Human Immunoglobulin Research Articles

Bevacizumab induces ferroptosis and enhances CD8+ T cell immune activity in liver cancer via modulating HAT1 and increasing IL-9.

Bevacizumab is a recombinant humanized monoclonal immunoglobulin (Ig) G1 antibody of VEGF, and inhibits angiogenesis and tumor growth in hepatocellular carcinoma (HCC). Ferroptosis, a new form of regulated cell death function independently of the apoptotic machinery, has been accepted as an attractive target for pharmacological intervention; the ferroptosis pathway can enhance cell immune activity of anti-PD1 immunotherapy in HCC. In this study we investigated whether and how bevacizumab regulated ferroptosis and immune activity in liver cancer. Firstly, we performed RNA-sequencing in bevacizumab-treated human liver cancer cell line HepG2 cells, and found that bevacizumab significantly altered the expression of a number of genes including VEGF, PI3K, HAT1, SLC7A11 and IL-9 in liver cancer, bevacizumab upregulated 37 ferroptosis-related drivers, and downregulated 17 ferroptosis-related suppressors in particular. We demonstrated that bevacizumab triggered ferroptosis in liver cancer cells by driving VEGF/PI3K/HAT1/SLC7A11 axis. Clinical data confirmed that the expression levels of VEGF were positively associated with those of PI3K, HAT1 and SLC7A11 in HCC tissues. Meanwhile, we found that bevacizumab enhanced immune cell activity in tumor immune-microenvironment. We identified that HAT1 up-regulated miR-143 targeting IL-9 mRNA 3'UTR in liver cancer cells; bevacizumab treatment resulted in the increase of IL-9 levels and its secretion via VEGF/PI3K/HAT1/miR-143/IL-9 axis, which led to the inhibition of tumor growth in vivo through increasing the release of IL-2 and Granzyme B from activated CD8+ T cells. We conclude that in addition to inhibiting angiogenesis, bevacizumab induces ferroptosis and enhances CD8+ T cell immune activity in liver cancer. This study provides new insight into the mechanisms by which bevacizumab synergistically modulates ferroptosis and CD8+ T cell immune activity in liver cancer.

MRNA-LNP HIV-1 trimer boosters elicit precursors to broad neutralizing antibodies.

Germline-targeting (GT) HIV vaccine strategies are predicated on deriving broadly neutralizing antibodies (bnAbs) through multiple boost immunogens. However, as the recruitment of memory B cells (MBCs) to germinal centers (GCs) is inefficient and may be derailed by serum antibody-induced epitope masking, driving further B cell receptor (BCR) modification in GC-experienced B cells after boosting poses a challenge. Using humanized immunoglobulin knockin mice, we found that GT protein trimer immunogen N332-GT5 could prime inferred-germline precursors to the V3-glycan-targeted bnAb BG18 and that B cells primed by N332-GT5 were effectively boosted by either of two novel protein immunogens designed to have minimum cross-reactivity with the off-target V1-binding responses. The delivery of the prime and boost immunogens as messenger RNA lipid nanoparticles (mRNA-LNPs) generated long-lasting GCs, somatic hypermutation, and affinity maturation and may be an effective tool in HIV vaccine development.

Acute Aseptic Meningitis Temporally Associated with Intravenous Polyclonal Immunoglobulin Therapy: A Systematic Review.

An acute aseptic meningitis has been occasionally observed on intravenous polyclonal human immunoglobulin therapy. Since case reports cannot be employed to draw inferences about the relationships between immunoglobulin therapy and meningitis, we conducted a systematic review and meta-analysis of the literature. Eligible were cases, case series, and pharmacovigilance studies. We found 71 individually documented cases (36 individuals ≤ 18years of age) of meningitis. Ninety percent of cases presented ≤ 3days after initiating immunoglobulin therapy and recovered within ≤ 7days (with a shorter disease duration in children: ≤ 3days in 29 (94%) cases). In 22 (31%) instances, the authors noted a link between the onset of meningitis and a rapid intravenous infusion of immunoglobulins. Cerebrospinal fluid analysis revealed a predominantly neutrophilic (N = 46, 66%) pleocytosis. Recurrences after re-exposure were observed in eight (N = 11%) patients. Eight case series addressed the prevalence of meningitis in 4089 patients treated with immunoglobulins. A pooled prevalence of 0.6% was noted. Finally, pharmacovigilance data revealed that meningitis temporally associated with intravenous immunoglobulin therapy occurred with at least five different products. In conclusion, intravenous immunoglobulin may cause an acute aseptic meningitis. The clinical features remit rapidly after discontinuing the medication.

