scholarly journals Enhancing natural killer cell function with gp41-targeting bispecific antibodies to combat HIV infection

2019 ◽  
Author(s):  
Nitya S. Ramadoss ◽  
Nancy Q. Zhao ◽  
Barbra A. Richardson ◽  
Philip M. Grant ◽  
Peter S. Kim ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
T Cells ◽  
Hiv Infection ◽  
Cd4 T Cells ◽  
Nk Cell ◽  
Killer Cell ◽  
Bispecific Antibodies ◽  
Target Cells ◽  
Infected Cells

AbstractObjective(s)To develop and evaluate the activity of bispecific antibodies (bsAbs) to enhance NK cell antibody-dependent cellular cytotoxicity (ADCC) against HIV-infected cells.DesignThese bsAbs are based on patient-derived antibodies targeting the conserved gp41 stump of HIV Env, and also incorporate a high affinity scFv targeting the activating receptor CD16 on NK cells. Overall, we expect the bsAbs to provide increased affinity and avidity over their corresponding monoclonal antibodies, allowing for improved ADCC activity against Env-expressing target cells.MethodsbsAbs and their corresponding mAbs were expressed in 293T cells and purified. The binding of bsAbs and mAbs to their intended targets was determined using Bio-Layer Interferometry, as well as flow cytometry-based binding assays on in vitro infected cells. The ability of these bsAbs to improve NK cell activity against HIV-infected cells was tested using in vitro co-culture assays, using flow cytometry and calcein release to analyze NK cell degranulation and target cell killing, respectively.ResultsThe bsAbs bound gp41 with similar affinity to their corresponding mAbs, and had increased affinity for CD16. The bsAbs also bound to primary CD4 T cells infected in vitro with two different strains of HIV. In addition, the bsAbs induce increased NK cell degranulation and killing of autologous HIV-infected CD4 T cells.ConclusionsThese bsAbs may provide a promising strategy to improve NK-mediated immune targeting of infected cells during HIV infection.

scholarly journals HLA-E Up-Regulation Induced by HIV Infection May Directly Contribute to CD94-Mediated Impairment of NK Cells

2005 ◽  
Vol 18 (2) ◽  
pp. 269-276 ◽  
Author(s):  
F. Martini ◽  
C. Agrati ◽  
G. D'Offizi ◽  
F. Poccia
Keyword(s):  
T Cells ◽  
Hiv Infection ◽  
Nk Cells ◽  
Cd4 T Cells ◽  
Nk Cell ◽  
Treatment Interruption ◽  
Cell Number ◽  
Hiv Replication

Alterations in NK cell numbers and function have been repeatedly shown during HIV infection. In this study, NK cell number and MHC class I expression on CD4+ T cells were studied in HIV patients at different stages of disease progression. An increased expression of HLA-E was seen on CD4+ T cells. In parallel, a reduced number of CD94+ NK cells was observed in advanced disease stages. Moreover, a decline in CD94 expression on NK cells was observed at the HIV replication peak in patients undergoing antiretroviral treatment interruption, suggesting a role of viral replication on NK cells alterations. In vitro HIV infection induced a rapid down-regulation of HLA-A,B,C expression, paralleled by an increased expression of HLA-E surface molecules, the formal ligands of CD94 NK receptors. HIV-infected HLA-E expressing cells were able to inhibit NK cell cytotoxicity through HLA-E expression, since cytotoxicity was restored by antibody masking experiments. These data indicate that the CD94/HLA-E interaction may contribute to NK cell dysfunction in HIV infection, suggesting a role of HIV replication in this process.

