| 1. |
- Gudmundsdotter, Lindvi
(författare)
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HIV-1 immune responses induced by natural infection or immunisation
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The development of an effective HIV-1 vaccine must be considered as one of today s greatest biomedical goals and challenges. The nature of the HIV-1 virus, characterised by its tropism for the CD4+ T cells of the immune system and its integration into the host genome, together with the vast viral variability, allows the HIV-1 virus to establish a latent infection and evade the host defence mechanisms. In our endeavour to develop a genetic HIV-vaccine that elicits broad and robust immune responses to several virus variants, we have demonstrated major cross-clade Gag responses in patients infected with different subtypes of HIV-1. This indicates that genetic vaccines encoding Gag from a few strains may act to induce immunity to broad ranges of HIV-1 clades. We also found that HIV-1 infection results in release of intracellular perforin into the serum of HIV infected individuals and in SIV/SHIV infected monkeys. As perforin secretion/production has been shown to be associated with control of HIV-1 infection, the aberrant perforin release may be a result of a yet unknown viral immune escape mechanism. Individuals enrolled in two therapeutic and one prophylactic HIV-1 vaccine trial were analysed for their vaccine-specific immune responses. Analyses of the therapeutic vaccine samples revealed that: 1) Multiple injections with recombinant HIV-1 glycoprotein 160 induces an increased central memory T cell population, which can be associated with increased antigenspecific cellular immune responses in treatment naïve HIV-1 infected individuals. 2) Topical DNA immunisation, combined with repeated treatment interruptions in patients on successful antiretroviral therapy, induced novel HIV-1 specific cellular immune responses. Such treatment did permit extended drug-free periods for all participants. Moreover, the viral load set points were significantly lower after the treatment protocol than before initial onset of any antiretroviral treatment. However, the decreased viral load set points were not related to the HIV-1 immunisation. In the prophylactic study, HIV-1 DNA followed by a recombinant vaccinia virus vector boost induced strong and broad HIV-1 specific cellular immune responses. In healthy individuals, we found that previous immunity to vaccinia only moderately reduced the HIV-specific immune responses when vaccinia was used as a vector for HIV genes. This finding suggests that vaccinia-based immunogens can be used despite the presence of pre-existing immunity to this vector. Immunisation of HIV-1 infected individuals is difficult, as HIV-1 infection leads to a dysfunctional immune system. Despite efforts to induce new and improve existing immune responses by therapeutic vaccination, no clinical trial has yet been able to show long-term sustained clinical effects of immunisation. The modest and transient effects observed by us with currently available DNA vaccines highlight the need to develop immunisation strategies which combine immunisation with novel antiviral therapies.
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| 2. |
- Klint, Susanne, et al.
(författare)
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Izokibep : Preclinical development and first-in-human study of a novel IL-17A neutralizing Affibody molecule in patients with plaque psoriasis
- 2023
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Ingår i: mAbs. - : Taylor & Francis. - 1942-0862 .- 1942-0870. ; 15:1
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Tidskriftsartikel (refereegranskat)abstract
- Psoriasis, an immune-mediated inflammatory disease, affects nearly 125 million people globally. The interleukin (IL)-17A homodimer is a key driver of psoriasis and other autoimmune diseases, including psoriatic arthritis, axial spondyloarthritis, hidradenitis suppurativa, and uveitis. Treatment with monoclonal antibodies (mAbs) against IL-17A provides an improvement in the Psoriasis Area and Severity Index compared to conventional systemic agents. In this study, the Affibody(CIRCLED LATIN CAPITAL LETTER R) technology was used to identify and optimize a novel, small, biological molecule comprising three triple helical affinity domains, izokibep (previously ABY-035), for the inhibition of IL-17A signaling. Preclinical studies show that izokibep, a small 18.6 kDa IL-17 ligand trap comprising two IL-17A-specific Affibody domains and one albumin-binding domain, selectively inhibits human IL-17A in vitro and in vivo with superior potency and efficacy relative to anti-IL-17A mAbs. A Phase 1 first-in-human study was conducted to establish the safety, pharmacokinetics, and preliminary efficacy of izokibep, when administered intravenously and subcutaneously as single doses to healthy subjects, and as single intravenous and multiple subcutaneous doses to patients with psoriasis (NCT02690142; EudraCT No: 2015-004531-13). Izokibep was well tolerated with no meaningful safety concerns identified in healthy volunteers and patients with psoriasis. Rapid efficacy was seen in all psoriasis patients after one dose which further improved in patients receiving multiple doses. A therapeutic decrease in joint pain was also observed in a single patient with concurrent psoriatic arthritis. The study suggests that izokibep has the potential to safely treat IL17A-associated diseases such as psoriasis, psoriatic arthritis, axial spondyloarthritis, hidradenitis suppurativa, and uveitis.