Severe gastrointestinal cytomegalovirus infection in a patient diagnosed with late onset combined immunodeficiency

Late onset combined immunodeficiency (LOCID) is a rare variant of common variable immunodeficiency (CVID), typically affecting adult patients who present with opportunistic infections (OI) and/or low CD4+ T lymphocytes. Diagnostic delay is common due to the rareness of this entity, increasing morbidity and mortality. We report on a 66-year-old male who developed a severe gastrointestinal cytomegalovirus (CMV) infection, refractory to antiviral treatment and anti-cytomegalovirus specific human immunoglobulin administration, with a fatal outcome due to an undiagnosed LOCID.

Anti-monkeypox virus-neutralizing activities of human immunoglobulin manufactured between 1999 and 2021 and derived from donors in the United States and Japan.

In May 2022, the United Kingdom reported the first case of chained transmission of the monkeypox (mpox) virus without any known epidemiological links to west or central Africa. The monthly number of mpox patients currently has passed a peak and is declining globally, and infected patients include both non-vaccinated and vaccinated individuals. Herein, the virus-neutralizing (VN) activity against vaccinia viruses, which are considered to cross-react with the mpox virus, in the intravenous immunoglobulin (IVIG) lots derived from donors, including vaccinated Japanese populations, was evaluated to clarify the status of the Japanese blood donor population. VN titres against vaccinia and human mpox viruses in IVIG lots derived from donors in Japan and the United States manufactured between 1999 and 2021 and 1995 and 2001, respectively, were evaluated by neutralization testing. VN titres of IVIG derived from donors in Japan and the United States against vaccinia and mpox viruses showed a slowly decreasing trend between 1999 and 2021. VN titres are expected to decrease in the future since the percentage of vaccinated donors in the donor population seems to have decreased. Therefore, continuous monitoring of VN titres is required.

Transforming waste into valuables: Preparation and evaluation of dual-ligand hydrophobic charge-induction chromatography using two poor performing ligands

In conventional chromatographic ligand screening, underperforming ligands are often dismissed. However, this practice may inadvertently overlook potential opportunities. This study aims to investigate whether these underperforming ligands can be repurposed as valuable assets. Hydrophobic charge-induction chromatography (HCIC) is chosen as the validation target for its potential as an innovative chromatographic mode. A novel dual-ligand approach is employed, combining two suboptimal ligands (5-Aminobenzimidazole and Tryptamine) to explore enhanced performance and optimization prospects. Various dual-ligand HCIC resins with different ligand densities were synthesized by adjusting the ligand ratio and concentration. The resins were characterized to assess appearance, functional groups, and pore features using SEM, FTIR, and ISEC techniques. Performance assessments were conducted using single-ligand mode resins as controls, evaluating the selectivity against human immunoglobulin G and human serum albumin. Static adsorption experiments were performed to understand pH and salt influence on adsorption. Breakthrough experiments were conducted to assess dynamic adsorption capacity of the novel resin. Finally, chromatographic separation using human serum was performed to evaluate the purity and yield of the resin. Results indicated that the dual-ligand HCIC resin designed for human antibodies demonstrates exceptional selectivity, surpassing not only single ligand states but also outperforming certain high-performing ligand types, particularly under specific salt and pH conditions. Ultimately, a high yield of 83.9 % and purity of 96.7 % were achieved in the separation of hIgG from human serum with the dual-ligand HCIC, significantly superior to the single-ligand resins. In conclusion, through rational design and proper operational conditions, the dual-ligand mode can revitalize underutilized ligands, potentially introducing novel and promising chromatographic modes.

