The present invention relates to a monoclonal antibody that inhibits immunosuppressive functions of pathogens, antigen-binding fragment thereof, and hybridomas producing such antibody. The monoclonal antibody or antigen-binding fragment thereof bind to a peptide consisting an amino acid sequence represented by MEKVGKDGVITVE (SEQ ID NO: 1). The present invention also discloses use of the invented monoclonal antibody or antigen-binding fragment thereof, and method of preparation for such hybridomas.
