Binding and internalization of the 163-171 fragment of human IL-1 beta

Multivalent Nanobody Conjugate with Rigid, Reactive Oxygen Species Scavenging Scaffold for Multi-Target Therapy of Alzheimer's Disease

Efficient therapeutic strategies that concurrently target both Aβ aggregation and oxidative stress in the Alzheimer's disease (AD) microenvironment emerge as a cutting-edge tool to combat the intricate pathogenesis of AD. Here, a multivalent nanobody conjugate with rigid, reactive oxygen species (ROS) scavenging scaffold is developed to achieve simultaneous Aβ amyloidogenesis mitigation, ROS elimination, and Aβ plaque clearance. Grafting Aβ segment (33-GLMVGGVVIA-42) into the third complementary-determining region of a parent nanobody generates an engineered nanobody NB that can recognize Aβ and inhibit its aggregation through homotypic interactions. NB is further genetically modified with a fragment of human interleukin-1β (163-VQGEESNDK-171), so that the obtained fusion nanobody NBIL can also facilitate the Aβ clearance by microglia. Linking NBIL covalently onto a rigid, ROS scavenging scaffold poly(deca-4,6-diynedioic acid) (PDDA) creates the multivalent nanobody conjugate PNBIL, which not only boosts the binding affinity between NBIL and Aβ aggregates for nearly 100 times but also possesses a long-term capability of oxidative stress alleviation, inflammation reduction, and neuron protection. PNBIL has significantly attenuated symptoms on two AD mouse models through amyloidogenesis inhibition and AD microenvironment modulation, validating that the multivalent nanobody conjugate design based on combinatory nanobody and molecular engineering is a promising approach of multi-target therapeutic strategies.

The family of the interleukin-1 receptors

The extracellular forms of the IL-1 cytokines are active through binding to specific receptors on the surface of target cells. IL-1 ligands bind to the extracellular portion of their ligand-binding receptor chain. For signaling to take place, a non-binding accessory chain is recruited into a heterotrimeric complex. The intracellular approximation of the Toll-IL-1-receptor (TIR) domains of the 2 receptor chains is the event that initiates signaling. The family of IL-1 receptors (IL-1R) includes 10 structurally related members, and the distantly related soluble protein IL-18BP that acts as inhibitor of the cytokine IL-18. Over the years the receptors of the IL-1 family have been known with many different names, with significant confusion. Thus, we will use here a recently proposed unifying nomenclature. The family includes several ligand-binding chains (IL-1R1, IL-1R2, IL-1R4, IL-1R5, and IL-1R6), 2 types of accessory chains (IL-1R3, IL-1R7), molecules that act as inhibitors of signaling (IL-1R2, IL-1R8, IL-18BP), and 2 orphan receptors (IL-1R9, IL-1R10). In this review, we will examine how the receptors of the IL-1 family regulate the inflammatory and anti-inflammatory functions of the IL-1 cytokines and are, more at large, involved in modulating defensive and pathological innate immunity and inflammation. Regulation of the IL-1/IL-1R system in the brain will be also described, as an example of the peculiarities of organ-specific modulation of inflammation.

Radioprotection by N-palmitoylated nonapeptide of human interleukin-1beta

Interleukin-1beta (IL-1beta) is a cytokine involved in homeostatic processes of the immune system and specifically in inflammatory reactions. The nonapeptide of human IL-1beta (VQGEESNDK, position 163-171) has been shown to retain adjuvant and immunostimulatory activities of the native molecule without any inflammatory and pyrogenic properties. A lipophilic derivative of IL-1beta nonapeptide having a palmitoyl residue at the amino terminus was synthesized in order to determine the effects of such structural modification on its bioactivities. The structurally modified peptide derivative, palmitoylated peptide, significantly protected C3H/HeN mice against potentially lethal doses of ionizing radiation. The dose reduction factor was found to be 1.07. Hematological studies show improved recovery of red blood cells and platelets in irradiated and palmitoylated peptide treated mice as compared with the untreated and irradiated group. These results suggest the importance of the derivatization of small peptides of radioprotective, but toxic cytokines in order to enhance radioprotective activity while reducing unwanted toxic side effects.