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| 3. |
- Kumawat, Ashok Kumar, 1982-, et al.
(författare)
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Inhibition of IL17A Using an Affibody Molecule Attenuates Inflammation in ApoE-Deficient Mice
- 2022
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Ingår i: Frontiers in Cardiovascular Medicine. - : Frontiers Media S.A.. - 2297-055X. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- The balance between pro- and anti-inflammatory cytokines released by immune and non-immune cells plays a decisive role in the progression of atherosclerosis. Interleukin (IL)-17A has been shown to accelerate atherosclerosis. In this study, we investigated the effect on pro-inflammatory mediators and atherosclerosis development of an Affibody molecule that targets IL17A. Affibody molecule neutralizing IL17A, or sham were administered in vitro to human aortic smooth muscle cells (HAoSMCs) and murine NIH/3T3 fibroblasts and in vivo to atherosclerosis-prone, hyperlipidaemic ApoE(-/-) mice. Levels of mediators of inflammation and development of atherosclerosis were compared between treatments. Exposure of human smooth muscle cells and murine NIH/3T3 fibroblasts in vitro to alpha IL-17A Affibody molecule markedly reduced IL6 and CXCL1 release in supernatants compared with sham exposure. Treatment of ApoE(-/-) mice with alpha IL-17A Affibody molecule significantly reduced plasma protein levels of CXCL1, CCL2, CCL3, HGF, PDGFB, MAP2K6, QDPR, and splenocyte mRNA levels of Ccxl1, Il6, and Ccl20 compared with sham exposure. There was no significant difference in atherosclerosis burden between the groups. In conclusion, administration of alpha IL17A Affibody molecule reduced levels of pro-inflammatory mediators and attenuated inflammation in ApoE(-/-) mice.
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| 4. |
- Malm, Magdalena, et al.
(författare)
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Engineering of a bispecific affibody molecule towards HER2 and HER3 by addition of an albumin-binding domain allows for affinity purification and in vivo half-life extension
- 2014
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Ingår i: Biotechnology Journal. - : Wiley. - 1860-6768 .- 1860-7314. ; 9:9, s. 1215-1222
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Tidskriftsartikel (refereegranskat)abstract
- Emerging strategies in cancer biotherapy include the generation and application of bispecific antibodies, targeting two tumor-associated antigens for improved tumor selectivity and potency. Here, an alternative format for bispecific molecules was designed and investigated, in which two Affibody molecules were linked by an albumin-binding domain (ABD). Affibody molecules are small (6 kDa) affinity proteins and this new format allows for engineering of molecules with similar function as full-length bispecific antibodies, but in a dramatically smaller size (around eight-fold smaller). The ABD was intended to function both as a tag for affinity purification as well as for in vivo half-life extension in future preclinical and clinical investigations. Affinity-purified bispecific Affibody molecules, targeting HER2 and HER3, showed simultaneous binding to the three target proteins (HER2, HER3, and albumin) when investigated in biosensor assays. Moreover, simultaneous interactions with the receptors and albumin were demonstrated using flow cytometry on cancer cells. The bispecific Affibody molecules were also able to block ligand-induced phosphorylation of the HER receptors, indicating an anti-proliferative effect. We believe that this compact and flexible format has great potential for developing new potent bispecific affinity proteins in the future, as it combines the benefits of a small size (e.g. improved tissue penetration and reduced cost of goods) with a long circulatory half-life.
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| 5. |
- Malm, Magdalena, 1983-, et al.
