"Anomalous" THY-1(+) killer cells in allogeneic and F1-anti-parental mixed leukocyte culture. Relation to natural killer cells and allospecific cytotoxic T lymphocytes

Anomalous killer cells are Thy-1(+) blasts that are cytolytic to the natural killer (NK)-sensitive lymphoma YAC-1, and that can be detected early (day 3-4) in the period preceeding the allospecific cytotoxic T lymphocyte (CTL) response in (CBA x A)F1 {arrow} C57B1 mixed leukocyte culture (MLC). We have investigated the origin and nature of anomalous killing (AK), with special emphasis on its relation to NK-and allospecific CTL-activity. AK was shown to be distinct from the previously described "NK(c)-cells" induced by cultivation in fetal calf serum (FCS)-supplemented medium when these two reactivities were examined in parallel. AK was detected in either FCS- or normal mouse serum (NMS)-supplemented allogeneic MLC, indicating that the response was not dependent on mitogenic or antigenic properties of heterologous serum. In addition to several H-2-incompatible combinations, AK was also observed in an Mls-incompatible (but H-2 compatible) and two F(1)- antiparental MLC responder/stimulator combinations. AK cells showed a similar selectivity pattern to NK cells, as demonstrated in cold target inhibition and direct cytotoxicity assays using variant or interferon-modulated YAC-1 cells with low expression of NK target structures. The AK-cells were NK- 1.2(-/weak). Thy-l.2(+), although they seem to be derived from non-adherent radiosensitive cells which are closely related, if not identical, to NK-cells (NK-1.2(+). Thy-l.2(-/weak)), as they could not be readily induced in responder populations with low NK-activity but normal allospecific CTL potential. Conversely, an in vivo thymectomy protocol or treatment of normal spleen cells with monoclonal anti-Thy-1.2 + C reduced the allospecific CTL response drastically but did not affect the AK response. Anomalous killers were not observed when MLC were prepared with responder as well as stimulator cells devoid of mature T cells. In such a combination, the AK response could be partially restored by the addition of irradiated +/nu (but not nu/nu) responder cells to the cultures. When normal (non-nude) spleen cells were used as responders, induction of AK did not require the presence of T cells in the stimulator population, whereas the removal of adherent and phagocytic cells from stimulators abrogated the response. Taken together, the results suggest that AK represents activation, blast transformation, and surface marker modulation of NK cells induced by alloantigen-stimulated T cells, resulting in Thy-1(+) cytolytic cells with similar properties to those described for NK lines, Although AK cells may be regarded as a more T cell-like NK phenotype, their induction is neither necessary, nor sufficient for generation of specific CTL in MLC.

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In Vivo Survival and Homeostatic Proliferation of Natural Killer Cells

Journal of Experimental Medicine ◽

10.1084/jem.20021847 ◽

2003 ◽

Vol 197 (8) ◽

pp. 967-976 ◽

Cited By ~ 167

Author(s):

Martin Prlic ◽

Bruce R. Blazar ◽

Michael A. Farrar ◽

Stephen C. Jameson

Keyword(s):

T Cells ◽

Natural Killer Cells ◽

Nk Cells ◽

Natural Killer ◽

Cell Sorting ◽

Functional Activity ◽

Homeostatic Proliferation ◽

Killer Cells ◽

Bystander Cells

While the specificity and development of natural killer (NK) cells have been intensely studied, little is known about homeostasis of the mature NK population. Here we show that mouse NK cells undergo homeostatic proliferation when transferred into NK-deficient Rag−/− γC−/− hosts. Normal NK functional activity is maintained during this process, although there are some changes in NK phenotype. Using cell sorting, we demonstrate that mature (Mac-1hi) NK cells undergo homeostatic proliferation in an NK-deficient environment, yet immature (Mac-1lo) NK cells also proliferate in such hosts. We find that mature NK cells survive but do not proliferate in hosts which possess an endogenous NK pool. However, we go on to show that mature NK survival is critically dependent on interleukin (IL)-15. Surprisingly, NK survival is also compromised after transfer of cells into IL-15Rα−/− mice, implying that IL-15 responsiveness by bystander cells is critical for NK maintenance. These data imply that, similar to T cells, homeostasis of the NK pool is much more dynamic than previously appreciated and this may be relevant to manipulation of NK cells for therapeutic purposes.

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Effects of Anti-CCR4 Antibody (KW-0761) on Regulatory T Cells and Natural Killer Cells in Patients with Cutaneous T-Cell Lymphoma

Blood ◽

10.1182/blood.v118.21.444.444 ◽

2011 ◽

Vol 118 (21) ◽

pp. 444-444 ◽

Cited By ~ 1

Author(s):

Xiao Ni ◽

Jeffrey L. Jorgensen ◽

Meghali Goswami ◽

Pramoda Challagundla ◽

William K Decker ◽

...

Keyword(s):

