Sign in to use this feature.

Years

Between: -

Subjects

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline

Journals

Article Types

Countries / Regions

Search Results (135)

Search Parameters:
Keywords = antibody-dependent cellular cytotoxicity (ADCC)

Order results
Result details
Results per page
Select all
Export citation of selected articles as:
34 pages, 30184 KB  
Article
An In Vitro Screen Identifies H1 Influenza Hemagglutinin Substitutions That Alter mRNA-LNP Vaccine Responses Against the Stalk Domain
by Samuel W. Rovito, Po-Ling Chen, Guohua Yang, Haley N. Writt, Ashley N. Zalla, Marissa A. Donofrio, Jonathan N. Fogo, Richard J. Webby, James D. Brien and Charles J. Russell
Vaccines 2026, 14(8), 701; https://doi.org/10.3390/vaccines14080701 - 13 Aug 2026
Viewed by 113
Abstract
Background: Conformational stability has been shown to modulate the immunogenicity of structural class 1 viral fusion glycoproteins, yet the relationship between influenza A hemagglutinin (HA) stability and antigenicity remains poorly understood. Methods: Here, we screened a panel of 21 A/Hawaii/70/2019 (H1N1) HA mutants [...] Read more.
Background: Conformational stability has been shown to modulate the immunogenicity of structural class 1 viral fusion glycoproteins, yet the relationship between influenza A hemagglutinin (HA) stability and antigenicity remains poorly understood. Methods: Here, we screened a panel of 21 A/Hawaii/70/2019 (H1N1) HA mutants for expression, cleavage, and acid and conformational stability in cells. Twelve mutant HA proteins expressed from transfected plasmid constructs that showed relatively robust expression compared to WT also exhibited either altered stability or glycosylation deletion. mRNA-LNPs were generated containing these 12 HAs, along with the wild-type (WT) HA, to investigate the mutational effects on mRNA-LNP vaccine immunogenicity and protection in mice. Hemagglutination inhibition, microneutralization, and total serum IgG ELISAs were performed using a panel of H1N1 antigens to evaluate humoral immune responses at 28 days post vaccination. The vaccinated mice were then subjected to lethal challenge with a forward-drifted H1N1 virus. Results: Most mutant HA candidates elicited WT-like serological responses and provided protection against challenge, although noticeable decreases in serological responses and, to a lesser extent, protection were observed, especially among G72K- and R109E-vaccinated mice. Of note, substitutions at position E107 enhanced total IgG responses against the HA stalk. Modest, but detectable, increases in antibody-dependent cellular cytotoxicity (ADCC) were also observed, particularly with E107R. Although substitution-specific differences in weight loss were found in E107-vaccinated mice challenged with a mouse-adapted Cal/09 virus, these differences were minor, and protection against the forward-drifted challenge virus and a heterologous PR8 challenge virus was no different from that in mice vaccinated with WT HA. Conclusions: These findings demonstrate the ability of specific substitutions to alter components of humoral immunity by shifting HA domain-specific antibody responses, which could prove useful in the design and development of HA vaccine antigens possessing optimized immunogenicity. Full article
(This article belongs to the Section Nucleic Acid (DNA and mRNA) Vaccines)
Show Figures

Figure 1

15 pages, 2883 KB  
Article
Dual Antiviral Functions of Antibodies Targeting African Swine Fever Virus p17 Protein: Viral Inhibition and ADCC Induction
by Shengmei Chen, Chunhao Jiang, Zhanhao Lu, Jing Lan, Qiang Fu, Yuan Sun, Tao Wang and Hua-Ji Qiu
Viruses 2026, 18(8), 841; https://doi.org/10.3390/v18080841 - 1 Aug 2026
Viewed by 302
Abstract
African swine fever virus (ASFV) causes African swine fever (ASF), a highly lethal disease in pigs. Vietnam has approved two ASF live-attenuated vaccines (LAVs), but their efficacy and safety remain controversial, and no reliable, highly effective commercial ASF vaccine is available yet. Humoral [...] Read more.
African swine fever virus (ASFV) causes African swine fever (ASF), a highly lethal disease in pigs. Vietnam has approved two ASF live-attenuated vaccines (LAVs), but their efficacy and safety remain controversial, and no reliable, highly effective commercial ASF vaccine is available yet. Humoral immunity plays an important role in protection against ASFV infection. However, there is still controversy regarding whether ASFV infection can induce antibodies with neutralizing activity. Antibody-dependent cellular cytotoxicity (ADCC), as an antibody-mediated protective mechanism, offers a novel perspective for screening protective ASFV antigens. This study evaluated five structural proteins (pCP312R, pA104R, pA151R, p17, and pF317L) as subunit vaccine candidates based on their ability to induce antibodies that inhibit viral replication and mediate ADCC. The recombinant proteins were expressed in Escherichia coli, purified, and used to immunize pigs. Immune sera collected two weeks after the third immunization were tested for their ability to inhibit ASFV replication in porcine alveolar macrophages (PAMs) using rASFV-Gluc/EGFP. ADCC activity was assessed using a stable HEK293T-p17 cell line as target cells and porcine peripheral blood mononuclear cells (PBMCs) as effectors, with cytotoxicity measured by lactate dehydrogenase release. All five recombinant proteins were successfully expressed and purified. Immunization with pCP312R, pA104R, p17, and pF317L induced the production of specific antibodies in pigs, but only anti-p17 antibodies significantly inhibited ASFV replication in PAMs. The p17 is highly conserved across different ASFV genotypes and is predicted to contain a transmembrane domain. Anti-p17 antibodies effectively mediated PBMCs to specifically kill target cells, demonstrating significant ADCC activity. Moreover, the HEK293T-p17 cell line was specifically recognized by anti-ASFV sera. These findings indicate that p17 is a dual-functional antigen capable of eliciting antibodies that both inhibit viral replication and mediate ADCC in vitro. Furthermore, we have developed an in vitro platform for screening protective ASFV antibodies based on viral inhibition and ADCC, providing candidate targets for the development of next-generation ASF subunit vaccines. Full article
(This article belongs to the Collection African Swine Fever Virus (ASFV))
Show Figures