Identification of a Fully Human Antibody VH Domain Targeting Anaplastic Lymphoma Kinase (ALK) with Applications in ALK-Positive Solid Tumor Immunotherapy

The anaplastic lymphoma kinase (ALK, CD247) is a potential target for antibody-based therapy. However, no antibody-based therapeutics targeting ALK have entered clinical trials, necessitating the development of novel antibodies with unique therapeutic merits. Single-domain antibodies (sdAb) bear therapeutic advantages compared to the full-length antibody including deeper tumor penetration, cost-effective production and fast washout from normal tissues. In this study, we identified a human immunoglobulin heavy chain variable domain (VH domain) (VH20) from an in-house phage library. VH20 exhibits good developability and high specificity with no off-target binding to ~6000 human membrane proteins. VH20 efficiently bound to the glycine-rich region of ALK with an EC50 of 0.4 nM and a KD of 6.54 nM. Both VH20-based bispecific T cell engager (TCE) and chimeric antigen receptor T cells (CAR Ts) exhibited potent cytolytic activity to ALK-expressing tumor cells in an ALK-dependent manner. VH20 CAR Ts specifically secreted proinflammatory cytokines including IL-2, TNFα and IFNγ after incubation with ALK-positive cells. To our knowledge, this is the first reported human single-domain antibody against ALK. Our in vitro characterization data indicate that VH20 could be a promising ALK-targeting sdAb with potential applications in ALK-expressing tumors, including neuroblastoma (NBL) and non-small cell lung cancer.

Refractory autoimmune hemolytic anemia in a patient with systemic lupus erythematosus and ulcerative colitis: A case report

BACKGROUND Ulcerative colitis (UC) and systemic lupus erythematosus (SLE) are both systemic immunoreactive diseases, and their pathogenesis depends on the interaction between genes and environmental factors. There are no reports of UC with SLE in China, but six cases of SLE with UC have been reported in China. The combination of these two diseases has distinct effects on the pathogenesis of both diseases. CASE SUMMARY A female patient (30 years old) came to our hospital due to dull umbilical pain, diarrhea and mucous bloody stool in August 2018 and was diagnosed with UC. The symptoms were relieved after oral administration of mesalazine (1 g po tid) or folic acid (5 mg po qd), and the patient were fed a control diet. On June 24, 2019, the patient was admitted for treatment due to anemia and tinnitus. During hospitalization, the patient had repeated low-grade fever and a progressively decreased Hb level. Blood tests revealed positive antinuclear antibody test, positive anti-dsDNA antibody, 0.24 g/L C3 (0.9-1.8 g/L), 0.04 g/L C4 (0.1-0.4 g/L), 32.37 g/L immunoglobulin (8-17 g/L), and 31568.1 mg/24 h total 24-h urine protein (0-150 mg/24 h). The patient was diagnosed with SLE involving the joints, kidneys and blood system. Previously reported cases of SLE were retrieved from PubMed to characterize clinicopathological features and identify prognostic factors for SLE. CONCLUSION The patient was discharged in remission after a series of treatments, such as intravenous methylprednisolone sodium succinate, intravenous human immunoglobulin, cyclophosphamide injection, and plasma exchange. After discharge, the patient took oral prednisone acetate tablets, cyclosporine capsules, hydroxychloroquine sulfate tablets and other treatments for symptoms and was followed up regularly for 1 month, after which the patient's condition continued to improve and stabilize.

Isolation and characterization of rabies monoclonal antibody charge variants.

Current postexposure prophylaxis of rabies includes vaccines, human rabies immunoglobulin (RIG), equine RIG, and recombinant monoclonal antibodies (mAb). In the manufacturing of rabies recombinant mAb, charge variants are the most common source of heterogeneity. Charge variants of rabies mAb were isolated by salt gradient cation exchange chromatography (CEX) to separate acidic and basic and main charge variants. Separated variants were further extensively characterized using orthogonal analytical techniques, which include secondary and tertiary structure determination by far and near ultraviolet circular dichroism spectroscopy. Charge and size heterogeneity were evaluated using CEX, isoelectric focusing (IEF), capillary-IEF, size exclusion chromatography, sodium dodecyl sulfate polyacrylamide gel electrophoresis, and western blotting. Antigen binding affinity was assessed by enzyme linked immuno-sorbent assay and rapid florescence foci inhibition test. Results from structural and physicochemical characterizations concluded that charge variants are formed due to posttranslational modification demonstrating that the charge heterogeneity, these charge variants did neither show any considerable physicochemical change nor affect its biological function. This study shows that charge variants are effective components of mAb and there is no need of deliberate removal, until biological functions of rabies mAb will get affected.

