her2 antigen  (ATCC)

Journal: Advanced Science

Article Title: PD‐L1‐Binding Antigen Presenters: Redirecting Vaccine‐Induced Antibodies for Cancer Immunotherapy

doi: 10.1002/advs.202519574

Figure Lengend Snippet: Mechanism of PBAP‐gE Complex Combined with LZ901 Vaccine in Enhancing NK Cell‐Mediated Antitumor Efficacy. The PBAP‐gE complex specifically binds to PD‐L1 on PD‐L1‐positive tumor cells via its sPD‐L1 domain, thereby labeling these cells with the gE antigen. Subsequently, the LZ901 vaccine activates the immune system to produce gE—specific antibodies (anti‐gE antibodies), which exert their effects through two distinct pathways. First, these antibodies directly bind to the FcγRIIIa receptors on NK cells, providing activation signals. Second, they specifically bind to the PBAP‐gE complex already present on tumor cells. Together, these dual actions trigger NK cell‐mediated ADCC, significantly augmenting NK cells’ ability to target and destroy PD‐L1‐positive tumor cells. Created with BioRender.com.

Article Snippet: Tumor sections (3 μm thick) were stained with HER2 specific antibody (Sinobiological, 310184‐T08, Rabbit PAb) to assess PBAP‐gE infiltration and anti‐human Fab (Abcam, ab771, Mouse Mab) to evaluate the penetration and localization of ADCs within the tumor tissue.

Techniques: Labeling, Activation Assay

Journal: Advanced Science

Article Title: PD‐L1‐Binding Antigen Presenters: Redirecting Vaccine‐Induced Antibodies for Cancer Immunotherapy

doi: 10.1002/advs.202519574

Figure Lengend Snippet: Serum from Herpes Zoster Vaccine (LZ901)‐immunized Mice Enhances PBAP‐Mediated ADCC Against PD‐L1 + Tumor Cells In Vitro. (A) Schematic diagram of the sPD‐1‐gE and PBAP‐gE fusion protein. The sPD‐1‐gE construct consists of sPD‐1 fused to gE. The PBAP‐gE construct comprises sPD‐1‐gE fused with an Fc domain (sPD‐1‐gE‐Fc). (B) Structural modeling of PBAP‐gE with AlphaFold 3. (C) Pharmacokinetic profiles of sPD‐1‐gE and PBAP‐gE following intravenous injection into C57BL/6J mice (n=3 mice/group, 100 µg/mice). Data are presented as the mean ± SD (n = 3). (D) The binding inhibition of PBAP‐gE on PD‐L1/PD‐1 interaction was assessed by ELISA. The absorbance was measured at 450 nm to determine the blocking effect. (E) The fluorescence intensity of the antibody‐cell binding was analyzed using a flow cytometry to assess the blocking effect on the PD‐1/PD‐L1 pathway. Data are presented as the mean ± SD (n = 3). (F) In vitro cytotoxicity assay. KIL C.2 cells were co‐incubated with PBAP‐gE and serum from LZ901‐immunized mice, against 4T1‐IFNγ (IFN‐γ‐induced, PD‐L1 + ) tumor cells and 4T1‐WT cells. KIL C.2 cells, KIL C.2 cells co‐incubated with gE and serum from LZ901‐immunized mice, KIL C.2 cells co‐incubated with PBAP‐gE and serum from saline vaccine‐immunized mice and all groups treated with anti‐FcγRIII blocking antibody were used as controls. Data are presented as mean ± SD of 3 independent experiments, each performed in triplicate. (G) Flow cytometry analysis of perforin, granzyme B, IFN‐γ and CD107a in KIL C.2 cells. Representative of 3 independent experiments.

Article Snippet: Tumor sections (3 μm thick) were stained with HER2 specific antibody (Sinobiological, 310184‐T08, Rabbit PAb) to assess PBAP‐gE infiltration and anti‐human Fab (Abcam, ab771, Mouse Mab) to evaluate the penetration and localization of ADCs within the tumor tissue.

