Assessing B cell diversification by antigen receptor and precursor cell analysis.
Assessing B cell diversification by antigen receptor and precursor cell analysis.
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通过抗原受体和前体细胞分析评估 B 细胞多样化。
DOI：
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发表时间：
1976
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通讯作者：
Susan K. Pierce
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作者：
N. Klinman;Allan R. Pickard;Nolan H. Sigal;Patricia J. Gearhart;E. Metcalf;Susan K. Pierce
理解B细胞特异性多样化的一个主要因素是成熟和发育中的B细胞群体中存在的多样性程度。目前有两种通用方法用于评估特异性库：（a）计数其受体可结合特异性抗原的细胞，和（B）计数可通过抗体形成细胞克隆产生对抗原刺激作出反应的细胞。我们的实验室已经利用后一种方法来确定B细胞对各种抗原决定簇的应答频率。调查结果表明：（a）原代鼠B细胞特异性库可能包括10（7）个以上的克隆型;（B）一些克隆型由大量B细胞代表（每只BALB/c小鼠40，000个TEPC 15前体），而大多数由每只小鼠少于B细胞代表;（c）该基因库的获得显然是抗原-独立性，因为无菌小鼠具有与常规小鼠相似的谱系，并且次级B细胞容易与初级B细胞区分开;（d）新生儿库在出生时似乎仅包含10（4）个克隆型，每个克隆型可能由200-400个细胞代表;（e）从新生儿到成人库的多样化过程似乎是高度有序和可重复的。抗原结合细胞研究现在已经与脾病灶试验结合使用，试图将这两种技术联系起来。结果表明，用于前体细胞分析的脾病灶测定法的效率对于原代和次级B细胞均为4-5%，并且与受体脾中滞留的供体B细胞的百分比相似。对于某些抗原（DNP-BSA），抗原结合细胞的数量可占总B细胞的4%，并且该数量与所用抗原的浓度直接相关;另一方面，刺激似乎具有仅0.02%的DNP特异性B细胞达到的亲和力阈值。相比之下，PC-BSA抗原结合细胞和脾病灶前体细胞的频率是相同的。这些发现被解释为表明抗原结合细胞分析证实了用于估计脾焦点技术中的前体频率的计算的有效性。然而，对于某些与细胞受体结合的抗原，检测到大量细胞属于不可刺激的B细胞亚类或其受体亲和力太低而不允许刺激。
A major element in the understanding of B cell specificity diversification is the extent of diversity present in mature and in developing B cell populations. Two general methods are currently used for assessing the specificity repertoire: (a) the enumeration of cells whose receptors can bind a specific antigen, and (b) the enumeration of cells which can respond to antigenic stimulation by antibody-forming cell clone production. Our laboratory has utilized the latter method to establish the frequency of B cells responsive to a wide variety of antigenic determinants. The findings indicate that: (a) the primary murine B cell specificity repertoire probably includes more than 10(7) clonotypes; (b) some clonotypes are represented by numerous B cells (40,000 TEPC 15 precursors per BALB/c mouse) while most are represented by fewer than to B cells per mouse; (c) the acquisition of the repertoire is apparently antigen-independent since germfree mice have repertoires similar to conventional mice and secondary B cells are easily distinguished from primary B cells; (d) the neonatal repertoire appears to contain only 10(4) clonotypes at birth, each represented by perhaps 200-400 cells; (e) the diversification process from neonatal to adult repertorie appears highly ordered and reproducible. Antigen binding cell studies have now used in conjunction with the splenic focus assay in an attempt to correlate these two techniques. The results indicate that the efficiency of the splenic focus assay used for precursor cell anlysis it 4-5% for both primary and secondary B cells and is similar to the percent of donor B cells lodged in recipient spleens. For certain antigens (DNP-BSA) the number of antigen-binding cells can represent 4% of the total B cells, and this number directly correlates with the concentration of antigen used; stimulation, on the other hand, appears to have an affinity threshold achieved by only 0,02% of the DNP-specific B cells. In contrast, PC-BSA antigen-binding cell and splenic focus precursor cell frequencies are identical. These findings are interpreted to indicate that antigen-binding cell analyses confirm the validity of the calculations used to estimate precursor frequencies in the splenic focus technique. However, for some antigens binding to cell receptors, one detects a large number of cells belonging either to a nonstimulatable B cell subclass or whose receptor affinity is too low to permit stimulation.