Figure 1

18 pages, 2319 KB  
Review
Next-Generation Multi-Engager Complexes Linking Natural Killer Cells to Tumor Cells and Targeting the Proteolytic Checkpoint ADAM17
by Kate J. Dixon and Bruce Walcheck
Cells 2026, 15(14), 1269; https://doi.org/10.3390/cells15141269 - 15 Jul 2026
Viewed by 488
Abstract
Natural killer (NK) cells are innate lymphocytes capable of killing transformed cells without prior sensitization through direct cytolytic activity and, in an antigen-specific manner, by antibody-dependent cellular cytotoxicity (ADCC). Human NK cells mediate ADCC exclusively via the IgG Fc receptor CD16 (FcγRIIIA), triggering [...] Read more.
Natural killer (NK) cells are innate lymphocytes capable of killing transformed cells without prior sensitization through direct cytolytic activity and, in an antigen-specific manner, by antibody-dependent cellular cytotoxicity (ADCC). Human NK cells mediate ADCC exclusively via the IgG Fc receptor CD16 (FcγRIIIA), triggering degranulation and cytokine production. Multi-engager complexes, such as BiKEs, TriKEs, TetraKEs, ANKETs, and ICEs, have been developed to link CD16 to tumor antigens. However, CD16 expression can be rapidly downregulated upon NK cell activation by the proteolytic checkpoint, a disintegrin and metalloproteinase-17 (ADAM17). ADAM17 induction in NK cells occurs in response to various stimuli, including the potent activating receptor CD16 and cytokine signaling. CD16 downregulation is further exacerbated within the tumor microenvironment, significantly diminishing ADCC potency by tumor-infiltrating NK cells. Moreover, ADAM17 expression and function are upregulated in various solid tumors, leading to the release of NK cell ligands and tumor-promoting factors. Consequently, developing strategies to inhibit ADAM17 to enhance NK cell function and suppress tumor cell growth is paramount to multi-engager efficacy. This review provides an overview of NK cell biology and the role of ADAM17 in regulating NK cell function and tumor cell growth. We examine the current landscape of NK cell multi-engager complexes in clinical development and discuss emerging strategies for incorporating an ADAM17-blocking component to optimize therapeutic outcomes. Full article
(This article belongs to the Special Issue Natural Killer (NK) Cells in Immunity: Limitations and Potential)
Show Figures

Figure 1

29 pages, 598 KB  
Review
Natural Killer (NK) Cells in Tumor Immunity: Limitations and Therapeutic Potential with a Focus on Nasopharyngeal Carcinoma and Comparison with T-Cell-Based Therapies
by Anna Makowska and Udo Kontny
Cells 2026, 15(10), 913; https://doi.org/10.3390/cells15100913 - 15 May 2026
Viewed by 1300
Abstract
Natural killer (NK) cells are increasingly recognized as a complementary platform to T-cell-based cancer immunotherapies. Their innate, MHC-unrestricted recognition, capacity to mediate antibody-dependent cellular cytotoxicity (ADCC) and comparatively favorable toxicity profile have given rise to a broad therapeutic pipeline that includes cytokine-supported regimens, [...] Read more.
Natural killer (NK) cells are increasingly recognized as a complementary platform to T-cell-based cancer immunotherapies. Their innate, MHC-unrestricted recognition, capacity to mediate antibody-dependent cellular cytotoxicity (ADCC) and comparatively favorable toxicity profile have given rise to a broad therapeutic pipeline that includes cytokine-supported regimens, adoptive NK products, bispecific and trispecific NK engagers, and chimeric antigen receptor (CAR)-engineered NK cells. Clinical data, particularly in hematologic malignancies, show that NK-cell-based strategies can be safe and biologically active, although limited persistence, suboptimal trafficking and immune escape remain key challenges. Nasopharyngeal carcinoma (NPC), an Epstein–Barr virus (EBV)-driven epithelial cancer, illustrates how a tumor microenvironment (TME) can simultaneously impair NK function and create specific vulnerabilities that NK-focused therapies can exploit. This review summarizes NK biology and current therapeutic platforms, analyzes major limitations, highlights the specific context of NK-cell-based strategies in NPC and compares NK- and T-cell-based therapies with an emphasis on clinical translation. Full article
(This article belongs to the Special Issue Natural Killer (NK) Cells in Immunity: Limitations and Potential)
Show Figures

