Functional epitopes on porcine endogenous retrovirus envelope protein interacting with neutralizing antibody combining sites.
Porcine cell and organ transplantation provides promise for maintaining normal physiological conditions in patients with end-stage organ failure. The approach however poses serious risk of transmitting pig pathogens to humans. Among many potential pathogens, porcine endogenous retroviruses (PERV) are of particular concern due to their ubiquitous nature in pigs and capability of infecting human cells. Major antigenic determinants and receptor binding domains on PERV remain unclear until now. Two monoclonal antibodies (mAb), named 8E10 and 7C4 capable of neutralizing PERV infection in HEK293 cells are isolated at an IC(50) of 3.0 and 2.7 microg/ml, respectively, in this work. Epitope location for mAb 8E10 was mapped to amino acids 427-434, residing at the C-terminal region of the gp70 component of type A PERV Env protein. The mAb 8E10 bound directly to the PERV indicating that the epitope is exposed on the virion surface. The mAb 7C4 epitope was assigned to the region comprising amino acids 517-537 on the p15E component of PERV. In contrast to mAb 8E10, the 7C4 mAb bound native PERV inefficiently suggesting that its epitope is accessible only after the virus interacts with its receptor. Finally, both mAbs variable regions were cloned and nucleotide sequence determined. All together, these results reveal that both mAbs 8E10 and 7C4 effectively neutralize PERV infection and may be used as a mean to prevent PERV infection in patients receiving xenotransplantation.
Chiang
Chen-Yi
CY
Institute of Molecular Medicine, National Tsing Hua University, Hsin Chu, Taiwan, ROC.
Pan
Yun-Ru
YR
Chou
Li-Fang
LF
Fang
Chih-Yeu
CY
Wang
Shih-Rong
SR
Yang
Chiou-Ying
CY
Chang
Hwan-You
HY
D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D000914:Antibodies, Viral / Q000276:immunology; D000918:Antibody Specificity; D002460:Cell Line; D020077:Endogenous Retroviruses / Q000276:immunology* / Q000378:metabolism; D018604:Epitope Mapping; D000939:Epitopes / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D006801:Humans; D008969:Molecular Sequence Data; D009500:Neutralization Tests; D017434:Protein Structure, Tertiary; D011991:Receptors, Virus / Q000378:metabolism; D012192:Retroviridae Infections / Q000821:virology*; D016415:Sequence Alignment; D014759:Viral Envelope Proteins / Q000235:genetics / Q000276:immunology* / Q000378:metabolism
D000911:Antibodies, Monoclonal; D000914:Antibodies, Viral; D000939:Epitopes; D011991:Receptors, Virus; D014759:Viral Envelope Proteins