Affinity Purification and Comparative Biosensor Analysis of Citrulline-Peptide-Specific Antibodies in Rheumatoid Arthritis
Affinity Purification and Comparative Biosensor Analysis of Citrulline-Peptide-Specific Antibodies in Rheumatoid Arthritis
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DOI：
10.3390/ijms19010326
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发表时间：
2018-01-01
影响因子：
5.6
通讯作者：
Sarmay, Gabriella
中科院分区：
文献类型：
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作者：
Szarka, Eszter;Aradi, Petra;Sarmay, Gabriella
背景资料：在类风湿性关节炎（RA）中，抗瓜氨酸化蛋白/肽抗体（ACPA）是疾病发作和进展的原因，然而，我们对具有不同瓜氨酸肽特异性的自身抗体的配体结合亲和力的了解有限。方法：亲和纯化瓜氨酸肽特异性ACPA IgG，ELISA检测。通过表面等离子体共振（SPR）分析比较ACPA IgG和血清抗体的结合亲和力。携带多表位瓜氨酸肽和补体激活肽的双功能纳米颗粒用于诱导产生ACPA的B细胞的选择性耗竭。结果：亲和纯化的ACPA IgG的K-D值在10（-6）和10（-8）M之间变化，与疾病活动性呈负相关。基于它们与瓜氨酸肽的交叉反应，我们设计了一种新的多表位肽，其包含两个拷贝的Cit-Gly和Ala-Cit基序，用一个短的中性间隔区隔开。ELISA检测RA血清抗体的敏感性为66%，特异性为98%，SPR检测RA血清抗体的阳性率为90%，而健康人血清均未检测到该肽。当与纳米颗粒偶联时，多表位肽特异性地靶向并耗尽离体产生ACPA的B细胞。结论：基于ACPA交叉反应性设计的独特多表位肽可能适用于开发更好的RA诊断和新的治疗方法。
Background: In rheumatoid arthritis (RA), anti-citrullinated protein/peptide antibodies (ACPAs) are responsible for disease onset and progression, however, our knowledge is limited on ligand binding affinities of autoantibodies with different citrulline-peptide specificity. Methods: Citrulline-peptide-specific ACPA IgGs were affinity purified and tested by ELISA. Binding affinities of ACPA IgGs and serum antibodies were compared by surface plasmon resonance (SPR) analysis. Bifunctional nanoparticles harboring a multi-epitope citrulline-peptide and a complement-activating peptide were used to induce selective depletion of ACPA-producing B cells. Results: K-D values of affinity-purified ACPA IgGs varied between 10(-6) and 10(-8) M and inversely correlated with disease activity. Based on their cross-reaction with citrulline-peptides, we designed a novel multi-epitope peptide, containing Cit-Gly and Ala-Cit motifs in two-two copies, separated with a short, neutral spacer. This peptide detected antibodies in RA sera with 66% sensitivity and 98% specificity in ELISA and was recognized by 90% of RA sera, while none of the healthy samples in SPR. When coupled to nanoparticles, the multi-epitope peptide specifically targeted and depleted ACPA-producing B cells ex vivo. Conclusions: The unique multi-epitope peptide designed based on ACPA cross-reactivity might be suitable to develop better diagnostics and novel therapies for RA.