance of GM-CSF was observed in 8 of 10 cases, whereas spontaneous IL-1 production was reduced in four of seven cases. By Northern hybridization, IL-1 beta gene transcripts were shown in 20 of 23 AML cases, whereas IL-1ra-specific messenger RNA was present in only two of the patients studied. These data show a role for IL-1 in the spontaneous proliferation and cytokine production of AML cells and suggest that an imbalanced synthesis of IL-1 and of its natural receptor antagonist may contribute to the unrestricted growth of AML cells.

Surgical synovectomy in the treatment of rheumatoid arthritis: the results obtained in a controlled study

The authors report the long-term results obtained after 2 and 4 years in a controlled study conducted on surgical synovectomies performed in articular and extra-articular regions in rheumatoid arthritis. Out of a total of 157 patients submitted to surgery between 1977 and 1987 admitted to the study were 82 patients with bilateral symmetric localizations, but who had been submitted to synovectomy only unilaterally. The collection and interpretation of data showed that synovectomy is truly effective and that clinical improvements is not related to a spontaneous regression in the rheumatoid process. Surgery must be performed when the degree of osteocartilaginous deficit is absent or moderate. It does not avoid local recurrence, but it does obtain an antalgic effect, better joint excursion, and a slowing down in the destructive osteocartilaginous processes.

Macrovascular and microvascular endothelium during long-term hypoxia: alterations in cell growth, monolayer permeability, and cell surface coagulant properties

In bovine aortic or capillary endothelial cells (ECs) incubated under hypoxic conditions, cell growth was slowed in a dose-dependent manner at lower oxygen concentrations, as progression into S phase from G1 was inhibited, concomitant with decreased thymidine kinase activity. Monolayers grown to confluence in ambient air, wounded, and then transferred to hypoxia showed decreased ability to repair the wound, as a result of both decreased motility and cell division. Hypoxic ECs demonstrated a approximately 3-fold increase in the total number of high-affinity fibroblast growth factor receptors, and levels of endogenous FGF were suppressed. Consistent with the presence of functional FGF receptors, addition of basic FGF overcame, at least in part, hypoxia-mediated suppression of EC growth, and enhanced wound repair in hypoxia, stimulating both motility and cell division. Despite slower growth in hypoxia, ECs could achieve confluence, and the monolayers consisted of larger cells with altered assembly of the actin-based cytoskeleton and small gaps between contiguous cells. The permeability of these hypoxic EC monolayers to macromolecules and lower molecular weight solutes was increased. Cell surface coagulant properties were also perturbed: the anticoagulant cofactor thrombomodulin was suppressed, and a novel Factor X activator appeared on the EC surface. These data indicate that micro- and macrovascular ECs can grow and be maintained at low oxygen tensions, but hypoxic endothelium exhibits a range of altered functional properties which can potentially contribute to the pathogenesis of vascular lesions.

Interleukin-1 and interleukin-2 control granulocyte- and granulocyte-macrophage colony-stimulating factor gene expression and cell proliferation in cultured acute myeloblastic leukemia

In vitro proliferation of leukemic cells purified from 10 cases of acute myeloblastic leukemia (AML) was analyzed in basal conditions or in the presence of exogenous recombinant (r) Interleukin (IL) 1. In parallel, blasts from 5 of these patients were studied for granulocyte-macrophage colony-stimulating factor (GM-CSF) or granulocyte-CSF (G-CSF) mRNA. IL-1 augmented the spontaneous AML cell proliferation in all cases and induced de novo expression or increased amounts of GM-CSF and/or G-CSF transcripts in 4 of the 5 cases evaluated. IL-1-induced AML cell proliferation was modulated by neutralizing anti-GM-CSF or anti-G-CSF antibodies in those cases in which CSF mRNAs were induced or increased by exogenous cytokine. In the same cases, biosynthetic labelling and immunoprecipitation studies using monospecific anti-GM-CSF antibodies showed that IL-1 also increased the levels of GM-CSF protein synthesis. Addition of neutralizing anti-IL-1 antibodies to AML cell cultures completely abolished ongoing GM-CSF synthesis, suggesting that endogenous IL-1 is needed to maintain autocrine production of CSFs. The effects of rIL-2 were investigated in a larger series of 21 patients. The cytokine reduced spontaneous AML cell proliferation in 8 cases. It caused complete disappearance of GM-CSF mRNA in 1 case, and marked reduction of G-CSF mRNA in 2 cases. Increased AML cell proliferation was observed in 2 of 21 cases. These findings suggest that expression of CSF genes and cell proliferation in AML are under the control of different cytokines acting in autocrine or paracrine fashion.