T Cells ◽

Natural Killer Cells ◽

Regulatory T Cells ◽

Nk Cells ◽

Natural Killer ◽

Board Of Directors ◽

Research Funding ◽

Advisory Committees ◽

Killer Cells ◽

Malignant T Cells

Abstract Abstract 444 The CC chemokine receptor 4 (CCR4) is expressed on malignant T-cells in cutaneous T-cell lymphoma (CTCL) and also on the surface of regulatory T cells (T-regs). T-regs also express the transcription factor, foxp3 and suppress effector immune cells, including natural killer (NK) cells. Thus, increased T-regs in the tumor microenvironment is associated with impaired anti-tumor immunity. KW-0761, a defucosylated, humanized monoclonal antibody, binds to CCR4 and induces effective antibody-dependent cellular cytotoxicity (ADCC) against CCR4+ malignant T-cells. The phase I/II clinical trial to determine the safety and efficacy of anti-CCR4 antibody (KW-0761) included a translational component to evaluate its effects on T-regs and NK cells in CTCL patients. Peripheral blood mononuclear cells (PBMCs) were collected from 20 patients [10 with mycosis fungoides (MF) and 10 with Sézary syndrome(SS)] pre- and post-treatment at two centers for flow cytometry analysis of CD3+CD4+CD25+CD127- T-regs, CCR4+ T-regs, and CD3-CD56+CD16+ NK cell subsets. Total RNA was extracted from PBMCs, and foxp3 and CCR4 mRNA were quantified using real-time PCR. The standard 4-hour 51Cr release assay was used to assess the cytotoxicity of NK cells. Fifteen of 20 patients (75.0%) had detectable CD3+CD4+CD25+CD127- T-regs (1.26±1.09 % or 33.79±46.88 /μl) at baseline with 60 –100 % of T-regs positive for CCR4. After 4–6 weeks of treatment with anti-CCR4 antibody (KW-0761), all 15 patients had a decrease in T-reg numbers (0.39±0.49 % or 5.65±8.95 /μl, *p<0.05, Figure 1). CCR4+ T-regs were significantly reduced from an average of 67.2% to 24.6% (p<0.01). In parallel, foxp3 and CCR4 mRNA levels were also significantly decreased from baseline levels (foxp3: from 0.57±0.91 to 0.07±0.08, **p<0.01, Figure 1; CCR4: from 23.40±33.50 to 1.73±2.35, p<0.05). The CD3-CD56+CD16+ NK cells were found at baseline in all 15 patients tested. Of 14 paired samples, 10 (71.4%) had increased NK cells after 4–16 weeks of treatment (pre-treatment: 16.02±15.86 % vs. post-treatment: 22.64±13.93 %, p=0.05, Figure 2) with reduced numbers of T-regs. Five of 6 patients studied also showed a dose dependent increase in NK cell cytotoxicity to target cells by 51Cr release assay (Figure 2). Ten patients with SS had a lower NK cells (13.37±18.48 %) and higher foxp3 (0.81±1.19) and CCR4 mRNA (34.60±39.90) at baseline compared to ten patients with MF (19.04±12.98%, 0.31±0.31; 10.94±20.07) respectively. Seven paired samples from SS patients all had increased NK cells post-treatment with a reduction of T-regs and foxp3 and CCR4 mRNA. Six of 7 SS patients had blood improvement with 3 complete and 3 partial blood responses.Figure 1.Effect of KW-0761 on regulatory T cells in CTCL patients.Figure 1. Effect of KW-0761 on regulatory T cells in CTCL patients.Figure 2.Effect of KW-0761 on natural killer cells in CTCL patients.Figure 2. Effect of KW-0761 on natural killer cells in CTCL patients. Our results suggest that in addition to ADCC towards malignant T-cells, the anti-neoplastic activity of the anti-CCR4 antibody (KW-0761) may include a reduction in T-regs in most CTCL patients and a subsequent increase in NK numbers and function in some patients. Follow up studies need to be performed to confirm these findings. Disclosures: Ni: KYOWA HAKKO KIRIN CO., LTD: Research Funding. Kim:kyowa: Consultancy, Research Funding; Merck: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Allos: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Seattle Genetics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Millenium: Consultancy. Duvic:KYOWA HAKKO KIRIN CO., LTD: Research Funding.

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Natural killer cells associated with SARS-CoV-2 viral RNA shedding, antibody response and mortality in COVID-19 patients

Experimental Hematology and Oncology ◽

10.1186/s40164-021-00199-1 ◽

2021 ◽

Vol 10 (1) ◽

Author(s):

Changqian Bao ◽

Xiandong Tao ◽

Wei Cui ◽

Yuanyuan Hao ◽

Shuaike Zheng ◽

...

Keyword(s):

T Cells ◽

Survival Rate ◽

Natural Killer Cells ◽

Nk Cells ◽

Natural Killer ◽

Viral Rna ◽

Igg Antibody ◽

Killer Cells ◽

Viral Shedding ◽

Severe Group

AbstractCoronavirus disease 2019 (COVID-19) is a novel infectious viral disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Two consecutively negative SARS-CoV-2 viral RNA test ( interval ≥ 24 hours), improved respiratory symptoms and obvious absorption of inflammation in pulmonary imaging are the discharge criteria for COVID-19 patients. The clearance profile of viral RNA in the upper respiratory tract specimens, including nasopharyngeal swab and/or oropharyngeal swabs, is related to innate immune cells such as Natural Killer cells. A total of 168 patients were included for the study. In this cohort, non-severe and severe groups showed significant differences in white blood cells, neutrophils, lymphocytes, basophils and platelets counts, as well as in infection related parameters such as CRP and serum cytokine IL-6. For lymphocyte subsets tests at admission, the severe group displayed significantly lower cell counts than the non-severe group. Higher counts of total T cells, CD4 + T cells, CD8 + T cells, and NK cells in peripheral blood showed a significant correlation with the shorter time taken to obtain the first negative viral RNA test and first positive IgM/ IgG antibody test. The number of B cells was only correlated with time to achieve the first positive IgM/IgG test. The count of NK cells was also correlated with a higher level of IgG antibody (p = 0.025). The lymphocytopenia group had a significantly worse survival rate (p = 0.022) and a longer duration (p = 0.023) of viral shedding than the normal lymphocyte count group. A lower NK cell count correlates the most with the worse survival rate (p<0.001) and a longer duration (p<0.001) of viral shedding. This study suggests the potential value of allo-Natural Killer cell therapy as an universal COVID-19 treatment strategy.

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