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Thomas ER, Tetzner DR, Roberts SL, Turner SD, Rose NL. First evidence of industrial fly-ash in an Antarctic ice core. Sci Rep 2023; 13:6529. [PMID: 37085561 PMCID: PMC10121663 DOI: 10.1038/s41598-023-33849-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Accepted: 04/19/2023] [Indexed: 04/23/2023] Open
Abstract
Spheroidal carbonaceous particles (SCPs) are a component of fly-ash, the particulate by-product of industrial high temperature combustion of fuel-oil and coal-series fuels. We provide the first evidence that these indelible markers of industrialisation have been deposited in Antarctic ice, thousands of kilometres from any potential source. The earliest observed particle was deposited in an ice layer from 1936 CE. While depositional fluxes are low, chemical analysis of individual SCPs indicates a coal combustion origin.
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Affiliation(s)
- E R Thomas
- Ice Dynamics and Paleoclimate, British Antarctic Survey, High Cross, Madingley Road, Cambridge, CB3 0ET, UK.
| | - D R Tetzner
- Ice Dynamics and Paleoclimate, British Antarctic Survey, High Cross, Madingley Road, Cambridge, CB3 0ET, UK
| | - S L Roberts
- Environmental Change Research Centre, Department of Geography, University College London, Gower Street, London, WC1E 6BT, UK
| | - S D Turner
- Environmental Change Research Centre, Department of Geography, University College London, Gower Street, London, WC1E 6BT, UK
| | - N L Rose
- Environmental Change Research Centre, Department of Geography, University College London, Gower Street, London, WC1E 6BT, UK
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2
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Wang W, Huang L, Hu Y, Thomas ER, Li X. Neuroprotective effects of notoginsenoside R1 by upregulating Trx-1 on acrylamide-induced neurotoxicity in PC12. Hum Exp Toxicol 2020; 39:797-807. [DOI: 10.1177/0960327120901586] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Acrylamide (ACR) is a water-soluble chemical that is commonly used in chemical and cosmetic manufacture. Many studies have been carried out to investigate the neurotoxicity mechanisms of ACR, resulting in oxidative stress and nerve damages. One of the commonly used traditional Chinese medicines is notoginsenoside R1 (NR1). However, its mitochondrial-mediated apoptotic effect caused in ACR-induced neurotoxicity has not been reported. Our results have shown that NR1 resisted the neurotoxicity induced by ACR by upregulating the levels of thioredoxin-1 (Trx-1) in Rat adrenal chromaffin cell tumor (PC12) cells. NR1 inhibited the increase in levels of Bax, caspase-9, and caspase-3, which was instigated by ACR. Moreover, NR1 inhibited the decrease in levels of B-cell lymphoma 2 and Trx-1 induced by ACR. The downregulation of Trx-1 aggravated the mitochondrial-mediated apoptosis and increased the expression of the above molecules, which was induced by ACR. In contrast, overexpression of Trx-1 attenuated the mitochondrial-mediated apoptosis and inhibited the expression of the mentioned molecules induced by ACR. Our results suggested that NR1 protected ACR-induced mitochondrial apoptosis by upregulating Trx-1.