Abstract PO5-04-02: Combination of trastuzumab competing and non-competing fully human internalizing anti-Her2 monoclonal antibodies drug conjugates increases their inhibitory effect on the growth of HER2 positive metastatic breast cancer cells

Abstract The human epidermal growth factor receptor (HER) family of receptors plays a key role in proliferation stimulator for several human cancers. In particular, HER2 is overexpressed in 15-30% of breast cancers with or without gene amplification with prognostic and predictive implications. HER2 overexpression is associated with shorter disease-free and overall survivals, resistance to hormonal agents and increased risk of brain metastasis. Trastuzumab is a humanized anti-HER2 monoclonal antibody that binds to domain IV of HER2 extracellular domain and blocks its signaling. More recently, two antibody drug conjugates using trastuzumab have been approved: Ado-Trastuzumab-Emtansine (Kadcyla) consisting of trastuzumab conjugated to the drug mertansine DM1 and fam-trastuzumab-deruxtecan-nhki (Enhertu to deliver the topoisomerase inhibitor deruxtecan. We are reporting here the development of fully human internalizing anti-HER2 antibodies with distinct epitopes on the HER2protein which compete or not with trastuzumab for binding to HER2. These monoclonal antibodies have been developed by immunizing fully human (TC-Mab mouse) mice with recombinant HER2 protein. After production of hybridoma secreting fully human immunoglobulins, the screening process included competition with trastuzumab for binding to Her2 by enzyme linked immunoassay and Octet epitope binning and affinity determination as well as internalization assay. Several internalizing antibodies able to compete or not with trastuzumab and with high affinity (Kd ranging from 10−9 M to 10−12 M) were selected. Their ability to deliver a cytotoxic payload in HER2 overexpressing breast cancer cells such as SKBR3, BT474 and AU565 was next investigated. Two groups of antibodies: one competing with trastuzumab and the other one non-competing were further characterized. Data related to these antibodies’ biochemical characteristics as well as their ability to inhibit proliferation in vitro and in vivo in mouse xenografts studies will be presented here. In conclusion, the use of fully human mice to develop monoclonal antibodies provides a powerful and attractive approach to develop fully human monoclonal antibodies against cancer targets by-passing the need for humanization and affinity maturation of antibodies. This work is supported by 5R44CA224718 SBIR grant from the National Cancer Institute. Citation Format: Ginette Serrero, Binbin Yue, Jianping Dong, Jun Hayashi. Combination of trastuzumab competing and non-competing fully human internalizing anti-Her2 monoclonal antibodies drug conjugates increases their inhibitory effect on the growth of HER2 positive metastatic breast cancer cells [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO5-04-02.

Site-selective antibody-lipid conjugates for surface functionalization of red blood cells and targeted drug delivery

Displaying antibodies on carrier surfaces facilitates precise targeting and delivery of drugs to diseased cells. Here, we report the synthesis of antibody-lipid conjugates (ALCs) through site-selective acetylation of Lys 248 in human Immunoglobulin G (IgG) and the development of antibody-functionalized red blood cells (immunoRBC) for targeted drug delivery. ImmunoRBC with the HER2-selective antibody trastuzumab displayed on the surface (called Tras-RBC) was constructed following a three-step procedure. First, a peptide-guided, proximity-induced reaction transferred an azidoacetyl group to the ε-amino group of Lys 248 in the Fc domain. Second, the azide-modified IgG was subsequently conjugated with dibenzocyclooctyne (DBCO)-functionalized lipids via strain-promoted azide–alkyne cycloaddition (SPAAC) to result in ALCs. Third, the lipid portion of ALCs was then inserted into the cell membranes, and IgGs were displayed on red blood cells (RBCs) to construct immunoRBCs. We then loaded Tras-RBC with a photosensitizer (PS), Zinc phthalocyanine (ZnPc), to selectively target HER2-overexpressing cells, release ZnPc into cancer cells following photolysis, and induce photodynamic cytotoxicity in the cancer cells. This work showcases assembling immunoRBCs following site-selective lipid conjugation on therapeutic antibodies and the targeted introduction of PS into cancer cells. This method could apply to the surface functionalization of other membrane-bound vesicles or lipid nanoparticles for antibody-directed drug delivery.

