Human lymphocytes subpopulations: rabbit red blood cell rosettes

Area of Science:

• Immunology
• Cell Biology

Background:

• Human lymphocytes can form rosettes with rabbit red blood cells (RRBC) in vitro.
• Rosette formation is observed in thymocytes and peripheral blood lymphocytes (PBL).

Purpose of the Study:

• To investigate the role of RRBC rosettes as markers of lymphocyte activation.
• To determine if rosette-forming cell (RFC) percentages can serve as an index of mitogenic responses.

Main Methods:

• Incubation of human lymphocytes with RRBC at 4°C overnight.
• Stimulation of PBL with mitogens and measurement of RFC formation.
• Assay of DNA synthesis, protein synthesis, and ATPase activity in the presence of inhibitors.

Main Results:

• Mitogen stimulation significantly increased RFC percentages in PBL, preceding DNA synthesis.
• High mitogen concentrations correlated with both high DNA synthesis and high RFC percentages.
• Inhibition of ATPase activity, but not DNA or protein synthesis, blocked RFC generation.

Conclusions:

• RRBC rosettes in mitogen-stimulated human PBL are reliable markers of activated lymphocytes.
• The percentage of RFC is a dependable index for quantifying mitogenic responses.
• This RFC index is independent of traditional protein and DNA synthesis criteria.