Figure 1

15 pages, 1791 KB  
Article
Antibody Responses After BA.5/BF.7 Breakthrough Infection in People Living with HIV
by Ying Liu, Zhaowei Guo, Zhuo Yang, Yaruo Qiu, Xinglin Li, Xin Li, Leidan Zhang, Danying Chen, Xuesen Zhao and Hongxin Zhao
Vaccines 2026, 14(4), 339; https://doi.org/10.3390/vaccines14040339 - 11 Apr 2026
Viewed by 893
Abstract
Background: People living with HIV (PLWH) constitute a vulnerable population during the COVID-19 pandemic; however, it remains uncertain whether long-term suppressive antiretroviral therapy (ART) restores sufficient immune competence to support robust hybrid immunity. While vaccination followed by breakthrough infection—termed hybrid immunity—typically elicits potent [...] Read more.
Background: People living with HIV (PLWH) constitute a vulnerable population during the COVID-19 pandemic; however, it remains uncertain whether long-term suppressive antiretroviral therapy (ART) restores sufficient immune competence to support robust hybrid immunity. While vaccination followed by breakthrough infection—termed hybrid immunity—typically elicits potent humoral responses in immunocompetent individuals, the functional quality and breadth of these responses against evolving Omicron subvariants remain poorly characterized in PLWH. This study aimed to assess functional antibody responses, including neutralizing activity and Fc effector functions, in vaccinated and unvaccinated PLWH who experienced breakthrough infection with Omicron subvariants BA.4/5 or BF.7. Methods: We enrolled three cohorts between December 5 and December 20, 2022: 25 HIV-negative individuals with breakthrough infection (BTI-HC), 20 ART-experienced PLWH with breakthrough infection following three-dose COVID-19 vaccination (BTI-HIV), and 10 ART-experienced PLWH with primary infection without prior vaccination (PI-HIV). All HIV-positive participants were receiving suppressive ART with regimens based on non-nucleoside reverse transcriptase inhibitors or integrase strand transfer inhibitors for a median of 3.4 years. We measured receptor-binding domain (RBD)-specific IgG, neutralizing antibody titers against ancestral D614G, Delta, BA.1, BA.4/5, BF.7, XDV, KP.2, and KP.3 variants, and antibody-dependent cellular cytotoxicity (ADCC) responses. Results: Despite lower absolute CD4+ T cell counts, BTI-HIV participants mounted RBD-binding IgG, neutralizing antibody, and ADCC responses that were comparable to BTI-HC and significantly exceeded PI-HIV across all tested variants. Both breakthrough infection cohorts exhibited immunological imprinting, with higher neutralizing titers against ancestral D614G than infecting BA.4/5 or BF.7 variants. Emerging variants XDV, KP.2, and KP.3 demonstrated substantial neutralization escape in all groups. PI-HIV showed markedly diminished neutralization breadth and failed to generate enough responses against all tested Omicron strains. Conclusions: Suppressive ART enables PLWH to mount hybrid immunity—conferred by vaccination followed by BF.7 or BA.4/5 breakthrough infection—with neutralizing and ADCC responses comparable to HIV-negative individuals, and significantly exceeding those of unvaccinated PLWH with primary infection. This underscores the critical role of vaccination in establishing effective hybrid immunity in this population. However, we observed immunological imprinting, with higher titers against ancestral strains than against infecting variants, and substantial escape by emerging sublineages XDV, KP.2, and KP.3 across all groups. These findings support prioritizing updated variant-containing vaccines for HIV-positive populations and reinforce the essential role of vaccination in this vulnerable group. Full article
Show Figures