N‐Palmitoylation of the Radioprotective Domain of Interleukin‐1 Affords Inhibition of LPS‐Induced Nitric Oxide Generation

Interleukin-1beta (IL-1beta), a cytokine involved in homeostatic processes such as the immune system and inflammatory reactions, is a potent inducer of nitric oxide. The nonapeptide of human IL-1beta (VQGEESNDK, position 163-171, specific radioprotective domain--SRD) has been shown to retain radioprotective, immunostimulatory, and adjuvant activities of the native molecule without any inflammatory and pyrogenic properties. Unlike the parent IL-1, SRD did not induce nitric oxide (NO) in control or irradiated RAW 264.7 cells nor did it affect inducible nitric oxide synthase (iNOS) as shown by ELISA based mRNA assay (Quantikine). A lipophillic derivative of the SRD (a palmitoyl residue at the amino terminus of the SRD) was synthesized (palmitoyl specific radioprotective domain, P-SRD) to find out if this structural derivatization would restore the NO-inducing ability of IL-1. Surprisingly, P-SRD not only did not induce NO, but significantly inhibited lipopolysaccharide (LPS) stimulated nitric oxide (NO) production. Quantikine studies indicated that P-SRD also inhibited iNOS in LPS stimulated macrophage cells, suggesting that decrease in NO production in the presence of P-SRD was the result of iNOS mRNA inhibition. These results indicate that N-palmitoylation of SRD may effectively ameliorate potentially fatal symptoms of LPS-induced endotoxemic hypotensive shock associated with IL-1 without inflammatory and pyrogenic toxic side effects.

Pineal peptide with an inhibiting effect on growth of HeLa S3 tumor cells

The aim of the present study was to assess whether a peptide fraction isolated from calf pineal glands has an effect on proliferation and morphology of HeLa S3 tumor cells. Under the experimental conditions adopted, the results showed that the peptide has a marked inhibitory effect on proliferation of HeLa S3 cells and that permeabilization with calcium phosphate of the plasmatic membrane increases this effect. Moreover, the pineal peptide affects the cytoskeletal morphology of HeLa cells by modifying the distribution of actin. The peptide is probably internalized by the cells and irreversibly modifies the cytoskeletal morphology with consequent inhibition of cellular proliferation.

Rainbow trout (Oncorhynchus mykiss) recombinant IL-1beta and derived peptides induce migration of head-kidney leucocytes in vitro

The present work provides the first information concerning the chemoattractant activity of trout recombinant IL-1beta and its derived peptides, referred to as P1, P2 and P3. The predicted rainbow trout mature interleukin-1beta peptide was produced as a recombinant protein in Escherichia coli. The first peptide, P1, corresponded to fragment 146-157 (YVTPVPIETEAR) of the trout sequence and had an MW of 137 kDa. It was equivalent to a region known to be part of the receptor binding domain from the mammalian crystal structure of IL-1beta complexed to its receptor. P2 was used as control peptide, consisting of the same 12 amino acids as P1, but arranged in a random sequence (VVEEYIRAPPTT). P3 was synthesised to complex with an adjacent region of the IL-1 receptor, and corresponded to fragment 207-216 (YRRNTGVDIS) of the trout sequence, with an MW of 1.18 kDa. Migration was stimulated when leucocytes were exposed to concentrations of > or = 10 ng ml(-1) rIL-1beta. Peptide P3 also induced leucocyte migration, with an optimal dose of 0.25 mM being recorded. While P1 had no effect on cell migration when used alone, synergism was evident as a consequence of combining P1 with a suboptimal dose (0.01 mM) of P3. No synergism occurred when cells were exposed to a combination of P3 and the control peptide P2.