Interleukin 1 is an autocrine regulator of human endothelial cell growth

Proliferation of endothelial cells is regulated through the autocrine production of growth factors and the expression of cognate surface receptors. In this study, we demonstrate that interleukin 1 (IL-1) is an inhibitor of endothelial growth in vitro and in vivo. IL-1 arrested growing, cultured endothelial cells in G1 phase; inhibition of proliferation was dose dependent and occurred in parallel with occupancy of endothelial surface IL-1 receptors. In an angiogenesis model, IL-1 could inhibit fibroblast growth factor-induced vessel formation. The autocrine nature of the IL-1 effect on endothelial proliferation was demonstrated by the observation that occupancy of cell-surface receptors by endogenous IL-1 depressed cell growth. The potential significance of this finding was emphasized by the detection of IL-1 in the native endothelium of human umbilical veins. A mechanism by which IL-1 may exert its inhibitory effect on endothelial cell growth was suggested by studies showing that IL-1 decreased the expression of high-affinity fibroblast growth factor binding sites on endothelium. These results point to a potentially important role of IL-1 in regulating blood vessel growth and suggest that autocrine production of inhibitory factors may be a mechanism controlling proliferation of normal cells.

A novel secretory pathway for interleukin-1 beta, a protein lacking a signal sequence

Interleukin 1 (IL-1) is a major soluble mediator of inflammation. Two human IL-1 genes, alpha and beta, have been isolated, which encode polypeptides with only 20-30% amino acid sequence homology. Unlike most secreted proteins, the two cytokines do not have a signal sequence, an unexpected finding in view of their biological role. Here we show that IL-1 beta is actively secreted by activated human monocytes via a pathway of secretion different from the classical endoplasmic reticulum--Golgi route. Drugs which block the intracellular transport of IL-6, of tumour necrosis factor alpha and of other secretory proteins do not inhibit secretion of IL-1 beta. Secretion of IL-1 beta is blocked by methylamine, low temperature or serum free medium, and is increased by raising the culture temperature to 42 degrees C or by the presence of calcium ionophores, brefeldin A, monensin, dinitrophenol or carbonyl cyanide chlorophenylhydrazone. IL-1 beta is contained in part within intracellular vesicles which protect it from protease digestion. In U937 cells large amounts of IL-1 beta are made but none is secreted. In these cells IL-1 beta is not found in the vesicular fraction, and all the protein is accessible to protease digestion. This suggests that intracellular vesicles that contain IL-1 beta are part of the protein secretory pathway. We conclude that IL-1 beta is released by activated monocytes via a novel mechanism of secretion which may involve translocation of intracellular membranes and is increased by stress conditions.

Echotomographic imaging in a case of plexiform von Recklinghausen neurofibromatosis

The authors present a case of plexiform von Recklinghausen neurofibromatosis with lumbosacral localisation and extension along the femoral nerve. The usefulness of echotomographic imaging is illustrated in clarifying the diagnosis, and excluding other pathological conditions which may present a similar clinical picture.

