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Pereskia bleo augments NK cell cytotoxicity against triple-negative breast cancer cells (MDA-MB-231)

Khalaf TK, Ismail N, Nazri NA, Ahmed N, Yajid AI, Mohamud R, et al.

PeerJ, 2024;12:e18420.
PMID: 39619199 DOI: 10.7717/peerj.18420

BACKGROUND: Natural killer cells (NK cells) are essential in cancer immunosurveillance in the body as they can recognize cancer cells that lacking MHC class 1 on their surface. Regulatory cytokines, including interleukin (IL)-18, IL-12, IL-10, IL-8, interferon-γ (IFN-γ), and secretory granules like perforin and granzyme are involved in NK cell-mediated cytotoxicity. Stimulating NK cells cytotoxicity towards cancer cells is an ideal strategy to combat cancer naturally. Medicinal plants have been reported to enhance immunity, with Pereskia bleo (P. bleo) particularly noteworthy due to its abundant bioactive compounds and ability to activate immune cells. This study aimed to evaluate the potential of methanol extract of P. bleo leaves (MEPB) for enhancing NK cell cytotoxicity against triple-negative human breast cancer cells (MDA-MB-231).
METHODS: The optimal concentration of MEPB to activate NK cells was determined using healthy blood samples, assessing the expression of IL-12, IL-18, IL-10, IL-8, IFN-γ, perforin, and granzyme B via an enzyme-linked immunosorbent assay (ELISA). NK cell purity from healthy donors and breast cancer patients was determined using specific antibodies, and the number of NK cells was assessed using flow cytometry and a hemocytometer. A co-culture experiment, ELISA, and apoptosis assay were used to evaluate NK-mediated cytotoxicity pathways.
RESULTS: ELISA data indicated that MEPB at 7.5 µg/ml significantly increased the expression of IFN-γ, IL-12, IL-18, perforin, and granzyme B while decreasing IL-8 and IL-10 expression after 20 hrs of incubation. The average NK cell purity was 87.09 ± 0.043%. Breast cancer patients exhibited lower NK cell counts than healthy donors. Co-culture experiments demonstrated that NK cells induced apoptosis in MDA-MB-231 breast cancer cells in the presence of MEPB by increasing perforin, granzyme B, and IFN-γ expression in both healthy donors and breast cancer patients-experimental groups. P. bleo enhances NK cell activation, promoting the apoptosis of triple-negative human breast cancer cells (MDA-MB-231), suggesting the potential use of MEPB leaves as an anti-cancer immunostimulant.

Matched MeSH terms: Perforin/metabolism
Regulation of CD8+ T-cell cytotoxicity in HIV-1 infection

Saeidi A, Buggert M, Che KF, Kong YY, Velu V, Larsson M, et al.

Cell Immunol, 2015 Nov-Dec;298(1-2):126-33.
PMID: 26520669 DOI: 10.1016/j.cellimm.2015.10.009

Understanding the mechanisms involved in cellular immune responses against control of human immunodeficiency virus (HIV) infection is key to development of effective immunotherapeutic strategies against viral proliferation. Clear insights into the regulation of cytotoxic CD8+ T cells is crucial to development of effective immunotherapeutic strategies due to their unique ability to eliminate virus-infected cells during the course of infection. Here, we reviewed the roles of transcription factors, co-inhibitory molecules and regulatory cytokines following HIV infection and their potential significance in regulating the cytotoxic potentials of CD8+ T cells.

Matched MeSH terms: Perforin/metabolism
Fulltext Rhaphidophora korthalsii modulates peripheral blood natural killer cell proliferation, cytokine secretion and cytotoxicity

Yeap SK, Omar AR, Ho WY, Beh BK, Ali AM, Alitheen NB

BMC Complement Altern Med, 2013;13:145.
PMID: 23800124 DOI: 10.1186/1472-6882-13-145

Rhaphidophora korthalsii (Araceae) is a root-climber plant which has been widely used in Chinese traditional medicine for cancer and skin disease treatment. Previous reports have recorded its immunomodulatory effects on mice splenocyte and human peripheral blood. This study investigated the potential immunostimulatory effect of Rhaphidophora korthalsii on human PBMC enriched NK cell.