Elevated CD54 Expression Renders CD4+ T Cells Susceptible to Natural Killer Cell-Mediated Killing

2019 ◽  
Vol 220 (12) ◽  
pp. 1892-1903 ◽  
Author(s):  
Xi Chen ◽  
Huihui Chen ◽  
Zining Zhang ◽  
Yajing Fu ◽  
Xiaoxu Han ◽  
...  
Keyword(s):  
Immune Response ◽  
T Cells ◽  
Nk Cells ◽  
Natural Killer ◽  
Cd4 T Cells ◽  
Nk Cell ◽  
Killer Cell ◽  
Adaptive Immune Response ◽  
Phenotypic Analysis

Abstract Background Natural killer (NK) cells are an important type of effector cell in the innate immune response, and also have a role in regulation of the adaptive immune response. Several studies have indicated that NK cells may influence CD4+ T cells during HIV infection. Methods In total, 51 HIV-infected individuals and 15 healthy controls participated in this study. We performed the flow cytometry assays and real-time PCR for the phenotypic analysis and the functional assays of NK cell-mediated deletion of CD4+ T cells, phosphorylation of nuclear factor-κB (NF-κB/p65) and the intervention of metformin. Results Here we detected high CD54 expression on CD4+ T cells in HIV-infected individuals, and demonstrate that upregulated CD54 is associated with disease progression in individuals infected with HIV. We also show that CD54 expression leads to the deletion of CD4+ T cells by NK cells in vitro, and that this is modulated by NF-κB/p65 signaling. Further, we demonstrate that metformin can suppress CD54 expression on CD4+ T cells by inhibiting NF-κB/p65 phosphorylation. Conclusions Our data suggest that further studies to evaluate the potential role of metformin as adjunctive therapy to reconstitute immune function in HIV-infected individuals are warranted.

scholarly journals HIV modulates the expression of ligands important in triggering natural killer cell cytotoxic responses on infected primary T-cell blasts

Blood ◽  
2007 ◽  
Vol 110 (4) ◽  
pp. 1207-1214 ◽  
Author(s):  
Jeffrey Ward ◽  
Matthew Bonaparte ◽  
Jennifer Sacks ◽  
Jacqueline Guterman ◽  
Manuela Fogli ◽  
...  
Keyword(s):  
T Cell ◽  
Hiv Infection ◽  
Nk Cells ◽  
Natural Killer ◽  
Nk Cell ◽  
Killer Cell ◽  
Target Cells ◽  
Nk Cell Receptors ◽  
Infected Cells ◽  
Cytotoxic Responses

AbstractThe ability of natural killer (NK) cells to kill virus-infected cells depends on the presence of ligands for activation receptors on the target cells. We found the presence of few, if any, NKp30 and NK46 ligands on T cell blasts infected with HIV, although NKp44 ligands were found on infected cells. HIV does induce the NKG2D ligands ULBP-1, -2, and -3. These ligands are involved in triggering NK cells to kill autologous HIV-infected cells, because interfering with the interaction between NKG2D, but not NKp46, on NK cells and its ligands on HIV-infected cells drastically reduced the lysis of infected cells. Interfering with the binding of the NK-cell coreceptors NTB-A and 2B4 to their ligands also decreased destruction by NK cells. The coreceptor ligands, NTB-A and CD48, were also found to be down-regulated during the course of HIV infection. Thus, ligands for NK-cell receptors are modulated during the course of HIV infection, which may greatly alter NK cells' ability to kill the infected cells.

scholarly journals Follicular CD8 T cells accumulate in HIV infection and can kill infected cells in vitro via bispecific antibodies

2017 ◽  
Vol 9 (373) ◽  
pp. eaag2285 ◽  
Author(s):  
Constantinos Petrovas ◽  
Sara Ferrando-Martinez ◽  
Michael Y. Gerner ◽  
Joseph P. Casazza ◽  
Amarendra Pegu ◽  
...  
Keyword(s):  
T Cells ◽  
Hiv Infection ◽  
Cd8 T Cells ◽  
Bispecific Antibodies ◽  
Infected Cells

scholarly journals HLA-F on Autologous HIV-Infected Cells Activates Primary NK Cells Expressing the Activating Killer Immunoglobulin-Like Receptor KIR3DS1

2019 ◽  
Vol 93 (18) ◽  
Author(s):  
Zahra Kiani ◽  
Julie Bruneau ◽  
Daniel E. Geraghty ◽  
Nicole F. Bernard
Keyword(s):  
T Cells ◽  
Hiv Infection ◽  
Nk Cells ◽  
Nk Cell ◽  
Target Cells ◽  
Cell Functions ◽  
Infected Cells ◽  
Hiv Exposed ◽  
Anti Hiv ◽  
Reduced Risk

