PubMed · 8383479
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1993. CDC revises AIDS definition.. https://pubmed.ncbi.nlm.nih.gov/8383479/
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Hodgkin disease (HD) is characterized by the presence of Hodgkin and Reed-Sternberg cells (H&RS) and a prominent lymphocytic infiltration. Various CXC and CC chemokines [e.g., interferon-gamma-inducible protein-10 (IP10), monokine induced by interferon-gamma (MIG) and TARC] are expressed on H&RS cells. Our study was designed to investigate the expression of MIG, IP10 and TARC on H&RS cells and their relations on lymphocyte infiltration. Immunohistochemical staining was performed using antibodies for CXCR3 (a specific receptor for IP10 and MIG), which is characteristic of Th1 helper phenotype and CCR3, CCR4 and ST2, which are features of Th2 cells. We studied 15 cases of HD [lymphocyte predominance (LP) type, 2; mixed cellularity (MC) type, 6; and nodular sclerosis (NS) type, 7]. All 6 MC cases contained TARC-, IP10- and MIG-expressing H&RS cells, however only 2 of 5 NS cases contained TARC-expressing H&RS cells, 3 of 7 NS contained MIG-expressing H&RS cells and only 1 of 7 NS contained IP10-expressing H&RS cells. Neither of the 2 LP cases contained HR&S cells that expressed these chemokines. The chemokines were more frequently expressed by MC than by NS and LP types. IP10-, MIG- and TARC-positive HD cases contained higher numbers of Th2 lymphocytes (ST2- CCR3- or CCR4-positive lymphocytes), compared to IP10-, MIG- and TARC-negative HD cases (p < 0.05 or <0.5). The number of CXCR3 (MIG and IP10 receptor)-positive lymphocytes (Th1 lymphocytes) was not different between MIG- and IP10-positive and -negative HD. Lymphocytes surrounding MIG- and IP10-positive H&RS cells were more frequently CXCR3-positive, however, compared to MIG- and IP10-negative cases. The CCR4 (TARC receptor)-positive lymphocytes, surrounding H&RS cells, were minority and the surrounding lymphocytes were not different between TARC-positive and negative cases. Our results indicate that MIG, IP10 and TARC chemokines influenced the response of Th2 cells in HD. It is possible, however, that IP10 and MIG may locally influence Th1 cells via cell migration.
The Cbl-family ubiquitin ligases function as negative regulators of activated receptor tyrosine kinases by facilitating their ubiquitination and subsequent targeting to lysosomes. Cbl associates with the lymphoid-restricted nonreceptor tyrosine kinase Lck, but the functional relevance of this interaction remains unknown. Here, we demonstrate that T cell receptor and CD4 coligation on human T cells results in enhanced association between Cbl and Lck, together with Lck ubiquitination and degradation. A Cbl(-/-) T cell line showed a marked deficiency in Lck ubiquitination and increased levels of kinase-active Lck. Coexpression in 293T cells demonstrated that Lck kinase activity and Cbl ubiquitin ligase activity were essential for Lck ubiquitination and negative regulation of Lck-dependent serum response element-luciferase reporter activity. The Lck SH3 domain was pivotal for Cbl-Lck association and Cbl-mediated Lck degradation, with a smaller role for interactions mediated by the Cbl tyrosine kinase-binding domain. Finally, analysis of a ZAP-70-deficient T cell line revealed that Cbl inhibited Lck-dependent mitogen-activated protein kinase activation, and an intact Cbl RING finger domain was required for this functional effect. Our results demonstrate a direct, ubiquitination-dependent, negative regulatory role of Cbl for Lck in T cells, independent of Cbl-mediated regulation of ZAP-70.
Macrophages, microglia, and other mononuclear phagocytes serve as cellular reservoirs for viral persistence in patients with acquired immunodeficiency syndrome. To understand host mechanisms that affect human immunodeficiency virus type 1 (HIV-1) pathogenesis by modulating expression of coreceptors, cytokine regulation of CC chemokine receptor 5 (CCR5) and CD4 expression on monocytes, monocyte-derived macrophages (MDMs), and microglia was investigated. Interleukin (IL)-4 and IL-10 enhanced the entry and replication of HIV-1 in microglia through up-regulation of CD4 and CCR5 expression, respectively. IL-4 stimulated HIV-1 replication in MDMs but down-regulated CD4 and CCR5 expression and inhibited virus entry, whereas IL-10 had the opposite effects. Thus, mechanisms independent of CCR5 and CD4 expression levels are involved in pathways that regulate HIV-1 replication in MDMs. CCR5 up-regulation by IL-10 was associated with increased migration of microglia in response to macrophage inflammatory protein-1beta. These findings suggest that increased production of T helper type 2 cytokines in the later stages of disease can enhance virus entry and replication in mononuclear phagocytes and facilitate chemotactic migration.