The nature and function of T-cell antigens

Area of Science:

• Immunology
• Cell Biology

Background:

• T-lymphocytes and B-lymphocytes exhibit distinct antigenic profiles.
• Understanding T-cell surface antigens is crucial for deciphering their migration patterns and mitogen responses.

Purpose of the Study:

• To investigate the role of T-cell surface antigens in T-cell migration in vivo.
• To determine the impact of surface antigens on T-cell responses to mitogens like Concanavalin A (Con-A) and Phytohemagglutinin (PHA).

Main Methods:

• Utilized anti-H2 sera and their Fab fragments to assess effects on lymphocyte migration to lymph nodes (LN) and spleen.
• Investigated the influence of Con-A interaction with cell-surface carbohydrates on lymphocyte localization.
• Analyzed antigenicity (H-2, Ly, theta) of T-cell subpopulations responding to Con-A and PHA.

Main Results:

• Exposure to anti-H2 serum significantly inhibited T-cell migration to LN compared to the spleen.
• Con-A preferentially inhibited lymphocyte localization in LN, without eliminating LN-seeking cells.
• T-cells responding to Con-A showed higher H-2 and lower Ly/theta antigenicity than PHA responders.
• PHA response varied with concentration, correlating with H-2 antigenicity.
• Anti-H2 antiserum markedly inhibited Con-A response in thymus cells but had a weaker effect on spleen cells.

Conclusions:

• T-cell surface antigens, particularly H-2, play a significant role in regulating lymphocyte migration to lymph nodes.
• Con-A's effect on lymphocyte localization is mediated by its interaction with cell-surface carbohydrates, influencing active localization.
• Distinct T-cell subpopulations with differential antigen expression are involved in responses to various mitogens.