Mobilization without immune depletion fails to restore immunological tolerance or preserve beta cell function in recent onset type 1 diabetes.

Granulocyte colony-stimulating factor (G-CSF) has been used to restore immune competence following chemoablative cancer therapy and to promote immunological tolerance in certain settings of autoimmunity. Therefore, we tested the potential of G-CSF to impact type 1 diabetes (T1D) progression in patients with recent-onset disease [n = 14; n = 7 (placebo)] and assessed safety, efficacy and mechanistic effects on the immune system. We hypothesized that pegylated G-CSF (6 mg administered subcutaneously every 2 weeks for 12 weeks) would promote regulatory T cell (Treg) mobilization to a degree capable of restoring immunological tolerance, thus preventing further decline in C-peptide production. Although treatment was well tolerated, G-CSF monotherapy did not affect C-peptide production, glycated haemoglobin (HbA1c) or insulin dose. Mechanistically, G-CSF treatment increased circulating neutrophils during the 12-week course of therapy (P < 0·01) but did not alter Treg frequencies. No effects were observed for CD4(+) : CD8(+) T cell ratio or the ratio of naive : memory (CD45RA(+)/CD45RO(+)) CD4(+) T cells. As expected, manageable bone pain was common in subjects receiving G-CSF, but notably, no severe adverse events such as splenomegaly occurred. This study supports the continued exploration of G-CSF and other mobilizing agents in subjects with T1D, but only when combined with immunodepleting agents where synergistic mechanisms of action have previously demonstrated efficacy towards the preservation of C-peptide.

Clinically relevant fatigue in recurrence-free prostate cancer survivors.

BACKGROUND: Little is known about the prevalence and associations of clinically relevant fatigue (CRF) in recurrence-free prostate cancer survivors. PATIENTS AND METHODS: Four hundred and sixteen recurrence-free prostate cancer survivors who were >1 year post-radiotherapy or radical prostatectomy were surveyed. The prevalence of CRF (defined as Brief Fatigue Inventory >3) was determined and compared with a noncancer control group. Other measures included the Hospital Anxiety and Depression Scale, International Prostate Symptom Score, European Organization for Research and Treatment of Cancer Quality of Life Questionnaire. Relationships between these factors and CRF were explored in univariate and multivariate analyses. RESULTS: Analyzable data were obtained from 91% (377/416) of patients. The prevalence of CRF was 29% (108/377) versus 16% (10/63) in the controls (P=0.031). CRF was more common in post-radiotherapy than in post-prostatectomy 33% (79/240) versus 22% (29/133), P=0.024. However, when other factors (current depression, anxiety, urinary symptoms, medical comorbidities, pain and insomnia) were controlled for, previous treatment did not predict CRF. Current depression [Hospital Anxiety and Depression Scale≥8 was by far the strongest association [odds ratio 9.9, 95% confidence interval 4.2-23.5)]. CONCLUSIONS: Almost one-third of recurrence-free prostate cancer survivors report CRF. Depression, anxiety, urinary symptoms, pain and insomnia measured at outcome are more strongly associated than type of cancer treatment previously received.

Clinically relevant fatigue in men with hormone-sensitive prostate cancer on long-term androgen deprivation therapy.

BACKGROUND: The purpose of the study was to determine the prevalence and associations of clinically relevant fatigue (CRF) in men with biochemically controlled prostate cancer on long-term androgen deprivation therapy (ADT). PATIENTS AND METHODS: One hundred and ninety-eight men were surveyed and the prevalence of CRF (Brief Fatigue Inventory score >3) determined. Associations with other measures (Hospital Anxiety and Depression Scale; International Prostate Symptom Score; European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire; Brief Pain Inventory worst pain; clinical and demographic information) were explored in univariate and multivariate analyses. RESULTS: Eight-one per cent (160 of 198) of questionnaires were analysable. CRF prevalence was 43% (68 of 160). CRF associations included moderate/severe urinary symptoms, anxiety and medical co-morbidities; the strongest associations were depression [odds ratio (OR) 9.8, 95% confidence interval (CI) 4.3-22.8] and pain (OR 9.2, 95% CI 4.0-21.5). After controlling for other factors, the independent associations were depression (OR 4.7, 95% CI 1.6-14.0) and pain (OR 3.1, 95% CI 1.0-8.9). There was no association with age, disease burden or treatment duration. CONCLUSIONS: Two-fifths of men with biochemically controlled prostate cancer on long-term ADT report CRF that interferes with function. Management aimed at improving CRF should address depression and pain.