Figure 1

21 pages, 2013 KB  
Article
Microsecond Dynamics of Fc–CD16a Recognition: Impact of Mutations, Core Fucosylation, and Fc Asymmetry
by Sébastien Estaran, Bernard Hehlen and Alain Chavanieu
Antibodies 2026, 15(1), 17; https://doi.org/10.3390/antib15010017 - 23 Feb 2026
Viewed by 1063
Abstract
Background/Objectives: Antibody-dependent cellular cytotoxicity relies on the interaction between the Fc region of immunoglobulin G1 (IgG1) and the CD16a receptor. While removal of core fucosylation on Fc and introduction of the DFTE mutation set (S239D, H268F, S324T, I332E) are known to enhance CD16a [...] Read more.
Background/Objectives: Antibody-dependent cellular cytotoxicity relies on the interaction between the Fc region of immunoglobulin G1 (IgG1) and the CD16a receptor. While removal of core fucosylation on Fc and introduction of the DFTE mutation set (S239D, H268F, S324T, I332E) are known to enhance CD16a binding, the detailed contributions of these engineered sites in solution remain incompletely defined. Methods: Here, we employed 1 µs molecular dynamics simulations to map, at atomic resolution, the interaction networks stabilizing pre-formed Fc-CD16a complexes, including afucosylated Fc-wild-type, DFTE-engineered, Fc-fucosylated, and asymmetrically engineered Fc variants. Results: Our results show that only S239D, present on both Fc chains, and H268F on chain A consistently contribute to stabilizing the CD16a interface, while I332E does not form persistent interactions. Glycan–protein contacts are primarily intrachain, with transient interchain glycan–glycan interactions not contributing significantly to complex stability. Fucosylation on Fc significantly reduces binding stability by disrupting peripheral interactions and critical glycan-mediated contacts. Notably, the asymmetric Fc variant, in which the two heavy chains carry distinct sets of substitutions, retains high-affinity binding despite lacking S239D and carrying core fucose, through a novel hydrophobic cluster and reinforced peripheral electrostatic interactions. Conclusions: Altogether, these findings provide a quantitative framework for how targeted mutations and fucose modifications remodel Fc-CD16a interactions, offering insights for the rational design of next-generation therapeutic antibodies. Full article
(This article belongs to the Section Antibody Discovery and Engineering)
Show Figures

Graphical abstract

22 pages, 3452 KB  
Article
Engineering Bi-Specific CAR-NK Cells to Restore Antibody-Dependent Cellular Cytotoxicity in Solid Tumors
by Jee Young Chung, Jung Eun Kim, Daseuri Cha, Hye Jin Lee, Els Verhoeyen, Hee Jung An and Jung Eun Park
Cells 2026, 15(4), 373; https://doi.org/10.3390/cells15040373 - 20 Feb 2026
Cited by 2 | Viewed by 1422
Abstract
Natural Killer (NK) cell-based immunotherapy relies on CD16-mediated Antibody-Dependent Cellular Cytotoxicity (ADCC), yet the ovarian tumor microenvironment (TME) severely compromises this function via Transforming Growth Factor-beta (TGF-β). This study investigated the molecular mechanisms driving this suppression and evaluated a bi-specific Chimeric Antigen Receptor [...] Read more.
Natural Killer (NK) cell-based immunotherapy relies on CD16-mediated Antibody-Dependent Cellular Cytotoxicity (ADCC), yet the ovarian tumor microenvironment (TME) severely compromises this function via Transforming Growth Factor-beta (TGF-β). This study investigated the molecular mechanisms driving this suppression and evaluated a bi-specific Chimeric Antigen Receptor (CAR) strategy to overcome this hurdle. Primary PBNK cells exposed to TGF-β showed sustained canonical SMAD2 phosphorylation, accompanied by a marked reduction in activating receptors such as CD16 and NKG2D and an increase in exhaustion markers such as PD-1. Functionally, these phenotypic alterations led to failed infiltration and cytotoxicity in vitro and within ovarian cancer-derived spheroids. To overcome this limitation, we engineered NK-92 cells with a bi-specific CAR-targeting Folate Receptor Alpha (FRα) and CD16. While TGF-β typically impairs NK cell function, our armed CAR-NK cells successfully infiltrated tumoroids and synergized with Trastuzumab to induce potent ADCC-mediated lysis. Our findings define the TGF-β/SMAD2 axis as a central driver of NK cell dysfunction in ovarian cancer and demonstrate that bi-specific CAR-NK platforms offer a robust therapeutic solution to bypass TME-induced suppression and restore antibody-mediated tumor suppression. Full article
(This article belongs to the Section Cell and Gene Therapy)
Show Figures