ABSTRACTHIV-exposed seronegativeKIR3DS1homozygotes have a reduced risk of HIV infection. HLA-F is the ligand for the activating NK cell receptor (NKR) KIR3DS1. HLA-F is expressed on HIV-infected CD4 T cells. Coculture of sorted, HIV-infected CD4−(siCD4−) T cells with NK cells activated a higher frequency of KIR3DS1+than KIR3DS1−NK cells fromKIR3DS1homozygotes to elicit anti-HIV functions such as CCL4, gamma interferon (IFN-γ), and CD107a expression. This was the case whether KIR3DS1+/−NK cells were analyzed inclusively or exclusively by gating out NK cells coexpressing the NKRs, KIR2DL1/L2/L3, 3DL2, KIR2DS1/S2/S3/S5, NKG2A, and ILT2. Blocking the interaction of HLA-F on siCD4−cells with KIR3DS1 on exclusively gated KIR3DS1+NK cells with KIR3DS1-Fc chimeric protein or an HLA-F-specific monoclonal antibody reduced the frequency of activated KIR3DS1+cells compared to that under control conditions. KIR3DS1+NK cell activation by HIV-infected CD4+cells may underlie the reduced risk of KIR3DS1 homozygotes to HIV infection.IMPORTANCEThis study investigated a mechanism that may underly epidemiological studies showing that carriage of theKIR3DS1homozygous genotype is more frequent among HIV-exposed seronegative subjects than among HIV-susceptible individuals. Carriage of this genotype is associated with a reduced risk of HIV infection. The protective mechanism involves the interaction of HLA-F on CD4+cells infected with replication-competent HIV with the activating NK receptor, KIR3DS1. This interaction leads to the activation of KIR3DS1+NK cells for secretion of cytokines and chemokines with anti-HIV activity. Among these is CCL4, which binds and blocks CCR5, the coreceptor for HIV entry of HIV into new target cells. In the setting of an exposure to HIV, incoming HIV-infected cells expressing HLA-F rapidly activate KIR3DS1+NK cells to elicit anti-HIV activity. Exclusive gating strategies and blocking experiments support the notion that the HLA-F/KIR3DS1 interaction is sufficient to activate NK cell functions.

scholarly journals Sustained effector function of IL-12/15/18–preactivated NK cells against established tumors

2012 ◽  
Vol 209 (13) ◽  
pp. 2351-2365 ◽  
Author(s):  
Jing Ni ◽  
Matthias Miller ◽  
Ana Stojanovic ◽  
Natalio Garbi ◽  
Adelheid Cerwenka
Keyword(s):  
T Cells ◽  
Antitumor Activity ◽  
Nk Cells ◽  
Cd4 T Cells ◽  
Rational Design ◽  
Nk Cell ◽  
Killer Cell ◽  
Effector Function

Natural killer cell (NK cell)–based immunotherapy of cancer is hampered by the transient effector function of NK cells. Recently, mouse IL-12/15/18–preactivated NK cells were shown to persist with sustained effector function in vivo. Our study investigated the antitumor activity of such NK cells. A single injection of syngeneic IL-12/15/18–preactivated NK cells, but neither naive nor IL-15– or IL-2–pretreated NK cells, combined with irradiation substantially reduced growth of established mouse tumors. Radiation therapy (RT) was essential for the antitumor activity of transferred NK cells. IL-12/15/18–preactivated NK cells expressed high levels of IL-2Rα (CD25), and their rapid in vivo proliferation depended on IL-2 produced by CD4+ T cells. IL-12/15/18–preactivated NK cells accumulated in the tumor tissue and persisted at high cell numbers with potent effector function that required the presence of CD4+ T cells. RT greatly increased numbers and function of transferred NK cells. Human IL-12/15/18–preactivated NK cells also displayed sustained effector function in vitro. Our study provides a better understanding for the rational design of immunotherapies of cancer that incorporate NK cells. Moreover, our results reveal an essential role of CD4+ T cell help for sustained antitumor activity by NK cells linking adaptive and innate immunity.

scholarly journals Recognition of virus-infected cells by natural killer cell clones is controlled by polymorphic target cell elements.

