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Query: UMLS:C0019693 (HIV)
 170,526 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In this review the features of B-cell development and differentiation are described for the bone marrow and peripheral B-cell system, in particular that in lymph nodes follicles. These features show many similarities to those of malignant B-cell populations. Frequently the "normal counterparts" of malignant B lineage cells are seen in particularly high frequency in the foetal lymphoid tissues. For example, foetal bone marrow shows abundant CD10+ precursors and foetal lymph nodes contain many CD5+ B cells. These similarities contribute to a better understanding of B-cell malignancy. On the other hand they provide observations also useful in interpretation of immunodeficiency such as X-linked agammaglobulinaemia and lymph nodes after HIV-1 infection. The identification of target cells in lymphoid malignancies will be important for understanding the mechanism of tumour development because the gene alterations also show target cell specificity.
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PMID:Human B-lymphoid differentiation: normal versus malignant. 179 86

T-lymphoid cell lines (H9/CBL-4 and CEM/CBL-4) persistently infected with HIV-1 were observed simultaneously for 6.5 months. The virus activity was characterized by such parameters as the number of infected cells determined by fluorescent antibody technique, the total level of virus--specific protein synthesis determined by immune blotting method, and the capacity to infect H9 and CEM cells. A comparative analysis of the two cell lines helped define the evaluation criteria for high and low productivity cultures. It was shown that a short-term virus persistence could exist in high-productivity cultures and long-term persistence in low-productivity cultures. The cytopathic activity of virus in cultures could be judged by accumulation of virus protein p24 in cell-free supernatants, this being one of the factors defining the efficacy of infection of H9 and CEM T-lymphoid cells.
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PMID:[A comparison of 2 T-lymphoid cell lines persistently infected with the human immunodeficiency virus (HIV-1) with different productive capacities]. 179 80

Considerable ultrastructural changes in the lymphoid cells of immunocompetent organs as well as in the epithelial and stromal cells of the rectum--the organ of the first contact with the virus in some cases--are found in HIV-infection. These alterations are of a quantitative nature and are the indications of important disturbances of the water-salt and protein metabolism. Changes in the lymphocytes and plasmacytes of the rectum lamina propria result in the damage to local immune defense. The presence of tubuloreticular and tubulo-annular structures in various cells of the rectum and lymphoid organs which are clearly seen in the biopsy material is most likely a characteristic sign of HIV-infection at its terminal stage.
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PMID:[HIV infections. Problems of morphologic diagnosis]. 179 20

Human immunodeficiency virus type 1 (HIV-1) isolates from 25 perinatally HIV-1 infected children were classified according to their capacity to replicate in vitro as rapid (R), intermediate (S/R) and slow (S) variants. R-type viruses replicated on peripheral blood mononuclear cells (PBMCs) and grew better in T-lymphoid cells, even though 9 out of 12 isolates also maintained tropism for monocytoid cells. The S/R-type isolates replicated efficiently after several days of culture, while the S-type viruses displayed only a low and transient replication activity; however, both S/R- and S-type isolates exerted viral transactivation activity in an indicator monocytoid cell line. Replication patterns in vitro were significantly associated in vivo with the number of HIV-1 copies in PBMCs as determined by polymerase chain reaction: in children with R-type isolates, the number of HIV-1 proviral DNA molecules/10(5) PBMCs ranged from 62 to 571, and in children with S/R and S isolates the range was 5-43. Seven children had severe symptomatic HIV-1 infection, and in all an R-type virus was identified; 18 children had no or only mild symptoms, and among these, S-, S/R-, and R-type isolates were found in 5, 8, and 5 cases, respectively. Besides demonstrating HIV-1 variability in perinatal infection, these findings suggest that R-type virus might be a prerequisite for disease progression.
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PMID:Perinatal infection by human immunodeficiency virus type 1 (HIV-1): relationship between proviral copy number in vivo, viral properties in vitro, and clinical outcome. 180 57

The effect of Rev on cytoplasmic accumulation of the singly spliced human immunodeficiency virus type 1 (HIV-1) vif, vpr, and env/vpu RNAs was examined by using a quantitative RNA polymerase chain reaction (PCR) analysis following transfection of complete proviral molecular clones into lymphoid cells. Previously published studies using subgenomic env constructs in nonlymphoid cell types concluded that Rev was necessary for cytoplasmic accumulation of high levels of unspliced env RNA and that, by analogy, Rev must be necessary for the cytoplasmic accumulation of all HIV-1 RNAs that contain the Rev-responsive element (RRE). We confirm those results in COS cells. Unexpectedly, in lymphoid cells, we find that although Rev acts somewhat to increase the cytoplasmic level of full-length HIV-1 RNA, Rev has little or no effect on cytoplasmic accumulation of singly spliced HIV-1 RNAs. However, Env protein expression was greatly reduced in the absence of Rev. Analysis of the cytoplasmic RNA revealed that in the absence of Rev or the RRE, the cytoplasmic vif, vpr, and env/vpu 2 RNAs were not associated with polysomes but with a complex of 40S-80S in size. Consequently, efficient expression of the Vif, Vpr, Vpu, and Env proteins from these RNAs is dependent on Rev. These results exclude a mechanism whereby the sole function of Rev is simply to export RNAs from nucleus to cytoplasm. We discuss other models to take into account the dependence on Rev for efficient translation of cytoplasmic HIV-1 RNAs.
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PMID:Rev is necessary for translation but not cytoplasmic accumulation of HIV-1 vif, vpr, and env/vpu 2 RNAs. 182 22

