China
Africa
Explore chapters and articles related to this topic
The maternal immune system during pregnancy
Published in Hung N. Winn, Frank A. Chervenak, Roberto Romero, Clinical Maternal-Fetal Medicine Online, 2021
Interestingly, peripheral NK cells maintain a nonpregnant phenotype during anembryonic gestations, ectopic pregnancies, and recurrent spontaneous abortions, all of which have been associated with increased NK activity (42,51,52). Thus, classic NK appear to have a differing phenotype in normal versus abnormal pregnancies and could serve as potential effector cells during the elimination of abnormal pregnancy. uNK cells with the phenotype CD56 bright/CD57-/CD16-are actively recruited to the endometrium and decidua during the late secretory phase of menstruation and early normal pregnancy (53–56) and remain in the decidua if implantation is successful (57). These cells comprise 70% to 80% of decidual leukocytes, but less than 1% of peripheral blood leukocytes, existing side by side at the trophoblast margin with macrophages (20% of leukocytes) and CD3+ T-cells (10% of leukocytes) (58,59).
The Immune System During HIV-1 Infection
Published in Niel T. Constantine, Johnny D. Callahan, Douglas M. Watts, Retroviral Testing, 2020
Niel T. Constantine, Johnny D. Callahan, Douglas M. Watts
Evaluation of the immune system using these markers requires a great deal of knowledge and expertise. Many of the cells of the immune system may contain the same marker even though they represent different cell populations. For example, some T lymphocytes also contain the CD56 marker that is common to NK cells. Therefore, when evaluating cells using this marker, T and NK cells can be enumerated simultaneously using dual markers to ensure that the T cells that are CD56+ are not included in the NK cell count and in the T cell count. The system is complex. Quality control measures must also be included in these evaluations. For example, an isotype control must be used to control for nonspecific binding of the monoclonals to the patient’s cells; the enumerations can be checked by determining the “lymphosum” (i.e., the sum of T + B + NK should approach 100%). Because of the variety of instruments and combinations of monoclonal markers available, it is not possible to describe the details of the necessary quality control measures required for cell phenotyping. Guidelines are available from organizations such as the National Committee for Clinical Laboratory Standards (NCCLS), the CDC, and the Association of State and Territorial Public Health Laboratory Directors (ASTPHLD).
The Endometrial Factor in Recurrent Pregnancy Loss
Published in Howard J.A. Carp, Recurrent Pregnancy Loss, 2020
Luiza Borges Manna, Ying Cheong
An additional role of the decidua is to ensure immune tolerance to the conceptus while at the same time protecting the mother from external insults. A change in the immune cell composition of the endometrium occurs after decidualization in order to recognize and accept the semi-allogenic embryo. The most abundant subtype of leucocytes in the decidua are the uterine natural killer (uNK) cells [20], representing approximately 70% of all endometrial leukocytes after the secretory phase [5]. uNK cells are a unique subset of natural killer cells, with a different antigen profile to their circulating counterparts—while the latter stain heavily for CD56 and CD16 antigens and are highly cytotoxic, uNK cells stain only for CD56 and show little evidence of cytotoxic activity [21]. Instead, they synthesize several angiogenic factors essential for the establishment of early pregnancy [20]. The amount of uNK cells significantly increases 6−7 days after the luteinizing hormone surge, a time that coincides with implantation and continues to rise in the first trimester of pregnancy [20,22]. These characteristics, taken together with the fact that uNK cells tend to cluster at the site of trophoblast invasion and around spiral arteries, suggest that they might play a role in their remodeling and implantation [23].
CD8+ and CD8- NKT Cells Exhibit Phenotypic Changes During Pregnancy
Published in Immunological Investigations, 2023
Matyas Meggyes, David U. Nagy, Iyad Saad Al Deen, Borbala Parkanyi, Laszlo Szereday
CD56 can be found on most natural killer (NK) cells and a subset on CD3+ T cells making up 1 -11-% of human peripheral blood lymphocytes (Romero-Olmedo et al. 2021). NK cells and their receptor expression were profoundly investigated in different malignancies and viral infections but there is limited data regarding NKT cell activity under the same circumstances (Konjevic et al. 2012; Konjević et al. 2016; Vuletić et al. 2013). However, the nomenclature of NKT cells is very controversial. They are often referred to as NK-like T cells or CD3+CD56+ NKT-like cells (Meggyes et al. 2019; Romero-Olmedo et al. 2021). NKT cells recognize lipid-based antigens and are separated into two broad classes: type 1 and type 2 NKT cells (Pellicci et al. 2020). Type 1 cells recognize the α-galactosylceramide (α-GalCer) and are less frequent, representing fewer than 1% of T cells in the human blood and liver, but they are still one of the most abundant TCR specificities (Godfrey et al. 2015; Miko et al. 2008). Humans appear to have greater numbers of type 2 NKT cells: those that express diverse TCRs with broader lipid antigen specificities. Nevertheless, these cells are difficult to identify, and little is known about how they develop (Pellicci et al. 2020).
Prognostic significance of CD56 expression in patients with multiple myeloma: a meta-analysis
Published in Hematology, 2022
Lijuan Zhang, Yun Huang, Yun Lin, Aili Zhang, Rong Zou, Huiying Xu, Sili Wang
CD56, a membrane glycoprotein belonging to the immunoglobulin superfamily, is also referred to as neural cell adhesion molecule (NCAM) [6,7]. It is first reported that the expression of CD56 was strongly positive in myeloma plasma cells in 1990 by Van Camp et al [8]. Subsequently, studies have reported that CD56 is expressed in 70–80% of MM patients [9]. It is widely accepted that CD56 is one of the important hallmarks of distinguishing benign and malignant diseases at present because it is hardly expressed on normal cells [10–12]. However, the expression of CD56 did not occur on all myeloma plasma cells, CD56 negative MM patients are also not uncommon. A large number of researches have focused on the clinical characteristics and prognostic factors of CD56 negative MM patients. Nevertheless, the results have not reached a consensus. In this study, a meta-analysis was performed for further comprehensive understanding of the prognostic significance of CD56 in MM.
Blood microbiota diversity determines response of advanced colorectal cancer to chemotherapy combined with adoptive T cell immunotherapy
Published in OncoImmunology, 2021
Duo Yang, Xiaoli Wang, Xinna Zhou, Jing Zhao, Huabing Yang, Shuo Wang, Michael A. Morse, Jiangping Wu, Yanhua Yuan, Sha Li, Amy Hobeika, Herbert Kim Lyerly, Jun Ren
CD3–/CD16+/CD56+ cells play a critical role in combating transformed and malignant cells.38,39 Increased peripheral blood CD8+/CD28+ T cells better predict early response to tumor therapy40 and are associated with length of progression-free survival (PFS) and overall survival (OS).41 As the number of CIK cells infused was associated with PFS and OS, it is possible that the DC-CIK product had direct antitumor effects but also may have enhanced the immune response by increasing the diversity of the blood microbiome. Therefore, modifications to increase the number of CIK cells infused and the proportion of CD3–/CD16+/CD56+ and CD8+/CD28+ T cell subtypes within the infused cellular product are warranted to enhance the efficacy of the ACT.