Association between CTL precursor frequency to HLA-C mismatches and HLA-C antigen cell surface expression

作者:Israeli Moshe*; Roelen Dave L; Carrington Mary; Petersdorf Effie Wang; Claas Frans H J; Haasnoot Geert W; Oudshoorn Machteld
来源:Frontiers in Immunology, 2014, 5: UNSP 547.
DOI:10.3389/fimmu.2014.00547

摘要

Previous studies showed the relevance of the cytotoxic T-cell precursor (CTLp) frequency assay for prediction of the outcome of HLA mismatched hematopoietic cell transplantation (HCT). Recently, it has been shown that HLA-C cell surface expression is correlated with virus specific cytotoxicT-cell responses and viremia control in HIV patients. The aim of the current study was to investigate the association between HLA-C antigen expression and the CTLp frequency to the mismatched HLA-C antigen. In total 115 recipient donor pairs, for whom a successful CTLp assay was performed, were evaluated for this pilot study. All donor recipient pairs were matched at 9/10 alleles with a single mismatch at the HLA-C locus. Antigen expression level of the mismatched HLA-C allele for each recipient and donor was based on the mean fluorescence intensity (MFI) values as described by Apps et al. (1). The cell surface expression of recipient%26apos;s mismatched HLA-C antigen was significantly lower among CTLp negative (n = 59) compared to CTLp positive (n = 56) pairs (154 and 193 MFI units, respectively, p = 0.0031). This difference was more pronounced in donor recipient pairs that were mismatched for amino-acid residue-116 located in the groove of the HLA-C antigen, suggesting that the importance of peptide binding in the allo-recognition. Furthermore, in the particular case of low expression of the recipient mismatched HLA-C antigen (MFI %26lt; 115), CTLp reactivity depended on HLA-C expression level in the donor, the median MFI of donor%26apos;s mismatched HLA-C antigen was 114 in CTLp negative cases (n = 26), while in CTLp positive cases (n = 15) the median MFI of donor%26apos;s HLA-C antigen was 193 (p = 0.0093). We conclude that the expression level of the donor and recipient mismatched HLA-C antigens affect CTLp outcome. HLA-C antigen expression levels in combination with the CTLp assay may prove useful for the prediction of the clinical outcome of HLA-C mismatched HCT.

  • 出版日期2014-10-27