Histamine-binding suppressor T cells in rabbit peripheral blood

Area of Science:

• Immunology
• Cell Biology
• T cell regulation

Background:

• Peripheral blood leukocytes (PBL) play a crucial role in immune regulation.
• Understanding the specific cell populations within PBL that modulate immune responses is essential.

Purpose of the Study:

• To identify and characterize the suppressor cells within rabbit PBL that inhibit antibody production.
• To investigate the role of histamine-binding cells in immune suppression and regulation.

Main Methods:

• Cell fractionation of PBL using insolubilized histamine columns.
• In vitro assessment of anti-sheep red blood cell (SRBC) plaque-forming cell (PFC) response.
• Radiobiological characterization of identified cell populations.

Main Results:

• A subpopulation of histamine-binding (H+) PBL cells was isolated and found to suppress the PFC response.
• PBL depleted of H+ cells showed an enhanced secondary anti-SRBC response in vitro.
• The H+ suppressor cell was identified as a radioresistant T cell.
• Low-dose irradiation of H- cells enhanced the PFC response, indicating the presence of a radiosensitive regulator.

Conclusions:

• Histamine-binding T cells in rabbit PBL act as potent suppressors of the in vitro antibody response.
• PBL contain distinct populations of regulatory cells, including radioresistant suppressor T cells and radiosensitive regulatory cells.
• Histamine affinity can be used to isolate functionally distinct cell subsets within PBL for immunological studies.