Expression and Characterization of a cDNA Clone Encoding an Immunodominant Surface Glycoprotein of Pneumocystis carinii

• Published in: The Journal of infectious diseases 1992-11, Vol.166 (5), p.1113-1123
• Main Authors: Haidaris, Patricia J., Wright, Terry W., Gigliotti, Francis, Haidaris, Constantine G.
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Amino acids; Animals; antigenic characteristics; antigens; antisera; Antiserum; Base Sequence; Blotting, Northern; Blotting, Southern; Blotting, Western; cDNA; cell surface; Chromatography, Affinity; Cloning, Molecular; Complementary DNA; DNA; DNA, Fungal - genetics; DNA, Fungal - isolation & purification; Ferrets; Fluorescent Antibody Technique; Fungal Proteins; gene expression; Gene Library; Genes; glycoproteins; gpA gene; Lung - microbiology; Major Articles; Membrane Glycoproteins - genetics; Membrane Glycoproteins - immunology; Membrane Glycoproteins - isolation & purification; Messenger RNA; Molecular Sequence Data; Molecular Weight; Molecules; Monoclonal antibodies; nucleotide sequence; Oligodeoxyribonucleotides; Pneumocystis - genetics; Pneumocystis carinii; Polymerase Chain Reaction; prediction; reactivity; Recombinant Fusion Proteins - isolation & purification; RNA, Messenger - genetics; RNA, Messenger - isolation & purification
• ISSN: 0022-1899; 1537-6613
• DOI: 10.1093/infdis/166.5.1113

Most studies of antigens of Pneumocystis carinii have focused on an abundant, immunogenic 95- to 140-kDa surface glycoprotein referred to as gpA. Expression cloning of gpA from P. carinii obtained from ferrets resulted in isolation of colinear fragments of gpA cDNA encoding ∼87 kDa of the core protein. Northern hybridization detected an abundant, single species of gpA-specific mRNA of 3600 nucleotides. Southern hybridization revealed gpA-specific bands only in P. carinii-infected lung genomic DNA, suggesting that the gpA cDNA did not result from induction of a host lung gene. Antiserum raised against a fragment of recombinant gpA detected P. carinii cysts and isolated native P. carinii gpA, indicating retention of epitopes between the nonglycosylated recombinant gpA and glycosylated native gpA. The deduced amino acid sequence is hydrophilic and contains 12 potential N-linked glycosylation sites and 47 cysteine residues, consistent with the surface orientation of gpA on the organism and other known characteristics of the native molecule.