To analyse the evolution of alveolar-lymphocyte-mediated cytotoxic activity directed against autologous alveolar macrophages (AM), cytotoxic assays against various HIV+ target cells were performed in a cohort of 75 patients with HIV-associated lymphoid interstitial pneumonitis (LIP) studied at distinct stages of HIV infection. Our data confirm that alveolar HIV-specific cytotoxic T lymphocytes (CTL) against AM were detectable before AIDS in patients with CD8+ LIP. Mild CD8+ lymphocytic alveolitis occurs silently in 62% of stage II and III patients with no respiratory symptoms. In these cases, the lack of spontaneous alveolar-lymphocyte-mediated cytotoxic activity against autologous AM may contrast with the detection of primary alveolar CTL specific for HIV proteins such as nef. In AIDS patients, the alveolar CTL lytic efficiency against both AM- and HIV-antigen-expressing cells can be inhibited by a suppressor factor produced by alveolar CD8+ CD57+ cells. Therefore, spontaneous CTL lysis of AM may be (1) limited to a subgroup of patients with active LIP and (2) controlled by distinct mechanisms, including suppressor phenomenons, and HIV replication levels in AM.
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PMID:HIV-specific cytotoxic T lymphocytes against alveolar macrophages: specificities and downregulation. 183 81

Three lines of transgenic mice carrying the human immunodeficiency virus type 1 (HIV-1) long terminal repeat fused to the simian virus 40 early region (HIV-1 Tag) were constructed. Expression of the transgenes was reproducibly observed in the lymphoid tissue and skin of all three transgenic lines studied. Interestingly, cell types other than T cells, i.e., B cells and thymic stromal cells, contributed most of the expression detectable in the lymphoid organs. Each transgenic line also displayed a different but consistent pattern of transgene expression in nonlymphoid organs. These individual patterns probably reflect the effects of particular chromosomal integration sites on transcriptional activity of the HIV-1 promoter.
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PMID:Expression of a human immunodeficiency virus type 1 long terminal repeat/simian virus 40 early region fusion gene in transgenic mice. 184 96

To search for broadly active enhancer elements within the human immunodeficiency virus type 1 (HIV-1) long terminal repeat, we have used a proto-enhancer amplification assay. In this assay, the enhancer region of simian virus 40 (SV40) is replaced by heterologous regulatory sequences. Upon passage in African green monkey kidney cells. SV40 growth revertants can arise by amplification (usually duplication) of active protoenhancers within the heterologous sequences. Most of the HIV-1 U3 regulatory sequences were assayed; only amplification of one or both of the HIV-1 enhancer core kappa B motifs consistently resulted in viable SV40 virus. Examination of the cell-specific enhancer activity of the individual HIV-1 kappa B proto-enhancers showed that, like the broadly active SV40 kappa B proto-enhancer (C proto-enhancer), they are all active in noninduced cell lines of either lymphoid (H9 and Jurkat) or nonlymphoid (HeLa and CV-1) origin. Unexpectedly, one of three kappa B point mutants that exhibit little or no activity in unstimulated cells is as highly induced in stimulated Jurkat cells as are the wild-type kappa B proto-enhancers. This point mutation shows that kappa B-related proto-enhancers can display markedly different activation properties in unstimulated cells yet still activate transcription to similar levels in stimulated cells.
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PMID:Functional similarities between human immunodeficiency virus type 1 and simian virus 40 kappa B proto-enhancers. 185 6

The clinicopathologic features of 45 human immunodeficiency virus (HIV)-infected patients (mainly intravenous drug users [IVDU]) with lymphoid neoplasias seen from September 1984 through July 1990 at an Italian cancer center are reviewed. Thirty-five had systemic non-Hodgkin's lymphoma (NHL), and ten had Hodgkin's disease (HD). Histologically, 27 NHL cases were intermediate grade (five cases) or high grade (22 cases, 14 of the small noncleaved cell type), according to the Working Formulation. Eight NHL cases, including four anaplastic large cell (ALC) BerH2 (CD30)-positive lymphomas, were in the miscellaneous group. Immunohistologic and/or gene rearrangement analysis showed the B-cell origin of 20 of the 24 NHL cases studied. At presentation, 71% of NHL patients had advanced stages (Stage III or IV), and 85% had extranodal disease (predominantly gastrointestinal tract and marrow). Of the 23 patients evaluable for treatment, only seven had a complete clinical response after lymphoma therapy; the median survival of 34 evaluable patients was 22 months after the diagnosis of NHL. Fifteen patients died; most deaths were attributable to progressive lymphoma and opportunistic infections. As with NHL, advanced disease, extranodal involvement, aggressive histologic findings, and poor response to therapy were also observed in patients with HD. This study shows that lymphoid neoplasias occurring in Italian IVDU with HIV infection and those previously reported in North American homosexual men with HIV infection share similar clinicopathologic features. However, some features such as the absence of history of Kaposi's sarcoma at diagnosis, the lack of detection of primary brain and rectal NHL, and the occurrence of B-cell ALC BerH2 (CD30)-positive NHL were observed uniquely in this series of patients.
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PMID:A clinicopathologic study of lymphoid neoplasias associated with human immunodeficiency virus infection in Italy. 185 83

This study was designed to determine whether human immunodeficiency virus type 1 (HIV-1) might enter the host by penetrating epithelial barriers through antigen-transporting M cells in lymphoid follicle-associated epithelia. Interaction of HIV-1 with epithelial cells was examined using mucosal explants from Peyer's patches of mice and rabbits. HIV-1 adhered to the luminal membranes of M cells of both species, and was endocytosed and delivered to intraepithelial spaces containing lymphocytes and macrophages. These observations suggest that M cells, which are numerous in the human rectal mucosa, may efficiently deliver HIV-1 to target cells in mucosal lymphoid tissue, and that such transport may contribute to sexual transmission of AIDS.
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PMID:Transepithelial transport of HIV-1 by intestinal M cells: a mechanism for transmission of AIDS. 185 88


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