1993 ◽  
Vol 178 (3) ◽  
pp. 961-969 ◽  
Author(s):  
M S Malnati ◽  
P Lusso ◽  
E Ciccone ◽  
A Moretta ◽  
L Moretta ◽  
...  
Keyword(s):  
T Cells ◽  
Nk Cells ◽  
Natural Killer ◽  
Target Cell ◽  
Nk Cell ◽  
Class I ◽  
Target Cells ◽  
Cell Recognition ◽  
Infected Cells ◽  
Nk Cell Recognition

Natural killer (NK) cells provide a first line of defense against viral infections. The mechanisms by which NK cells recognize and eliminate infected cells are still largely unknown. To test whether target cell elements contribute to NK cell recognition of virus-infected cells, human NK cells were cloned from two unrelated donors and assayed for their ability to kill normal autologous or allogeneic cells before and after infection by human herpesvirus 6 (HHV-6), a T-lymphotropic herpesvirus. Of 132 NK clones isolated from donor 1, all displayed strong cytolytic activity against the NK-sensitive cell line K562, none killed uninfected autologous T cells, and 65 (49%) killed autologous T cells infected with HHV-6. A panel of representative NK clones from donors 1 and 2 was tested on targets obtained from four donors. A wide heterogeneity was observed in the specificity of lysis of infected target cells among the NK clones. Some clones killed none, some killed only one, and others killed more than one of the different HHV-6-infected target cells. Killing of infected targets was not due to complete absence of class I molecules because class I surface levels were only partially affected by HHV-6 infection. Thus, target cell recognition is not controlled by the effector NK cell alone, but also by polymorphic elements on the target cell that restrict NK cell recognition. Furthermore, NK clones from different donors display a variable range of specificities in their recognition of infected target cells.

scholarly journals Betamethasone induces potent immunosuppression and reduces HIV infection in a PBMC in vitro model

2020 ◽  
Vol 69 (1) ◽  
pp. 28-40 ◽  
Author(s):  
Ross Cromarty ◽  
Alexander Sigal ◽  
Lenine Julie Liebenberg ◽  
Lyle Robert Mckinnon ◽  
Salim Safurdeen Abdool Karim ◽  
...  
Keyword(s):  
T Cells ◽  
Hiv Infection ◽  
Immune Activation ◽  
Cd4 T Cells ◽  
Drug Targets ◽  
Complex Nature ◽  
Peripheral Blood Mononuclear ◽  
Established Risk Factor ◽  
Anti Inflammatory

Genital inflammation is an established risk factor for increased HIV acquisition risk. Certain HIV-exposed seronegative populations, who are naturally resistant to HIV infection, have an immune quiescent phenotype defined by reduced immune activation and inflammatory cytokines at the genital tract. Therefore, the aim of this study was to create an immune quiescent environment using immunomodulatory drugs to mitigate HIV infection. Using an in vitro peripheral blood mononuclear cell (PBMC) model, we found that inflammation was induced using phytohemagglutinin and Toll-like receptor (TLR) agonists Pam3CSK4 (TLR1/2), lipopolysaccharide (LPS) (TLR4) and R848 (TLR7/8). After treatment with anti-inflammatory drugs, ibuprofen (IBF) and betamethasone (BMS), PBMCs were exposed to HIV NL4-3 AD8. Multiplexed ELISA was used to measure 28 cytokines to assess inflammation. Flow cytometry was used to measure immune activation (CD38, HLA-DR and CCR5) and HIV infection (p24 production) of CD4+ T cells. BMS potently suppressed inflammation (soluble cytokines, p<0.05) and immune activation (CD4+ T cells, p<0.05). BMS significantly reduced HIV infection of CD4+ T cells only in the LPS (0.98%) and unstimulated (1.7%) conditions (p<0.02). In contrast, IBF had minimal anti-inflammatory and immunosuppressive but no anti-HIV effects. BMS demonstrated potent anti-inflammatory effects, regardless of stimulation condition. Despite uniform immunosuppression, BMS differentially affected HIV infection according to the stimulation conditions, highlighting the complex nature of these interactions. Together, these data underscore the importance of interrogating inflammatory signaling pathways to identify novel drug targets to mitigate HIV infection.

