Cutting Edge: Granzymes A and B Are Not Essential for Perforin-Mediated Tumor Rejection

Essential for Perforin-Mediated Tumor Cutting Edge: Granzymes A and B Are Not

Cutting edge: tumor rejection mediated by NKG2D receptor-ligand interaction is dependent upon perforin.

We have investigated the primary immunity generated in vivo by MHC class I-deficient and -competent tumor cell lines that expressed the NKG2D ligand retinoic acid early inducible-1 (Rae-1) beta. Rae-1beta expression on class I-deficient RMA-S lymphoma cells enhanced primary NK cell-mediated tumor rejection in vivo, whereas RMA-Rae-1beta tumor cells were rejected by a combination of NK cells and...

Granzyme B and perforin are important for regulatory T cell-mediated suppression of tumor clearance.

Granzyme B is important for the ability of NK cells and CD8(+) T cells to kill their targets. However, we showed here that granzyme B-deficient mice clear both allogeneic and syngeneic tumor cell lines more efficiently than do wild-type (WT) mice. To determine whether regulatory T (Treg) cells utilize granzyme B to suppress immune responses against these tumors, we examined the expression and f...

Independent of Antibody Secretion Salmonella Protective Immunity against Cutting Edge: B Cells Are Essential for

Cutting edge: contact-mediated suppression by CD4+CD25+ regulatory cells involves a granzyme B-dependent, perforin-independent mechanism.

CD4+CD25+ regulatory T cells (Treg) are potent immunosuppressive cells that are pivotal in the regulation of peripheral tolerance. In this report, we identify granzyme B (GZ-B) as one of the key components of Treg-mediated suppression. Induction of regulatory activity is correlated with the up-regulation of GZ-B expression. Proof of a functional involvement of GZ-B in contact-mediated suppressi...