Construction of chimeric immunogens: Bioactive fragment of human IL-1β or polytuftsin (PT) capable of eliciting immune responses to HIV peptides

In this study, we have examined the effect of linking of bloactive fragment of human IL-1β (163-171) or polytuftsin (PT, a synthetic polymer of natural immunomodulator "tuftsin") with synthetic peptides of HIV on the induction of immune response to the synthetic peptides. A panel of synthetic peptides representing defined region of gp41, gp120 and gag were used as antigens. Immunomodulators linked peptides (i.e. peptide-IL-1β or peptide-PT) or peptide dimers were employed for immunization in Balb/c mice. Mice immunized with the peptide-immunomodulator develop effective T-cell proliferation,in vitro cytokine release and higher antibody production, but not with peptide dimers. We also found that peptide-immunomodulators induced high level of IgG2a antibody production. Furthermore, there was a positive correlation between the levels of cytokine (IL-2 & IFN-γ) and IgG isotype production. Thus it would appear that incorporation of IL-1β fragment or PT selectively enhances the Th1 type response to these peptides and may therefore be important for virus neutralization and clearance. However, the effect of IL-1β fragment was found to be more pronounced than polytuftsin. Such an approach may provide effective vaccination against other infectious diseases.

Bioactive fragment of human IL-1beta [163-171] modulates the immune response to synthetic peptides of HIV

The activation of T helper cells specific for viral antigens is critical for antibody production and the generation of cytotoxic T cells during retroviral infection. In this study, we examined the effect of linking HIV peptides with a bioactive fragment of human interleukin-1beta (IL-1beta) (163-171) on the induction of immune response to the peptides. A panel of highly purified synthetic peptides representing defined regions of gp41, Gag and gp120 were used as antigens. Mouse spleen cells primed with the peptide conjugates produced greater proliferation on in vitro stimulation than spleen cells primed with peptide alone. In addition, antibody production as assessed by ELISA was observed after immunization with conjugated peptides but not with peptide alone, indicating B-cell activation. We also found that a high level of IgG2a antibody production correlated with a high level of IFN-gamma production. These findings favor the notion that IL-1beta plays an important role in immune responses. These observations support the formulation and design of synthetic vaccines against HIV using synthetic HIV peptides conjugated with immunomodulators. Such an approach may provide an effective vaccination against other infectious agents.

Interleukin-1 beta fragment (163-171) modulates bovine granulosa cell proliferation in vitro: dependence on size of follicle

The biological effects of IL-1 on ovarian function have been considered as an inflammatory-like reaction. The peptide fragment of IL-1 (163-171 aa), which belongs to the active site of the whole protein, has been shown to exert an immunostimulatory activity without inducing inflammatory effects. The aim of this study was to investigate whether IL 163-171, alone or associated with bFSH, modulates granulosa cell proliferation; in addition, we wanted to assess if IL 163-171 interferes with FSH binding to receptors. Bovine follicles were divided according to their size. Cell proliferation, assessed by [3H]-thymidine uptake and [125I]-FSH binding, were studied in cells treated with IL 163-171(0, 0.5, 5 and 20 ng/ml) with or without bFSH (100 ng/ml) for 24, 48 or 72 h. Basal incorporation of [3H]-thymidine into granulosa cells from small follicles was always 3-fold higher (P < 0.01) than that by cells from large follicles. IL 163-171 did not show any effect in granulosa cells from large follicles but stimulated (P < 0.01) [3H]-thymidine uptake into granulosa cells from small follicles; furthermore IL 163-171 interacted positively with bFSH (P < 0.01) after 48 and 72 h. IL 163-171 significantly reduced (P < 0.05) FSH binding in cells from small follicles after 24 h, but not after 48 and 72 h. This data demonstrates that: (1) Follicular size and cell proliferation are inversely related; (2) IL 163-171 modulates granulosa cell proliferation only in cells from small follicles; and (3) the interaction between IL 163-171 and FSH does not mainly occur at receptor level.

Immunomodulating activity of analogs of noninflammatory fragment 163-171 of human interleukin-1beta