Paradoxic inhibition of human natural interferon-producing cells by the activating receptor NKp44

Blood ◽  
2005 ◽  
Vol 106 (6) ◽  
pp. 2076-2082 ◽  
Author(s):  
Anja Fuchs ◽  
Marina Cella ◽  
Takayuki Kondo ◽  
Marco Colonna
Keyword(s):  
T Cells ◽  
Cd8 T Cells ◽  
Nk Cell ◽  
Close Contact ◽  
Killer Cell ◽  
Adaptor Protein ◽  
Interferon Α ◽  
Memory Cd8 T Cells ◽  
Activating Receptor

Abstract Natural killer (NK) cell-mediated cytotoxicity is triggered by multiple activating receptors associated with the signaling adaptor protein DNAX activation protein 12/killer cell-activating receptor-associated protein (DAP12/KARAP). Here, we show that one of these receptors, NKp44, is present on a subset of natural interferon-producing cells (IPCs) in tonsils. NKp44 expression can also be induced on blood IPCs after in vitro culture with interleukin 3 (IL-3). Crosslinking of NKp44 does not trigger IPC-mediated cytotoxicity but, paradoxically, inhibits interferon α (IFN-α) production by IPCs in response to cytosine-phosphate-guanosine (CpG) oligonucleotides. We find that IPCs in tonsils are in close contact with CD8+ T cells and demonstrate that a subset of memory CD8+ T cells produces IL-3. Therefore, IL-3-mediated induction of NKp44 on IPCs may be an important component of the ongoing crosstalk between the innate and adaptive immune response that allows memory CD8+ T cells to control the IPC response to virus. (Blood. 2005;106: 2076-2082)

scholarly journals Preferential infection and depletion of Mycobacterium tuberculosis–specific CD4 T cells after HIV-1 infection

2010 ◽  
Vol 207 (13) ◽  
pp. 2869-2881 ◽  
Author(s):  
Christof Geldmacher ◽  
Njabulo Ngwenyama ◽  
Alexandra Schuetz ◽  
Constantinos Petrovas ◽  
Klaus Reither ◽  
...  
Keyword(s):  
T Cells ◽  
Mycobacterium Tuberculosis ◽  
Hiv Infection ◽  
Cd4 T Cells ◽  
Staphylococcal Enterotoxin B ◽  
Opportunistic Pathogens ◽  
Rapid Loss ◽  
Hiv 1

HIV-1 infection results in the progressive loss of CD4 T cells. In this study, we address how different pathogen-specific CD4 T cells are affected by HIV infection and the cellular parameters involved. We found striking differences in the depletion rates between CD4 T cells to two common opportunistic pathogens, cytomegalovirus (CMV) and Mycobacterium tuberculosis (MTB). CMV-specific CD4 T cells persisted after HIV infection, whereas MTB-specific CD4 T cells were depleted rapidly. CMV-specific CD4 T cells expressed a mature phenotype and produced very little IL-2, but large amounts of MIP-1β. In contrast, MTB-specific CD4 T cells were less mature, and most produced IL-2 but not MIP-1β. Staphylococcal enterotoxin B–stimulated IL-2–producing cells were more susceptible to HIV infection in vitro than MIP-1β–producing cells. Moreover, IL-2 production was associated with expression of CD25, and neutralization of IL-2 completely abrogated productive HIV infection in vitro. HIV DNA was found to be most abundant in IL-2–producing cells, and least abundant in MIP-1β–producing MTB-specific CD4 T cells from HIV-infected subjects with active tuberculosis. These data support the hypothesis that differences in function affect the susceptibility of pathogen-specific CD4 T cells to HIV infection and depletion in vivo, providing a potential mechanism to explain the rapid loss of MTB-specific CD4 T cells after HIV infection.

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