Production and characterization of a panel of anti-mouse placenta-specific protein 1 (plac1) monoclonal antibodies

Anal Biochem. 2025 Jan:696:115682. doi: 10.1016/j.ab.2024.115682. Epub 2024 Sep 26.

Abstract

Placenta-Specific Protein 1 (PLAC1) is essential for normal placental and embryonic development. It is widely expressed in various types of cancer cells. We produced a panel of anti-mouse plac1 monoclonal antibodies (mAbs) with different applications. Two recombinant proteins were produced containing either the extracellular domain (ED) plus tetanus toxin P2, P30, pan-DR epitope (PADRE), and KDEL3 (main plac1) or ED plus KDEL3 (control plac1). Recombinant proteins were used for immunization and screening. Positive clones were selected by ELISA and flow cytometry. Purified mAbs were tested by ELISA, WB, flow cytometry, immunohistochemistry (IHC), and immunofluorescent (IF). A combination of bioinformatics tools was used to predict the target epitope(s) of the mAbs. Eight anti-mouse plac1 mAbs (all IgG1/κ1) were generated, all reacting with high affinity in ELISA. Seven clones recognized plac1 in both reduced and non-reduced Western blots, while one only recognized the non-reduced form. Cross-inhibition ELISA revealed that all mAbs recognized overlapping epitopes with a shared motif except for 5C9. Four clones reacted with the native antigen in flow cytometry, but none were functional in IF or IHC staining. The produced multifunctional mAbs can be used to investigate different aspects of PLAC1 biology in reproduction and cancer.

Keywords: Cancer; Flow cytometry; Monoclonal antibody; Mouse plac1; Western blot.

MeSH terms

  • Animals
  • Antibodies, Monoclonal* / chemistry
  • Antibodies, Monoclonal* / immunology
  • Enzyme-Linked Immunosorbent Assay
  • Epitopes / chemistry
  • Epitopes / immunology
  • Female
  • Flow Cytometry
  • Humans
  • Mice
  • Mice, Inbred BALB C
  • Pregnancy Proteins* / chemistry
  • Pregnancy Proteins* / immunology
  • Pregnancy Proteins* / metabolism
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / immunology

Substances

  • Pregnancy Proteins
  • Antibodies, Monoclonal
  • Epitopes
  • Recombinant Proteins
  • PLAC1 protein, human