Graphical abstract

14 pages, 2391 KB  
Article
The Anti-SLAMF7 Antibody, Elotuzumab, Induces Antibody-Dependent Cellular Cytotoxicity Against CLL Cell Lines
by Dominik Kľoc, Bianca Dubiková, Simona Žiláková, Ján Sykora, Michaela Šuliková, Slavomír Kurhajec, Ján Sabo, Tomáš Guman and Marek Šarišský
Molecules 2026, 31(3), 531; https://doi.org/10.3390/molecules31030531 - 3 Feb 2026
Viewed by 1171
Abstract
SLAMF7, also known as CD319, a SLAM (signaling lymphocytic activation molecule) family receptor, is relatively weakly expressed on chronic lymphocytic leukemia (CLL) B cells. This study evaluated the ability of elotuzumab (E), an anti-SLAMF7/CD319 antibody, to induce antibody-dependent cellular cytotoxicity (ADCC) against CLL [...] Read more.
SLAMF7, also known as CD319, a SLAM (signaling lymphocytic activation molecule) family receptor, is relatively weakly expressed on chronic lymphocytic leukemia (CLL) B cells. This study evaluated the ability of elotuzumab (E), an anti-SLAMF7/CD319 antibody, to induce antibody-dependent cellular cytotoxicity (ADCC) against CLL cell lines (MEC-1, MEC-2, CI, HG-3, PGA-1, WA-OSEL). ADCC was assessed by flow cytometry using E (100 μg/mL), rituximab (R, 100 μg/mL), and their combination (E + R). CLL lines served as targets (T), while peripheral blood mononuclear cells (PBMCs) or NK cells from healthy donors served as effectors (E) at an 8:1 E:T ratio for 4 h. With PBMCs, E-induced ADCC ranged from 1.3 ± 1.2% (PGA-1) to 14.6 ± 8.1% (MEC-1); R-induced ADCC ranged from 9.2 ± 4.6% (PGA-1) to 16.6 ± 9.4% (WA-OSEL). With NK cells, E-induced ADCC ranged from 1.8 ± 3.7% (PGA-1) to 27.3 ± 4.7% (MEC-1); R-induced ADCC ranged from 5.1 ± 4.3% (PGA-1) to 27.5 ± 13.6% (CI). E outperformed R in MEC-1, while R was superior elsewhere. Cell lines with higher SLAMF7/CD319 expression displayed increased sensitivity to E. Cell lines with del17p showed higher SLAMF7/CD319 expression. The combination of E + R showed no significant synergy over monotherapies. In conclusion, elotuzumab induced significant ADCC in CLL cells, warranting further therapeutic evaluation. Full article
Show Figures

Figure 1

15 pages, 678 KB  
Article
Development of an Ultrasensitive ELISA Assay for Evaluating HIV-1 Envelope Glycoprotein as a Marker for Targeted Activator of Cell Kill
by Guoxin Wu, Luca Sardo, Yuan Li, Steven D. Heron, BaoJen Shyong, Matthew Mazur, Daniel M. Gorman, Carl J. Balibar, Brian C. Magliaro, Craig Leach, Thomas Rush and Bonnie J. Howell
Viruses 2026, 18(1), 46; https://doi.org/10.3390/v18010046 - 28 Dec 2025
Viewed by 1469
Abstract
The HIV-1 envelope glycoprotein gp120 is prominently exposed on the surface of both HIV-1 virions and infected host cells, serving as a key marker of infection. gp120 plays a pivotal role in viral entry by interacting with the primary receptor, CD4, on host [...] Read more.
The HIV-1 envelope glycoprotein gp120 is prominently exposed on the surface of both HIV-1 virions and infected host cells, serving as a key marker of infection. gp120 plays a pivotal role in viral entry by interacting with the primary receptor, CD4, on host cells. Therapeutic strategies targeting the HIV-1 reservoir, such as anti-gp120 antibodies that trigger antibody-dependent cellular cytotoxicity (ADCC) and chimeric antigen receptor T (CAR-T) cells, rely on the presence of gp120 on the surface of infected cells to exert their effects. Consequently, accurate monitoring of gp120 expression on infected cells is essential for evaluating the pharmacological efficacy of these interventions. In this study, a sensitive, specific, and inexpensive enzyme-linked immunosorbent assay (ELISA) for quantifying HIV-1 gp120 glycoprotein was developed using a selected pair of anti-gp120 antibodies. The assay achieved a lower limit of quantitation (LLOQ) of 0.16 pM, demonstrating sensitivity comparable to that of the digital single molecule array (Simoa) platform, which exhibited a LLOQ of 0.23 pM and requires specialized instrumentation. The binding specificity of the antibodies used in the novel assay was confirmed using liquid chromatography–mass spectrometry (LC-MS), and the assay was pharmacologically validated with lysates obtained from 2D10 and MOLT IIIB cell lines. Furthermore, treatment of HIV-infected human primary CD4+ T cells with a targeted activator of cell kill (TACK) compound significantly reduced gp120 concentration in CD4+ T cell lysate compared to controls. The gp120 marker from infected cell lysates correlated with the number of gp120-positive cells detected by immunocytochemistry, as well as with HIV-1 p24 levels and cell-associated viral RNA measurements. In summary, a novel, simple, and sensitive HIV-1 gp120 ELISA has been developed and validated. This assay holds potential for investigating HIV-1 persistence and evaluating the efficacy of therapeutic agents targeting infected cells. Full article
(This article belongs to the Special Issue HIV Reservoirs, Latency, and the Factors Responsible)
Show Figures

