The discovery of broadly neutralizing antibodies (bNAbs) that target conserved epitopes on the HIV-1 envelope glycoprotein (Env) has garnered significant attention for its potential in the development of effective therapeutic and vaccine strategies. In this study, we isolated and characterized a CD4 binding site (CD4bs) antibody, FD22, from an elite neutralizer in China who had been infected with a clade B virus through contaminated blood plasma for 23 years. The heavy chain of FD22 was derived from a rarely reported IGHV3-30 germline gene and exhibited an exceptionally high degree of somatic hypermutation (SHM) (37%), along with a long and unique CDRH3 loop of 20-amino acids. FD22 exhibited potent and broad neutralizing activity, comparable to that of the well-known bNAb VRC01. It effectively neutralized 82% of a panel of 145 diverse HIV-1 pseudoviruses, including the two major circulating strains in China, CRF01_AE and CRF07_BC. FD22 bound strongly to HIV-1-infected cell lines, efficiently engaged FcγRIIIa receptors, triggered NK cell degranulation and the release of key cytokines such as IFN-γ and β-chemokines, and robustly induced antibody-dependent cellular cytotoxicity (ADCC) against HIV-1-infected target cells. Structural prediction for FD22 and the HIV Env SOSIP trimer performed by AlphaFold3, site-mutagenesis, and autologous virus reverse mutation assays revealed that the epitope of FD22 spans key CD4 binding site, including Loop D, the CD4 binding loop (CD4 BLP), and the V5 Loop. The unique long CDRH3 loop of FD22 interacts with the CD4 binding site through its negatively charged residue R102, distinguishing it from other CD4bs antibodies. Our findings provide valuable insights into the mechanisms of FD22 in viral neutralization and ADCC. The dual functionality of FD22 enhances its potential as a promising therapeutic antibody and offers new avenues for designing CD4bs-targeting vaccines with enhanced ADCC capabilities.
© 2025. The Author(s).

In 2022, a global mpox outbreak occurred, and remains a concern today. The T cell memory response to MPXV (monkeypox virus) infection has not been fully investigated. In this study, we evaluate this response in convalescent and MVA-BN (Modified Vaccinia Ankara - Bavarian Nordic) vaccinated individuals using VACV-infected cells. Strong CD8+ and CD4+ T cell responses are observed, and T cell responses are biased towards viral early expressed proteins. We identify seven immunodominant HLA-A*02:01 restricted MPXV-specific epitopes and focus our detailed phenotypic and scRNAseq analysis on the immunodominant HLA-A*02:01-G5R18-26-specific CD8+ T cell response. While tetramer+CD8+ T cells share similar differentiation and activation phenotypes, T cells from convalescent individuals show greater cytotoxicity, migratory potential to site of infection and TCR clonal expansion. Our data suggest that effective functional profiles of MPXV-specific memory T cells induced by Mpox infection may have an implication on the long-term protective responses to future infection.
© 2025. The Author(s).