Delayed presentation and management approach of autonomic dysfunction associated with severe tetanus

Introduction: In 2019, there were over 73 000 estimated tetanus cases globally, including more than 27 000 cases of neonatal tetanus, and the worldwide deaths caused by tetanus were almost 34 684. The mortality rate of tetanus is greater than 50% in countries without ICUs and 10% in developed countries, mostly attributed to autonomic dysfunction. Countries with the greatest rates of post-neonatal tetanus mortality (greater than five fatalities per 100 000 people) were Somalia, South Sudan, and Kenya. Case presentation: A 66-year-old unvaccinated male patient came to our hospital emergency department with generalized rigidity, neck stiffness, lockjaw, and an altered level of consciousness for 5 days. His symptoms started with stiffness in his neck and back 4 days before. The patient was diagnosed with tetanus, as he was unimmunized, had a recent injury, and presented clinical findings. The authors started treatment by administering intramuscular human tetanus immunoglobulin and metronidazole. He was admitted to the ICU and placed in an isolation room with minimal auditory and visual stimuli. Following 2 weeks after admission his blood pressure began to fall, and his pulse rate started to fluctuate with alternating tachycardia and bradycardia. After 1 month in the ICU, he was discharged from the ICU and transferred to the ward. A catch-up immunization regimen was established. Clinical discussion: Tetanus is a rare condition in the Western world, primarily due to widespread vaccination programs from infancy to adulthood. There are crucial barriers that still exist to overcoming this disease in our country, including a lack of reliable immunization programs. In tetanus, the increase in survival is associated with the use of intensive care facilities for the management of tetanus, besides expanding the knowledge of the disease, which is a challenge for developing countries. Conclusion: It is essential to have enough immunization at an early stage of trauma since severe autonomic dysfunction linked to tetanus might be lethal.

Garadacimab for hereditary angioedema attack prevention: long-term efficacy, quality of life, and safety data from a phase 2, randomised, open-label extension study

Garadacimab is a fully human immunoglobulin G4 monoclonal antibody targeting activated factor XII. This study evaluated long-term efficacy, health-related quality of life (HRQoL), and safety data for garadacimab in adults with hereditary angioedema. This global phase 2 study comprised a treatment period 1 (TP1: 12 weeks, double-blind, placebo-controlled) and a treatment period 2 (TP2: ≥44-week open-label extension). Patients aged 18-65 years with clinically confirmed hereditary angioedema were eligible. In TP1, 32 patients were randomly assigned (1:1:1:1) to receive subcutaneous garadacimab (75 mg, 200 mg, or 600 mg) or placebo every 4 weeks (once monthly). Randomisation was done using interactive response technology via block randomisation (block sizes 1-4). Subsequently, six additional patients in TP1 were assigned to open-label garadacimab 400 mg every 2 weeks. At the start of TP2, patients were re-randomised (if receiving placebo, garadacimab 75 mg, or garadacimab 400 mg) or continued to receive garadacimab 200 mg or garadacimab 600 mg once monthly. After a protocol amendment on March 20, 2020, patients originally assigned to the 600 mg dose were down-titrated to 200 mg at their next visit. The primary endpoint (published previously) was monthly attack rate for patients receiving 200 mg or 600 mg garadacimab in TP1 in the intention-to-treat population. Here, we assessed the impact of garadacimab on patient-reported and investigator-reported outcomes and HRQoL as well as long-term efficacy and safety. This trial is registered with ClinicalTrials.gov, NCT03712228, and is completed. Of 54 patients screened between Oct 29, 2018, and Aug 28, 2019, 32 randomised and six open-label patients completed TP1 and entered TP2 (20 in the garadacimab 200 mg group; 18 in the garadacimab 600 mg group; total 38 patients). Median age was 39·0 years (IQR 27·0-53·0), and 21 patients (55%) were female and 17 (45%) were male. In TP2, the median garadacimab exposure was 87·9 weeks (IQR 50·0-106·6) in the garadacimab 200 mg group and 44·1 weeks (24·1-56·1) in the garadacimab 600 mg group. Median monthly attack rates were 0·0 (IQR 0·0-0·1) in the garadacimab 200 mg group and 0·1 (0·0-0·4) in the garadacimb 600 mg group. Median reduction in monthly attack rate versus run-in was 100% (IQR 98-100) with garadacimab 200 mg. HRQoL improvements observed during TP1 with garadacimab were sustained throughout TP2. TP2 safety signals were consistent with TP1. Two patients experienced serious adverse events of diverticular perforation and asthma (not garadacimab-related). Treatment-emergent adverse events were mostly mild or moderate in severity. The most common adverse events were headache (nine of 38, 24%) and abdominal pain (seven of 38, 18%). There were no treatment-related deaths. Once-monthly garadacimab for more than 2 years in patients with hereditary angioedema was well tolerated and efficacious in reducing monthly attack rate and improving HRQoL. These results reveal the potential of long-term prophylactic treatment with 200 mg once-monthly garadacimab towards complete disease control of patients with hereditary angioedema. CSL Behring.

