RESUMO
For decades, intravenous immunoglobulin (IVIg) has provided safe and effective therapy for immunodeficient patients. This proof-of-principle study describes a novel approach to generate personalized IVIg for chronic, antibiotic-resistant infection in real time.
Assuntos
Antibacterianos/uso terapêutico , Terapia Biológica , Imunoglobulinas Intravenosas/uso terapêutico , Infecções por Mycoplasma/terapia , Medicina de Precisão , Infecção da Ferida Cirúrgica/terapia , Idoso , Animais , Bovinos , Humanos , Imunoglobulinas Intravenosas/efeitos adversos , Síndromes de Imunodeficiência/terapia , Masculino , Infecções por Mycoplasma/diagnóstico , Mycoplasma hominis/efeitos dos fármacos , Estudo de Prova de Conceito , Infecção da Ferida Cirúrgica/microbiologiaRESUMO
Antibody class switch recombination (CSR) in B lymphocytes joins two DNA double-strand breaks (DSBs) lying 100-200 kb apart within switch (S) regions in the immunoglobulin heavy-chain locus (IgH). CSR-activated B lymphocytes generate multiple S-region DSBs in the donor Sµ and in a downstream acceptor S region, with a DSB in Sµ being joined to a DSB in the acceptor S region at sufficient frequency to drive CSR in a large fraction of activated B cells. Such frequent joining of widely separated CSR DSBs could be promoted by IgH-specific or B-cell-specific processes or by general aspects of chromosome architecture and DSB repair. Previously, we found that B cells with two yeast I-SceI endonuclease targets in place of Sγ1 undergo I-SceI-dependent class switching from IgM to IgG1 at 5-10% of normal levels. Now, we report that B cells in which Sγ1 is replaced with a 28 I-SceI target array, designed to increase I-SceI DSB frequency, undergo I-SceI-dependent class switching at almost normal levels. High-throughput genome-wide translocation sequencing revealed that I-SceI-generated DSBs introduced in cis at Sµ and Sγ1 sites are joined together in T cells at levels similar to those of B cells. Such high joining levels also occurred between I-SceI-generated DSBs within c-myc and I-SceI- or CRISPR/Cas9-generated DSBs 100 kb downstream within Pvt1 in B cells or fibroblasts, respectively. We suggest that CSR exploits a general propensity of intrachromosomal DSBs separated by several hundred kilobases to be frequently joined together and discuss the relevance of this finding for recurrent interstitial deletions in cancer.