Production of interleukin-1 by bone marrow myeloma cells

Plasma cells isolated from bone marrow (BM) aspirates of 12 patients with multiple myeloma (MM) and nine patients with monoclonal gammopathy of undetermined significance (MGUS) were analyzed for production of cytokines with bone-resorbing activity, such as interleukin-1 (IL-1), tumor necrosis factor (TNF), and lymphotoxin (LT). Culture supernatants of plasma cells from MM, but not from MGUS or normal donor, invariably contained high amounts of IL-1-beta and lower amounts of IL-1-alpha. With a single exception, TNF/LT biologic activity was not detected in the same supernatants. IL-6 was present in two of five supernatants tested. Normal B lymphocytes released both IL-1 and TNF/LT activities for four days after activation in vitro; however, production of these cytokines ceased at the final stage of plasma cell. Unexpectedly, the mRNA extracted from MM plasma cell hybridized with TNF- and LT-specific, as well as IL-1-specific probes, although the culture supernatants did not contain detectable TNF/LT biologic activity. When tested in the fetal rat long bone assay, MM plasma cell supernatants displayed a strong osteoclast-activating factor (OAF) activity, which was greatly reduced but not completely abolished by neutralizing anti-IL-1 antibodies. Anti-TNF or anti-LT antibodies were ineffective in the same test. We conclude that the IL-1 released in vivo by malignant plasma cells has a major role in pathogenesis of lytic bone lesions of human MM.

Interleukin 1 as an autocrine growth factor for acute myeloid leukemia cells

Production of interleukin 1 (IL-1) by leukemic cells was studied in 13 cases of acute myeloid leukemia. Intracytoplasmic immunofluorescence studies showed that the cells invariably contained the cytokine. Endogenous labeling studies demonstrated that acute myeloid leukemia cells produced either only the 33-kDa propeptide or both the propeptide and the 17-kDa mature form of IL-1 beta. The 33-kDa propeptide IL-1 alpha was always produced but was less frequently released. Involvement of IL-1 in leukemic cell growth was investigated using two antibodies specific for IL-1 subtypes, which inhibited spontaneous cell proliferation in the six cases studied. After acid treatment of the cells, a surface receptor for IL-1 could be demonstrated, which mediated 125I-labeled IL-1-specific uptake by leukemic cells. Furthermore, recombinant IL-1 alpha or IL-1 beta induced significant cell proliferation in 10 of 12 cases. The above findings were uncorrelated with the cytologic type (French-American-British classification) of leukemia. Our studies suggest that IL-1 may act as an autocrine growth factor in most cases of acute myeloid leukemia.

Interleukin-6 gene expression in human endothelial cells: RNA start sites, multiple IL-6 proteins and inhibition of proliferation

Interleukin-6 (IL-6) is a cytokine which is not only produced by a wide variety of different cells but one which also affects the function of diverse tissues. We have studied the expression of the IL-6 gene in freshly explanted human umbilical vein endothelial cells (HUVEC) and have also evaluated the effect of IL-6 on HUVEC proliferation. Cytokines like interleukin-1 alpha (IL-1 alpha) and tumor necrosis factor (TNF) as well as bacterial products such as the lipopolysaccharide (LPS) rapidly enhance production of biologically active IL-6 by HUVEC (IL-6 bioassay: increase in alpha 1-antichymotrypsin secretion by Hep3B2 cells and its neutralization by antiserum to E. coli-derived human IL-6). The two inducible RNA start sites in the IL-6 gene that are used in cytokine-induced fibroblasts (at +1 and -21) are also used in the same relative proportion (+1 greater than -21) in cytokine or LPS-induced HUVEC as determined by S1-nuclease protection assays for IL-6 transcripts. Immunoaffinity chromatography followed by Western blotting shows that IL-6 species secreted by IL-1 alpha-induced HUVEC are of molecular mass 23-25, 27-30 and 45 kDa as judged by SDS-PAGE under reducing conditions. Finally, rIL-6 inhibits [3H]-thymidine incorporation by HUVEC in a dose-dependent manner. Thus IL-6 is not only produced by HUVEC but may also affect its proliferation. The ability of the vascular endothelium to rapidly secrete IL-6 in response to inflammation-associated cytokines is of strategic value since it generates a circulatory signal which helps mobilize the acute phase plasma protein response and enlists the immune system in host defence.

