TY - JOUR
T1 - Differential antigenicity of recombinant polyepitope-antigens based on loop- and helix-forming B and T cell epitopes
AU - Theisen, D. M.
AU - Bouche, F. B.
AU - El Kasmi, K. C.
AU - Von Der Ahe, I.
AU - Ammerlaan, W.
AU - Demotz, S.
AU - Muller, C. P.
N1 - Funding Information:
The authors thank Dr. N. Kieffer (Laboratoire Franco-Luxembourgeois, Luxembourg) for support with fluorescence microscopy and Dr. S. Kreis and Dr. F. Fack for critical reading of the manuscript. Financial support from the Centre de Recherche Public-Santé auprès du Laboratoire National de Santé, the EU Biotechnology Programme (BIO4-CT98-0242), the Ministère de l’Education Nationale et de la Formation Professionelle (Bourse F&R to D.M. Theisen and F.B. Bouche) and the Ministère de la Santé, Luxembourg, is gratefully acknowledged. K.C. El Kasmi was supported, in part, by the Leonardo da Vinci Programme.
PY - 2000/8/28
Y1 - 2000/8/28
N2 - To investigate a strategy for the design of chimeric antigens based on B cell epitopes (BCEs) we have genetically recombined multiple copies of loop- (L) and helix-forming (H) sequential and protective BCEs of the measles virus hemagglutinin protein (MVH) in a number of high-molecular-weight polyepitope constructs (24.5-45.5 kDa). The BCE cassettes were combined semi-randomly together with a promiscuous T cell epitope (TCE; tt830-844) to yield 13 different permutational constructs. When expressed in mammalian cells, all constructs were detectable by Western blot as distinct bands of predicted molecular weight. Flow cytometry with conformation-specific antibodies revealed the Cys-loop in two [(L4T4)2 and (L2T2)4] and the helix conformation in one [(H2T2)4] of the different permutational constructs. The larger constructs, containing 16 epitope cassettes, seemed more likely to express the BCEs in their native conformation than the 8-mers. In the T cell proliferation assay, constructs with a higher copy number of TCEs, such as (L2T2)4, were more antigenic, as long as tandem repeats were separated by spacers. Since the conformation of even sequential BCEs and the processing of TCEs are both sensitive to their molecular environment it is difficult to predict the antigenic properties of polyepitopes. However, with the permutational approach we have developed several polyepitope constructs [(L4T4)2, (L2T2)4, (H2T2)4] based on complex sequential BCEs that are antigenic for both T and B cells. Several constructs induced sera that reacted with reporter peptides, demonstrating that the sequential nature of the viral epitopes was conserved in the polyepitopes. Although several sera contained antibodies directed against amino acids critical for neutralization, only one construct induced antibodies that cross-reacted with the virus. Our results show the difficulty of designing chimeric antigens based on B cell epitopes mimicking their antigenic and immunologic properties even when these are sequential in nature. (C) 2000 Elsevier Science B.V.
AB - To investigate a strategy for the design of chimeric antigens based on B cell epitopes (BCEs) we have genetically recombined multiple copies of loop- (L) and helix-forming (H) sequential and protective BCEs of the measles virus hemagglutinin protein (MVH) in a number of high-molecular-weight polyepitope constructs (24.5-45.5 kDa). The BCE cassettes were combined semi-randomly together with a promiscuous T cell epitope (TCE; tt830-844) to yield 13 different permutational constructs. When expressed in mammalian cells, all constructs were detectable by Western blot as distinct bands of predicted molecular weight. Flow cytometry with conformation-specific antibodies revealed the Cys-loop in two [(L4T4)2 and (L2T2)4] and the helix conformation in one [(H2T2)4] of the different permutational constructs. The larger constructs, containing 16 epitope cassettes, seemed more likely to express the BCEs in their native conformation than the 8-mers. In the T cell proliferation assay, constructs with a higher copy number of TCEs, such as (L2T2)4, were more antigenic, as long as tandem repeats were separated by spacers. Since the conformation of even sequential BCEs and the processing of TCEs are both sensitive to their molecular environment it is difficult to predict the antigenic properties of polyepitopes. However, with the permutational approach we have developed several polyepitope constructs [(L4T4)2, (L2T2)4, (H2T2)4] based on complex sequential BCEs that are antigenic for both T and B cells. Several constructs induced sera that reacted with reporter peptides, demonstrating that the sequential nature of the viral epitopes was conserved in the polyepitopes. Although several sera contained antibodies directed against amino acids critical for neutralization, only one construct induced antibodies that cross-reacted with the virus. Our results show the difficulty of designing chimeric antigens based on B cell epitopes mimicking their antigenic and immunologic properties even when these are sequential in nature. (C) 2000 Elsevier Science B.V.
KW - Measles virus
KW - Recombinant polyepitopes
KW - Sequential B cell epitopes
KW - tt830-844, Hemagglutinin protein
UR - http://www.scopus.com/inward/record.url?scp=0034726403&partnerID=8YFLogxK
U2 - 10.1016/S0022-1759(00)00197-6
DO - 10.1016/S0022-1759(00)00197-6
M3 - Article
C2 - 10986397
AN - SCOPUS:0034726403
SN - 0022-1759
VL - 242
SP - 145
EP - 157
JO - Journal of Immunological Methods
JF - Journal of Immunological Methods
IS - 1-2
ER -