Qed-1--a target for unrestricted killing by T cells

Area of Science:

• Immunology
• Genetics
• T cell biology

Background:

• T cell-mediated cytotoxicity plays a crucial role in immune responses.
• Understanding target determinants is key to deciphering immune recognition.
• The Tla region influences T cell recognition and responses.

Purpose of the Study:

• To define novel target determinants recognized by T cells.
• To investigate the genetic basis and mapping of these determinants.
• To explore the distribution and induction of T cell responses related to these determinants.

Main Methods:

• Generation of effector T cells and target cells from various mouse strains.
• In vivo priming and in vitro restimulation protocols.
• Inhibition assays to type mouse strains for target determinants.
• Genetic mapping of the Qed-1 locus relative to Qa-2.

Main Results:

• Two prototype target determinants, Qed-1a and Qed-1b, were identified.
• 52 out of 55 inbred mouse strains expressed either Qed-1a or Qed-1b, suggesting alleles of a single locus, Qed-1.
• A third determinant, Qed-1c, was proposed for three H-2r strains.
• The Qed-1 locus was mapped distal to Qa-2.
• Qed-1b was found on various lymphocyte populations.
• H-2 non-restricted cytotoxic responses specific for Tla region antigens were induced in H-2-identical strains differing at Qed-1.

Conclusions:

• Qed-1 represents a single genetic locus with at least three alleles (Qed-1a, Qed-1b, Qed-1c).
• The Qed-1 locus is located distal to Qa-2.
• T cell responses specific for Qed-1 determinants can be induced independently of H-2 restriction.
• Certain mouse strains exhibit direct responses without prior in vivo priming.