Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA.
Immunobiology. 2012 Jan;217(1):1-7. doi: 10.1016/j.imbio.2011.09.001. Epub 2011 Sep 16.
We investigated in two inbred mouse strains the submolecular recognition of botulinum neurotoxin type A (BoNT/A) by Abs (B cells) and by T lymphocytes. For mapping, we employed a set of overlapping synthetic peptides that encompassed the entire light (L) chain of BoNT/A. After 3 BoNT/A toxoid injections, BALB/c T cells responded in vitro to challenge by peptides L18 (residues 239-257), L23 (309-327), L27 (365-383), L29 (393-411), or L31 (421-439) and more weakly to peptides L3 (29-47), L9/L10 (113-145), L15 (197-215), L17 (225-243), or L26 (351-369). The other peptides stimulated little or no T cell responses. SJL mice mounted, after 3 BoNT/A injections, stronger T cell responses that were medium-to-strong to peptides L2/L3 (15-47), L10/L11 (127-159), L19 (253-271), or L23 (309-327) and low to peptides L17 (225-243), L21 (281-299), L27 (365-383), or L30/L31 (407-439). After 3 BoNT/A injections, BALB/c and SJL antisera protected mice against lethal BoNT/A doses, but displayed restricted epitope profiles compared to outbred (ICR) mice Abs. BALB/c Abs displayed medium-to-high binding to peptides L4/L5 (43-75), L10/L11 (127-159), L18 (239-257) or L27 (365-383). SJL Abs were high to peptides L4/L5 (43-75), L14 (183-201), L16 (211-229), or L18/L19 (239-271), and medium to peptides L10 (127-145), L11 (141-159), L12 (155-173) or L29 (393-411). The other peptides had little or no binding. Responses to each T cell or Ab epitope were under separate genetic control. T and B (antibody) cell recognition regions may coincide, but there were also regions recognized only by Abs or by T cells.
我们在两种近交系小鼠中研究了肉毒梭菌神经毒素 A 型（BoNT/A）的亚分子识别，该识别由 Abs（B 细胞）和 T 淋巴细胞完成。为了作图，我们使用了一套涵盖 BoNT/A 全长轻链的重叠合成肽。经过 3 次 BoNT/A 类毒素注射后，BALB/c T 细胞在体外对肽 L18（残基 239-257）、L23（309-327）、L27（365-383）、L29（393-411）或 L31（421-439）的挑战产生应答，对肽 L3（29-47）、L9/L10（113-145）、L15（197-215）、L17（225-243）或 L26（351-369）的应答则较弱。其他肽几乎没有或没有刺激 T 细胞反应。经过 3 次 BoNT/A 注射后，SJL 小鼠产生了更强的 T 细胞反应，对肽 L2/L3（15-47）、L10/L11（127-159）、L19（253-271）或 L23（309-327）的反应为中-强，对肽 L17（225-243）、L21（281-299）、L27（365-383）或 L30/L31（407-439）的反应则较弱。经过 3 次 BoNT/A 注射后，BALB/c 和 SJL 抗血清能够保护小鼠免受致死性 BoNT/A 剂量的影响，但与杂交（ICR）小鼠 Abs 相比，其显示出有限的表位谱。BALB/c Abs 对肽 L4/L5（43-75）、L10/L11（127-159）、L18（239-257）或 L27（365-383）具有中-高结合。SJL Abs 对肽 L4/L5（43-75）、L14（183-201）、L16（211-229）或 L18/L19（239-271）具有高结合，对肽 L10（127-145）、L11（141-159）、L12（155-173）或 L29（393-411）具有中结合。其他肽几乎没有或没有结合。每个 T 细胞或 Ab 表位的反应均受单独的遗传控制。T 和 B（抗体）细胞识别区可能重合，但也有仅被 Abs 或 T 细胞识别的区域。