(författare)
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Inhibiting HER3-Mediated Tumor Cell Growth with Affibody Molecules Engineered to Low Picomolar Affinity by Position-Directed Error-Prone PCR-Like Diversification
- 2013
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Ingår i: PLOS ONE. - : Public Library Science, USA. - 1932-6203. ; 8:5, s. e62791-
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Tidskriftsartikel (refereegranskat)abstract
- The HER3 receptor is implicated in the progression of various cancers as well as in resistance to several currently used drugs, and is hence a potential target for development of new therapies. We have previously generated Affibody molecules that inhibit heregulin-induced signaling of the HER3 pathways. The aim of this study was to improve the affinity of the binders to hopefully increase receptor inhibition efficacy and enable a high receptor-mediated uptake in tumors. We explored a novel strategy for affinity maturation of Affibody molecules that is based on alanine scanning followed by design of library diversification to mimic the result from an error-prone PCR reaction, but with full control over mutated positions and thus less biases. Using bacterial surface display and flow-cytometric sorting of the maturation library, the affinity for HER3 was improved more than 30-fold down to 21 PM. The affinity is among the higher that has been reported for Affibody molecules and we believe that the maturation strategy should be generally applicable for improvement of affinity proteins. The new binders also demonstrated an improved thermal stability as well as complete refolding after denaturation. Moreover, inhibition of ligand-induced proliferation of HER3-positive breast cancer cells was improved more than two orders of magnitude compared to the previously best-performing clone. Radiolabeled Affibody molecules showed specific targeting of a number of HER3-positive cell lines in vitro as well as targeting of HER3 in in vivo mouse models and represent promising candidates for future development of targeted therapies and diagnostics.
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| 6. |
- Mebrahtu, Aman, et al.
(författare)
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Co-culture platform for tuning of cancer receptor density allows for evaluation of bispecific immune cell engagers
- 2024
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Ingår i: New Biotechnology. - : Elsevier BV. - 1871-6784 .- 1876-4347. ; 79, s. 120-126
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Tidskriftsartikel (refereegranskat)abstract
- Cancer immunotherapy, where a patient's immune system is harnessed to eradicate cancer cells selectively, is a leading strategy for cancer treatment. However, successes with immune checkpoint inhibitors (ICI) are hampered by reported systemic and organ-specific toxicities and by two-thirds of the patients being non-responders or subsequently acquiring resistance to approved ICIs. Hence substantial efforts are invested in discovering novel targeted immunotherapies aimed at reduced side-effects and improved potency. One way is utilizing the dual targeting feature of bispecific antibodies, which have made them increasingly popular for cancer immunotherapy. Easy and predictive screening methods for activation ranking of candidate drugs in tumor contra non-tumor environments are however lacking. Herein, we present a cell-based assay mimicking the tumor microenvironment by co-culturing B cells with engineered human embryonic kidney 293 T cells (HEK293T), presenting a controllable density of platelet-derived growth factor receptor β (PDGFRβ). A target density panel with three different surface protein levels on HEK293T cells was established by genetic constructs carrying regulatory elements limiting RNA translation of PDGFRβ. We employed a bispecific antibody-affibody construct called an AffiMab capable of binding PDGFRβ on cancer cells and CD40 expressed by B cells as a model. Specific activation of CD40-mediated signaling of immune cells was demonstrated with the two highest receptor-expressing cell lines, Level 2/3 and Level 4, while low-to-none in the low-expressing cell lines. The concept of receptor tuning and the presented co-culture protocol may be of general utility for assessing and developing novel bi-specific antibodies for immuno-oncology applications.
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| 7. |
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| 8. |
- Nowroozalizadeh, Salma, et al.
(författare)
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Short-term HIV-1 treatment interruption is associated with dysregulated TLR-stimuli responsiveness.
- 2013
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Ingår i: Human Vaccines & Immunotherapeutics. - : Informa UK Limited. - 2164-5515 .- 2164-554X. ; 9:10, s. 2103-2110
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Tidskriftsartikel (refereegranskat)abstract
- Viremia during human immunodeficiency virus type-1 (HIV-1) infection results in progressive impairment of several components of the immune system. Here a unique model of repeated treatment interruptions (TIs) was used with the aim to reveal the effect of controlled short-term viremia on innate stimuli responsiveness and circulating dendritic cells (DCs). Sequential peripheral blood samples from HIV-1-infected patients on combination antiretroviral therapy, subjected to repeated TI cycles as part of a therapeutic DNA vaccination study, were analyzed. In vitro responsiveness of peripheral blood mononuclear cells to toll-like receptor (TLR) stimuli was analyzed by cytokine secretion, and frequencies of plasmacytoid DCs (pDCs) and myeloid DCs (mDCs) were monitored by flow cytometry. These parameters were found not to be significantly different between the vaccinated and placebo groups. Instead, independent of vaccination altered in vitro TLR responsiveness was observed in parallel with TI cycles. TLR7/8-triggered secretion of IL-12 and IFN-α, as well as TLR9-triggered secretion of IL-12, was hyperactivated. In contrast, expression of IFN-α after TLR9 stimulation decreased during the initial cycle of TI. Reduced frequencies of pDCs and mDCs, compared with baseline, were noted before and during the second TI, respectively. Furthermore, spontaneous ex vivo release of IL-12 from PBMC was noted during cycles of TI. In conclusion, these results suggest that consequences of short-term TI include dysregulated TLR responses and fluctuations in the frequencies of circulating DCs. Knowledge of these immunological factors may influence the continuation of stringent treatment schedules during HIV infections.