Figure 1

14 pages, 2315 KB  
Article
Therapeutic Potential of an Anti-CD44v6 Monoclonal Antibody in Xenograft Models of Colorectal and Gastric Cancer
by Aoi Hirayama, Tomohiro Tanaka, Tomokazu Ohishi, Keisuke Shinoda, Takuya Nakamura, Airi Nomura, Naoki Kojo, Haruto Araki, Kaito Suzuki, Mika K. Kaneko, Hiroyuki Suzuki and Yukinari Kato
Cells 2025, 14(23), 1873; https://doi.org/10.3390/cells14231873 - 26 Nov 2025
Cited by 3 | Viewed by 1572
Abstract
CD44 variant (CD44v) isoforms are involved in promoting cancer metastasis, sustaining cancer stem cell (CSC) properties, and conferring resistance to therapeutic interventions. Consequently, the development of monoclonal antibodies (mAbs) targeting CD44v represents a crucial strategy for eliminating CD44v-positive cancer cells. Previously, an anti-CD44v6 [...] Read more.
CD44 variant (CD44v) isoforms are involved in promoting cancer metastasis, sustaining cancer stem cell (CSC) properties, and conferring resistance to therapeutic interventions. Consequently, the development of monoclonal antibodies (mAbs) targeting CD44v represents a crucial strategy for eliminating CD44v-positive cancer cells. Previously, an anti-CD44v6 mAb, C44Mab-9 (mouse IgG1, κ), was established. C44Mab-9 recognizes explicitly the epitope encoded by the variant exon 6-encoded region of CD44 and applies to flow cytometry, western blotting, and immunohistochemistry. To assess the therapeutic potential, a mouse IgG2a isotype of C44Mab-9 (designated C44Mab-9-mG2a) was generated, and the in vitro and in vivo antitumor activities were evaluated using gastric and colorectal cancer cell lines. C44Mab-9-mG2a demonstrated specific binding to CD44v3–10-overexpressed Chinese hamster ovary cells (CHO/CD44v3–10), as well as gastric cancer (NUGC-4) and colorectal cancer (COLO201 and COLO205) in flow cytometry. C44Mab-9-mG2a exerted antibody-dependent cellular cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC) against CHO/CD44v3–10, NUGC-4, COLO201, and COLO205. Moreover, systemic administration of C44Mab-9-mG2a significantly inhibited tumor growth in CHO/CD44v3–10, NUGC-4, COLO201, and COLO205 xenografts compared with the control IgG2a. These findings indicate that C44Mab-9-mG2a could be applied to the mAb-based therapy against CD44v6-positive tumors. Full article
(This article belongs to the Special Issue Cellular Mechanisms of Anti-Cancer Therapies)
Show Figures

Figure 1

17 pages, 3216 KB  
Article
The DNA Vaccines for the Gn and Gc Heterologous Polymer of Severe Fever with Thrombocytopenia Syndrome Virus Induce Potent Immunogenicity in Mice
by Qiuju He, Xiaojuan Liu, Jincheng Tong, Huan Li, Heng Zhang, Jiamin Chen, Mengyi Zhang, Zhihua Li and Qianqian Li
Vaccines 2025, 13(12), 1186; https://doi.org/10.3390/vaccines13121186 - 24 Nov 2025
Cited by 2 | Viewed by 1475
Abstract
Introduction/Background: Severe fever with thrombocytopenia syndrome virus (SFTSV) poses a threat to global public health with a mortality rate of up to 30%. However, there is currently no commercialized SFTSV vaccine. This study focused on the construction of DNA vaccines with different structures [...] Read more.
Introduction/Background: Severe fever with thrombocytopenia syndrome virus (SFTSV) poses a threat to global public health with a mortality rate of up to 30%. However, there is currently no commercialized SFTSV vaccine. This study focused on the construction of DNA vaccines with different structures based on the surface glycoproteins Gn and Gc to identify the immunodominant conformations. Methods: The DNA vaccines encoding secretory proteins including Gn or Gc monomer, heterodimer of Gn and Gc (dimer), two forms of hexamer composed of the Gn and Gc heterodimer (hexamer-1 and hexamer-2) or ferritin nanoparticles of Gn, and non-secretory proteins including Gn (Gn-TM) and Gc (Gc-TM) were constructed. Western blot confirmed the expression level and the specificity of those DNA vaccines. After vaccinating mice with those DNA vaccines, its induced humoral and cellular immunity were comprehensively evaluated. Results: The DNA vaccines were constructed successfully. The DNA vaccines of Gn and polymers including dimer, hexamer-2, and ferritin nanoparticles inducing stronger binding antibody, neutralizing antibody, and antibody-dependent cellular cytotoxicity (ADCC) activity. The neutralizing antibody induced by these constructs was also cross-recognized by other five SFTSV pseudovirus strains. However, the T cell response induced by Gc, dimer or hexamer-2 DNA vaccines were significantly higher than those in most other groups, including Gn. Conclusion: The DNA vaccines encoding dimer or hexamer-2 demonstrated superior immunogenicity over other conformations, after taking the results of humoral and cellular responses into account. This study revealed the advantages of using polymer conformations in SFTSV vaccine design and provided new targets in SFTSV vaccine development. Full article
Show Figures

