Decrease In Granzyme Research Articles

Differential Regulation of Granzyme and Perforin in Effector and Memory T Cells following Smallpox Immunization

Primary immunization of healthy adults with vaccinia virus induces a local vesicle or "take" in the majority of vaccinees that previously has been shown to correlate with protection against smallpox. However, the immunologic mechanisms underlying this protective response in humans are not well characterized. We have studied human CD8+ T cells for the expression patterns of phenotypic markers and cytolytic effector molecules before and after primary smallpox immunization using nine-color polychromatic flow cytometry. One month after immunization, vaccinees developed vaccinia virus-specific CD8+ T cells with an effector cell phenotype containing both granzyme A and granzyme B. One year after immunization, we found a significant decrease in granzyme B containing cells and an increased memory cell phenotype in virus-specific CD8+ T cells. Perforin was rarely expressed directly ex vivo, but was highly expressed after Ag-specific activation in vitro. Together, these data suggest an important role for effector CD8+ T cells in controlling poxvirus infection, and have implications for our understanding of human CD8+ T cell differentiation.

Doseamento das granzimas A e B na sarcoidose pulmonar (estudo experimental)

Sarcoidosis is a systemic disease of unknown aetiology, morphologically characterized by well-formed epithelioid granulomas, which show little or no cen-tral necrosis. These may be present in any organ or tissue. The lung is the most frequently and promi-nently involved target.The granuloma is often very sharply demarcated from the adjacent tissue and is surrounded by a mantle of lymphocytes, which mediate lysis of target cells by various mechanisms, including exocytosis of lytic proteins, perforins and granzymes.Sarcoidosis laboratorial diagnosis is usually made by SACE and Lisozyme dosages. The granzymes A and B could be two other markers of the disease, since the sarcoidosis granuloma is rich in cytotoxic and NK cells.An ELISA Kit was used to measure Granzyme A and B in serum of a normal control group (NC) (n=30), and in two groups with lung pathology: one without sarcoidosis, disease control (DC) (n=21) and other with sarcoidosis (S) (n=11).Our results showed that SACE activity is significantly augmented in S group comparing with NC and DC, respectively: 82,6±32,7/31,9±17,8 - p=0,00017 and 82,6±32,7/31,9±17,8 - p=0,00024. Lisozyme activity is significantly augmented in S and DC groups comparing with NC. Granzyme B showed a significant decrease in DC and S groups comparing with NC. Granzyme A showed a significant decrease between S/NC groups.Our results suggest that the decrease of Granzyme A and B in sarcoidotic patients could be related to an ineffective inflammatory local response related to the formation of sarcoidosis granulomas. More studies are needed, particularly in BAL.Rev Port Pneumol 2005; XI (2): 111-133

Stably Transfected Antisense Granzyme B and Perforin Constructs Inhibit Human Granule-Mediated Lytic Ability

In human NK cells and CTL it has been shown that release of lytic molecules is, at least in part, responsible for the lysis of target cells (TC). Of the various types of molecules thought to be involved in cell-mediated cytotoxicity (CMC), perforin and the serine proteases (granzymes A and B) are the best described. Using mammalian expression vectors (pRSV-neo and pSV 2-neo), antisense constructs for perforin and granzyme B were independently electroporated into YT-INDY, a human non-MHC-restricted, IL-2-independent, cytotoxic lymphocyte. Transfected YT-INDY was then selected for expression of the plasmid by antibiotic G418 resistance. The presence of plasmid was confirmed by detection of the integrated plasmid G418 resistance gene using PCR. The presence of antisense perforin in YT-INDY (YT-xPFP) inhibited lytic ability by >95% compared to YT-INDY transfected with plasmid alone or plasmid with unrelated antisense (YT-neo, YT-ctrl, respectively). Likewise, the presence of antisense GrB (YT-xGrB) inhibited the lytic ability of YT-INDY by >95%. Western analysis revealed a 30% decrease in the level of perlatin and a 55% decrease in granzyme B protein levels compared to YT-neo. Northern analysis using oligo probes complementary to perforin and granzyme B mRNA showed a decrease in their respective message levels. In conclusion, stably transfected antisense constructs for perforin and granzyme B essentially eliminated the lytic ability of YT-INDY. These results strongly indicate that both perforin and granzyme B are required by this human cytotoxic lymphocyte for effective TC lysis.