In vitro enhancement of Zika virus infection by preexisting West Nile virus antibodies in human plasma-derived immunoglobulins revealed after P2 binding site-specific enrichment.

Human immunoglobulin preparations contain a diverse range of polyclonal antibodies that reflect past immune responses against pathogens encountered by the blood donor population. In this study, we examined a panel of intravenous immunoglobulins (IGIVs) manufactured over the past two decades (1998-2020) for their capacity to neutralize or enhance Zika virus (ZIKV) infection in vitro. These IGIVs were selected specifically based on their production dates in relation to the occurrences of two flavivirus outbreaks in the U.S.: the West Nile virus (WNV) outbreak in 1999 and the ZIKV outbreak in 2015. As demonstrated by enzyme-linked immunosorbent assay (ELISA) experiments, IGIVs made before the ZIKV outbreak already harbored antibodies that bind to various peptides across the envelope protein of ZIKV because of the WNV outbreak. Using phage display, the most dominant binding site was mapped precisely to the P2 peptide between residues 211 and 230 within domain II, where BF1176-56, an anti-ZIKV monoclonal antibody, also binds. When tested in permissive Vero E6 cells for ZIKV neutralization, the IGIVs, even after undergoing rigorous enrichment for P2 binding specificity, failed, as did BF1176-56. Meanwhile, BF1176-56 enhanced ZIKV infection in both FcγRII-expressing K562 cells and human peripheral blood mononuclear cells. However, for enhancement by the IGIVs to be detected in these cells, a substantial increase in their P2 binding specificity was required, thus linking the P2 site with ZIKV enhancement in vitro. Our findings warrant further study of the significance of elevated levels of anti-WNV antibodies in IGIVs, considering that various mechanisms operating in vivo may modulate ZIKV infection outcomes.IMPORTANCEWe investigated the capacity of intravenous immunoglobulins manufactured previously over two decades (1998-2020) to neutralize or enhance Zika virus infection in vitro. West Nile virus antibodies in IGIVs could not neutralize Zika virus initially; however, once the IGIVs were concentrated further, they enhanced its infection. These findings lay the groundwork for exploring how preexisting WNV antibodies in IGIVs could impact Zika infection, both in vitro and in vivo. Our observations are historically significant, since we tested a panel of IGIV lots that were carefully selected based on their production dates which covered two major flavivirus outbreaks in the U.S.: the WNV outbreak in 1999 and the ZIKV outbreak in 2015. These findings will facilitate our understanding of the interplay among closely related viral pathogens, particularly from a historical perspective regarding large blood donor populations. They should remain relevant for future outbreaks of emerging flaviviruses that may potentially affect vulnerable populations.

Acute rejection post lung transplant.

