Suppression of FVIII-Specific Memory B Cells by Chimeric BAR Receptor-Engineered Natural Regulatory T Cells.
Front Immunol
; 11: 693, 2020.
Article
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| MEDLINE
| ID: mdl-32373126
ABSTRACT
Anti-drug antibody formation poses tremendous obstacles for optimal treatment of hemophilia A (HA). In this study, we sought to utilize chimeric receptor-modified natural regulatory T cells (Tregs) to target FVIII-specific memory B cells, which are responsible for persistent anti-FVIII neutralizing antibodies (inhibitors) in HA patients. Thus, CD4+CD25 hi CD304+ natural Tregs were FACS sorted from naïve C57BL/6 mice and retrovirally transduced to express a chimeric B-cell antibody receptor (BAR) containing the immunodominant A2 domain of FVIII. Plasmablast-depleted (CD138 neg ) splenocytes from FVIII immunized FVIII-knockout HA mice served as the source for FVIII-specific memory B cells, which were specifically stimulated in vitro with FVIII and enumerated in a B-cell ELISPOT assays. Adding A2-BAR Tregs (1 per 150 splenocytes), but not conventional T cells, to the CD138- splenocytes significantly suppressed the formation of anti-FVIII antibody secreting cells (ASC), compared to the non-relevant OVA-BAR Tregs control group. The observation that A2-BAR Tregs can suppress the response to FVIII suggests that bystander suppression can occur in the local milieu in this system. Transwell experiments confirmed that the suppression was contact-dependent. Moreover, even in the presence of antibodies to FVIII (so-called inhibitors), similarly prepared CD4+CD25 hi CD127 low A2-BAR human natural Tregs completely suppressed polyclonal anti-FVIII ASC formation. In conclusion, we demonstrated in vitro that FVIII domain-expressing BAR Tregs could efficiently target and suppress FVIII-specific memory B cells.
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Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
Factor VIII
/
Linfocitos B
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Linfocitos T Reguladores
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Ingeniería Celular
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Receptores Quiméricos de Antígenos
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Memoria Inmunológica
Límite:
Animals
Idioma:
En
Revista:
Front Immunol
Año:
2020
Tipo del documento:
Article
País de afiliación:
Estados Unidos