Dono M, Zupo S, Masante R, Taborelli G, Chiorazzi N, Ferrarini M
Laboratory of Clinical Immunology, Istituto Nazionale per la Ricerca sul Cancro, Genova, Italy.
Eur J Immunol. 1993 Apr;23(4):873-81. doi: 10.1002/eji.1830230416.
This study investigated the response of different CD5- B cell subsets to CD40 monoclonal antibody (mAb) in various combinations with interleukin (IL)-4 or rabbit anti-human mu chain antibody (a-mu-Ab). The different CD5- B cell subsets were isolated from tonsillar B cell suspensions depleted of CD5+ B cells and subsequently fractionated on Percoll density gradients. While resting CD5+ B cells proliferated and produced IgM molecules in response to a-mu-Ab, IL-4 and CD40 mAb as well as to Staphylococcus aureus Cowan strain I (SAC) and IL-2, resting CD5- B cells, which were co-purified in the same 60% Percoll fractions, consistently failed to respond. These cells were, however, activated by the stimuli employed, as demonstrated by their capacity to express the surface activation markers CD69, CD25 and CD71. Resting CD5+ B cells had the typical phenotype of mantle zone B cells (IgM+ IgD+ CD39+ CD38- CD10- CDw75dim), whereas resting CD5- B cells were CD38- CD39- CD10- CDw75 intermediate and expressed surface IgM but relatively little surface IgD and could not be classified as mantle zone or germinal center cells. The finding that purified germinal center cells (CD38+ CD10+ CD39- CDw75bright, IgG+) responded to CD40 mAb and IL-4 and also to SAC plus IL-2 further underlined the differences to resting CD5- B cells. However, some of the data collected suggest possible relationships between CD5- B cells and germinal center cells. The CD5- B cells isolated from the 50% Percoll fraction proliferated in response to a-mu-Ab, CD40 mAb and IL-4 as well as to SAC and IL-2. These cells had the same mantle zone B cell phenotype as the CD5+ B cells, but their capacity to respond to the stimuli in vitro was unrelated to a possible contamination with CD5+ B cells, as documented by the appropriate controls. Furthermore, upon exposure to SAC or phorbol esters, the large majority of CD5- B cells from the 50% Percoll fraction did not express surface CD5 and there was very little if any accumulation of CD5 mRNA. Finally, most of the cycling cells in the stimulated CD5- B cells did not express CD5. The CD5- B cells from the 50% Percoll fraction were comprised of a consistent proportion of cells that expressed surface activation markers.(ABSTRACT TRUNCATED AT 400 WORDS)
本研究调查了不同的CD5 - B细胞亚群在与白细胞介素（IL）-4或兔抗人μ链抗体（α - μ - Ab）以各种组合形式存在时对CD40单克隆抗体（mAb）的反应。不同的CD5 - B细胞亚群是从去除了CD5 + B细胞的扁桃体B细胞悬液中分离出来的，随后在Percoll密度梯度上进行分级分离。静止的CD5 + B细胞在受到α - μ - Ab、IL - 4和CD40 mAb以及金黄色葡萄球菌考恩I株（SAC）和IL - 2刺激时会增殖并产生IgM分子，而在相同的60% Percoll组分中共同纯化得到的静止CD5 - B细胞始终无反应。然而，这些细胞可被所用刺激激活，这可通过它们表达表面激活标志物CD69、CD25和CD71的能力得以证明。静止的CD5 + B细胞具有套区B细胞的典型表型（IgM + IgD + CD39 + CD38 - CD10 - CDw75dim），而静止的CD5 - B细胞为CD38 - CD39 - CD10 - CDw75中等水平，表达表面IgM但表面IgD相对较少，且不能归类为套区或生发中心细胞。纯化的生发中心细胞（CD38 + CD10 + CD39 - CDw75bright，IgG +）对CD40 mAb和IL - 4以及SAC加IL - 2有反应，这一发现进一步凸显了其与静止CD5 - B细胞的差异。然而，收集到的一些数据表明CD5 - B细胞与生发中心细胞之间可能存在关联。从50% Percoll组分中分离出的CD5 - B细胞在受到α - μ - Ab、CD40 mAb和IL - 4以及SAC和IL - 2刺激时会增殖。这些细胞具有与CD5 + B细胞相同的套区B细胞表型，但它们在体外对刺激的反应能力与可能被CD5 + B细胞污染无关，适当的对照已证明了这一点。此外，在暴露于SAC或佛波酯后，来自50% Percoll组分的大多数CD5 - B细胞不表达表面CD5，且CD5 mRNA几乎没有积累。最后，受刺激的CD5 - B细胞中的大多数循环细胞不表达CD5。来自50% Percoll组分的CD5 - B细胞由一定比例表达表面激活标志物的细胞组成。（摘要截取自400字）