To review what is currently known about the pathogenesis, diagnosis, treatment, and prevention of acute rejection (AR) in lung transplantation. Epigenomic and transcriptomic methods are gaining traction as tools for earlier detection of AR, which still remains primarily a histopathologic diagnosis. Acute rejection is a common cause of early posttransplant lung graft dysfunction and increases the risk of chronic rejection. Detection and diagnosis of AR is primarily based on histopathology, but noninvasive molecular methods are undergoing investigation. Two subtypes of AR exist: acute cellular rejection (ACR) and antibody-mediated rejection (AMR). Both can have varied clinical presentation, ranging from asymptomatic to fulminant ARDS, and can present simultaneously. Diagnosis of ACR requires transbronchial biopsy; AMR requires the additional measuring of circulating donor-specific antibody (DSA) levels. First-line treatment in ACR is increased immunosuppression (pulse-dose or tapered dose glucocorticoids); refractory cases may need antibody-based lymphodepletion therapy. First line treatment in AMR focuses on circulating DSA removal with B and plasma cell depletion; plasmapheresis, intravenous human immunoglobulin (IVIG), bortezomib, and rituximab are often employed.

Model acetylcholinesterase‐Fc fusion glycoprotein biotechnology system for the manufacture of an organophosphorus toxicant bioscavenging countermeasure

AbstractOrganophosphate (OP) toxicants remain an active threat to public health and to warfighters in the military. Current countermeasures require near immediate administration following OP exposure and are reported to have controversial efficacies. Acetylcholinesterase (AChE) fused to the human immunoglobulin 1 (IgG1) Fc domain (AChE‐Fc) is a potential bioscavenger for OP toxicants, but a reproducible AChE‐Fc biomanufacturing strategy remains elusive. This report is the first to establish a comprehensive laboratory‐scale bioprocessing strategy that can reproducibly produce AChE‐Fc and AChE(W86A)‐Fc which is a mutated AChE protein with reduced enzymatic activity. Characterization studies revealed that AChE‐Fc and AChE(W86A)‐Fc are N‐glycosylated dimeric fusion glycoproteins but only AChE‐Fc had the capability to bind to paraoxon (a model OP). This AChE‐Fc fusion glycoprotein bioprocessing strategy can be leveraged during industrial biomanufacturing development, while the research‐grade AChE‐Fc proteins can be used to determine the potential clinical relevance of the countermeasure against OP toxicants.

Harnessing Bioluminescent Bacteria to Develop an Enzymatic-free Enzyme-linked immunosorbent assay for the Detection of Clinically Relevant Biomarkers.

Enzyme-linked immunosorbent assay (ELISA) is the gold standard technique for measuring protein biomarkers due to its high sensitivity, specificity, and throughput. Despite its success, continuous advancements in ELISA and immunoassay formats are crucial to meet evolving global challenges and to address new analytical needs in diverse applications. To expand the capabilities and applications of immunoassays, we introduce a novel ELISA-like assay that we call Bioluminescent-bacteria-linked immunosorbent assay (BBLISA). BBLISA is an enzyme-free assay that utilizes the inner filter effect between the bioluminescent bacteriaAllivibrio fischeriand metallic nanoparticles (gold nanoparticles and gold iridium oxide nanoflowers) as molecular absorbers. Functionalizing these nanoparticles with antibodies induces their accumulation in wells upon binding to molecular targets, forming the classical immune-sandwich complex. Thanks to their ability to adsorb the light emitted by the bacteria, the nanoparticles can suppress the bioluminescence signal, allowing the rapid quantification of the target. To demonstrate the bioanalytical properties of the novel immunoassay platform, as a proof of principle, we detected two clinically relevant biomarkers (human immunoglobulin G and SARS-CoV-2 nucleoprotein) in human serum, achieving the same sensitivity and precision as the classic ELISA. We believe that BBLISA can be a promising alternative to the standard ELISA techniques, offering potential advancements in biomarker detection and analysis by combining nanomaterials with a low-cost, portable bioluminescent platform.

Safety, Pharmacokinetics, Pharmacodynamics, and Antitumor Activity from a Phase I Study of Simlukafusp Alfa (FAP-IL2v) in Advanced/Metastatic Solid Tumors.