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Affiliation(s)
- W Wang
- Institute for Cancer Medicine and School of Basic Medical Sciences, Southwest Medical University, Luzhou, China
- The authors contributed equally to this work
| | - L Huang
- Department of Biochemistry and Molecular Biology, School of Basic Medical Science, Southwest Medical University, Luzhou, China
- The authors contributed equally to this work
| | - Y Hu
- Department of Biochemistry and Molecular Biology, School of Basic Medical Science, Southwest Medical University, Luzhou, China
| | - ER Thomas
- Department of Biotechnology and Bioinformatics, North Eastern Hill University, Shillong, Meghalaya, India
| | - X Li
- Department of Biochemistry and Molecular Biology, School of Basic Medical Science, Southwest Medical University, Luzhou, China
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Severi M, Becagli S, Caiazzo L, Ciardini V, Colizza E, Giardi F, Mezgec K, Scarchilli C, Stenni B, Thomas ER, Traversi R, Udisti R. Sea salt sodium record from Talos Dome (East Antarctica) as a potential proxy of the Antarctic past sea ice extent. Chemosphere 2017; 177:266-274. [PMID: 28314231 DOI: 10.1016/j.chemosphere.2017.03.025] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Revised: 02/17/2017] [Accepted: 03/07/2017] [Indexed: 06/06/2023]
Abstract
Antarctic sea ice has shown an increasing trend in recent decades, but with strong regional differences from one sector to another of the Southern Ocean. The Ross Sea and the Indian sectors have seen an increase in sea ice during the satellite era (1979 onwards). Here we present a record of ssNa+ flux in the Talos Dome region during a 25-year period spanning from 1979 to 2003, showing that this marker could be used as a potential proxy for reconstructing the sea ice extent in the Ross Sea and Western Pacific Ocean at least for recent decades. After finding a positive relationship between the maxima in sea ice extent for a 25-year period, we used this relationship in the TALDICE record in order to reconstruct the sea ice conditions over the 20th century. Our tentative reconstruction highlighted a decline in the sea ice extent (SIE) starting in the 1950s and pointed out a higher variability of SIE starting from the 1960s and that the largest sea ice extents of the last century occurred during the 1990s.
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Affiliation(s)
- M Severi
- University of Florence, Chemistry Dept. "Ugo Schiff", Via della Lastruccia, 3, 50019, Sesto Fiorentino, FI, Italy.
| | - S Becagli
- University of Florence, Chemistry Dept. "Ugo Schiff", Via della Lastruccia, 3, 50019, Sesto Fiorentino, FI, Italy
| | - L Caiazzo
- University of Florence, Chemistry Dept. "Ugo Schiff", Via della Lastruccia, 3, 50019, Sesto Fiorentino, FI, Italy
| | - V Ciardini
- Laboratory for Earth Observations and Analyses, ENEA, Rome, Italy
| | - E Colizza
- Department of Mathematics and Geosciences, University of Trieste, Trieste, Italy
| | - F Giardi
- University of Florence, Chemistry Dept. "Ugo Schiff", Via della Lastruccia, 3, 50019, Sesto Fiorentino, FI, Italy
| | - K Mezgec
- Department of Mathematics and Geosciences, University of Trieste, Trieste, Italy
| | - C Scarchilli
- Laboratory for Earth Observations and Analyses, ENEA, Rome, Italy
| | - B Stenni
- Department of Environmental Sciences, Informatics and Statistics, "Ca' Foscari" University of Venice, Italy
| | | | - R Traversi
- University of Florence, Chemistry Dept. "Ugo Schiff", Via della Lastruccia, 3, 50019, Sesto Fiorentino, FI, Italy
| | - R Udisti
- University of Florence, Chemistry Dept. "Ugo Schiff", Via della Lastruccia, 3, 50019, Sesto Fiorentino, FI, Italy; ISAC CNR, Via Gobetti 101, 40129, Bologna, Italy
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Dunfee RL, Thomas ER, Gabuzda D. Enhanced macrophage tropism of HIV in brain and lymphoid tissues is associated with sensitivity to the broadly neutralizing CD4 binding site antibody b12. Retrovirology 2009; 6:69. [PMID: 19619305 PMCID: PMC2717910 DOI: 10.1186/1742-4690-6-69] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2009] [Accepted: 07/20/2009] [Indexed: 11/16/2022] Open
Abstract
Macrophages in the central nervous system (CNS) and other tissues are an important cellular reservoir for human immunodeficiency virus type 1 (HIV) infection, particularly in the later stages of disease. Macrophage-tropic HIV strains have an enhanced capacity to enter cells expressing low levels of CD4 through mechanisms that are not well understood. Here, we use a panel of primary HIV envelopes from brain and lymphoid tissues to examine the relationship between neutralization sensitivity to reagents targeting the CD4 binding site and virus entry into macrophages. Neutralization assays using pseudotyped viruses showed an association between the capacity of HIV to enter macrophages and increased sensitivity to the broadly neutralizing monoclonal antibody (mAb) b12, which recognizes a conserved epitope overlapping the CD4 binding site, but not sensitivity to soluble CD4 (sCD4) or b6, a non-neutralizing CD4 binding site mAb. Furthermore, loss of an N-linked glycosylation site at position 386 in the V4 region of Env enhanced macrophage tropism together with b12 sensitivity, but not neutralization by sCD4, b6, or a broadly neutralizing AIDS patient serum. These findings suggest that exposure of the b12 epitope, rather than exposure of the CD4 binding site per se, enhances HIV macrophage tropism, possibly by exposing a region on the outer domain of gp120 that is initially recognized by CD4. These findings suggest overlap between specific gp120 determinants in or near the b12 epitope and those conferring macrophage tropism.