Techniques: In Vitro, Construct, Injection, Binding Assay, Inhibition, Enzyme-linked Immunosorbent Assay, Blocking Assay, Fluorescence, Flow Cytometry, Cytotoxicity Assay, Incubation, Saline

Journal: Advanced Science

Article Title: PD‐L1‐Binding Antigen Presenters: Redirecting Vaccine‐Induced Antibodies for Cancer Immunotherapy

doi: 10.1002/advs.202519574

Figure Lengend Snippet: Trop2‐CAR‐T Cells Coexpressing PBAP‐gE or Combined with Intratumoral Injection of PBAP‐gE Induces Tumor Regression in LZ901‐Vaccinated Mice. (A) Schematic of CAR constructs. The control CAR fuses scFv VH/VL domains to the CD28 transmembrane (TM) and CD3ζ signaling domains. The experimental CAR adds a C‐terminal PBAP‐gE module under NFAT promoter control for tumor‐inducible expression. (B) Schematic of the CAR‐T‐PBAP system. Upon tumor antigen recognition by the CAR ectodomain, NFAT‐driven expression and secretion of PBAP‐gE recruits vaccine‐elicited or virus‐induced antibodies to FcγRIIIa + NK cells, bridging them to PD‐L1 + tumor cells to trigger ADCC‐mediated lysis. Created with BioRender.com. (C) Experimental Design. C57BL/6J mice (n = 8 mice/group) received LZ901 vaccine (5 µg/dose) on days 0 and 21; Serum was collected on day 27 for anti‐gE IgG detection. B16‐Trop2 cells (5 × 10 5 ) were subcutaneously implanted On day 28. When tumors reached ∼100 mm 3 (day 35), mice were treated with a single infusion of CAR‐T cells (± PBAP‐gE) via intravenous ( i.v .), intraperitoneal ( i.p .), or intratumoral ( i.t .) injection. Endpoint serum samples were collected on day 42 for anti‐gE IgG analysis. Created with BioRender.com. (D) Tumor volumes were measured every 1‐2 days from day 35 to day 41 in all groups, and all mice were euthanized on day 41. Tumor growth curves were plotted for the five experimental groups: CD19‐CAR, Trop2‐CAR, Trop2‐CAR‐PBAP, Trop2‐CAR + PBAP ( i . v .), Trop2‐CAR + PBAP ( i . p .), Trop2‐CAR + PBAP ( i . t .). (E) Representative tumor images are shown in the left panel, and tumor volumes at the experimental endpoint are presented in the right panel. The PBAP‐coexpressing CAR‐T cell group exhibited tumor regression that was not statistically different from that in the intratumoral injection group. Data are presented as the mean ± SD, (n = 6–8). Statistical significance was determined using one‐way ANOVA. ns indicates not significant (p > 0.05). (F) Flow cytometric analysis of tumor‐infiltrating immune cells revealed that both the Trop2‐CAR‐PBAP and Trop2‐CAR + PBAP ( i . t .) groups exhibited significantly elevated frequencies of B cells and NK cells. Data are presented as the mean ± SD, (n = 8). Statistical significance was determined using one‐way ANOVA. ns indicates not significant (p > 0.05). (G) ELISA was used to analyze the binding affinity of serum (collected on days 27 and 42) from LZ901‐vaccinated mice to gE in both the Trop2‐CAR‐PBAP and Trop2‐CAR + PBAP treatment groups. Data are presented as the mean ± SD (n = 8). (H) Correlation analysis was performed to examine the relationship between tumor volume and gE‐specific IgG antibody levels (endpoint titer) at days 27 and 42 in the Trop2‐CAR‐PBAP and Trop2‐CAR + PBAP‐gE ( i . t .) treatment groups.