Combinatorial treatment of bone marrow stem cells and stromal cell-derived factor 1 improves glycemia and insulin production in diabetic mice.

Transdifferentiation of stem cells into insulin-producing cells for the treatment of diabetes have shown promising but inconsistent results. We examined the potential for attracting bone marrow stem cells (BMSCs) to the pancreas using a chemokine, stromal cell-derived factor 1 (SDF-1). SDF-1 treatment markedly increased the number of GFP labeled BMSCs in the pancreas, but surprisingly, the majority was observed in liver. The liver cells had typical pancreatic endocrine cell gene expression including insulin I, insulin II, PDX-1, somatostatin, and glucagon. Combined treatment with SDF-1 and BMSC transplant reduced hyperglycemia and prolonged the long-term survival of diabetic mice, and a sub group had complete normoglycemia (<150 mg/dl), restored blood insulin levels, and normal glucose tolerance. Our results suggest that SDF-1 could potentially be used to improve the homing of stem cells and ß-cell regeneration. The mechanism appears to involve an increase in insulin producing cells mainly in the liver.

Influence of serum and soluble CD25 (sCD25) on regulatory and effector T-cell function in hepatocellular carcinoma.

Our previous studies showed that high levels of soluble CD25 (sCD25) in the serum of patients with hepatocellular carcinoma (HCC) correlated with blunted effector T-cells (Teff) responses, tumour burden and poor survival. Understanding the interactions between Teff, CD4+CD25+ regulatory T cells (Treg) and soluble factors can identify novel therapeutic targets. In this study, we characterize the mechanisms by which HCC serum and sCD25 mediate suppression of Teff and evaluate the effect of sCD25 on the suppression assays with normal healthy control cells (NHC) at a 1:1 Treg to Teff cell ratio to determine whether sCD25 has any impact on Treg suppression. HCC serum and sCD25 suppressed Teff proliferation and downregulated CD25 expression on HCC Teff in a dose-dependent fashion with sCD25 doses above 3000 pg/ml. Treg from HCC and cirrhosis patients suppressed proliferation of target CD4+CD25- Teff in serum-free medium (SFM). HCC Treg showed a higher degree of suppression than cirrhosis-derived Treg. In contrast, Treg from NHC did not suppress target Teff in SFM. However, isolated Treg from all three study subjects (HCC, cirrhosis and NHC) suppressed CD4+CD25- Teff in serum conditions or in the presence of sCD25 in the range 6000-12,000 pg/ml. In conclusion, downregulation of CD25 cell surface expression on Teff is part of the overall suppressive mechanism of sCD25 and HCC serum on Teff responses. The observed sCD25 and HCC serum-mediated suppression is further influenced via novel immune-inhibitory interaction between CD4+CD25+ Treg and sCD25.

Pancreatic adenocarcinoma patients with localised chronic severe pancreatitis show an increased number of single beta cells, without alterations in fractional insulin area.

AIMS/HYPOTHESIS: Recent histological analysis of pancreases obtained from patients with long-standing type 1 diabetes identified chronic islet inflammation and limited evidence suggestive of beta cell replication. Studies in rodent models also suggest that beta cell replication can be induced by certain inflammatory cytokines and by gastrin. We therefore tested the hypothesis that beta cell replication is observed in non-autoimmune human pancreatic disorders in which localised inflammation or elevated gastrin levels are present. METHODS: Resected operative pancreatic specimens were obtained from patients diagnosed with primary adenocarcinoma (with or without chronic severe pancreatitis) or gastrinoma. Additional pancreatic tissue was obtained from autopsy control patients. Immunohistochemistry was used to assess fractional insulin area, beta cell number and replication rate and differentiation factors relevant to beta cell development. RESULTS: Fractional insulin area was similar among groups. Patients with pancreatic adenocarcinoma and localised chronic severe pancreatitis displayed significant increases in the number of single beta cells, as well as increased beta cell replication rate and levels of neurogenic differentiation 1 in islets. Patients with gastrinoma demonstrated significant increases in the number of single beta cells, but the beta cell replication rate and islet differentiation factor levels were similar to those in the control group. CONCLUSIONS/INTERPRETATION: These findings indicate that chronic severe pancreatic inflammation can be associated with significant effects on beta cell number or replication rate, depending on the distribution of the cells. This information may prove useful for attempts seeking to design therapies aimed at inducing beta cell replication as a means of reversing diabetes.

