TY - JOUR
T1 - Role of L2 cysteines in papillomavirus infection and neutralization
AU - Gambhira, Ratish
AU - Jagu, Subhashini
AU - Karanam, Balasubramanyam
AU - Day, Patricia M.
AU - Roden, Richard
N1 - Funding Information:
Funding for this study was provided by the National Institutes of Health (National Cancer Institute, SPORE in Cervical Cancer, P50 CA098252 and CA118790 to RBSR), the American Cancer Society (RSG-08-116-01-CCE to RBSR) and the Prevent Cancer Foundation, Alexandria, VA (fellowship to SJ) and the intramural program (PMD). We are grateful for the helpful comments and numerous clones kindly provided by Christopher Buck (NCI, NIH). We thank Philip Cole and Tatania Boronina of the Johns Hopkins University Proteomics Core for performing the mass spectrometry analysis and Martin Mûller (Deutsches Krebsforschungszentrum, Germany) for codon-modified HPV16 L1 and L2.
Funding Information:
RBSR is a paid consultant of Merck & Co, Inc., and Knobbe Martens Olson & Bear LLC. SJ and RBSR have received unrestricted educational grant funding from GlaxoSmithKline. RBSR, SJ and RG are co-inventors on L2 patents licensed to Shantha Biotechnics, Ltd., PaxVax, Inc. and Acambis, Inc. The terms of these arrangements are being managed by Johns Hopkins University in accordance with its conflict of interest policies.
PY - 2009
Y1 - 2009
N2 - Vaccination of mice with minor capsid protein L2 or passive transfer with the L2-specific neutralizing monoclonal antibody RG-1 protects against human papillomavirus type 16 (HPV16) challenge. Here we explored the nature of the RG-1 epitope and its contribution to viral infectivity. RG-1 bound equivalently HPV16 L2 residues 17-36 with or without an intact C22-C28 disulphide bridge. HPV16 L2 mutations K20A, C22A, C22S, C28A, C28S, or P29A prevented RG-1 binding, whereas Y19A, K23A or Q24A had no impact. Mutation of either C22 or C28 to alanine or serine compromises HPV16 pseudoviral infectivity both in vitro and in the murine vaginal tract, but does not impact pseudovirion assembly. Despite their lack of infectivity, HPV16 pseudovirions containing C22S or C28S mutant L2 bind to cell surfaces, are taken up, and expose the 17-36 region on the virion surface as for wild type HPV16 pseudovirions suggesting normal furin cleavage of L2. Mutation of the second cysteine residue in Bovine papillomavirus type 1 (BPV1) L2 to serine (C25S) dramatically reduced the infectivity of BPV1 pseudovirions. Surprisingly, in contrast to the double mutation in HPV16 L2, the BPV1 L2 C19S, C25S double mutation reduced BPV1 pseudovirion infectivity of 293TT cells by only half.
AB - Vaccination of mice with minor capsid protein L2 or passive transfer with the L2-specific neutralizing monoclonal antibody RG-1 protects against human papillomavirus type 16 (HPV16) challenge. Here we explored the nature of the RG-1 epitope and its contribution to viral infectivity. RG-1 bound equivalently HPV16 L2 residues 17-36 with or without an intact C22-C28 disulphide bridge. HPV16 L2 mutations K20A, C22A, C22S, C28A, C28S, or P29A prevented RG-1 binding, whereas Y19A, K23A or Q24A had no impact. Mutation of either C22 or C28 to alanine or serine compromises HPV16 pseudoviral infectivity both in vitro and in the murine vaginal tract, but does not impact pseudovirion assembly. Despite their lack of infectivity, HPV16 pseudovirions containing C22S or C28S mutant L2 bind to cell surfaces, are taken up, and expose the 17-36 region on the virion surface as for wild type HPV16 pseudovirions suggesting normal furin cleavage of L2. Mutation of the second cysteine residue in Bovine papillomavirus type 1 (BPV1) L2 to serine (C25S) dramatically reduced the infectivity of BPV1 pseudovirions. Surprisingly, in contrast to the double mutation in HPV16 L2, the BPV1 L2 C19S, C25S double mutation reduced BPV1 pseudovirion infectivity of 293TT cells by only half.
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U2 - 10.1186/1743-422X-6-176
DO - 10.1186/1743-422X-6-176
M3 - Article
C2 - 19860897
AN - SCOPUS:72449124661
SN - 1743-422X
VL - 6
JO - Virology Journal
JF - Virology Journal
M1 - 176
ER -