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ABSTRACT: Natural killer (NK) cells derived from the human female reproductive tract (FRT) are phenotypically and functionally distinct from those obtained from peripheral blood. Because the FRT is a primary site of human immunodeficiency virus type 1 (HIV-1) infection in women, we determined whether soluble factors secreted by uterine-derived NK (uNK) cells inhibit HIV-1 infection. Clonal populations of uNK cells were activated with interleukin-12 (IL-12) and IL-15, and conditioned media (CM) from these cultures evaluated for their ability to inhibit infection of cells by HIV-1(IIIB), HIV-1(NL4.3), and HIV-1(HC4) (X4-tropic) or HIV-1(BaL) (R5-tropic) viruses. We found that soluble factors secreted by activated uNK cells significantly inhibited X4-tropic virus infection of TZM-bl cells, peripheral blood mononuclear cells, and primary human endometrial cells, but not infection by HIV-1(BaL). In contrast, CM from peripheral blood NK (bNK) cells did not inhibit HIV-1 infection of cells. Analysis of factors secreted from uNK clones with anti-HIV-1 activity demonstrated significantly higher levels of CXCL12 compared to uNK clones without this activity, and the HIV inhibitory activity was neutralized by antibodies to CXCL12. Collectively, these data demonstrate that human uNK cells release chemokines with anti-HIV-1 activity for X4-tropic strains and this suggest that these chemokines may contribute to the inhibition of X4-tropic strain transmission across mucosal tissues.
Journal of Virology 09/2009; 83(21):11188-95. · 5.40 Impact Factor
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ABSTRACT: Although replete with cytotoxic machinery, uterine NK (uNK) cells remain tolerant at the maternal-fetal interface. The mechanisms that facilitate the uNK cell tolerance are largely unknown. In this study, we demonstrate that vascular endothelial growth factor (VEGF) C, a proangiogenic factor produced by uNK cells, is responsible for their noncytotoxic activity. VEGF C-producing uNK cells support endovascular processes as demonstrated in a three-dimensional coculture model of capillary tube formation on Matrigel. Peripheral blood NK cells fail to produce VEGF C and remain cytotoxic. This response can be reversed by exogenous VEGF C. We show that cytoprotection by VEGF C can be related to induction of the TAP-1 expression and MHC class I assembly in target cells. Small interfering RNA-mediated silencing of TAP-1 expression abolished the VEGF C-imparted protection. Overall, these results demonstrate that empowerment of uNK cells with angiogenic factors keeps them noncytotoxic. This phenotype is critical to their pregnancy-compatible immunovascular role during placentation and fetal development.
The Journal of Immunology 05/2009; 182(7):4085-92. · 5.79 Impact Factor
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ABSTRACT: The initiation of an immune response often involves the cooperation of various innate immune cells. In the human endometrium, uterine natural killer (uNK) cells and uterine macrophages are present in significant numbers and in close proximity, yet how they cooperatively respond to infectious challenge is poorly understood.
Primary autologous uNK cells and macrophages were co-cultured to determine functional interactions after stimulation with pathogen-associated molecular patterns.
After stimulation by polyI:C, human uNK cells interact with autologous uterine macrophages and produce interferon-gamma in an NKG2D-dependent manner. Stimulated primary uterine macrophages up-regulated the expression of MHC Class I chain-related protein A (MICA), but expression of the cognate receptor NKG2D remained unchanged on uNK cells, even in the presence of cytokines.
This study demonstrates that the NKG2D-MICA interaction is an important molecular mechanism that is involved in the innate immune response to microbial signals in the human uterine endometrium.
American Journal Of Reproductive Immunology 02/2009; 61(1):52-61. · 2.17 Impact Factor
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ABSTRACT: In this study, we have analyzed the presence and subsets of NK cells throughout the tissues of the FRT. We demonstrate that there are NK cells in the various FRT tissues and that their phenotype and regulation are largely dependent upon the FRT tissue where they reside. NK cells in the Fallopian tube, endometrium, cervix, and ectocervix expressed CD9 while blood NK cells did not. We have also found that unique subsets of NK cells are in specific locations of the FRT. The NK cells in the lower reproductive tract did not express CD94, but they did express CD16. In contrast, NK cells in the upper FRT express high amounts of CD94 and CD69, but few NK cells expressed CD16. All of these FRT NK cells were able to produce IFN-gamma upon stimulation with cytokines. Furthermore, the number of NK cells varied with the menstrual cycle in the endometrium but not in the cervix or ectocervix. These data suggest that unique characteristics of the tissues may account of specific localization of different NK cell subsets.
Clinical Immunology 08/2007; 124(1):69-76. · 4.05 Impact Factor
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ABSTRACT: The human endometrium (EM) contains macrophages, NK cells, T cells, B cells, and neutrophils in contact with a variety of stromal and epithelial cells. The interplay between these different cell types and their roles in defense against pathogen invasion in this specialized tissue are important for controlling infection and reproduction. TLRs are a family of receptors able to recognize conserved pathogen-associated molecular patterns. In this study, we determined the expression of TLRs on uterine NK (uNK) cells from the human EM and the extent to which uNK cells responded to TLR agonist stimulation. uNK cells expressed TLRs 2, 3, and 4, and produced IFN-gamma when total human endometrial cells were stimulated with agonists to TLR2 or TLR3 (peptidoglycan or poly(I:C), respectively). Activated uNK cell clones produced IFN-gamma upon stimulation with peptidoglycan or poly(I:C). However, purified uNK cells did not respond directly to TLR agonists, but IFN-gamma was produced by uNK cells in response to TLR stimulation when cocultured with APCs. These data indicate that uNK cells express TLRs and that they can respond to TLR agonists within EM by producing IFN-gamma. These data also indicate that the uNK cells do not respond directly to TLR stimulation, but rather their production of IFN-gamma is dependent upon interactions with other cells within EM.
The Journal of Immunology 06/2006; 176(10):6219-24. · 5.79 Impact Factor