Potential role of interleukin-1 as the trigger for diffuse intravascular coagulation in acute nonlymphoblastic leukemia

Abnormalities of coagulation are common in patients with acute nonlymphoblastic leukemia, although the mechanisms involved are unclear, except in a few cases. To investigate the pathogenesis of this coagulopathy, suspensions of purified leukemic cells were prepared and tested for procoagulant activity. Neither the leukemic cells nor their supernatants directly accelerated the clotting of plasma. Since the leukemic cells did not possess direct procoagulant activity, their ability or inability to elaborate a mediator of cellular coagulant properties, interleukin-1, was studied. Leukemic cells from patients with coagulopathy elaborated interleukin-1, and addition of phytohemagglutinin increased interleukin-1 release. In contrast, no interleukin-1 was released, before or after stimulation with phytohemagglutinin, from leukemic cells from patients without coagulopathy. Leukemic cells from another group of patients with abnormalities of coagulation released interleukin-1 only after phytohemagglutinin treatment. In terms of the coagulation mechanism, interleukin-1 containing supernatants from leukemic cell cultures induced the procoagulant receptor tissue factor, a co-factor in the initiation of coagulation, on the endothelial cell surface. There was coordinate suppression of the anticoagulant endothelial cell receptor thrombomodulin, a co-factor for the antithrombotic protein C pathway. Antibody to interleukin-1 prevented these changes in cellular coagulant properties. Taken together, these changes result in a shift in the balance of endothelial cell coagulant properties to an activated state in which mechanisms promoting procoagulant reactions on the vessel surface predominate. Synthesis and release of the mediator interleukin-1 by leukemic cells thus defines a new mechanism through which malignant cells can potentially activate the coagulation mechanism.

In vitro interleukin-1 production by different dialysis membranes

This study investigates the Il-1 production in vitro by normal peripheral blood monocytes or non-T cells following contact with different dialysis membranes (cuprophan, polysulphone, polymethylmethacrylate and polyacrylonitrile), in the presence or absence of lipopolysaccharide. The results of this study show that the physical contact between dialysis membranes and Il-1 producing cells is not by itself able to induce abundant Il-1 production unless exogenous lipopolysaccharide is added. A modest Il-1 production, however, could be observed with synthetic membranes (polysulphone and polyacrylonitrile), but not with cellulose membranes (cuprophan). Used membranes are completely ineffective as a trigger of Il-1 synthesis.

Characterization of cells from invaded lymph nodes in patients with solid tumors. Lymphokine requirement for tumor-specific lymphoproliferative response

The specific immune response against the malignant cells was investigated in patients with urinary bladder or larynx cancer. Lymphocytes from lymph nodes that drain the tumor site were tested for their proliferative and cytotoxic capacities against autologous malignant cells isolated from the primary tumor. In no occasion was a proliferative or a cytotoxic response observed. However, when the lymph node cell suspensions were depleted of cells expressing both OKM1 and Leu-7 markers by rosetting with the appropriate mAbs, a proliferative response could be observed. The lymphocytes responded to autologous tumor cells only if IL-2 was added to the cultures. IL-2 alone induced some cell proliferation, which was not, however, comparable to that observed in response to both IL-2 and tumor cells. A panel of allogeneic tumor cells consistently failed to stimulate OKM1-, Leu-7- cells in vitro. Response to autologous tumor cells was not caused by HLA-encoded molecules, as occurs in the autologous mixed lymphocyte reaction, since OKM1-, Leu-7- cells failed to be stimulated by autologous non-T cells. A proliferative response was observed only with cells from lymph nodes that had been classified as invaded by malignant cells according to histopathologic criteria. Cells from noninvaded lymph nodes consistently failed to respond. Cells stimulated with autologous tumor cells could be expanded in short-term lines by continuous addition of IL-2 and malignant cells. One of these lines, which comprised mainly T8+ cells, was stimulated to proliferate only by autologous tumor cells, and its proliferative response was inhibitable by anti-class I and not by anti-class II mAbs. This line showed lytic capacities against autologous malignant targets, while it was inefficient against all of the other allogeneic cells tested. In another set of experiments, the mechanisms whereby exogenous IL-2 had to be added to the cultures to sustain a proliferative response against neoplastic cells were investigated. When cocultured with autologous malignant cells, OKM1-, Leu-7- lymphocytes expressed IL-2 receptors, as could be assessed by anti-Tac fluorescent staining. Under these culture conditions, these cells did not produce IL-2, and no proliferation was observed. Addition of purified IL-1 to the cultures induced IL-2 production and cell proliferation. It is concluded that metastatic lymph nodes contain a T cell population that can be detected in a proliferative assay when both suppressor cells are removed and the appropriate molecular signals are supplied.