Adeno-associated viral vector-mediated interleukin-10 prolongs allograft survival in a rat kidney transplantation model.

Interleukin-10 (IL-10) is a pleiotropic cytokine that plays a pivotal role in the regulation of immune responses. Hence, we evaluated the effects of a recombinant adeno-associated viral vector 1 (rAAV1) encoding rat IL-10 (rAAV1-IL-10) in a rat model of kidney allograft rejection. Dark Agouti rat kidneys were transplanted into Wistar-Furth (WF) rats 8 weeks following a single intramuscular administration of either rAAV1-IL-10 or rAAV1-green fluorescence protein (GFP). Isografts (WF-WF) served as an additional experimental control. Both allograft and isograft recipients received daily cyclosporine (10 mg/kg) for 14 days after transplantation. Serum IL-10 levels increased at 8, 12 and 16 weeks following vector administration in rAAV1-IL-10-treated animals, but not in rAAV1-GFP and isograft groups. rAAV1-IL-10 treatment resulted in lower BUN and creatinine levels (p<0.001), as well as increased allograft survival rates from 22% to 90%. Allograft histological abnormalities were significantly attenuated in the rAAV1-IL-10-treated rats compared with those of rAAV1-GFP controls. Serum levels of proinflammatory cytokines such as growth-related oncogene were also significantly higher in the rAAV1-GFP group than in the rAAV1-IL-10 group. These data suggest delivery of IL-10 using a rAAV1 vector improves renal function and prolongs graft survival in a rat model of kidney transplant rejection.

Immunity to adeno-associated virus serotype 2 delivered transgenes imparted by genetic predisposition to autoimmunity.

Adeno-associated virus (AAV) is widely considered a promising vector for therapeutic gene delivery. This promise is based on previous studies assessing AAVs safety and toxicity, ability to infect nondividing cells, elicit a limited immune response and provide long-term gene expression. However, we now find that earlier studies underappreciated the degree of AAV immunogenicity as well as the extent to which genetic background, through regulation of immune responsiveness, influences the duration of gene expression and thereby the effectiveness of AAV-mediated gene therapy. We evaluated antibody responses in 12 mouse strains to AAV serotype 2 (AAV2) and AAV2-expressed transgene products including green fluorescent protein (GFP), human alpha1-antitrypsin and murine interleukin-10. As expected, all immunocompetent mice administered AAV2 developed serologic evidence of immune responsiveness to the virus. However, a previously unidentified serologic prozone effect was observed suggesting that the concentrations of anti-AAV2 antibodies may have historically been subject to marked underestimation. Furthermore, strains with genetic predisposition to autoimmunity (eg, NOD, NZW, MRL-lpr) specifically imparted a functionally deleterious immune response to AAV-delivered transgene products. These findings suggest that more thorough studies of anti-AAV immunity should be performed, and that genetic predisposition to autoimmunity should be considered when assessing AAV efficacy and safety in humans.

Recombinant adeno-associated virus-mediated alpha-1 antitrypsin gene therapy prevents type I diabetes in NOD mice.

Type I diabetes results from an autoimmune destruction of the insulin-producing pancreatic beta cells. Although the exact immunologic processes underlying this disease are unclear, increasing evidence suggests that immunosuppressive, immunoregulatory and anti-inflammatory agents can interrupt the progression of the disease. Alpha 1 antitrypsin (AAT) is a multifunctional serine proteinase inhibitor (serpin) that also displays a wide range of anti-inflammatory properties. To test the ability of AAT to modulate the development of type I diabetes, we performed a series of investigations involving recombinant adeno-associated virus vector (rAAV)-mediated gene delivery of human alpha-1 antitrypsin (hAAT) to nonobese diabetic (NOD) mice. Recombinant AAV-expressing hAAT (rAAV2-CB-AT) was administered intramuscularly to 4-week-old female NOD mice (1 x 10(10) i.u./mouse). A single injection of this vector reduced the intensity of insulitis, the levels of insulin autoantibodies, and the frequency of overt type I diabetes (30% (3/10) at 32 weeks of age versus 70% (7/10) in controls). Transgene expression at the injection sites was confirmed by immunostaining. Interestingly, antibodies against hAAT were present in a majority of the vector-injected mice and circulating hAAT was undetectable when assessed 10 weeks postinjection. This study suggests a potential therapeutic role for AAT in preventing type I diabetes as well as the ability of AAV gene therapy-based approaches to ameliorate disease effectively.