Figure 1

26 pages, 8862 KB  
Article
Enhanced ADCC Activity of a C-Terminal Lysine Variant of an IgG1 Antibody Driven by N-Linked MAN5 Glycan Using a Reporter Gene Assay
by Ming-Ching Hsieh, Kristiina Dorofejeva, Jingming Zhang, Diane L. Vy, Jun Qian, Alice M. Matathia, Timothy Blanc, Chao Richard Li and Babita S. Parekh
Antibodies 2025, 14(4), 89; https://doi.org/10.3390/antib14040089 - 17 Oct 2025
Cited by 1 | Viewed by 2941
Abstract
Background: Antibody-dependent cellular cytotoxicity (ADCC) is an immune response where antibodies bind to target cells and activate effector cells through Fcγ receptors, ultimately leading to the destruction of the target cells. Methods: This study examined the ADCC activities of charge variants of a [...] Read more.
Background: Antibody-dependent cellular cytotoxicity (ADCC) is an immune response where antibodies bind to target cells and activate effector cells through Fcγ receptors, ultimately leading to the destruction of the target cells. Methods: This study examined the ADCC activities of charge variants of a therapeutic IgG1, MAB1, using an internally developed reporter gene assay. In this assay, the proprietary target was expressed on DiFi cells, while FcγRIIIa was expressed on Jurkat effector cells. Results: The results revealed that different charge variants had varying levels of ADCC activity, with variants containing C-terminal lysine residues showing enhanced activity. The charge variants arose from modifications such as the presence of sialic acid at the glycan moiety, deamidation, and C-terminal lysine truncation, including K2 (two C-terminal lysine residues), K1 (one C-terminal lysine residue), and K0 (no C-terminal lysine residues) variants. Notably, the K1 and K2 variants demonstrated higher ADCC activity compared to the K0 and acidic variants. However, the observed increase was attributed not to the lysine residue itself, but rather to the MAN5 glycan associated with the lysine-containing variants. Conclusion: These findings challenge previous assumptions about the role of C-terminal lysine in ADCC, suggesting a shift in understanding the functional significance of charge variants and emphasizing the critical influence of glycan composition in therapeutic antibody efficacy. Full article
(This article belongs to the Section Antibody-Based Therapeutics)
Show Figures

Graphical abstract

19 pages, 625 KB  
Review
The Yin and Yang of Antibodies in Viral Infectious Diseases
by Jianning He, Yiu-Wing Kam and Fok-Moon Lum
Diseases 2025, 13(10), 341; https://doi.org/10.3390/diseases13100341 - 15 Oct 2025
Viewed by 1897
Abstract
Antibodies are a cornerstone of the adaptive immune response, serving as key defenders against viral infections; however, they can also act as a double-edged sword, contributing to immune-mediated pathologies. This review advances a “Yin-Yang” framework to integrate the dual activities of antibodies. The [...] Read more.
Antibodies are a cornerstone of the adaptive immune response, serving as key defenders against viral infections; however, they can also act as a double-edged sword, contributing to immune-mediated pathologies. This review advances a “Yin-Yang” framework to integrate the dual activities of antibodies. The protective ‘Yin’ functions are driven by high-affinity antibodies generated through processes like somatic hypermutation and class-switch recombination. These antibodies execute viral neutralization, activate the complement system, and engage Fc receptors (FcRs) to drive antibody-dependent cellular cytotoxicity (ADCC) and phagocytosis. These mechanisms form the immunological basis of effective vaccines, which aim to elicit durable and functionally specialized antibody isotypes like IgG and mucosal IgA. Conversely, the pathogenic ‘Yang’ of the response can be detrimental. This includes antibody-dependent enhancement (ADE) of infection, notably observed with flaviviruses, and the development of autoimmunity through mechanisms like molecular mimicry and bystander activation, which can lead to conditions such as multiple sclerosis and Guillain-Barré Syndrome. The balance between protection and pathology is tipped by a confluence of factors. These include viral evasion strategies like antigenic mutation and glycan shielding, as well as host-based determinants such as genetic polymorphisms in FcRs, immune history, and the gut microbiome. Understanding these molecular determinants informs the rational design of next-generation interventions. Promising strategies, such as Fc-region glyco-engineering and the design of tolerogenic vaccines, aim to selectively promote protective functions while minimizing pathological risks, offering a clear path forward in combating viral threats. Full article
Show Figures