Matched MeSH terms: Perforin/genetics; Perforin/immunology
Fulltext Evaluation of Hydra HALT-1 as a toxin moiety for recombinant immunotoxin

Jiemy WF, Hiew LF, Sha HX, In LLA, Hwang JS

BMC Biotechnol, 2020 Jun 17;20(1):31.
PMID: 32552895 DOI: 10.1186/s12896-020-00628-9

BACKGROUND: Immunotoxin is a hybrid protein consisting of a toxin moiety that is linked to a targeting moiety for the purpose of specific elimination of target cells. Toxins used in traditional immunotoxins are practically difficult to be produced in large amount, have poor tissue penetration and a complex internalization process. We hypothesized that the smaller HALT-1, a cytolysin derived from Hydra magnipapillata, can be used as the toxin moiety in construction of a recombinant immunotoxin.
RESULTS: In this study, pro-inflammatory macrophage was selected as the target cell due to its major roles in numerous inflammatory and autoimmune disorders. We aimed to construct macrophage-targeted recombinant immunotoxins by combining HALT-1 with anti-CD64-scFv in two orientations, and to assess whether their cytotoxic activity and binding capability could be preserved upon molecular fusion. The recombinant immunotoxins, HALT-1-scFv and scFv-HALT-1, were successfully constructed and expressed in Escherichia coli (E. coli). Our data showed that HALT-1 still exhibited significant cytotoxicity against CD64+ and CD64- cell lines upon fusion with anti-CD64 scFv, although it had half cytotoxic activity as compared to HALT-1 alone. As positioning HALT-1 at N- or C-terminus did not affect its potency, the two constructs demonstrated comparable cytotoxic activities with IC50 lower in CD64+ cell line than in CD64- cell line. In contrast, the location of targeting moieties anti-CD64 scFv at C-terminal end was crucial in maintaining the scFv binding capability.
CONCLUSIONS: HALT-1 could be fused with anti-CD64-scFv via a fsexible polypeptide linker. Upon the successful production of this recombinant HALT-1 scFv fusion protein, HALT-1 was proven effective for killing two human cell lines. Hence, this preliminary study strongly suggested that HALT-1 holds potential as the toxin moiety in therapeutic cell targeting.

Matched MeSH terms: Perforin
Fulltext Immunomodulatory effects of Newcastle disease virus AF2240 strain on human peripheral blood mononuclear cells

Lam HY, Yusoff K, Yeap SK, Subramani T, Abd-Aziz S, Omar AR, et al.

Int J Med Sci, 2014;11(12):1240-7.
PMID: 25317070 DOI: 10.7150/ijms.8170

Immunotherapy has raised the attention of many scientists because it hold promise to be an attractive therapeutic strategy to treat a number of disorders. In this study, the immunomodulatory effects of low titers of Newcastle disease virus (NDV) AF2240 on human peripheral blood mononuclear cells (PBMC) were analyzed. We evaluated cytokine secretion and PBMC activation by cell proliferation assay, immunophenotyping and enzyme linked immunosorbent assay. The proliferation of the human PBMC was measured to be 28.5% and 36.5% upon treatment with 8 hemaglutinin unit (HAU) and 2 HAU of NDV respectively. Interestingly, the percentage of cells with activating markers CD16 and CD56 were increased significantly. Furthermore, the intracellular perforin and granzyme levels were also increased upon virus infection. Human PBMC treated with NDV titer 8 HAU was found to stimulate the highest level of cytokine production including interferon-γ, interleukin-2 and interleukin-12. The release of these proteins contributes to the antitumor effect of PBMC against MCF-7 breast cancer cells. Based on the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide assay, activated human PBMC showed high cytolytic efficiency towards human breast tumor cells. In summary, NDV was able to stimulate PBMC proliferation, cytokine secretion and cytolytic activity.

Matched MeSH terms: Perforin/metabolism
Concurrent loss of co-stimulatory molecules and functional cytokine secretion attributes leads to proliferative senescence of CD8(+) T cells in HIV/TB co-infection

Saeidi A, Chong YK, Yong YK, Tan HY, Barathan M, Rajarajeswaran J, et al.

Cell Immunol, 2015 Sep;297(1):19-32.
PMID: 26071876 DOI: 10.1016/j.cellimm.2015.05.005

The role of T-cell immunosenescence and functional CD8(+) T-cell responses in HIV/TB co-infection is unclear. We examined and correlated surrogate markers of HIV disease progression with immune activation, immunosenescence and differentiation using T-cell pools of HIV/TB co-infected, HIV-infected and healthy controls. Our investigations showed increased plasma viremia and reduced CD4/CD8 T-cell ratio in HIV/TB co-infected subjects relative to HIV-infected, and also a closer association with changes in the expression of CD38, a cyclic ADP ribose hydrolase and CD57, which were consistently expressed on late-senescent CD8(+) T cells. Up-regulation of CD57 and CD38 were directly proportional to lack of co-stimulatory markers on CD8(+) T cells, besides diminished expression of CD127 (IL-7Rα) on CD57(+)CD4(+) T cells. Notably, intracellular IFN-γ, perforin and granzyme B levels in HIV-specific CD8(+) T cells of HIV/TB co-infected subjects were diminished. Intracellular CD57 levels in HIV gag p24-specific CD8(+) T cells were significantly increased in HIV/TB co-infection. We suggest that HIV-TB co-infection contributes to senescence associated with chronic immune activation, which could be due to functional insufficiency of CD8(+) T cells.

Matched MeSH terms: Perforin/metabolism