Targeting recombinant adeno-associated virus vectors to enhance gene transfer to pancreatic islets and liver.

Human pancreatic islet cells and hepatocytes represent the two most likely target cells for genetic therapy of type I diabetes. However, limits to the efficiency of rAAV serotype 2 (rAAV2)-mediated gene transfer have been reported for both of these cell targets. Here we report that nonserotype 2 AAV capsids can mediate more efficient transduction of islet cells, with AAV1 being the most efficient serotype in murine islets, suggesting that receptor abundance could be limiting. In order to test this, we generated rAAV particles that display a ligand (ApoE) that targets the low-density lipoprotein receptor, which is present on both of these cell types. The rAAV/ApoE viruses greatly enhanced the efficiency of transduction of both islet cells ex vivo and murine hepatocytes in vivo when compared to native rAAV2 serotype (220- and four-fold, respectively). The use of receptor-targeted rAAV particles may circumvent the lower abundance of receptors on certain nonpermissive cell types.

Adeno-associated virus vector-mediated IL-10 gene delivery prevents type 1 diabetes in NOD mice.

The development of spontaneous autoimmune diabetes in nonobese diabetic (NOD) mice provides for their use as a model of human type 1 diabetes. To test the feasibility of muscle-directed gene therapy to prevent type 1 diabetes, we developed recombinant adeno-associated virus (rAAV) vectors containing murine cDNAs for immunomodulatory cytokines IL-4 or IL-10. Skeletal muscle transduction of female NOD mice with IL-10, but not IL-4, completely abrogated diabetes. rAAV-IL-10 transduction attenuated the production of insulin autoantibodies, quantitatively reduced pancreatic insulitis, maintained islet insulin content, and altered splenocyte cytokine responses to mitogenic stimulation. The beneficial effects were host specific, as adoptive transfer of splenocytes from rAAV IL-10-treated animals rapidly imparted diabetes in naive hosts, and the cells contained no protective immunomodulatory capacity, as defined through adoptive cotransfer analyses. These results indicate the utility for rAAV, a vector with advantages for therapeutic gene delivery, to transfer immunoregulatory cytokines capable of preventing type 1 diabetes. In addition, these studies provide foundational support for the concept of using immunoregulatory agents delivered by rAAV to modulate a variety of disorders associated with deleterious immune responses, including allergic reactions, transplantation rejection, immunodeficiencies, and autoimmune disorders.

Adeno-associated virus (AAV) as a vehicle for therapeutic gene delivery: improvements in vector design and viral production enhance potential to prolong graft survival in pancreatic islet cell transplantation for the reversal of type 1 diabetes.

Most viral gene delivery syslems utilized to date have demonstrated significant limitations in practicality and safety due to the level and duration of recombinant transgene expression as well as their induction of host immunogenicity to vector proteins. Recombinant adeno-associated virus (rAAV) vectors appear to offer a vehicle for safe, long-term therapeutic gene transfer; factors afforded through the propensity of rAAV to establish long-term latency without deleterious effects on the host cell and the relative non-immunogenicity of the virus or viral expressed transgenes. The principal historical limitation of this vector system, efficiency of rAAV-mediated transduction, has recently observed a dramatic increase as the titer, purity, and production capacity of rAAV preparations have improved. In terms of systems that could benefit from such improvements, rAAV gene therapy to enhance solid organ transplantation would appear an obvious choice with islet transplantation forming a promising candidate due to the ability to perform viral transductions ex vivo. Currently, islet transplantation can be used to treat type 1 diabetes yet persisting alloimmune and autoimmune responses represent major obstacles to the clinical success for this procedure. The delivery of transgenes capable of interfering with antigenic recognition and/or cell death [e.g., Fas ligand (FasL), Bcl-2, Bcl-XL] as well as imparting tolerance/immunoregulation [e.g., interleukin(IL)-4, IL-10, transforming growth factor (TGF)-beta], or cytoprotection [e.g., heme oxygenase-1 (HO-1), catalase, manganese superoxide dismutase (MnSOD)] may prevent recurrent type 1 diabetes in islet transplantation and offer a promising form of immunotherapy. Research investigations utilizing such systems may also provide information vital to understanding the immunoregulatory mechanisms critical to the development of both alloimmune and autoimmune islet cell rejection mechanisms and recurrent type 1 diabetes.

