Baslund B, Gregers J, Nielsen C H
Department of Rheumatology, Rigshospitalet and the University of Copenhagen, Denmark.
Rheumatology (Oxford). 2008 Apr;47(4):451-3. doi: 10.1093/rheumatology/ken073. Epub 2008 Mar 3.
To examine if polymorphism 80G --> A in the Reduced Folate Carrier (RFC) affects uptake of MTX in B- and CD4+ T-cells.
Mononuclear cells were isolated from peripheral blood of healthy persons. Real-time PCR was used to detect the RFC80 variants. FITC-labelled MTX was added to cells stimulated with Candida albicans or tetanus toxoid, and the uptake of MTX was measured by flow cytometry. A FITC-conjugated monoclonal antibody against RFC was used to detect the cellular RFC expression.
Antigen-stimulated CD4+ T cells and B cells from individuals with the GG variant (n = 9) exhibited lower uptake of MTX than individuals expressing the AA variant (n = 8), or the GA variant (n = 8). No difference could be demonstrated between the three groups with respect to the expression of RFC by CD4+ T cells and B cells, and CD4+ T cells from individuals homozygous for the G allele exhibited lower uptake of MTX per receptor than CD4+ T cells from individuals homozygous for the A allele.
MTX is taken up more efficiently via the A allele than via the G allele. This difference between the variant forms of RFC suggests that genotyping could be relevant for determining the relevant dosage of MTX in the treatment of neoplastic and autoimmune disease.
研究还原型叶酸载体（RFC）基因80G→A多态性是否影响甲氨蝶呤（MTX）在B细胞和CD4⁺T细胞中的摄取。
从健康人的外周血中分离单核细胞。采用实时聚合酶链反应（PCR）检测RFC80变体。将异硫氰酸荧光素（FITC）标记的MTX加入经白色念珠菌或破伤风类毒素刺激的细胞中，通过流式细胞术检测MTX的摄取情况。使用抗RFC的FITC偶联单克隆抗体检测细胞RFC表达。
GG变体个体（n = 9）的抗原刺激CD4⁺T细胞和B细胞对MTX的摄取低于表达AA变体（n = 8）或GA变体（n = 8）的个体。三组CD4⁺T细胞和B细胞的RFC表达无差异，且G等位基因纯合个体的CD4⁺T细胞每个受体对MTX的摄取低于A等位基因纯合个体的CD4⁺T细胞。
MTX通过A等位基因的摄取比通过G等位基因更有效。RFC变体形式之间的这种差异表明，基因分型可能与确定MTX在肿瘤和自身免疫性疾病治疗中的相关剂量有关。
