Welcome to the Recombinant Antibody Network

@article{pmid40614208,

title = {A universal chimeric antigen receptor (CAR)-fragment antibody binder (FAB) split system for cancer immunotherapy},

author = {Ainhoa Arina and Edwin Arauz and Elham Masoumi and Karolina W Warzecha and Annika Sääf and Łukasz Widło and Tomasz Slezak and Aleksandra Zieminska and Karolina Dudek and Zachary P Schaefer and Maria Lecka and Svitlana Usatyuk and Ralph R Weichselbaum and Anthony A Kossiakoff},

doi = {10.1126/sciadv.adv4937},

issn = {2375-2548},

year  = {2025},

date = {2025-07-01},

urldate = {2025-07-01},

journal = {Sci Adv},

volume = {11},

number = {27},

pages = {eadv4937},

abstract = {Chimeric antigen receptor (CAR) T cell therapy has shown extraordinary results in treating hematological cancer but faces challenges like antigen loss, toxicity, and complex manufacturing. Universal and modular CAR constructs offer improved flexibility, safety, and cost-effectiveness over conventional CAR constructs. We present a CAR-fragment antibody binder (Fab) platform on the basis of an engineered protein G variant (GA1) and Fab scaffolds. Expression of GA1CAR on human CD8 T cells leads to antigen recognition and T cell effector function that can be modulated according to the affinity of the CAR for the Fab and of the Fab for the target. GA1CAR T cells can recognize multiple Fab-antigen pairs on breast and ovarian cancer cell lines. Adoptively transferred GA1CAR T cells control tumors in breast cancer xenograft models, and their targeting can be quickly redirected using different Fabs. This versatile "plug-and-play" CAR T platform has potential for application in personalized therapy, preventing antigen loss variant escape, decreasing toxicity, and increasing access.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid40575703,

title = {Biophysical basis of tight junction barrier modulation by a pan-claudin-binding molecule},

author = {Chinemerem P Ogbu and Mason de Las Alas and Alexandria M Mandriota and Xiangdong Liu and Srajan Kapoor and Jagrity Choudhury and Yasmeen N Ruma and Michael C Goodman and Charles R Sanders and Tamir Gonen and Anthony A Kossiakoff and Michael E Duffey and Alex J Vecchio},

doi = {10.1093/pnasnexus/pgaf189},

issn = {2752-6542},

year  = {2025},

date = {2025-06-01},

urldate = {2025-06-01},

journal = {PNAS Nexus},

volume = {4},

number = {6},

pages = {pgaf189},

abstract = {Claudins are a 27-member family of membrane proteins that form and fortify specialized cell contacts in endothelium and epithelium called tight junctions. Tight junctions restrict paracellular transport through tissues by forming molecular barriers between cells. Claudin-binding molecules thus hold promise for modulating tight junction permeability to deliver drugs or as therapeutics to treat tight junction-linked disease. The development of claudin-binding molecules, however, is hindered by their physicochemical intractability and small targetable surfaces. Here, we determine that a synthetic antibody fragment (sFab) that we developed binds with nanomolar affinity directly to 10 claudin subtypes and other distantly related claudin family members but not to other tight junction-localized membrane proteins. It does so by targeting the extracellular surfaces of claudins, which we verify by applying this sFab to a model intestinal epithelium and observe that it opens paracellular barriers comparable to a known, but application limited, tight junction modulating protein. This pan-claudin-binding molecule holds potential for both basic and translational applications as it is a probe of claudin and tight junction structure in vitro and in vivo and a tool to modulate the permeability of tight junctions broadly across tissue barriers.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid40489625,

title = {Conformation-specific synthetic intrabodies modulate mTOR signaling with subcellular spatial resolution},

author = {Kelly M O'Leary and Tomasz Slezak and Anthony A Kossiakoff},

doi = {10.1073/pnas.2424679122},

issn = {1091-6490},

year  = {2025},

date = {2025-06-01},

urldate = {2025-06-01},

journal = {Proc Natl Acad Sci U S A},

volume = {122},

number = {24},

pages = {e2424679122},

abstract = {Subcellular compartmentalization is integral to the spatial regulation of mechanistic target of rapamycin (mTOR) signaling. However, the biological outputs associated with location-specific mTOR signaling events are poorly understood and challenging to decouple. Here, we engineered synthetic intracellular antibodies (intrabodies) that are capable of modulating mTOR signaling with genetically programmable spatial resolution. Epitope-directed phage display was exploited to generate high affinity synthetic antibody fragments (Fabs) against the FKBP12-Rapamycin binding site of mTOR (mTOR). We determined high-resolution crystal structures of two unique Fabs that discriminate distinct conformational states of mTOR through recognition of its substrate recruitment interface. By leveraging these conformation-specific binders as intracellular probes, we uncovered the structural basis for an allosteric mechanism governing mTOR complex 1 (mTORC1) stability mediated by subtle structural adjustments within mTOR. Furthermore, our results demonstrated that synthetic binders emulate natural substrates by employing divergent yet complementary hydrophobic residues at defined positions, underscoring the broad molecular recognition capability of mTOR. Intracellular signaling studies showed differential time-dependent inhibition of S6 kinase 1 and Akt phosphorylation by genetically encoded intrabodies, thus supporting a mechanism of inhibition analogous to the natural product rapamycin. Finally, we implemented a feasible approach to selectively modulate mTOR signaling in the nucleus through spatially programmed intrabody expression. These findings establish intrabodies as versatile tools for dissecting the conformational regulation of mTORC1 and should be useful to explore how location-specific mTOR signaling influences disease progression.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}