No alteration in T lymphocyte expression of CD40 ligand (CD154) in individuals with or at increased risk for insulin-dependent diabetes mellitus.

CD40 ligand (CD40L) regulates multiple phases of the humoral and cellular immune response through binding to CD40. Previous investigations have suggested that insulin-dependent diabetes (IDDM) in both humans and nonobese diabetic mice may be strongly influenced by similar immunoregulatory molecules. As persons with or at increased risk for the disease are characterized by a number of immunological abnormalities, including that of self-reactive autoantibody production (e.g. islet cell cytoplasmic autoantibodies), we analyzed the expression of CD40L on T lymphocytes (CD3+ cells) in a series of individuals with newly diagnosed IDDM (n = 11), nondiabetic relatives of IDDM probands at increased risk for the disease (n = 21; islet cell cytoplasmic autoantibodies positive; Juvenile Diabetes Foundation titer, > or = 20), and healthy controls (n = 13). Both phorbol myristate acetate (PMA)-stimulated and unstimulated peripheral blood mononuclear cells from study subjects were analyzed by flow cytometry with a series of phenotypic antibody markers (CD3, CD40L, and isotype controls). The kinetics of CD3 and CD40L expression on peripheral blood mononuclear cells under PMA-stimulated and unstimulated conditions were similar in the three study groups (6, 24, and 48 h; all P = NS). Similarly, unstimulated and PMA stimulated CD40L expressions (percentage of positive cells and level) on CD3+ cells from newly diagnosed IDDM patients and persons at increased risk for the disease were similar to those in healthy controls (6, 24, and 48 h; all P = NS). These findings do not support abnormal CD40L expression as the mechanism underlying the functional defect(s) in communication between T lymphocytes and antigen-presenting cells that allows for autoantibody production or the inability of individuals to regulate antiself immunity in IDDM.

Retardation or acceleration of diabetes in NOD/Lt mice mediated by intrathymic administration of candidate beta-cell antigens.

A single injection of syngeneic islet cells into the thymus of 4-week-old NOD/Lt female mice strongly retards diabetogenesis. The present study used the intrathymic route of antigen administration to compare the relative efficacy of peptides/proteins derived from two major candidate pancreatic beta-cell autoantigens, insulin and GAD65, to modulate diabetogenesis. Intrathymic administration of insulin B chain or recombinant human GAD65 significantly suppressed diabetogenesis during a 20-week follow-up period, whereas no protection was mediated by either insulin A chain or a synthetic peptide (A2) derived from it. Quite unexpectedly, two GAD65-derived peptides near the COOH-terminus (p34 and p35) accelerated diabetes onset. Semiquantitative reverse transcription-polymerase chain reaction analysis was performed on cDNAs from isolated islets or whole pancreases of NOD/Lt females 4 weeks after intrathymic injections. Protection mediated by intrathymic administration with either intact islet cells or GAD65 were correlated with an upregulation of mRNA for T-helper 2 (Th2)-associated cytokines (interleukin [IL]-4, IL-10), concomitant with downregulation of Th1-associated interferon (IFN) transcripts (all normalized to T-cell receptor Cbeta transcripts) in islet-infiltrating lymphocytes. Protection mediated by the intrathymic administration of insulin B chain, however, correlated only with a modest upregulation of IL-4 and IL-10 transcript levels, and no diminution in IFN-gamma transcripts. In contrast, the diabetes-accelerating GAD65 p34 and p35 peptides were not associated with an immune deviation, expressing levels of IFN-gamma characteristic of islet-infiltrating lymphocytes in vehicle-injected NOD controls. Hence, Th1-to-Th2 immune deviation provides only a partial explanation for peptide immunotherapy of diabetes in NOD mice. The finding that certain peptides can accelerate rather than retard diabetogenesis as a function of route and age of administration adds a cautionary note to this type of therapy.