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Affiliation(s)
- Rebecca L Dunfee
- Department of Cancer Immunology and AIDS, Dana Farber Cancer Institute, Boston MA, USA.
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Dunfee RL, Thomas ER, Wang J, Kunstman K, Wolinsky SM, Gabuzda D. Loss of the N-linked glycosylation site at position 386 in the HIV envelope V4 region enhances macrophage tropism and is associated with dementia. Virology 2007; 367:222-34. [PMID: 17599380 PMCID: PMC2201988 DOI: 10.1016/j.virol.2007.05.029] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2007] [Revised: 05/14/2007] [Accepted: 05/23/2007] [Indexed: 11/17/2022]
Abstract
HIV infects macrophages and microglia in the central nervous system (CNS). Mechanisms that enhance HIV macrophage/microglial tropism are not well understood. Here, we identify an HIV Env variant in the V4 region of gp120, Asp 386 (D386), that eliminates an N-linked glycosylation site at position 386, enhances viral replication in macrophages, and is present at a higher frequency in AIDS patients with HIV-associated dementia (HAD) compared with non-HAD patients. D386 enhances HIV entry and replication in macrophages but not in microglia or peripheral blood mononuclear cells, possibly due to differential glycosylation in these cell types. A D386N mutation in the UK1br Env, which restores the N-linked glycan site, reduced neutralization sensitivity to the IgG1b12 (b12) monoclonal antibody, which recognizes a conserved neutralization epitope that overlaps the CD4 binding site. Molecular modeling suggested that loss of the glycan at position 386 increases exposure of the CD4 and b12 binding sites on gp120. Loss of a glycan at 386 was more frequent in Envs from HAD patients (26%; n=185) compared with non-HAD patients (7%; n=99; p<0.001). The most significant association of these Env variants with HAD was in blood or lymphoid tissue rather than brain. These findings suggest that increased exposure of the b12 epitope overlapping the CD4 binding site via elimination of a glycan at position 386 is associated with enhanced HIV macrophage tropism, and provide evidence that determinants of macrophage and microglia tropism are overlapping but distinct.
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Affiliation(s)
- Rebecca L. Dunfee
- Department of Cancer Immunology and AIDS, Dana Farber Cancer Institute, Boston, MA, USA
- Department of Pathology, Harvard Medical School, Boston, MA, USA
| | - Elaine R. Thomas
- Department of Cancer Immunology and AIDS, Dana Farber Cancer Institute, Boston, MA, USA
- Department of Pathology, Harvard Medical School, Boston, MA, USA
| | - Jianbin Wang
- Department of Cancer Immunology and AIDS, Dana Farber Cancer Institute, Boston, MA, USA
- Department of Pathology, Harvard Medical School, Boston, MA, USA
| | - Kevin Kunstman
- Department of Medicine, Northwestern University Medical School, Chicago, IL, USA
| | - Steven M. Wolinsky
- Department of Medicine, Northwestern University Medical School, Chicago, IL, USA
| | - Dana Gabuzda
- Department of Cancer Immunology and AIDS, Dana Farber Cancer Institute, Boston, MA, USA
- Department of Neurology, Harvard Medical School, Boston, MA, USA
- Corresponding Author. Mailing Address: Dana-Farber Cancer Institute, JFB 816, 44 Binney St., Boston, MA 02115, Phone: (617) 632-2154, Fax: (617) 632 3113, E-mail:
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Thomas ER, Dunfee RL, Stanton J, Bogdan D, Kunstman K, Wolinsky SM, Gabuzda D. High frequency of defective vpu compared with tat and rev genes in brain from patients with HIV type 1-associated dementia. AIDS Res Hum Retroviruses 2007; 23:575-80. [PMID: 17451348 DOI: 10.1089/aid.2006.0246] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Human immunodeficiency virus type 1 (HIV) infection of the central nervous system frequently causes HIV-associated dementia (HAD) and other neurological disorders. The role of HIV regulatory and accessory proteins in the pathogenesis of these disorders is unclear. Here we analyzed sequences of tat, rev, and vpu genes in 55 subgenomic clones previously shown to encode functional env genes from brain and lymphoid tissues of four AIDS patients with HAD. Phylogenetic analysis showed distinct compartmentalization of tat, rev, and vpu genes in brain versus lymphoid tissues. Nine of 19 vpu sequences from brain of two patients had premature stop codons at positions between amino acids 2 and 30, compared with 0 of 8 from lymphoid tissues. Tat sequences from brain (n = 8 of 8) but not lymphoid (n = 0 of 6) tissue from one patient had a 35 amino acid truncation at the C-terminus. Rev sequences from the brain of one patient (n = 6 of 8) had a 5 amino acid truncation. These results demonstrate a high frequency of defective vpu compared with tat and rev genes in brain from HAD patients, and identify sequence variants of these regulatory/accessory genes that may influence the pathogenesis of HIV-associated neurological disease.
