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Etemad B, Gonzalez OA, White L, Laeyendecker O, Kirk GD, Mehta S, Sagar M. Characterization of HIV-1 envelopes in acutely and chronically infected injection drug users. Retrovirology 2014; 11:106. [PMID: 25430652 PMCID: PMC4253609 DOI: 10.1186/s12977-014-0106-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Accepted: 11/08/2014] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND Mucosally acquired human immunodeficiency virus type 1 (HIV-1) infection results from a limited number of variants, and these infecting strains potentially have unique properties, such as increased susceptibility to entry blockers, relative interferon-alpha (IFN-α) resistance, and replication differences in some primary cells. There is no data about the phenotypic properties of HIV-1 envelope variants found early after acquisition among subjects infected through injection drug use (IDU). For the first time, we compared the characteristics of virus envelopes among injection drug users sampled prior to seroconversion (HIV RNA+/Ab-), within 1 year (early), and more than 2 years (chronic) after estimated acquisition. RESULTS Virus envelopes from 7 HIV RNA+/Ab- subjects possessed lower genetic diversity and divergence compared to 7 unrelated individuals sampled during the chronic phase of disease. Replication competent recombinant viruses incorporating the HIV RNA+/Ab- as compared to the chronic phase envelopes were significantly more sensitive to a CCR5 receptor inhibitor and IFN-α and showed a statistical trend toward greater sensitivity to a fusion blocker. The early as compared to chronic infection envelopes also demonstrated a statistical trend or significantly greater sensitivity to CCR5 and fusion inhibitor and IFN- α. The HIV RNA+/Ab- as compared to chronic envelope viruses replicated to a lower extent in mature monocyte derived dendritic cells - CD4+ T cell co-cultures, but there were no significant replication differences in other primary cells among the viruses with envelopes from the 3 different stages of infection. CONCLUSIONS Similar to mucosal acquisition, HIV-1 envelope quasispecies present in injection drug users prior to seroconversion have unique phenotypic properties compared to those circulating during the chronic phase of disease.
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Affiliation(s)
- Behzad Etemad
- Boston University School of Medicine, Boston, MA, USA.
| | | | - Laura White
- Boston University School of Public Health, Boston, MA, USA.
| | - Oliver Laeyendecker
- Johns Hopkins University School of Medicine, Baltimore, MD, USA.
- Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA.
| | - Gregory D Kirk
- Johns Hopkins University School of Medicine, Baltimore, MD, USA.
- Johns Hopkins University, Bloomberg School of Public Health, Baltimore, MD, USA.
| | - Shruti Mehta
- Johns Hopkins University School of Medicine, Baltimore, MD, USA.
- Johns Hopkins University, Bloomberg School of Public Health, Baltimore, MD, USA.
| | - Manish Sagar
- Boston University School of Medicine, Boston, MA, USA.
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202
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Poles J, Alvarez Y, Hioe CE. Induction of intestinal immunity by mucosal vaccines as a means of controlling HIV infection. AIDS Res Hum Retroviruses 2014; 30:1027-40. [PMID: 25354023 DOI: 10.1089/aid.2014.0233] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
CD4(+) T cells in the mucosa of the gastrointestinal (GI) tract are preferentially targeted and depleted by HIV. As such, the induction of an effective anti-HIV immune response in the mucosa of the GI tract-through vaccination-could protect this vulnerable population of cells. Mucosal vaccination provides a promising means of inducing robust humoral and cellular responses in the GI tract. Here we review data from the literature about the effectiveness of various mucosal vaccination routes--oral (intraintestinal/tonsilar/sublingual), intranasal, and intrarectal--with regard to the induction of immune responses mediated by cytotoxic T cells and antibodies in the GI mucosa, as well as protective efficacy in challenge models. We present data from the literature indicating that mucosal routes have the potential to effectively elicit GI mucosal immunity and protect against challenge. Given their capacity for the induction of anti-HIV immune responses in the GI mucosa, we propose that mucosal routes, including the nonconventional sublingual, tonsilar, and intrarectal routes, be considered for the delivery of the next generation HIV vaccines. However, further studies are necessary to determine the ideal vectors and vaccination regimens for these routes of immunization and to validate their efficacy in controlling HIV infection.