Article Snippet: Tumor sections (3 μm thick) were stained with HER2 specific antibody (Sinobiological, 310184‐T08, Rabbit PAb) to assess PBAP‐gE infiltration and anti‐human Fab (Abcam, ab771, Mouse Mab) to evaluate the penetration and localization of ADCs within the tumor tissue.

Techniques: Injection, Construct, Control, Expressing, Virus, Lysis, Enzyme-linked Immunosorbent Assay, Binding Assay

Journal: Advanced Science

Article Title: PD‐L1‐Binding Antigen Presenters: Redirecting Vaccine‐Induced Antibodies for Cancer Immunotherapy

doi: 10.1002/advs.202519574

Figure Lengend Snippet: PBAP‐gE Elicits a Robust Antitumor Immune Response, Predominantly Mediated by NK Cells through gE‐Specific Antibody Production by B Cells. (A) Experimental design to assess the contributions of antibody versus CD8 + T cells in PBAP‐gE‐mediated tumor suppression. On day 0, C57BL/6J mice (n=5 mice/group) were initially vaccinated with the LZ901 vaccine (5 µg/dose), followed by a booster immunization on day 21. On day 28, a subcutaneous inoculation of 5×10 5 B16‐Trop2 tumor cells was performed to establish the tumor model. On day 33, immune cell depletion was conducted via intraperitoneal injection of antibodies targeting NK cells (anti‐NK1.1), B cells (anti‐CD19), and CD8 + T cells (anti‐CD8), respectively. On day 34, each mouse received an intratumoral injection of 150 µg PBAP‐gE. Subsequently, tumor growth was monitored via bioluminescence imaging on days 36, 38, 40, and 42. (B) Tumor volumes were measured every 2 days from day 32 to day 42 in all groups, and all mice were euthanized on day 42. Tumor growth curves were plotted for the five experimental groups: untreated, NK cell block (αNK cell), B cell block (αB cell), CD8 + T cell block (αCD8 + T cell), IgG2a isotype block (control). Corresponding changes of tumor volum levels are shown on the right‐down panel. (C) Representative images of excised tumors are displayed in the left panel, and tumor weights (measured at the experimental endpoint on day 42) are presented in the right panel. Mice in the B cell depletion (αB cell) or NK cell depletion (αNK cell) groups exhibited significantly greater tumor weights compared to those in the CD8 + T cell depletion (αCD8 + T cell) group. In contrast, tumor weights in the CD8 + T cell depletion group were comparable to those in the IgG2a isotype control group. Data are presented as the mean ± SD (n = 6). Statistical significance was determined using one‐way ANOVA. ns indicates not significant (p > 0.05). (D) The gE‐specific IgG antibody levels (OD450) were measured every 2‐4 days from day 32 to day 42 across five experimental groups: Untreated, NK cell depletion (αNK cell), B cell depletion (αB cell), CD8 + T cell depletion (αCD8 + T cell), and IgG2a isotype control. Data are presented as the mean ± SD (n = 6). (E) Kinetics of initial body weight changes and serum levels of interferon‐gamma (IFN‐γ), tumor necrosis factor‐α (TNF‐α), and interleukin‐6 (IL‐6) across five experimental cohorts: Untreated, NK cell depletion (αNK cell), B cell depletion (αB cell), CD8 + T cell depletion (αCD8 + T cell), and IgG2a isotype control. Data are presented as the mean ± SD (n = 6).

Article Snippet: Tumor sections (3 μm thick) were stained with HER2 specific antibody (Sinobiological, 310184‐T08, Rabbit PAb) to assess PBAP‐gE infiltration and anti‐human Fab (Abcam, ab771, Mouse Mab) to evaluate the penetration and localization of ADCs within the tumor tissue.