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Affiliation(s)
- Elaine R Thomas
- Department of Cancer Immunology and AIDS, Dana-Farber Cancer Institute, Boston, MA 02115, USA
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Thomas ER, Dunfee RL, Stanton J, Bogdan D, Taylor J, Kunstman K, Bell JE, Wolinsky SM, Gabuzda D. Macrophage entry mediated by HIV Envs from brain and lymphoid tissues is determined by the capacity to use low CD4 levels and overall efficiency of fusion. Virology 2006; 360:105-19. [PMID: 17084877 PMCID: PMC1890014 DOI: 10.1016/j.virol.2006.09.036] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2006] [Revised: 08/28/2006] [Accepted: 09/22/2006] [Indexed: 01/09/2023]
Abstract
HIV infects macrophages and microglia in the central nervous system (CNS), which express lower levels of CD4 than CD4+ T cells in peripheral blood. To investigate mechanisms of HIV neurotropism, full-length env genes were cloned from autopsy brain and lymphoid tissues from 4 AIDS patients with HIV-associated dementia (HAD). Characterization of 55 functional Env clones demonstrated that Envs with reduced dependence on CD4 for fusion and viral entry are more frequent in brain compared to lymphoid tissue. Envs that mediated efficient entry into macrophages were frequent in brain but were also present in lymphoid tissue. For most Envs, entry into macrophages correlated with overall fusion activity at all levels of CD4 and CCR5. gp160 nucleotide sequences were compartmentalized in brain versus lymphoid tissue within each patient. Proline at position 308 in the V3 loop of gp120 was associated with brain compartmentalization in 3 patients, but mutagenesis studies suggested that P308 alone does not contribute to reduced CD4 dependence or macrophage-tropism. These results suggest that HIV adaptation to replicate in the CNS selects for Envs with reduced CD4 dependence and increased fusion activity. Macrophage-tropic Envs are frequent in brain but are also present in lymphoid tissues of AIDS patients with HAD, and entry into macrophages in the CNS and other tissues is dependent on the ability to use low receptor levels and overall efficiency of fusion.
