Rheumatology Advance Access originally published online on January 23, 2007
Rheumatology 2007 46(3):556-557; doi:10.1093/rheumatology/kel391
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Response to Ziegler and Ziegler
Department of Pathology, Tennis Court Road, Cambridge CB2 1QP, UK.
Correspondence to: Rachel L. Allen, Department of Pathology, Tennis Court Road, Cambridge, CB2 1QP, UK. E-mail: rla25{at}cam.ac.uk
SIR, We thank Dr Ziegler for her interest in our article, and for this opportunity to respond and discuss some interesting points concerning the study of MHC-I biology.
The central aim of our study was not, as Dr Ziegler suggests, to study a single allele (HLA B27). We would like to emphasize that it was our intent to consider multiple alleles and haplotypes, in case other readers may have reached a similar misunderstanding. In order to analyse human samples expressing multiple MHC-I alleles (rather than the single-allele transfectants used as examples by Dr Ziegler), we required reagents with broad specificity that could detect more than just one allele. We selected HC10 and W6/32 as the antibodies available to us with the broadest specificity for free heavy chains and conformed MHC-I, respectively. Although Dr Ziegler's asserts that HC10 recognizes only HLA-B and -C alleles, a more recent epitope analysis has confirmed that HC10 also recognizes some HLA-A alleles [1]. In an ideal world, the best way to perform our study would have been to tissue type patients for HLA haplotype, then select a folded MHC-I/unfolded MHC-I antibody pair specific for every individual allele expressed by each patient. However, such panels do not exist and the examples provided by Dr Ziegler were used to characterize trophoblast, a tissue that expresses only HLA-C from the available classical alleles.
The majority of concerns raised by Dr Ziegler regard the trophoblast work detailed in Figure 4 of our manuscript. In contrast to her claim that HC10 does not recognize HLA-G, we would like to draw readers’ attention to Figure 2A of an article published by Sernee and colleagues [2] that demonstrates that HC10 can immunoprecipitate both HLA-C and HLA-G, but has a preference for HLA-C. Any bias introduced by this preference for HLA-C would result in the increased levels of FHC we observed for trophoblast being an underestimate. Therefore, from our initial results, we believe that analysis of the alternative MHC-I forms on trophoblast merits a full study of its own, but would be best suited to a journal other than Rheumatology.
Our intent was to determine whether free heavy chains might be worthy of investigation with respect to arthritic disease. Use of HC10 allowed us to survey MHC-I over all patient allotypes. HC10 reactive forms of MHC-I are of particular interest as this antibody has been shown to reduce the incidence of disease in arthritic mouse models [3]. Irrespective of the points discussed above, our data support the conclusion that HC10-reactive material is more abundant in arthritic patients than healthy controls. Details of specific HLA types can be comprehensively studied in patients as appropriate reagents become available in the future.
The authors have declared no conflicts of interest.
 |
References |
|---|
 Top References |
|---|
- Perosa F, Luccarelli G, Prete M, et al. (2003) ß2-microglobulin-free HLA class I heavy chain epitope mimicry by monoclonal antibody HC-10-specific peptide. J Immunol 171:1918–26.
[Abstract/Free Full Text] - Sernee MF, Ploegh HL, Schust DJ. (1998) Why certain antibodies cross-react with HLA-A and HLA-G: Epitope mapping of two common MHC class I reagents. Mol Immunol 35:177–88.[CrossRef][Web of Science][Medline]
- Khare SD, Bull MJ, Hanson J, Luthra HS, David CS. (1998) Spontaneous inflammatory disease in HLA-B27 transgenic mice is independent of MHC class II molecules: a direct role for HLA B27 heavy chains and not B27-derived peptides. J Immunol 160:101–06.
[Abstract/Free Full Text]
CiteULike 
Connotea 
Del.icio.us What's this?
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||