TCR T cells targeting IgA- and IgG-expressing multiple myeloma

K Karolos Douvlataniotis (Oslo University Hospital Radiumhospitalet and The Precision Immunotherapy Alliance, University of Oslo, Oslo, Norway, Norway) A Aleksei Titov (Oslo University Hospital Radiumhospitalet and The Precision Immunotherapy Alliance, University of Oslo, Oslo, Norway, Norway) J Julia Zeun (Oslo University Hospital Radiumhospitalet and The Precision Immunotherapy Alliance, University of Oslo, Oslo, Norway, Norway) M Merve Bilici H Heyilimu Palashati (Oslo University Hospital Radiumhospitalet and The Precision Immunotherapy Alliance, University of Oslo, Oslo, Norway, Norway) W Waywen Loh (University of Oxford, Oxford, United Kingdom) E Even Holth Rustad (Oslo University Hospital Radiumhospitalet and The Precision Immunotherapy Alliance, University of Oslo, Oslo, Norway, Norway) W Weiwen Yang (Oslo University Hospital Radiumhospitalet and The Precision Immunotherapy Alliance, University of Oslo, Oslo, Norway, Norway) T Trung T Tran (Oslo University Hospital Rikshospitalet and The Precision Immunotherapy Alliance, University of Oslo, Oslo, Norway, Norway) F Fridtjof Lund-Johansen R Ravi Chand Bollineni (The Precision Immunotherapy Alliance, University of Oslo and Oslo University Hospital Rikshospitalet, Oslo, Norway, Norway) J Jessica D. Kepple (University of Oxford, Oxford, United Kingdom) L Luis P. Huth (BIH Center for Regenerative Therapies, Berlin Institute of Health, Germany) L Ludvig A Munthe (Oslo University Hospital Rikshospitalet and The Precision Immunotherapy Alliance, University of Oslo, Oslo, Norway, Norway) T Thorstein Boxaspen (Oslo University Hospital Radiumhospitalet, The Precision Immunotherapy Alliance, University of Oslo and Oslo Myeloma Center, Oslo University Hospital, Oslo, Norway, Norway) F Fredrik Schjesvold A Anders Waage (Institute of Clinical and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway) D Dimitrios L. Wagner K Katherine R. Bull (University of Oxford, Oxford, United Kingdom) J Joanna Hester F Fadi Issa E Eirini Giannakopoulou (Oslo University Hospital Rikshospitalet and The Precision Immunotherapy Alliance, University of Oslo, Oslo, Norway, Norway) J Johanna Olweus (Oslo University Hospital Rikshospitalet and The Precision Immunotherapy Alliance, University of Oslo, Oslo, Norway, Norway)

Abstract

T cell-based therapies have shown remarkable efficacy in multiple myeloma (MM), yet the disease remains largely incurable. Here, we investigated the constant domains of the immunoglobulin heavy chain (IgH) as novel targets for therapeutic T cell receptors (TCRs), after confirming high and homogeneous IGH expression in >95% of MM patients. MM cells secrete excessive monoclonal immunoglobulins (M-proteins) that drive complications but are inaccessible to CAR T-cell or antibody targeting. Peptides from IgA and IgG constant regions were eluted from HLA-A*02:01, and reactive TCRs were isolated from healthy donors using allo-HLA-A*02:01 presentation to circumvent self-tolerance. T cells engineered with two TCRs specific for IgA or IgG passed a stringent multi-tier safety screen and selectively eliminated MM cells from 20 HLA-A*02:01+ patients secreting the relevant IgH in vitro. In vivo, IgA-TCR T cells eradicated IgA+HLA-A*02:01+ MM cells in xenograft models and reduced circulating IgA in humanized mice. These findings establish immunoglobulin constant domains as viable TCR targets in MM, potentially making ~40% of patients of European descent eligible for TCR T cell therapy, and extension to additional HLA alleles could further broaden eligibility. The approach may also be applicable to lymphoma and antibody-mediated autoimmune diseases.

Article Details

Journal Blood
Volume / Issue Vol. 1, Issue 1
Published March 02, 2026
ISSN 0006-4971
Publisher Elsevier BV

Journal Info

Blood

Elsevier BV

ISSN: 0006-4971 Health Sciences

Authors (23)

K

Karolos Douvlataniotis

Oslo University Hospital Radiumhospitalet and The Precision Immunotherapy Alliance, University of Oslo, Oslo, Norway, Norway

A

Aleksei Titov

Oslo University Hospital Radiumhospitalet and The Precision Immunotherapy Alliance, University of Oslo, Oslo, Norway, Norway

J

Julia Zeun

Oslo University Hospital Radiumhospitalet and The Precision Immunotherapy Alliance, University of Oslo, Oslo, Norway, Norway

M

Merve Bilici

H

Heyilimu Palashati

Oslo University Hospital Radiumhospitalet and The Precision Immunotherapy Alliance, University of Oslo, Oslo, Norway, Norway

W

Waywen Loh

University of Oxford, Oxford, United Kingdom

E

Even Holth Rustad

Oslo University Hospital Radiumhospitalet and The Precision Immunotherapy Alliance, University of Oslo, Oslo, Norway, Norway

W

Weiwen Yang

Oslo University Hospital Radiumhospitalet and The Precision Immunotherapy Alliance, University of Oslo, Oslo, Norway, Norway

T

Trung T Tran

Oslo University Hospital Rikshospitalet and The Precision Immunotherapy Alliance, University of Oslo, Oslo, Norway, Norway

F

Fridtjof Lund-Johansen

R

Ravi Chand Bollineni

The Precision Immunotherapy Alliance, University of Oslo and Oslo University Hospital Rikshospitalet, Oslo, Norway, Norway

J

Jessica D. Kepple

University of Oxford, Oxford, United Kingdom

L

Luis P. Huth

BIH Center for Regenerative Therapies, Berlin Institute of Health, Germany

L

Ludvig A Munthe

Oslo University Hospital Rikshospitalet and The Precision Immunotherapy Alliance, University of Oslo, Oslo, Norway, Norway

T

Thorstein Boxaspen

Oslo University Hospital Radiumhospitalet, The Precision Immunotherapy Alliance, University of Oslo and Oslo Myeloma Center, Oslo University Hospital, Oslo, Norway, Norway

F

Fredrik Schjesvold

A

Anders Waage

Institute of Clinical and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway

D

Dimitrios L. Wagner

K

Katherine R. Bull

University of Oxford, Oxford, United Kingdom

J

Joanna Hester

F

Fadi Issa

E

Eirini Giannakopoulou

Oslo University Hospital Rikshospitalet and The Precision Immunotherapy Alliance, University of Oslo, Oslo, Norway, Norway

J

Johanna Olweus

Oslo University Hospital Rikshospitalet and The Precision Immunotherapy Alliance, University of Oslo, Oslo, Norway, Norway