Simlukafusp alfa (FAP-IL2v), a tumor-targeted immunocytokine, comprising an interleukin-2 variant moiety with abolished CD25 binding fused to human immunoglobulin G1, is directed against fibroblast activation protein-α. This phase I, open-label, multicenter, dose-escalation and extension study (NCT02627274) evaluated the safety, pharmacokinetics, pharmacodynamics, and antitumor activity of FAP-IL2v in patients with advanced/metastatic solid tumors. Participants received FAP-IL2v intravenously once weekly. Dose escalation started at 5 mg; flat dosing (≤25 mg) and intra-participant up-titration regimens (15/20 mg, 20/25 mg, 20/20/35 mg, 20/35/35 mg) were evaluated. Primary objectives were dose-limiting toxicities (DLT), maximum tolerated dose (MTD), recommended expansion dose, and pharmacokinetics. Sixty-one participants were enrolled. DLTs included fatigue (flat dose 20 mg: n = 1), asthenia (25 mg: n = 1), drug-induced liver injury (up-titration regimen 20/25 mg: n = 1), transaminase increase (20/25 mg: n = 1), and pneumonia (20/35/35 mg: n = 1). Up-titration regimen 15/20 mg was the MTD and was selected as the recommended expansion dose. Increases in peripheral blood absolute immune cell counts were seen for all tested doses (natural killer cells, 13-fold; CD4+ T cells [including Tregs], 2-fold; CD8+ T cells, 3.5-fold), but without any percentage change in Tregs. Clinical activity was observed from 5 mg (objective response rate, 5.1% [n = 3]; disease control rate, 27.1% [n = 16]). Responses were durable (n = 3; 2.8 [censored], 6.3, and 43.4 months). FAP-IL2v had a manageable safety profile and showed initial signs of antitumor activity in advanced/metastatic solid tumors.

Pozelimab, a human monoclonal immunoglobulin for the treatment of CHAPLE disease.

The complement is a crucial factor of the innate immune system. However, its activation can lead to various diseases, so it needs to be controlled. In mammals, surface-bound complement regulatory proteins safeguard cells from uncontrolled complement-mediated lysis. One of the human complement regulators is CD55, also known as the decay-accelerating factor (DAF), a single-chain, type I cell surface protein anchored to glycosylphosphatidylinositol (GPI). The genetic loss of the complement regulatory protein CD55 leads to a fatal illness known as CHAPLE disease. The complement and innate immunity become hyperactive in this disease, causing angiopathic thrombosis and protein-losing enteropathy. Patients with CHAPLE disease experience abdominal pain, nausea, vomiting, diarrhea, loss of appetite, weight loss, impaired growth, and swelling. This genetic condition has no known cure, and managing its symptoms can be challenging. Pozelimab, a human monoclonal immunoglobulin IgG4 antibody, is a drug that targets the terminal complement protein C5. The drug has a high affinity for both wild-type and variant human C5. Pozelimab has received designations such as fast track, orphan drug, and rare pediatric disease, making it a significant medical breakthrough. It is currently the only available treatment for this disease. In this review, we have summarized the preclinical and clinical data on pozelimab.

Cancer therapy related cardiac dysfunction as a result of Panitumumab

Panitumumab is a human immunoglobulin monoclonal antibody designed to target the epidermal growth factor receptor (EGFR) which is used in the treatment of metastatic colorectal cancer alone or in combination with chemotherapy. In this report, we present a case of new onset heart failure with reduced ejection fraction in a patient following panitumumab therapy. A 73-year-old gentleman with metastatic rectal adenocarcinoma presented to his local hospital with increased shortness of breath, two months after his first and only dose of panitumumab. A transthoracic echocardiogram demonstrated dilated left ventricle with global hypokinesis and an estimated left ventricular ejection fraction of 25%. Our patient underwent a comprehensive diagnostic assessment at his presentation, including ECG, transthoracic echocardiogram, cardiac magnetic resonance, computed tomography coronary angiography (CTCA), invasive coronary angiogram and 18F-FDG PET-CT. These investigations revealed no evidence of ischemic events or inflammatory processes that could account for the severe left ventricular dysfunction. To our knowledge, this is the first reported case of heart failure with reduced ejection fraction linked to panitumumab with subsequent deep phenotyping. The current guidelines do not recommend specific cardiovascular monitoring protocols for patients receiving anti-EGFR monoclonal antibodies. Until more data are available, it would be prudent to implement the same cardiovascular surveillance measures outlined for individuals receiving osimertinib, which is an EGFR tyrosine kinase inhibitor.