A chicken leukocyte common antigen: biochemical characterization and ontogenetic study

Area of Science:

• Immunology
• Developmental Biology
• Hematology

Background:

• Chicken peripheral blood lymphocytes (PBL) express various cell surface antigens crucial for immune function.
• Understanding the ontogeny of the hematopoietic system requires specific markers for different cell populations.
• Existing markers in other species, like mouse T-200 and B-220, highlight the need for homologous markers in chickens.

Purpose of the Study:

• To produce and characterize a novel monoclonal antibody (CL-1) against chicken hemopoietic cells.
• To identify the cell surface antigen recognized by CL-1 and its expression patterns.
• To evaluate the utility of CL-1 in studying chicken hematopoiesis and in interspecies chimera experiments.

Main Methods:

• Production of monoclonal antibody CL-1 through mouse immunization with chicken PBL.
• Selection of CL-1 using an indirect immunofluorescence assay.
• Analysis of CL-1 reactivity with chicken hemopoietic cells and embryonic tissues.
• Protein characterization of CL-1-reactive antigens via Western blot.

Main Results:

• CL-1 recognizes a cell surface antigen present on all chicken hemopoietic cells, excluding mature erythrocytes.
• The antigen is detectable early in embryonic development across various hemopoietic compartments.
• CL-1 binds to two chicken PBL proteins (200 kDa and 215 kDa), likely homologous to mouse T-200 and B-220.
• CL-1 does not react with quail hemopoietic tissues.

Conclusions:

• Monoclonal antibody CL-1 is a valuable tool for identifying chicken hemopoietic progenitor cells.
• CL-1 can be used to trace the developmental origins of hemopoietic cells in chickens.
• The differential reactivity with quail makes CL-1 useful for quail-chick chimera studies of hematopoietic ontogeny.