The synthetic nonapeptide Val-Gln-Gly-Glu-Glu-Ser-Asn-Asp-Lys corresponding to the amino acid sequence 163-171 of human interleukin-1beta (IL-1beta) has been reported to retain considerable immunostimulatory activity of the native protein without the induction of the inflammatory or pyrogenic responses. Two lipophilic derivatives of this nonapeptide, one having a lauroyl residue (1) and the other having a palmitoyl residue (2) at the N-terminus of the peptide, and a more stable analog carrying D-Val residue at position 1 of the peptide (3) were synthesized with a view to find out if these structural modifications had a favorable effect on in vitro mouse thymocyte proliferation and IL-1 dependent inhibition of A375 cells. We have found that analogs (1) and (2) are active in both the tests like the parent nonapeptide. The lipophilic analog (2) is in fact, effective at a lower dose as compared to the parent nonapeptide in mouse thymocyte proliferation assay. Although the analog (3) has the ability to inhibit A375 cells, it does not stimulate mouse thymocyte proliferation in vitro. The IL-1beta fragment (163-171) and the analog (2) were further compared for their effects on pyrogenicity, blood glucose level, acute phase response and radioprotection. Unlike IL-1beta, its fragment (163-171) and the analog (2) do not induce pyrogenicity and any of the acute phase related changes such as the increase in C-reactive protein and hypoglycemia following their administration in Balb/c mice. We have found that 40% of animals treated with analog (2) survive more than 21 days after lethal irradiation as compared to 20% survivors in groups treated with recombinant IL-1beta or its nonapeptide fragment (163-171), under conditions when all the control animals died within 10 days. This study may help in designing small peptides which may be more effective and stable.

Interleukin-1 (IL-1)-induced resistance to bacterial infection: role of the type I IL-1 receptor

Pretreatment with a low dose of recombinant human interleukin-1 beta (IL-1) (3 to 30 micrograms/kg) 24 h before a lethal Pseudomonas aeruginosa infection prolongs survival in neutropenic mice. We investigated the role of the type I IL-1 receptor (IL-1RI) and IL-1RII in this IL-1-induced protection by using a specific IL-1 receptor antagonist (IL-1-Ra), which blocks effects mainly via IL-1RI. Pretreatment with IL-1Ra before IL-1 partially blocked the IL-1-induced enhanced survival, whereas pretreatment with a specific neutralizing monoclonal antibody to IL-1RI (35F5) eliminated the IL-1 induced protection. The nonapeptide fragment 163-171 of recombinant human IL-1 beta, which possesses the immunoadjuvant but not the inflammatory effect of the entire molecule via a non-receptor-mediated signal transduction process, did not reproduce the IL-1-induced protection. IL-1-induced protection was associated with reduced serum aspartate aminotransferase and alanine aminotransferase concentrations in conjunction with ameliorated histopathology of the liver. These findings may be due to reduced cytokine production and cytokine sensitivity of target cells after infection. We conclude that the IL-1-induced nonspecific resistance to infection is mediated by cells bearing IL-1RI and is associated with a reduction of liver damage.

SV40-immortalized and primary cultured human retinal pigment epithelial cells share similar patterns of cytokine-receptor expression and cytokine responsiveness

Retinal pigment epithelial (RPE) cells produce and respond to a variety of cytokines; however, molecular and biochemical studies are restricted by the limited access to large numbers of pure cells and the variability associated with different donor sources. Despite success in establishing primary human RPE (HRPE) cell cultures, the inability to sustain consistent proliferation rates and morphology over several passages remains a concern. This problem was approached by using an immortalized line of simian virus (SV)40 transformed fetal HRPE cells (SVRPE). Cytokine production, receptor expression and responsiveness in the SVRPE cell line was analyzed to determine the usefulness of this model for studying HRPE-cytokine interactions. Using reverse transcriptase polymerase chain reaction (RT-PCR), HRPE and SVRPE cells demonstrated an identical pattern of interleukin-1 receptor (IL-1R), IL-2R (alpha sub-unit), IL-6R, interferon (IFN)-gamma R and tumor necrosis factor-alpha (TNF)R p55 expression. No amplification products for TNFR p75 or granulocyte/macrophage colony stimulating factor (GM-CSF)R were demonstrated in either population. IFN-gamma stimulation induced surface human leukocyte antigen (HLA)-DR in both SVRPE and HRPE, while TNF treatment induced surface expression of intercellular adhesion molecule (ICAM)-1 on SVRPE and upregulated ICAM from basal levels on HRPE. Both cell types showed amplification products for interleukin (IL)-1 beta, IL-6 and transforming growth factor (TGF)-beta 1 using RT-PCR. The bioassays demonstrated that both populations of unstimulated cells constitutively secrete very low levels of TGF-beta and no IL-6.(ABSTRACT TRUNCATED AT 250 WORDS)