title: Discordant regulation of granzyme H and granzyme B expression in human lymphocytes.
abstract: We analyzed the expression of granzyme H in human blood leukocytes, using a novel monoclonal antibody raised against recombinant granzyme H. 33-kDa granzyme H was easily detected in unfractionated peripheral blood mononuclear cells, due to its high constitutive expression in CD3(-)CD56(+) natural killer (NK) cells, whereas granzyme B was less abundant. The NK lymphoma cell lines, YT and Lopez, also expressed high granzyme H levels. Unstimulated CD4(+) and particularly CD8(+) T cells expressed far lower levels of granzyme H than NK cells, and various agents that classically induce T cell activation, proliferation, and enhanced granzyme B expression failed to induce granzyme H expression in T cells. Also, granzyme H was not detected in NK T cells, monocytes, or neutrophils. There was a good correlation between mRNA and protein expression in cells that synthesize both granzymes B and H, suggesting that gzmH gene transcription is regulated similarly to gzmB. Overall, our data indicate that although the gzmB and gzmH genes are tightly linked, expression of the proteins is quite discordant in T and NK cells. The finding that granzyme H is frequently more abundant than granzyme B in NK cells is consistent with a role for granzyme H in complementing the pro-apoptotic function of granzyme B in human NK cells.
authors.affiliation: Cancer Immunology Laboratory, Peter MacCallum Cancer Centre, Locked Bag 1, A'Beckett Street, East Melbourne, 8006, Australia.
authors.forename: Karin A
authors.initials: KA
authors.lastname: Sedelies
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Sayers
authors.forename: Kirsten M
authors.initials: KM
authors.lastname: Edwards
authors.forename: Weisan
authors.initials: W
authors.lastname: Chen
authors.forename: Daniel G
authors.initials: DG
authors.lastname: Pellicci
authors.forename: Dale I
authors.initials: DI
authors.lastname: Godfrey
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Trapani
mesh_terms: D000818:Animals; D017209:Apoptosis; D015152:Blotting, Northern; D015153:Blotting, Western; D017252:CD3 Complex / Q000096:biosynthesis; D019002:CD56 Antigen / Q000096:biosynthesis; D018414:CD8-Positive T-Lymphocytes / Q000378:metabolism; D002455:Cell Division; D002460:Cell Line; D045744:Cell Line, Tumor; D018076:DNA, Complementary / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D015971:Gene Expression Regulation, Enzymologic; D053804:Granzymes; D006801:Humans; D007150:Immunohistochemistry; D007694:Killer Cells, Natural / Q000378:metabolism; D007962:Leukocytes / Q000201:enzymology / Q000378:metabolism; D008214:Lymphocytes / Q000201:enzymology*; D051379:Mice; D008807:Mice, Inbred BALB C; D011485:Protein Binding; D011506:Proteins / Q000737:chemistry; D012333:RNA, Messenger / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry; D012697:Serine Endopeptidases / Q000096:biosynthesis* / Q000737:chemistry; D013347:Subcellular Fractions / Q000378:metabolism; D013997:Time Factors
chemical_list: D017252:CD3 Complex; D019002:CD56 Antigen; D018076:DNA, Complementary; D011506:Proteins; D012333:RNA, Messenger; D011994:Recombinant Proteins; C509213:GZMB protein, human; C069434:GZMH protein, human; D053804:Granzymes; C509214:Gzmb protein, mouse; D012697:Serine Endopeptidases