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Affiliation(s)
- Jordan Poles
- Department of Microbiology, New York University School of Medicine, New York, New York
| | - Yelina Alvarez
- VA New York Harbor Healthcare System–Manhattan Campus and Department of Pathology, New York University School of Medicine, New York, New York
| | - Catarina E. Hioe
- VA New York Harbor Healthcare System–Manhattan Campus and Department of Pathology, New York University School of Medicine, New York, New York
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203
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Ho TH, Cohen BL, Colombel JF, Mehandru S. Review article: the intersection of mucosal pathophysiology in HIV and inflammatory bowel disease, and its implications for therapy. Aliment Pharmacol Ther 2014; 40:1171-86. [PMID: 25267394 DOI: 10.1111/apt.12976] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/18/2014] [Revised: 09/04/2014] [Accepted: 09/10/2014] [Indexed: 12/11/2022]
Abstract
BACKGROUND The immunopathology of inflammatory bowel diseases (IBD) and HIV in the gastrointestinal (GI) tract can be viewed as ends of a spectrum with IBD being associated with 'immune excess' and HIV with 'immune paucity' within the GI tract. AIM To review the pathophysiology of IBD and HIV as they intersect in the gut immune system. METHODS A search was conducted in PubMed using defined keywords 'IBD, inflammatory bowel disease, Crohn's disease, ulcerative colitis, HIV, innate immunity, mucosal layer, macrophage, cytokine, dendritic cells, adaptive immunity, CD4, T cells, Th1, Th2, natural killer T cells (NKT)'. RESULTS Both the mucosal innate defence and adaptive immunity are profoundly affected by IBD and HIV. The pathophysiology of IBD and HIV with regard to mucosal barrier, macrophages, dendritic cells, NK cells, NKT cells and T-cell subsets is distinct yet closely interwoven. There is limited information on the clinical manifestations of patients who have both IBD and HIV. However, recent studies suggest that the clinical course of IBD may be attenuated by concurrent HIV infection - a premise that is reasonably supported by what is known of their pathophysiology. CONCLUSIONS It is apparent that through specific pathophysiological mechanisms, HIV is capable of attenuating inflammation in IBD. In the absence of experimental models, further clinical studies are necessary to better understand patients with concurrent disease and decipher the clinical and mechanistic relationship between HIV and IBD at mucosal surfaces. Such studies are critical to guide therapeutic decisions in the management of patients with IBD infected with HIV.
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Affiliation(s)
- T H Ho
- Division of Gastroenterology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, USA
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204
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Kim JH, Excler JL, Michael NL. Lessons from the RV144 Thai phase III HIV-1 vaccine trial and the search for correlates of protection. Annu Rev Med 2014; 66:423-37. [PMID: 25341006 DOI: 10.1146/annurev-med-052912-123749] [Citation(s) in RCA: 131] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
RV144 remains the only HIV-1 vaccine trial to demonstrate efficacy against HIV-1 acquisition. The prespecified analysis of immune correlates of risk showed that antibodies directed against the V1V2 region of gp120, in particular the IgG1 and IgG3 subclass mediating antibody-dependent cell-mediated cytotoxicity, seem to play a predominant role in protection against HIV-1 acquisition and that plasma envelope (Env)-specific IgA antibodies were directly correlated with risk. RV144 and recent nonhuman primate challenge studies suggest that Env is essential, and perhaps sufficient, to induce protective antibody responses against mucosal HIV-1 acquisition. Follow-up clinical trials are ongoing to further dissect the immune responses elicited by the RV144 ALVAC-HIV and AIDSVAX® B/E regimen. The study of gp120 Env immunogens and immune correlates of risk has resulted in the development of improved antigens. Whether the RV144 immune correlates of risk will generalize to other populations vaccinated with similar immunogens with different modes and intensity of transmission remains to be demonstrated. Efficacy trials are now planned in heterosexual populations in southern Africa and men who have sex with men in Thailand.