Functional characterization of an antigen involved in an early step of T-cell activation

An activation antigen, identified by the monoclonal antibody MLR3, is described that is present on activated T lymphocytes and thymocytes but not on resting T lymphocytes. Immunoprecipitation of radiolabeled membranes from an activated T-cell line showed that the MLR3-binding molecule has a molecular size of 28-34 kDa. Immunofluorescence analysis showed that the appearance of the MLR3 antigen is an early event and precedes that of the interleukin 2 receptor both in T lymphocytes and thymocytes. The proliferative response of resting T cells to OKT3-Sepharose and interleukin 1 or accessory cells, but not the interleukin 2-dependent proliferation, was inhibited by the addition of MLR3 monoclonal antibodies. Similar results wer also obtained in an interleukin 1-dependent human thymocyte proliferation assay. In addition when MLR3-positive cells were cultured with purified interleukin 1, MLR3 surface antigen expression was not observed. Thus MLR3 monoclonal antibody appears to recognize an antigen involved in an early step of T-cell activation related to interleukin 1-dependent functions and on both T lymphocytes and thymocytes.

Production of colony-stimulating activity by normal and neoplastic human B lymphocytes

Normal human B cells were purified from peripheral blood or tonsils and tested for their ability to release colony-stimulating activity (CSA) in short-term cultures. The target cells used in the CSA assays were from peripheral blood or bone marrow. Unstimulated B cells produced CSA in amounts similar to those present in the GCT-conditioned medium used as a positive control. The B cell-derived CSA predominantly promoted the growth of colonies that contained macrophages alone or macrophages and granulocytes. CSA eluted in a single peak from a G-75 Sephadex column with an approximate molecular weight (mw) of 65 to 70 kilodaltons (kd). Fractionation of tonsil B lymphocytes on Percoll density gradients showed that large B cells, probably already activated in vivo, were the main source of CSA. By contrast, small, resting B cells recovered from a different fraction of the Percoll gradient released minimum amounts or no CSA. However, these B cells became CSA producers following stimulation with Staphylococcus aureus Cowan (SAC) in vitro. B cells purified from the peripheral blood of nine out of 12 patients with B-cell chronic lymphocytic leukemia (B-CLL) also released CSA in vitro in the absence of stimuli. These findings suggest that by releasing CSA, B cells may have a role in the regulation of hematopoiesis and in the control of the inflammatory process.

Presence of activated T-cells with a T8+ M1+ Leu 7+ surface phenotype in invaded lymph nodes from patients with solid tumors

The lymphocyte surface phenotype of lymph nodes from patients with larynx or urinary bladder carcinoma was investigated by using a panel of monoclonal antibodies. The phenotype pattern of lymphocytes from lymph nodes invaded by malignant cells (as assessed by histopathology) was different from that of the cells from noninvaded or normal control nodes. Although the proportion of natural killer cells or macrophages was similar in the 3 groups of lymph nodes, invaded lymph nodes contained a higher proportion of T-cells and a lower B-cell percentage. Furthermore, cells from invaded nodes comprised 15-20% of T3+ T8+ cells that coexpressed the M1 marker and, to some extent, also the Leu 7 marker. A large proportion of cells with multiple markers were activated, as shown by the expression of Tac and HLA-DR antigens. In 2 patients activated T8+ cells expressing also M1 and Leu 7 markers infiltrated the tumor site. The presence of these activated cells both in involved nodes and tumor mass may indicate that they originate in response to cancer.

In vitro production of interleukin 1 by normal and malignant human B lymphocytes

In this study, the capacity of normal and neoplastic B lymphocytes to release interleukin 1 (IL 1) has been investigated. Peripheral blood B cells from normal donors were isolated by depletion of E rosetting cells and by positive selection of cells expressing surface immunoglobulin (sIg) or the B1 marker. Peripheral blood B cells from patients with B cell chronic lymphocytic leukemia (B-CLL) were purified by removal of E rosetting cells followed by complement-mediated cytotoxicity with selected monoclonal antibodies. All of the normal B cell suspensions and the large majority of the B-CLL cells produced in culture high amounts of IL 1 in the absence of any apparent stimulus. Control experiments ruled out that small numbers of monocytes in the B cell suspensions could represent the source of IL 1. These data support the contention that B cells participate to the immune response as accessory cells for T cell activation not only by physically presenting antigen, but also by releasing IL 1.

