de Boer B A, Kruize Y C, Yazdanbakhsh M
Department of Parasitology, Leiden University Medical Centre, Leiden University, The Netherlands.
Clin Exp Immunol. 1998 Nov;114(2):252-7. doi: 10.1046/j.1365-2249.1998.00732.x.
IgG4 and IgE isotypes contribute marginally to the pool of circulating antibodies in healthy individuals, but are elevated during atopic diseases and particularly upon helminth infections. To examine whether the high levels of these isotypes in circulation are reflected in a higher capacity of PBMC to produce IgG4 and IgE, we examined cells from patients infected with filarial nematodes that exhibit high levels of IgG4 and IgE. Indeed, IgG4 production by PBMC correlated strongly with plasma levels of IgG4 (r=0.534, P=0.002), but such correlation was not found for IgE. The replacement of CD19+ cells from PBMC by IgD+ cells abrogated the high capacity of PBMC to make IgG4. This indicates that an altered B cell compartment accounts for the high IgG4-producing capacity of the PBMC. The high production of IgG4 in vitro was not dependent on IL-4 and IL-13, as neutralizing antibodies to these cytokines did not inhibit IgG4. However, IgE release by PBMC was dependent on IL-4 and IL-13. Antifilarial IgG4 was detected in culture supernatants from filarial patients and its production was independent of IL-4 and IL-13. These results demonstrate that in individuals with elevated IgG4. the B cell compartment in PBMC carries cells that are already committed to IgG4 production and are independent of IL-4 and IL-13.
在健康个体中，IgG4和IgE亚型对循环抗体库的贡献微乎其微，但在特应性疾病期间，尤其是在蠕虫感染时会升高。为了研究循环中这些亚型的高水平是否反映在PBMC产生IgG4和IgE的能力增强上，我们检测了感染丝虫线虫的患者的细胞，这些患者表现出高水平的IgG4和IgE。事实上，PBMC产生的IgG4与血浆中IgG4水平密切相关（r=0.534，P=0.002），但未发现IgE有这种相关性。用IgD+细胞替代PBMC中的CD19+细胞消除了PBMC产生IgG4的高能力。这表明B细胞区室的改变是PBMC产生IgG4高能力的原因。体外IgG4的高产生不依赖于IL-4和IL-13，因为针对这些细胞因子的中和抗体不会抑制IgG4。然而，PBMC释放IgE依赖于IL-4和IL-13。在丝虫病患者的培养上清液中检测到抗丝虫IgG4，其产生不依赖于IL-4和IL-13。这些结果表明，在IgG4升高的个体中，PBMC中的B细胞区室携带已致力于产生IgG4且不依赖于IL-4和IL-13的细胞。