Nasal administration of glutamate decarboxylase (GAD65) peptides induces Th2 responses and prevents murine insulin-dependent diabetes.

We previously demonstrated that a spontaneous Th1 response against glutamate decarboxylase (GAD65) arises in NOD mice at four weeks in age and subsequently T cell autoimmunity spreads both intramolecularly and intermolecularly. Induction of passive tolerance to GAD65, through inactivation of reactive T cells before the onset of autoimmunity, prevented determinant spreading and the development of insulin-dependent diabetes mellitus (IDDM). Here, we examined whether an alternative strategy, designed to induce active tolerance via the engagement of Th2 immune responses to GAD65, before the spontaneous onset of autoimmunity, could inhibit the cascade of Th1 responses that lead to IDDM. We observed that a single intranasal administration of GAD65 peptides to 2-3-wk-old NOD mice induced high levels of IgG1 antibodies to GAD65. GAD65 peptide treated mice displayed greatly reduced IFN gamma responses and increased IL-5 responses to GAD65, confirming the diversion of the spontaneous GAD65 Th1 response toward a Th2 phenotype. Consistent with the induction of an active tolerance mechanism, splenic CD4+ (but not CD8+) T cells from GAD65 peptide-treated mice, inhibited the adoptive transfer of IDDM to NOD-scid/scid mice. This active mechanism not only inhibited the development of proliferative T cell responses to GAD65, it also limited the expansion of autoreactive T cell responses to other beta cell antigens (i.e., determinant spreading). Finally, GAD65 peptide treatment reduced insulitis and long-term IDDM incidence. Collectively, these data suggest that the nasal administration of GAD65 peptides induces a Th2 cell response that inhibits the spontaneous development of autoreactive Th1 responses and the progression of beta cell autoimmunity in NOD mice.

Immunological and metabolic effects of prophylactic insulin therapy in the NOD-scid/scid adoptive transfer model of IDDM.

Prophylactic insulin therapy prevents IDDM in spontaneous animal models of the disease and has shown promise in preventing the disease in humans. Although large clinical trials have been formed to use this therapy, a comparative analysis of the efficiency of different pharmaceutical forms and doses of insulin in preventing IDDM has not been performed, and the mechanism underlying the observed prevention of disease is unknown. In the NOD-scid/scid adoptive transfer model of IDDM (10(7) new-onset NOD splenocytes injected intravenously into 6- to 8-week NOD/scid-scid recipients; insulitis develops at 6-9 days post-transfer and 100% IDDM by 32 days post-transfer), life-table (log-rank) analyses revealed that IDDM can be delayed (compared with insulin-free diluent, once daily, n = 8) with equivalent efficiency by prophylactic administration (-9-50 days post-transfer) of high (metabolism-altering) doses of short-acting (0.5 U, once daily, regular, n = 13) or long-acting (0.5 U, once daily, ultralente, n = 9) insulin as well as non-metabolism-altering low-dose insulin (0.02 U, once daily, regular, n = 8). Furthermore, IDDM was delayed with somatostatin (0.2 microgram, twice daily, n = 11), an agent that suppresses endogenous insulin production. No significant difference was seen between the preventative effects of these agents. In an assessment of when therapies can be initiated and still maintain clinical efficiency, only prophylactic somatostatin therapy delayed IDDM (n = 10, P = 0.02) when initiated at 14 days post-transfer, whereas the short-acting insulin regimen did not retard the onset of IDDM (n = 8, P = 0.25) compared with diluent-treated controls. The 24-h urinary C-peptide levels were significantly reduced with short-acting (-56%, P = 0.01) and long-acting (-67%, P = 0.02) insulin products and somatostatin (-59%, P = 0.02) compared with diluent-treated controls. These results indicate that both immunological and metabolic (i.e., beta-cell rest) factors may contribute to the beneficial effects of prophylactic insulin therapy.

The thymus as a site for evaluating the potency of candidate beta cell autoantigens in NOD mice.