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Affiliation(s)
- Elaine R. Thomas
- Department of Cancer Immunology and AIDS, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Rebecca L. Dunfee
- Department of Cancer Immunology and AIDS, Dana-Farber Cancer Institute, Boston, MA, USA
| | | | - Derek Bogdan
- Northwestern University Medical School, Chicago, IL, USA
| | - Joann Taylor
- Northwestern University Medical School, Chicago, IL, USA
| | - Kevin Kunstman
- Northwestern University Medical School, Chicago, IL, USA
| | - Jeanne E. Bell
- Department of Pathology, Western General Hospital, University of Edinburgh, Edinburgh, UK
| | | | - Dana Gabuzda
- Department of Cancer Immunology and AIDS, Dana-Farber Cancer Institute, Boston, MA, USA
- Department of Neurology, Harvard Medical School, Boston, MA, USA
- *Corresponding Author. Mailing Address: Dana-Farber Cancer Institute, JFB 816 44 Binney St. Boston, MA 02115 Phone: (617) 632-2154 Fax: (617) 632 3113 E-mail:
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Dunfee RL, Thomas ER, Gorry PR, Wang J, Taylor J, Kunstman K, Wolinsky SM, Gabuzda D. The HIV Env variant N283 enhances macrophage tropism and is associated with brain infection and dementia. Proc Natl Acad Sci U S A 2006; 103:15160-5. [PMID: 17015824 PMCID: PMC1586182 DOI: 10.1073/pnas.0605513103] [Citation(s) in RCA: 130] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2006] [Indexed: 11/18/2022] Open
Abstract
HIV infects tissue macrophages and brain microglia, which express lower levels of CD4 and CCR5 than CD4+ T cells in peripheral blood. Mechanisms that enhance HIV tropism for macrophages in the CNS and other tissues are not well understood. Here, we identify an HIV envelope glycoprotein (Env) variant in the CD4-binding site of gp120, Asn 283 (N283), that is present at a high frequency in brain tissues from AIDS patients with HIV-associated dementia (HAD). N283 increases gp120 affinity for CD4 by decreasing the gp120-CD4 dissociation rate, enhancing the capacity of HIV Envs to use low levels of CD4 for virus entry and increasing viral replication in macrophages and microglia. Structural modeling suggests that the enhanced ability of Envs with N283 to use low levels of CD4 is due to a hydrogen bond formed with Gln 40 of CD4. N283 is significantly more frequent in brain-derived Envs from HAD patients (41%; n=330) compared with non-HAD patients (8%; n=151; P<0.001). These findings suggest that the macrophage-tropic HIV Env variant N283 is associated with brain infection and dementia in vivo, representing an example of a HIV variant associated with a specific AIDS-related complication.
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Affiliation(s)
- Rebecca L. Dunfee
- *Department of Cancer Immunology and AIDS, Dana–Farber Cancer Institute, Boston, MA 02115
- Departments of Pathology and
| | - Elaine R. Thomas
- *Department of Cancer Immunology and AIDS, Dana–Farber Cancer Institute, Boston, MA 02115
- Departments of Pathology and
| | - Paul R. Gorry
- *Department of Cancer Immunology and AIDS, Dana–Farber Cancer Institute, Boston, MA 02115
- Departments of Pathology and
| | - Jianbin Wang
- *Department of Cancer Immunology and AIDS, Dana–Farber Cancer Institute, Boston, MA 02115
- Departments of Pathology and
| | - Joann Taylor
- Department of Medicine, Northwestern University Medical School, Chicago, IL 60611
| | - Kevin Kunstman
- Department of Medicine, Northwestern University Medical School, Chicago, IL 60611
| | - Steven M. Wolinsky
- Department of Medicine, Northwestern University Medical School, Chicago, IL 60611
| | - Dana Gabuzda
- *Department of Cancer Immunology and AIDS, Dana–Farber Cancer Institute, Boston, MA 02115
- Neurology, Harvard Medical School, Boston, MA 02115; and
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Abstract
Human immunodeficiency virus type 1 (HIV) infects macrophages and microglia in the CNS and frequently causes neurocognitive impairment. Although antiviral therapy generally reduces the viral load in the CNS and improves HIV-associated neurological dysfunction, most current antiviral drugs have poor CNS penetrance and cannot completely suppress viral replication. Furthermore, drug-resistance mutations can evolve independently in the CNS. Thus, a long-lived viral reservoir persists in macrophages and microglia in the brain despite antiviral therapy. This review discusses mechanisms underlying the neurotropism of HIV, focusing on the role of the HIV envelope glycoproteins and their interactions with CD4 and the chemokine receptors CCR5 and CXCR4. We review data from studies of neurotropic HIV derived from the brains of patients with HIV-associated neurocognitive impairment as well as studies of nonhuman primate models. Understanding mechanisms that underlie HIV neurotropism and neurovirulence is critical for development of therapeutics to inhibit CNS infection and preventing neurological injury in HIV-infected individuals.