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| 9. |
- Orlova, Anna, 1960-, et al.
(författare)
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Evaluation of the Therapeutic Potential of a HER3-Binding Affibody Construct TAM-HER3 in Comparison with a Monoclonal Antibody, Seribantumab
- 2018
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Ingår i: Molecular Pharmaceutics. - : AMER CHEMICAL SOC. - 1543-8384 .- 1543-8392. ; 15:8, s. 3394-3403
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Tidskriftsartikel (refereegranskat)abstract
- Human epidermal growth factor receptor type 3 (HER3) is recognized to be involved in resistance to HER targeting therapies. A number of HER3-targeting monoclonal antibodies are under clinical investigation as potential cancer therapeutics. Smaller high-affinity scaffold proteins are attractive non-Fc containing alternatives to antibodies. A previous study indicated that anti-HER3 affibody molecules could delay the growth of xenografted HER3-positive tumors. Here, we designed a second-generation HER3-targeting construct (TAM-HER3), containing two HER3-specific affibody molecules bridged by an albumin-binding domain (ABD) for extension of blood circulation. Receptor blocking activity was demonstrated in vitro. In mice bearing BxPC-3 xenografts, the therapeutic efficacy of TAM-HER3 was compared to the HER3-specific monoclonal antibody seribantumab (MM-121). TAM-HER3 inhibited heregulin-induced phosphorylation in a panel of HER3-expressing cancer cells and was found to be equally as potent as seribantumab in terms of therapeutic efficacy in vivo and with a similar safety profile. Median survival times were 60 days for TAM-HER3, 54 days for seribantumab, and 41 days for the control group. No pathological changes were observed in cytopathological examination. The multimeric HER3-binding affibody molecule in fusion to ABD seems promising for further evaluation as candidate therapeutics for treatment of HER3-overexpressing tumors.
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| 10. |
- Yu, Feifan, et al.
(författare)
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An affibody-adalimumab hybrid blocks combined IL-6 and TNF-triggered serum amyloid A secretion in vivo
- 2014
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Ingår i: mAbs. - : Informa UK Limited. - 1942-0862 .- 1942-0870. ; 6:6, s. 1598-1607
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Tidskriftsartikel (refereegranskat)abstract
- In inflammatory disease conditions, the regulation of the cytokine system is impaired, leading to tissue damages. Here, we used protein engineering to develop biologicals suitable for blocking a combination of inflammation driving cytokines by a single construct. From a set of interleukin (IL)-6-binding affibody molecules selected by phage display, five variants with a capability of blocking the interaction between complexes of soluble IL-6 receptor a (sIL-6R alpha) and IL6 and the co-receptor gp130 were identified. In cell assays designed to analyze any blocking capacity of the classical or the alternative (trans) signaling IL-6 pathways, one variant, Z(IL-6_13) with an affinity (K-D) for IL-6 of similar to 500 pM, showed the best performance. To construct fusion proteins ("AffiMabs") with dual cytokine specificities, Z(IL-6_13) was fused to either the N-or C-terminus of both the heavy and light chains of the anti-tumor necrosis factor (TNF) monoclonal antibody adalimumab (Humira (R)). One AffiMab construct with Z(IL-6_13) positioned at the N-terminus of the heavy chain, denoted Z(IL-6_13)-HCAda, was determined to be the most optimal, and it was subsequently evaluated in an acute Serum Amyloid A (SAA) model in mice. Administration of the AffiMab or adalimumab prior to challenge with a mix of IL-6 and TNF reduced the levels of serum SAA in a dose-dependent manner. Interestingly, the highest dose (70 mg/kg body weight) of adalimumab only resulted in a 50% reduction of SAA-levels, whereas the corresponding dose of the Z(IL-6_13)-HCAda AffiMab with combined IL-6/TNF specificity, resulted in SAA levels below the detection limit.
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