Graphical abstract

34 pages, 6702 KB  
Article
Development of Novel Neratinib and Docetaxel Core-Loaded and Trastuzumab Surface-Conjugated Nanoparticle for Treatment of HER-2 Positive Breast Cancer
by Victor Ejigah, Gantumur Battogtokh, Bharathi Mandala and Emmanuel O. Akala
Pharmaceutics 2025, 17(10), 1265; https://doi.org/10.3390/pharmaceutics17101265 - 26 Sep 2025
Cited by 1 | Viewed by 1669
Abstract
Background/Objectives: This study developed a targeted drug delivery nanoplatform for treating HER2-positive breast cancer. The nanoplatform encapsulated two hydrophobic anticancer agents, neratinib (NTB) and docetaxel (DTX), within nanoparticles (DTX+NTB−NP) functionalized for conjugation to trastuzumab to form trastuzumab-tagged nanoparticles (TRZ−NP). Trastuzumab is a [...] Read more.
Background/Objectives: This study developed a targeted drug delivery nanoplatform for treating HER2-positive breast cancer. The nanoplatform encapsulated two hydrophobic anticancer agents, neratinib (NTB) and docetaxel (DTX), within nanoparticles (DTX+NTB−NP) functionalized for conjugation to trastuzumab to form trastuzumab-tagged nanoparticles (TRZ−NP). Trastuzumab is a HER2-specific monoclo-nal antibody that binds to HER2 receptors, blocking signal transduction and inducing an-tibody-dependent cellular cytotoxicity (ADCC). Upon receptor-mediated endocytosis, neratinib inhibits cytosolic HER2 signaling, while docetaxel disrupts mitotic cell division, collectively leading to tumor cell death. Methods: Nanoparticles were fabricated by the nanoprecipitation technique, followed by surface modification with a crosslinker and a targeting moiety. DTX+NTB−NP, TRZ−NP, and singly loaded nanoparticles (NTB−NP and DTX−NP) were characterized and their effects evaluated in HER2-positive cancer cell line and xenograft model. Results: In vitro antiproliferation assay in SKBR-3 cell line re-veals a dose and time-dependent cytotoxicity. There was no significant difference in cyto-toxicity observed between DTX+NTB−NP and its free form (DTX+NTB) [p = 0.9172], and between TRZ−NP and its free form (TRZ+DTX+NTB) [p = 0.6750]. However, TRZ−NP, at half the concentration of the singly loaded nanoparticles, significantly reduced the viabil-ity of SKBR-3 cells compared to pure trastuzumab (TRZ) [p < 0.001], NTB−NP [p = 0.0019], and DTX−NP [p = 0.0002]. In vivo evaluation in female athymic nude mice showed sig-nificant log relative tumor volume (%) reduction in groups treated with TRZ−NP and DTX+NTB−NP compared to PBS (phosphate-buffered saline) controls (p ≤ 0.001 and p ≤ 0.001), respectively. Notably, TRZ−NP demonstrated a statistically significant regression in the log relative tumor volume (%) compared to DTX+NTB−NP (p = 0.001). Conclusions: These findings underscore the therapeutic potential and suitability of these nanoplatforms for the precise and controlled targeting of HER2-positive tumors. This study is the first to synchronize the delivery of multiple agents-docetaxel, neratinib, and trastuzumab-within a nanoparticle system for treating HER2-positive tumors, offering a promising strategy to enhance treatment outcomes for HER2 positive breast cancer patients. Full article
(This article belongs to the Special Issue Advanced Nanotechnology for Combination Therapy and Diagnosis)
Show Figures

Figure 1

14 pages, 3043 KB  
Article
Antitumor Activity by an Anti-CD44 Variant 9 Monoclonal Antibody in Gastric and Colorectal Cancer Xenograft Models
by Mayuki Tawara, Hiroyuki Suzuki, Tomokazu Ohishi, Mika K. Kaneko and Yukinari Kato
Int. J. Mol. Sci. 2025, 26(18), 9170; https://doi.org/10.3390/ijms26189170 - 19 Sep 2025
Cited by 1 | Viewed by 1802
Abstract
CD44 variants (CD44v) play essential roles in the promotion of tumor metastasis, maintenance of cancer stem cell properties, and resistance to treatments. Therefore, the development of anti-CD44v mAbs is essential for targeting CD44v-positive tumor cells. An anti-CD44v9 mAb, C44Mab-1 (mouse, IgG [...] Read more.
CD44 variants (CD44v) play essential roles in the promotion of tumor metastasis, maintenance of cancer stem cell properties, and resistance to treatments. Therefore, the development of anti-CD44v mAbs is essential for targeting CD44v-positive tumor cells. An anti-CD44v9 mAb, C44Mab-1 (mouse, IgG1, kappa), was previously established. C44Mab-1 recognizes the variant exon 9-encoded region and applies to multiple research techniques. A mouse IgG2a version of C44Mab-1 (C44Mab-1-mG2a) was generated to evaluate the in vitro and in vivo antitumor activities using gastric and colorectal cancer cell lines. C44Mab-1-mG2a showed a reactivity to CD44v3–10-overexpressed Chinese hamster ovary-K1 (CHO/CD44v3–10), gastric cancer MKN45, and colorectal cancer COLO205 in flow cytometry. C44Mab-1-mG2a exhibited both antibody-dependent cellular cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC) against CHO/CD44v3–10, MKN45, and COLO205. Furthermore, administration of C44Mab-1-mG2a significantly suppressed CHO/CD44v3–10, MKN45, and COLO205 xenograft tumor growth compared with control mouse IgG2a. These results indicated that C44Mab-1-mG2a, which possesses ADCC/CDC activities, could be applied to the mAb-based therapy against CD44v9-positive carcinomas. Full article
(This article belongs to the Special Issue Novel Molecular Pathways in Oncology, 3rd Edition)
Show Figures

Figure 1

Back to TopTop