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Affiliation(s)
- Rebecca Dunfee
- Department of Cancer Immunology and AIDS, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA
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Abstract
Human immunodeficiency virus-1 (HIV-1) Vif overcomes the anti-viral activity of APOBEC3G by targeting it for ubiquitination via a Cullin 5-ElonginB-ElonginC (Cul5-EloBC) E3 ligase. Vif associates with Cul5-EloBC through a BC-box motif that binds EloC, but the mechanism by which Vif selectively recruits Cul5 is poorly understood. Here we report that a region of Vif (residues 100-142) upstream of the BC-box binds selectively to Cul5 in the absence of EloC. This region contains a zinc coordination site HX5CX17-18CX3-5H (HCCH), with His/Cys residues at positions 108, 114, 133, and 139 coordinating one zinc ion. The HCCH zinc coordination site, which is conserved among primate lentivirus Vif proteins, does not correspond to any known class of zinc-binding motif. Mutations of His/Cys residues in the HCCH motif impair zinc coordination, Cul5 binding, and APOBEC3G degradation. Mutations of conserved hydrophobic residues (Ile-120, Ala-123, and Leu-124) located between the two Cys residues in the HCCH motif disrupt binding of the zinc-coordinating region to Cul5 and inhibit APOBEC3G degradation. The Vif binding site maps to the first cullin repeat in the N terminus of Cul5. These data suggest that the zinc-binding region in Vif is a novel cullin interaction domain that mediates selective binding to Cul5. We propose that the HCCH zinc-binding motif facilitates Vif-Cul5 binding by playing a structural role in positioning hydrophobic residues for direct contact with Cul5.
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Affiliation(s)
- Andrew Mehle
- Department of Cancer Immunology and AIDS, Dana Farber Cancer Institute, Boston, Massachusetts 02115; Departments of Pathology, Harvard Medical School, Boston, Massachusetts 02115
| | - Elaine R Thomas
- Department of Cancer Immunology and AIDS, Dana Farber Cancer Institute, Boston, Massachusetts 02115; Departments of Pathology, Harvard Medical School, Boston, Massachusetts 02115
| | - Kottampatty S Rajendran
- Department of Cancer Immunology and AIDS, Dana Farber Cancer Institute, Boston, Massachusetts 02115; Departments of Pathology, Harvard Medical School, Boston, Massachusetts 02115
| | - Dana Gabuzda
- Department of Cancer Immunology and AIDS, Dana Farber Cancer Institute, Boston, Massachusetts 02115; Departments of Neurology, Harvard Medical School, Boston, Massachusetts 02115.
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Abstract
BACKGROUND HIV-2 is less pathogenic than HIV-1. In contrast to HIV-1, many isolates of HIV-2, including primary isolates, can infect cells independently of CD4. OBJECTIVE To compare the sensitivity of CD4-dependent and CD4-independent isolates of HIV-2 to antibody-mediated neutralization. METHODS The neutralization sensitivity of CD4-dependent and CD4-independent molecular clones of HIV-2 to a panel of HIV-2-positive serum samples was tested. Monoclonal antibodies to various epitopes across the viral envelope were used to determine whether a specific epitope conferred neutralization sensitivity. Neutralization sensitivity of primary isolates of HIV-2 able to infect in the absence of cellular CD4 was also investigated. Antibody binding to sensitive and resistant envelopes was analysed using enzyme-linked immunosorbent assay and flow cytometry. RESULTS CD4-independent ROD B was highly sensitive to neutralization by HIV-2-positive sera compared with the CD4-dependent isolate ROD A. Induction of ROD A to infect CD4-negative cells by soluble CD4 rendered it equally sensitive to antibody neutralization. Similarly, primary X4, R5 or dual-tropic isolates of HIV-2 were significantly more susceptible to neutralization when utilizing a CD4-independent route of infection. Neutralization sensitivity was not epitope specific but several conformation-dependent antibodies accentuated this phenotype. Antibody binding to monomeric or oligomeric envelope did not correlate with neutralization sensitivity. CONCLUSIONS HIV-2 isolates utilizing a CD4-independent route of infection are more sensitive to antibody-mediated neutralization. Cellular CD4 may protect HIV-2 from neutralization. This sensitivity to neutralization may, in part, explain the lower virus load and slower progression to disease in HIV-2-infected individuals.
