Topic
CD69
About: CD69 is a research topic. Over the lifetime, 448 publications have been published within this topic receiving 20639 citations. The topic is also known as: early lymphocyte activation antigen & early T-cell activation antigen p60.
Papers published on a yearly basis
Papers
TL;DR: Treatment with the IFN-α/β inducer polyinosine polycytidylic acid inhibited egress by a mechanism that was partly lymphocyte-intrinsic, and observations indicate that CD69 forms a complex with and negatively regulates S1P1 and that it functions downstream ofIFN- α/β, and possibly other activating stimuli, to promote lymphocyte retention in lymphoid organs.
Abstract: Naive lymphocytes continually enter and exit lymphoid organs in a recirculation process that is essential for immune surveillance. During immune responses, the egress process can be shut down transiently. When this occurs locally it increases lymphocyte numbers in the responding lymphoid organ; when it occurs systemically it can lead to immunosuppression as a result of the depletion of recirculating lymphocytes. Several mediators of the innate immune system are known to cause shutdown, including interferon alpha/beta (IFN-alpha/beta) and tumour necrosis factor, but the mechanism has been unclear. Here we show that treatment with the IFN-alpha/beta inducer polyinosine polycytidylic acid (hereafter 'poly(I:C)') inhibited egress by a mechanism that was partly lymphocyte-intrinsic. The transmembrane C-type lectin CD69 was rapidly induced and CD69-/- cells were poorly retained in lymphoid tissues after treatment with poly(I:C) or infection with lymphocytic choriomeningitis virus. Lymphocyte egress requires sphingosine 1-phosphate receptor-1 (S1P1), and IFN-alpha/beta was found to inhibit lymphocyte responsiveness to S1P. By contrast, CD69-/- cells retained S1P1 function after exposure to IFN-alpha/beta. In coexpression experiments, CD69 inhibited S1P1 chemotactic function and led to downmodulation of S1P1. In a reporter assay, S1P1 crosslinking led to co-crosslinking and activation of a CD69-CD3zeta chimaera. CD69 co-immunoprecipitated with S1P1 but not the related receptor, S1P3. These observations indicate that CD69 forms a complex with and negatively regulates S1P1 and that it functions downstream of IFN-alpha/beta, and possibly other activating stimuli, to promote lymphocyte retention in lymphoid organs.
1,151 citations
TL;DR: Immunohistochemical localization during intermediate stages of externalization suggests that the lectin becomes concentrated in evaginations of plasma membrane, which pinch off to form labile lectin- rich extracellular vesicles, which suggests a possible mechanism for lectin export from the cytosol to theextracellular matrix.
Abstract: A soluble lactose-binding lectin with subunit Mr of 14,500 is believed to function by interacting with extracellular glycoconjugates, because it has been detected extracellularly by immunohistochemistry. This localization has been questioned, however, since the lectin lacks a secretion signal sequence, which challenges the contention that it is secreted. We have demonstrated externalization of this lectin from C2 mouse muscle cells by both immunoprecipitation of metabolically labeled protein and immunohistochemical localization. We further show that externalization of the lectin is a developmentally regulated process that accompanies myoblast differentiation and that the lectin codistributes with laminin in myotube extracellular matrix. Immunohistochemical localization during intermediate stages of externalization suggests that the lectin becomes concentrated in evaginations of plasma membrane, which pinch off to form labile lectin-rich extracellular vesicles. This suggests a possible mechanism for lectin export from the cytosol to the extracellular matrix.
497 citations
TL;DR: HIntL is a new type lectin recognizing galactofuranose, and that hIntL plays a role in the recognition of bacteria-specific components in the host.
383 citations
TL;DR: The human CD69 gene maps to the natural-killer gene complex on chromosome 12p, not chromosome 19 as stated incorrectly in this Review.
Abstract: Nature Reviews Immunology 2, 77–84 (2002) The human CD69 gene maps to the natural-killer gene complex on chromosome 12p, not chromosome 19 as stated incorrectly in this Review. For further details, see Lopez-Cabrera et al. Molecular cloning, expression and chromosomal localization of the human earliest lymphocyte activation antigen AIM/CD69, a new member of the C-type animal lectin superfamily of signal-transmitting receptors.
308 citations
TL;DR: The lectin activity of CD22 is restricted by endogenous sialylation in resting B cells and may be transiently unmasked during in vivo activation, perhaps to modulate intercellular or intracellular interactions at this critical stage in the humoral response.
Abstract: CD22 is a B cell-restricted glycoprotein involved in signal transduction and modulation of cellular activation. It is also an I-type lectin (now designated Siglec-2), whose extracellular domain can specifically recognize alpha2-6-linked sialic acid (Sia) residues. This activity is postulated to mediate intercellular adhesion and/or to act as a coreceptor in antigen-induced B cell activation. However, studies with recombinant CD22 indicate that the lectin function can be inactivated by expression of alpha2-6-linked Sia residues on the same cell surface. To explore whether this masking phenomenon affects native CD22 on B cells, we first developed a probe to detect the lectin activity of recombinant CD22 expressed on Chinese hamster ovary cells (which have no endogenous alpha2-6-linked Sia residues). This probe is inactive against CD22-positive B lymphoma cells and Epstein-Barr virus-transformed lymphoblasts which express high levels of alpha2-6-linked Sia residues. Enzymatic desialylation unmasks the CD22 lectin activity, indicating that endogenous Sia residues block the CD22 lectin-binding site. Truncation of the side chains of cell surface Sia residues by mild periodate oxidation (known to abrogate Sia recognition by CD22) also had this unmasking effect, indicating that the effects of desialylation are not due to a loss of negative charge. Normal resting B cells from human peripheral blood gave similar findings. However, the lectin is partially unmasked during in vitro activation of these cells. Thus, the lectin activity of CD22 is restricted by endogenous sialylation in resting B cells and may be transiently unmasked during in vivo activation, perhaps to modulate intercellular or intracellular interactions at this critical stage in the humoral response.
260 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2025 | 8 |
| 2024 | 15 |
| 2023 | 27 |
| 2022 | 28 |
| 2021 | 4 |
| 2019 | 1 |