Adoptive cell therapy (ACT) has shown promising results in cancer treatment, however, achieving effective ex vivo expansion of potent, functionally active, and cytotoxic T cells remains challenging. To overcome this, we loaded the engineered cytokine Neoleukin-2/15 (Neo2/15) on our recently established artificial antigen-presenting scaffolds (Ag-scaffolds) to expand antigen-specific T cells. Neo2/15 selectively binds to IL-2Rβ/γ receptors, enhancing CD8 + T cell proliferation while limiting regulatory T cell expansion. Our study assessed the efficacy of Neo2/15-loaded Ag-scaffolds (Ag-Neo2/15 scaffolds) in expanding antigen-specific T cells from peripheral blood mononuclear cells (PBMCs) of healthy donors. We optimized Ag-scaffold configurations by varying the number of Neo2/15 molecules loaded on Ag-scaffolds and evaluated their impact on T-cell expansion and functionality. We showed that Ag-Neo2/15 scaffolds promoted significant T-cell expansion, with a comparable frequency of antigen-specific CD8 + T cells compared to IL-2/IL-21-loaded Ag-scaffolds (Ag-IL2/21 scaffolds). The CD8 + T cells expanded with Ag-Neo2/15 scaffolds exhibited potent TNFα and IFNγ production and expressed high levels of α4β7 integrin, a homing molecule which is important for directing T cells to specific tissues, potentially enhancing their therapeutic potential. T cells expanded with Ag-Neo2/15 scaffolds had superior and durable cytotoxicity against tumor target cells compared to T cells expanded with Ag-IL2/21 scaffolds. These findings were further supported by our single-cell analysis revealing that T cells expanded with Ag-Neo2/15 scaffolds had higher cytotoxic scores and lower dysfunctionality scores compared to T cells expanded with Ag-IL2/21 scaffolds. The single-cell analysis also indicated increased expression of genes linked to cell division and enhanced proliferative capacity in Ag-Neo2/15 expanded T cells. Furthermore, TCR clonality analysis demonstrated that Ag-Neo2/15 scaffolds promoted the expansion of functionally superior T-cell clones. The top clones of CD8 + T cells expanded with Ag-Neo2/15 scaffolds exhibited a favorable phenotype, essential for effective antigen recognition and sustained T-cell mediated cytotoxicity. Our findings suggest that Ag-Neo2/15 scaffolds represent an advancement in ACT by producing high-quality, functional antigen-specific T cells. This method has the potential to improve clinical outcomes in cancer therapy by generating large numbers of highly functional T cells, thereby optimizing the balance between cytotoxicity and proliferation capacity with less exhausted T-cells in expansion protocols.

Chimeric antigen receptor (CAR) immunotherapy has revolutionized anticancer therapy, as it accurately targets cancer cells by recognizing specific antigens expressed in cancer cells. This innovative therapeutic strategy has attracted considerable attention. However, few therapeutics are available for treating non-small cell lung cancer (NSCLC), which accounts for most lung cancer cases and is one of the deadliest cancers with low survival rates.
In this study, we developed a new antibody targeting erythropoietin-producing hepatocellular carcinoma A2 (EphA2), which is highly expressed in NSCLC, and established CAR-T/ natural killer (NK) immune cells to verify its potential for immune cell therapy. The killing capacity, cytokine secretion and solid tumor growth inhibition of EphA2 CAR-T/NK cells were compared to normal T/NK cells.
EphA2 CAR-T cells demonstrated superior killing capacity, enhanced cytokine secretion, and significant solid tumor growth inhibition. Additionally, they exhibited improved tumor infiltration in lung cancer models compared to normal T cells. The anticancer efficacy of the developed EphA2 CAR-NK cells was also confirmed, showcasing their potential as robust candidates for immune cell therapy.
The findings of this study highlight the potential of CAR-T/NK cell therapy targeting EphA2 as an effective treatment for lung cancer, particularly NSCLC with high EphA2 expression. By leveraging the specific targeting capabilities of CAR-T cells and the unique properties of CAR-NK cells, this approach provides a promising therapeutic strategy to address the unmet needs in NSCLC treatment.
Copyright © 2025 Kim, Lee, Kim, Bae, Hong, Jo, Kim, Chung and Kim.

The Janus kinase/signal transducers and activators of transcription (JAK-STAT) control natural killer (NK) cells development and cytotoxic functions, however, whether long non-coding RNAs (lncRNAs) are involved in this pathway remains unknown. We found that miR155HG was elevated in activated NK cells and promoted their proliferation and effector functions in both NK92 and induced-pluripotent stem cells (iPSCs)-derived NK (iPSC-NK) cells, without reliance on its derived miR-155 and micropeptide P155. Mechanistically, miR155HG bound to miR-6756 and relieved its repression of JAK3 expression, thereby promoting the JAK-STAT pathway and enhancing NK cell proliferation and function. Further investigations disclosed that upon cytokine stimulation, STAT3 directly interacts with miR155HG promoter and induces miR155HG transcription. Collectively, we identify a miR155HG-mediated positive feedback loop of the JAK-STAT signaling. Our study will also provide a power target regarding miR155HG for improving NK cell generation and effector function in the field of NK cell adoptive transfer therapy against cancer, especially iPSC-derived NK cells.
© 2025 The Authors.