In vitro production of interleukin 1 by normal and malignant human B lymphocytes

In this study, the capacity of normal and neoplastic B lymphocytes to release interleukin 1 (IL 1) has been investigated. Peripheral blood B cells from normal donors were isolated by depletion of E rosetting cells and by positive selection of cells expressing surface immunoglobulin (sIg) or the B1 marker. Peripheral blood B cells from patients with B cell chronic lymphocytic leukemia (B-CLL) were purified by removal of E rosetting cells followed by complement-mediated cytotoxicity with selected monoclonal antibodies. All of the normal B cell suspensions and the large majority of the B-CLL cells produced in culture high amounts of IL 1 in the absence of any apparent stimulus. Control experiments ruled out that small numbers of monocytes in the B cell suspensions could represent the source of IL 1. These data support the contention that B cells participate to the immune response as accessory cells for T cell activation not only by physically presenting antigen, but also by releasing IL 1.

Production of B cell growth factor by a Leu-7+, OKM1+ non-T cell with the features of large granular lymphocytes (LGL)

The present study reports the characterization of a non-T cell from human peripheral blood which is capable of releasing BCGF. This BCGF-producing non-T cell had a T3-, T8-, Leu-7+, OKM1+, HLA-DR-, Leu-11- surface phenotype and was likely to belong to the so-called large granular lymphocyte (LGL) subset because: after fractionation of non-T cells according to the expression of Leu-7 or HLA-DR markers, it was found in the Leu-7+, HLA-DR- fractions that were particularly enriched in LGL; it co-purified with LGL on Percoll density gradients; and it expressed Leu-7 and OKM1 markers that are shared by a large fraction of LGL. Although co-purified with cells with potent NK capacities, the BCGF-producing cell was not cytotoxic, because treatment of Leu-7+ cells with Leu-11 monoclonal antibody and complement abolished the NK activity but left the BCGF activity unaltered. The factor released by this LGL subset was not IL 1 or IL 2 mistakenly interpreted as BCGF, because: a) cell supernatants particularly rich in BCGF activity contained very little or no IL 1 or IL 2; b) BCGF-induced B cell proliferation was not inhibitable by anti-Tac antibodies (this in spite of the expression of IL 2 receptor by a proportion of activated B cells); and c) BCGF activity was absorbed by B but not T blasts.

Production of B cell growth factor by a Leu-7+, OKM1+ non-T cell with the features of large granular lymphocytes (LGL)

The present study reports the characterization of a non-T cell from human peripheral blood which is capable of releasing BCGF. This BCGF-producing non-T cell had a T3-, T8-, Leu-7+, OKM1+, HLA-DR-, Leu-11- surface phenotype and was likely to belong to the so-called large granular lymphocyte (LGL) subset because: after fractionation of non-T cells according to the expression of Leu-7 or HLA-DR markers, it was found in the Leu-7+, HLA-DR- fractions that were particularly enriched in LGL; it co-purified with LGL on Percoll density gradients; and it expressed Leu-7 and OKM1 markers that are shared by a large fraction of LGL. Although co-purified with cells with potent NK capacities, the BCGF-producing cell was not cytotoxic, because treatment of Leu-7+ cells with Leu-11 monoclonal antibody and complement abolished the NK activity but left the BCGF activity unaltered. The factor released by this LGL subset was not IL 1 or IL 2 mistakenly interpreted as BCGF, because: a) cell supernatants particularly rich in BCGF activity contained very little or no IL 1 or IL 2; b) BCGF-induced B cell proliferation was not inhibitable by anti-Tac antibodies (this in spite of the expression of IL 2 receptor by a proportion of activated B cells); and c) BCGF activity was absorbed by B but not T blasts.