Techniques: Injection, Imaging, Blocking Assay, Control

Journal: Advanced Science

Article Title: PD‐L1‐Binding Antigen Presenters: Redirecting Vaccine‐Induced Antibodies for Cancer Immunotherapy

doi: 10.1002/advs.202519574

Figure Lengend Snippet: Antibody Titiers Dominate PBAP Antitumor Activity. (A) Schematic representation of the other two recombinant protein vaccines used in the study: the low‐immunogenicity gE subunit vaccine and the high‐immunogenicity GE‐I53‐50 virus‐like particle (VLP) vaccine formulated by I53‐50B and GE‐I53‐50A. (B) Coomassie Blue staining of gE and GE‐I53‐50 nanoparticles confirming the expression and purity of the recombinant proteins (left panel). Transmission electron microscopy (TEM) image showing the morphology of GE‐I53‐50 nanoparticles (right panel). Scale bars, 100 nm. (C) Overview of Experimental Design. C57BL/6J mice (8 mice per group) were immunized with the vaccine (5 µg per dose) on days 0 and 21. Serum samples collected on day 27 were analyzed to determine anti‐gE IgG titers. On day 28, 5 × 10 5 B16‐Trop2 cells were subcutaneously implanted to establish tumor xenografts. On day 33, B cell depletion (via intraperitoneal injection of 150 µg/mouse each of anti‐CD19, anti‐CD22, and anti‐B220 antibodies) and CD8 + T cell depletion (via intraperitoneal injection of 150 µg/mouse anti‐CD8 antibody) were performed. On day 35, 150 µg/mouse PBAP‐gE was administered intratumorally, and tumor progression was monitored thereafter. Tumor volumes were measured every 1–2 days until day 42, at which point mice were euthanized for assessments of tumor burden and serum anti‐gE IgG levels. Created with BioRender.com. (D) Tumor growth curves were plotted for the six experimental groups: saline control, gE subunit vaccine, LZ901 vaccine, GE‐I53‐50 VLP vaccine, GE‐I53‐50 VLP + αCD8 + T cell depletion, and GE‐I53‐50 VLP + αB cell depletion. Corresponding anti‐gE‐specific IgG antibody levels are shown on the right, illustrating the correlation between vaccine‐induced antibody responses and tumor growth suppression. (E) Representative tumor images are shown on the left, with tumor volumes at the experimental endpoint shown in the right panel. The GE‐I53‐50 VLP vaccine groups showed significant tumor regression. Data are presented as the mean ± SD (n = 8). Statistical significance was determined using one‐way ANOVA. ns indicates not significant (p > 0.05). (F) Analysis of tumor‐infiltrating immune cells by flow cytometry, revealed that NK cells frequencies were significantly elevated in the tumor tissue of mice vaccinated with LZ901 or GE‐I53‐50 VLP, treated with PBAP‐gE. Data are presented as the mean ± SD (n = 8). Statistical significance was determined using one‐way ANOVA. ns indicates not significant (p > 0.05). (G) Analysis of NK cells in the spleen by flow cytometry revealed that NK cells frequencies were significantly elevated in the spleen of mice vaccinated with LZ901 or GE‐I53‐50 VLP, treated with PBAP‐gE. Data are presented as the mean ± SD (n = 8). Statistical significance was determined using one‐way ANOVA. ns indicates not significant (p > 0.05).

Article Snippet: Tumor sections (3 μm thick) were stained with HER2 specific antibody (Sinobiological, 310184‐T08, Rabbit PAb) to assess PBAP‐gE infiltration and anti‐human Fab (Abcam, ab771, Mouse Mab) to evaluate the penetration and localization of ADCs within the tumor tissue.

