A bispecific antibody targeting Gd-IgA1 and TfR1 enhances Gd-IgA1 degradation and mitigates IgA nephropathy

Certificate Output Instructions

For best output, select "Paper Size" as "A4" and "Margin" as "0" or "None".

To save or print to PDF, please select Print Destination > Save as PDF, enable Background Graphics under "More Settings", then click "Save".

Presented the abstract " "
(Abstract co-author(s): )

Back

E-Poster Presentation

During the congress, E-Posters will be accessible to all participants on the congress website 24/7, as well as in the E-poster stations in the congress center.

Preparing your E-Poster

Please review the E-Poster format requirements carefully when preparing your E-Poster. Should your E-Poster not meet the mentioned requirements, it may not be displayed as described above.

E-Poster Submission Deadline

Please prepare and upload your E-Poster no later than March 14, 2026 11.59PM CET. After this date, you will no longer be able to prepare and upload your E-poster and it will not be displayed and accessible on the congress website.

E-Poster Format Requirements

PDF file
Layout: Portrait (vertical orientation)
One page only (Dim A4: 210 x 297mm or PPT)
E-Poster can be prepared in PowerPoint (one (1) PowerPoint slide) but must be saved and submitted as PDF file.
File Size: Maximum file size is 2 Megabytes (2 MB)
No hyperlinks, animated images, animations, and slide transitions
Language: English
Include your abstract number
E-posters can include QR codes, tables and photos

E-Poster

Abstract Title *

A bispecific antibody targeting Gd-IgA1 and TfR1 enhances Gd-IgA1 degradation and mitigates IgA nephropathy

Please follow the instructions below to input your abstract title.

Abstract titles should be brief and reflect the content of the abstract.

The title will not be accepted if it exceeds 25 words.
Type in CAPITAL LETTERS.
Lowercase may be used for abbreviations only, for example, mRNA.

Co-author 1

Mengting Fang fang70320@163.com Guangdong Provincial People’s Hospital Department of Nephrology guangzhou China *

Co-author 2

Xueqing Yu yuxueqing@gdph.org.cn Guangdong Provincial People’s Hospital Department of Nephrology guangzhou China -

Co-author 3

Co-author 4

Co-author 5

Co-author 6

Co-author 7

Co-author 8

Co-author 9

Co-author 10

Co-author 11

Co-author 12

Co-author 13

Co-author 14

Co-author 15

Introduction

IgA nephropathy (IgAN), the most common primary glomerulonephritis worldwide, is characterized by glomerular mesangial deposition of IgA1 immune complexes. Galactose-deficient IgA1 (Gd-IgA1) is a key pathogenic driver of the disease. Reducing its levels represents a promising therapeutic strategy.

Methods

Here, we leverage the rapid endocytic recycling of transferrin receptor 1 (TfR1) to design a bispecific antibody that co-binding Gd-IgA1 and TfR1. This approach aims to redirect Gd-IgA1 into the lysosomal degradation pathway via TfR1-mediated internalization.

Results

We isolated an anti-Gd-IgA1 antibody using phage display and engineered it into a TfR1-targeting bispecific antibody. Biolayer interferometry confirmed dual binding specificity. Cellular assays demonstrated efficient internalization of the bispecific antibody, with colocalization observed in early, late, and recycling endosomes marked by Rab5, Rab7, and Rab11.

Conclusion

Our study establishes TfR1 as an effective membrane protein for targeted degradation of pathogenic Gd-IgA1 and highlights the therapeutic potential of this bispecific antibody platform for the treatment of IgAN.

Kewords