Intrathymic (i.t.) injection of islet cells or whole islets retards development of insulin dependent diabetes mellitus (IDDM) in spontaneous animal models of the disease. Protection of 4-week-old prediabetic NOD/Lt female mice from subsequent IDDM development was specific for the it route of administration since intraperitoneal injection of an equal number of syngeneic islets failed to retard IDDM. The protective effect of i.t. injection of islet cells was compared with the effect of i.t. injection of syngeneic peritoneal exudate cells, NIT-1 cells, bovine serum albumin (BSA), ABBOS peptide, a 52 kDa islet cell membrane protein, various synthetic peptides from human glutamic acid decarboxylase (GAD) and a Coxsackievirus B4-derived peptide with homology to GAD. Interestingly, only a GAD-derived peptide containing sequence homology to Coxsackie-virus B4, and the corresponding Coxsackievirus B4-derived peptide, delayed IDDM onset. To establish the immunological mechanism underlying the reduced IDDM incidence following i.t. injection of islet cells, adoptive transfer of splenic leukocytes into NOD-scid/scid mice was performed. Splenic leukocytes from i.t.-injected non-diabetic females transferred IDDM into NOD-scid/scid recipients, but more slowly than splenocytes from unmanipulated, diabetic (control) donors. Co-transfer of 1:1 mixtures of splenic leukocytes from it islet-injected (and diabetes-free) NOD/Lt females and from untreated NOD/Lt diabetic donors produced IDDM as rapidly as splenocytes from diabetic donors injected alone. Hence, any peripheral suppression generated in i.t.-protected females was not sufficiently strong to prevent IDDM transfer by committed T-effector cells from the diabetic donors.(ABSTRACT TRUNCATED AT 250 WORDS)

A synthetic peptide which specifically inhibits heat-treated interleukin-8 binding and chemotaxis for neutrophils.

Interleukin-8 (IL-8) is a peptide which is secreted by stimulated human monocytes and which is chemotactic for human neutrophils. We synthesized three overlapping peptides spanning the amino-terminal region of the IL-8 sequence. None of the peptides retained the chemotactic activity of the native molecule. One of the peptides, IL-8(3-25), inhibited the neutrophil chemotactic activity of recombinant IL-8 (rIL-8) which had been preheated to 40 degrees C but did not reduce neutrophil chemokinesis, or the chemotactic activity of unheated rIL-8, FMLP, C5a or LTB4. Interleukin-8 exhibited similar binding kinetics and chemotaxis for neutrophils regardless of whether it had been pretreated at 40 degrees C. In addition, IL-8(3-25) was also able to decrease the binding of preheated IL-8 to neutrophils. IL-8(3-25), which can self-associate, binds directly to receptors on the neutrophil. The data suggest that heat-treated, but not untreated, IL-8 causes the IL-8(3-25) multimers to disaggregate, allowing the monomeric peptide to directly bind to the IL-8 receptor and thus inhibiting IL-8/receptor binding.

Neutrophil-activating peptide-2 in patients with pulmonary edema from congestive heart failure or ARDS.

We carried out studies to determine whether the neutrophil-activation peptide-2 (NAP-2) plays a role in the recruitment and/or degranulation of neutrophils into the lungs of patients with the adult respiratory distress syndrome (ARDS) or congestive heart failure (CHF). NAP-2 precursors plus NAP-2 (beta-thromboglobulin-like antigen) were measured in lung fluids and plasmas with a radioimmunoassay, and NAP-2 was separated from its precursors by high-performance liquid chromatography. Pulmonary edema fluids (PEFs) from patients with CHF contained higher concentrations of the beta-thromboglobulin-like antigen than PEFs from patients with ARDS, and bronchoalveolar lavage fluids (BALs) from patients with ARDS contained higher concentrations of beta-thromboglobulin-like antigen than BALs from normal subjects. beta-Thromboglobulin-like antigen concentration was 4.1-fold greater in PEFs from patients with CHF than in their plasmas. Chemotactically active NAP-2 was also demonstrated in PEFs but not in plasmas from patients with CHF and ARDS. These data suggest that significant platelet degranulation occurred into the lungs of the patients with CHF and that NAP-2 and other platelet constituents may contribute to fluid formation in patients with CHF.