Techniques: Activity Assay, Recombinant, Vaccines, Immunopeptidomics, Virus, Staining, Expressing, Transmission Assay, Electron Microscopy, Injection, Saline, Control, Flow Cytometry

Journal: Advanced Science

Article Title: PD‐L1‐Binding Antigen Presenters: Redirecting Vaccine‐Induced Antibodies for Cancer Immunotherapy

doi: 10.1002/advs.202519574

Figure Lengend Snippet: PBAP Conjugated with Tumor‐Specific Antigens Enhances Synergistic Anti‐Tumor Activity When Combined with Clinical Antibodies and Antibody‐Drug Conjugates (ADCs) In Vitro. A) Schematic representation of the design of sPD‐1‐HER2 and PBAP‐HER2 (sPD‐1‐HER2‐Fc). PBAP‐HER2 was engineered via the fusion of extracellular domain of human PD‐1 (sPD‐1) with Domain IV of HER2 protein, followed by the incorporation of an Fc region to enhance protein stability and prolong in vivo half‐life. vB) Structural modeling of PBAP‐HER2 with AlphaFold 3. (C) Pharmacokinetic profiles of sPD‐1‐HER2 and PBAP‐HER2 following intravenous injection into C57BL/6J mice (n=3 mice/group, 100 µg/mice). Data are presented as the mean ± SD (n = 3). (D) The binding inhibition of PBAP‐HER2 on PD‐L1/PD‐1 interaction was assessed by ELISA. The absorbance was measured at 450 nm to determine the blocking effect. Data are presented as the mean ± SD (n = 3). (E) The fluorescence intensity of the antibody‐cell binding was analyzed using a flow cytometry to assess the blocking effect on the PD‐1/PD‐L1 pathway. (F) Diagram illustrating the mechanism by which PBAP‐HER2 synergizes with Herceptin and Kadcyla to kill PD‐L1‐positive target cells. Created with BioRender.com. (G) ADCC and ADCP activities were assessed using Jurkat‐FcγR reporter systems: ADCC (FcγRIIIa‐V158 variant) and ADCP (FcγRIIa‐R131 variant) in response to PBAP‐HER2/PBAP‐gE combined with Herceptin. PBAP‐HER2 in combination with Herceptin significantly enhanced ADCC and ADCP activities against HER2‐negative MDA‐MB‐231 cells. Representative of 3 independent experiments. Data are presented as mean ± SD (n = 3). (H) NK cells were co‐incubated with PBAP‐Her2 and Herceptin, against MDA‐MB‐231‐IFN‐γ (IFN‐γ induced, PD‐L1 + ) tumor cells and MDA‐MB‐231‐WT cells. NK cells, NK cells co‐incubated with PBAP‐Her2, NK cells co‐incubated with Herceptin, and all groups treated with anti‐FcγRIII blocking antibody were used as controls. Data are presented as mean ± SD of 3 independent experiments, each performed in triplicate. (I) Flow cytometry analysis of perforin, granzyme B, IFN‐γ and CD107a in NK cells. Representative of 3 independent experiments. (J) The CCK8 assay was used to evaluate the cytotoxicity of commercial ADCs (Kadcyla and Adcetris) combined with PBAP‐HER2. MDA‐MB‐231‐PD‐L1‐OE cells were treated with PBAP‐HER2 (10 µg/well) for 4 h, followed by ADC drugs (Kadcyla or Adcetris) at various concentrations (0.1, 1, 10, 100, 1000 ng/mL). After 24 h of incubation, cell viability was measured using the CCK8 assay. PBAP‐HER2 with Adcetris and HER2 protein with Kadcyla were used as controls. Representative of 3 independent experiments. Data are presented as mean ± SD (n = 3).

Article Snippet: Tumor sections (3 μm thick) were stained with HER2 specific antibody (Sinobiological, 310184‐T08, Rabbit PAb) to assess PBAP‐gE infiltration and anti‐human Fab (Abcam, ab771, Mouse Mab) to evaluate the penetration and localization of ADCs within the tumor tissue.

Techniques: Activity Assay, In Vitro, In Vivo, Injection, Binding Assay, Inhibition, Enzyme-linked Immunosorbent Assay, Blocking Assay, Fluorescence, Flow Cytometry, Variant Assay, Incubation, CCK-8 Assay