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Affiliation(s)
- Elaine R Thomas
- The Wohl Virion Centre, Windeyer Institute of Medical Sciences, University College London, London W1T 4JF, UK
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Smith KM, Pottage L, Thomas ER, Leishman AJ, Doig TN, Xu D, Liew FY, Garside P. Th1 and Th2 CD4+ T cells provide help for B cell clonal expansion and antibody synthesis in a similar manner in vivo. J Immunol 2000; 165:3136-44. [PMID: 10975827 DOI: 10.4049/jimmunol.165.6.3136] [Citation(s) in RCA: 125] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The relative ability of Th1 and Th2 T cells to help B cells remains controversial as do the mechanisms by which both T cell subsets provide help in vivo. Whether this help affects the clonal expansion and/or differentiation of B cells has been difficult to assess due to the low frequency of Ag-specific T and B lymphocytes. We have employed a novel technique to directly monitor the clonal expansion of Ag-specific T and B lymphocytes in vivo. OVA-specific TCR transgenic T lymphocytes were polarized toward a Th1 or Th2 phenotype in vitro. These cells were then transferred into syngeneic recipients, along with B cell receptor transgenic hen egg lysozyme-specific B lymphocytes. Our results indicate that Th1 and Th2 cells support B cell responses to a similar extent in vivo and that they achieve this in the same manner by migrating into B cell follicles to promote CD154-dependent B cell clonal expansion and Ab production.
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Affiliation(s)
- K M Smith
- Department of Immunology and Bacteriology, University of Glasgow, Western Infirmary, Glasgow, United Kingdom
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Abstract
OBJECTIVES To evaluate how lack of immunization history contributes to missed opportunities for immunization and to document the effort required to obtain immunization history. DESIGN Cross-sectional. SETTING Urban, inner-city primary care pediatric clinic serving a low-income, multiethnic population. PATIENTS Ninety-five new patients seen for either well-child care (53 patients) or acute illnesses (42 patients) during a 4-month period in 1993. Fifty-nine patients were aged 3 to 59 months and 36 were aged 5 to 15 years. MEASUREMENTS Efforts to obtain immunization history were documented by means of a standardized data collection form. RESULTS Immunization history was obtained for only 26 (27%) of 95 patients during the initial visit. Caregivers of 74 (78%) of 95 patients did not bring immunization records to the initial visit; they were no more likely to bring records for well-child care than for acute care or for younger vs older children. Parents brought immunization records more often than did nonparents. A total of 145 telephone calls were made and 30 letters were sent in an attempt to obtain immunization histories. Immunization records were never found for 10 new patients (11%). Thirty-two patients (34%) were found to be lacking immunizations. Of these, only three patients had contraindications to immunization at the initial visit. Therefore, in one third of our new patients, opportunities to immunize were missed solely because their immunization records were unavailable at the initial visit. In another one third of cases, caregivers had incorrectly believed their child's immunizations to be up to date. CONCLUSIONS Opportunities to immunize children were often missed because of a lack of immunization history. Our experience supports the need for improved documentation of immunization histories.
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Affiliation(s)
- M A Watson
- Odessa Brown Children's Clinic, Seattle, USA
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Papadopoulos NM, Thomas ER. A biochemical approach for the study of uveitis by protein and LDH-isoenzyme analysis of serum and aqueous humor. Proc Soc Exp Biol Med 1969; 131:450-3. [PMID: 5787124 DOI: 10.3181/00379727-131-33899] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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16
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Thomas ER. Thomas paracentesis needle. Trans Am Acad Ophthalmol Otolaryngol 1968; 72:259-60. [PMID: 5659909] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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Thomas ER. Modified Barraquer brush. Trans Am Acad Ophthalmol Otolaryngol 1967; 71:136. [PMID: 6050310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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Thomas ER. Cryoptor interchangeable cryosurgical probes. Trans Am Acad Ophthalmol Otolaryngol 1967; 71:129-31. [PMID: 6050307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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19
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Thomas ER. Cryoptor cataract unit. Trans Am Acad Ophthalmol Otolaryngol 1967; 71:133-4. [PMID: 6050308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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Thomas ER. Cryoptor retinal detachment unit. Trans Am Acad Ophthalmol Otolaryngol 1967; 71:135. [PMID: 6050309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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