Production of specific monoclonal antibody against CD3ε in olive flounder

Abstract

T cell activation is initiated by the binding of antigen to the specific T cell receptor (TCR) that triggers the formation of CD3-signal transduction complex and ends in proliferation and differentiation of antigenspecific T cells. CD3, an essential component of the CD3-TCR complex, has been classified into γ, δ, e, and ζ chains. The CD3γ, CD3δ, and CD3e chains are highly related to cell surface proteins of the immunoglobulin superfamily containing a single extracellular immunoglobulin domain. In mammals, T cells were characterized by detecting one of the CD3 molecules through the use of specific antibody for CD3e. This suggests that CD3 molecules can be used as markers in identifying T cells in teleost fish; hence, it is essential to produce CD3-specific antibodies that could serve as T cell markers in fish. Here, we produced a CD3e-specific monoclonal antibody. Western blot result showed a distinct band at approximately 15 kDa detecting the CD3e antibody while MALDI-TOF analysis, clearly identified the band as olive flounder CD3e. Once a monoclonal antibody has been produced, it can be used to detect the presence of a substance specific to it. The results from this study revealed that the CD3e monoclonal antibody produced could detect CD3e in olive flounder. However, cell markers for T cell differentiation in olive flounder were not fully investigated yet so we hope that this antibody could be useful in elucidating T cell differentiation in teleosts.