B-CELL CHANGES ASSOCIATED WITH HIV-1 THROMBOCYTOPENIA

描述(改编自申请人的摘要) 申请者表现出一种不同寻常的联系，显然 一组HIV-L感染者的非相关血液学异常 个人。HIV-L血清阳性，血小板减少者显示 他们的B细胞亚群发生了明显的变化。尽管B细胞数量 正常，CD5+细胞比例及其绝对数均为 CD5-B细胞绝对数明显减少。 在一些患者中，90%的循环B细胞是CD5+ (正常=18.2+2.3%)。B细胞亚群的改变既不是 可归因于CD4或CD8细胞数量、CD4/CD8比率的变化，或 淋巴细胞绝对计数与病情严重程度无关，也与AZT无关 治疗。 申请人认为，这是不可能的协会 通过以下途径发生血小板减少和异常的B细胞 偶然性。他们的提案旨在调查 协会。我们将研究三种可能的解释：(1)两者 这些异常可能是自身免疫反应的后果， 与CD5+B细胞的流行有关，并针对 要么是成熟细胞，要么是骨髓中的祖细胞。来自中国的血清 将对感染患者进行与B病毒反应的自身抗体检测 细胞和血小板或其祖细胞。申请者还将寻求 细胞结合的自身抗体或免疫复合体，类似于 HIV-1阳性ITP患者的血小板如果抗B细胞抗体是 他们将确定CD5+B细胞如何逃脱这种自身免疫 回应。(2)这些异常可能是艾滋病毒的直接影响--L 对造血祖细胞或细胞的感染 B细胞和巨核细胞的发育。两者都是长期骨骼 骨髓细胞培养和短期克隆培养将用于 病毒、HIV-L感染细胞和血清对小鼠免疫功能的影响 B细胞的发育。(3)淋巴造血功能的改变可能是 由CD4+T细胞缺乏引起的调节失调的结果 细胞或CD8+T细胞过多。T细胞衍生的细胞因子是已知的 对MK和B细胞的发育都有深远的影响。相对的 CD5+亚群的T-无关性可能是其持久性的原因。 这种可能性将使用两个模型系统进行检验。首先， 从未感染的受试者中挑选出的人类细胞群体将是 转移到免疫缺陷(SCID)小鼠。将使用单元格排序 分离高度浓缩的CD5+和CD5-B细胞群体，或其 表达CD4或CD8的前体细胞和T细胞群。 这些人群的各种组合将被注射，并 B细胞亚群存活率测定。在第二个模型中，一个 将尝试在一只完全小鼠身上重现这种现象 系统。同样，必要表型的细胞将通过以下方式制备 细胞分选并注射到SCID小鼠，但在这个模型中只有细胞 来自同基因小鼠的基因将被转移，消除了 组织不相容的问题会扰乱发育 学习。

DESCRIPTION (Adapted from the applicant's abstract) The applicants have demonstrated an unusual association of apparently unrelated hematological abnormalities in a group of HIV-l infected individuals. HIV-l seropositive, thrombocytopenic individuals showed marked alterations in their B-cell subsets. Although B-cell numbers were normal, both the proportion of CD5+ cells and their absolute number were increased and the absolute number of CD5- B-cells were markedly reduced. In some patients 90 percent of the circulating B-cells were CD5+ (normal=18.2 + 2.3%). The alteration in the B-cell subsets was neither attributable to changes in CD4 or CD8 cell number, CD4/CD8 ratio, or absolute lymphocyte count nor to severity of disease nor to AZT treatment. The applicants suggest that it is improbable that the association of thrombocytopenia and aberrant B-cell profile occurred through happenstance. Their proposal is designed to investigate the basis of the association. Three possible explanations will be examined: (1) Both the abnormalities could be consequences of an autoimmune response, associated with the prevalence of CD5+ B cells, and directed against either the mature cells or their progenitors in the marrow. Sera from infected patients will be assayed for autoantibodies reactive with B cells and platelets or their progenitors. The applicants will also seek cell-bound autoantibodies or immune complexes similar to those found on platelets of patients with HIV-1 + ITP. If anti-B-cell antibodies are found, they will determine how CD5+ B-cells escape this autoimmune response. (2) The abnormalities could be a direct effect of HIV-l infection on either a hematopoietic precursor or a cell necessary for the development of B-cells and megakaryocytes. Both long term bone marrow cell cultures and short-term clonal cultures will be used to study the effects of virus, HIV-l infected cells and serum on the development of B-cells. (3) The changes in lympho-hematopoiesis could be a result of dysregulation induced by either the deficiency of CD4+ T- cells or the excess of CD8+ T-cells. T-cell derived cytokines are known to have profound effects on both MK and B-cell development. The relative T-independence of the CD5+ subset may account for their persistence. This possibility will be examined using two model systems. In the first, selected populations of human cells from uninfected subjects will be transferred to immunodeficient (SCID) mice. Cell sorting will be used to isolate highly enriched populations of CD5+ and CD5- B-cells, or their precursors as well as T-cell populations expressing either CD4 or CD8. Various combinations of these populations will be injected and the survival of the B-cell subsets determined. In the second model, an attempt will be made to reproduce the phenomenon in a totally murine system. Again, cells of the necessary phenotypes will be prepared by cell sorting and injected into SCID mice, but in this model only cells from syngeneic mice will be transferred, eliminating the possibility that problems of histo-incompatibility will confound the developmental studies.