CD56 expression in feline lymphoid cells

Area of Science:

• Immunology
• Cell Biology
• Veterinary Medicine

Background:

• Neural-cell adhesion molecule (N-CAM) exists in multiple polypeptide forms (180, 140, 120 kDa) with variations in transmembrane and cytoplasmic domains.
• CD56 is a cell surface glycoprotein recognized as the 140 kDa form of N-CAM and is expressed on various immune cells.

Purpose of the Study:

• To generate a monoclonal antibody for feline CD56 (fCD56) detection.
• To investigate the expression of fCD56 in feline lymphoid cells.

Main Methods:

• Generated a monoclonal antibody (SZK1) using a baculovirus expression system targeting the 140 kDa form of N-CAM.
• Utilized flow cytometry to analyze fCD56 expression on feline T-lymphoblastoid cell line MYA-1 and peripheral blood lymphocytes (PBLs).
• Performed immunoblotting and reverse transcription-polymerase chain reaction (RT-PCR) to characterize the antigen recognized by SZK1.

Main Results:

• The SZK1 antibody specifically recognized the 140 kDa form of N-CAM (fCD56) in feline cells.
• SZK1 detected fCD56 on the MYA-1 cell line and a small population (1.1-1.7%) of freshly isolated feline PBLs.
• fCD56 expression on PBLs increased significantly (>10%) after interleukin-2 stimulation and concanavalin A treatment.
• Immunoblotting detected a ~160 kDa antigen, while RT-PCR confirmed a fragment resembling the 140 kDa N-CAM form.

Conclusions:

• The generated antibody SZK1 is effective for detecting feline CD56.
• Feline CD56 is expressed on a minor population of PBLs, with increased expression upon immune stimulation.
• These findings indicate that feline CD56 shares characteristics with its human counterpart, suggesting conserved functions in immune responses.