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Affiliation(s)
- Jerome H Kim
- US Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, Maryland 20910; ,
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205
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Wang Y, Yao WR, Duan JZ, Xu W, Yang GB. Mucosal addressin cell adhesion molecule-1 of rhesus macaques: molecular cloning, expression, and alteration after viral infection. Dig Dis Sci 2014; 59:2433-43. [PMID: 24828920 DOI: 10.1007/s10620-014-3209-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2014] [Accepted: 05/07/2014] [Indexed: 12/31/2022]
Abstract
BACKGROUND Mucosal addressin cell adhesion molecule-1 (MAdCAM-1), a member of the immunoglobulin superfamily, is essential for gut-specific homing of leukocytes; however, it has not been well characterized in rhesus macaques. AIMS To obtain the complete nucleotide sequence of rhesus macaque MAdCAM-1 cDNA and determine its distribution in gut-associated lymphoid tissues (GALT) and its alteration in duodenal mucosa after simian/human immunodeficiency virus (SHIV) infection. METHODS MAdCAM-1 cDNA was cloned from the colon mucosa of a rhesus macaque by 3'- and 5'-RACE. The distribution and abundance of MAdCAM-1 mRNA in the GALT were examined by nested and real-time RT-PCR. The alterations of MAdCAM-1 mRNA levels in SHIV-infected duodenal mucosa were determined by real-time RT-PCR. RESULTS The nucleotide sequence of rhesus macaque MAdCAM-1 cDNA (1,503 bp nucleotides) including the 5'- and 3'-untranslated regions was obtained. The coding region (1,086 bp) showed 87.56% and the Ig-like domain 1, 2 and TM + cytoplasmic domains showed >93% nucleotide sequence identity to that of humans. Like humans, rhesus macaques lacked MAdCAM-1 IgA1-like domain, which could be a common feature for all primates appeared later during vertebrate evolution. Two species of MAdCAM-1 mRNA were detected and high-level transcripts were observed primarily in the GALT. The full-length MAdCAM-1 expressed in vitro could bind to human α4β7. MAdCAM-1 mRNA levels were statistically significantly reduced in SHIV-infected duodenal mucosa. CONCLUSIONS These data provided a basis for using rhesus macaques in pathological and therapeutic studies on leukocyte homing related diseases such as inflammatory bowel disease and HIV/AIDS.
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Affiliation(s)
- Yue Wang
- National Center for AIDS/STD Control and Prevention, China-CDC, 155 Changbai Road, Changping District, Beijing, 102206, People's Republic of China
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206
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Cryptic determinant of α4β7 binding in the V2 loop of HIV-1 gp120. PLoS One 2014; 9:e108446. [PMID: 25265384 PMCID: PMC4180765 DOI: 10.1371/journal.pone.0108446] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Accepted: 08/21/2014] [Indexed: 11/30/2022] Open
Abstract
The peptide segment of the second variable loop of HIV-1 spanning positions 166–181 harbors two functionally important sites. The first, spanning positions 179–181, engages the human α4β7 integrin receptor which is involved in T-cell gut-homing and may play a role in human immunodeficiency virus (HIV)-host cell interactions. The second, at positions 166–178, is a major target of anti-V2 antibodies elicited by the ALVAC/AIDSVAX vaccine used in the RV144 clinical trial. Notably, these two sites are directly adjacent, but do not overlap. Here, we report the identity of a second determinant of α4β7 binding located at positions 170–172 of the V2 loop. This segment – tripeptide QRV170–172– is located within the second site, yet functionally affects the first site. The absence of this segment abrogates α4β7 binding in peptides bearing the same sequence from position 173–185 as the V2 loops of the RV144 vaccines. However, peptides exhibiting V2 loop sequences from heterologous HIV-1 strains that include this QRV170–172 motif bind the α4β7 receptor on cells. Therefore, the peptide segment at positions 166–178 of the V2 loop of HIV-1 viruses appears to harbor a cryptic determinant of α4β7 binding. Prior studies show that the anti-V2 antibody response elicited by the RV144 vaccine, along with immune pressure inferred from a sieve analysis, is directed to this same region of the V2 loop. Accordingly, the anti-V2 antibodies that apparently reduced the risk of infection in the RV144 trial may have functioned by blocking α4β7-mediated HIV-host cell interactions via this cryptic determinant.
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207
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Brandenberg OF, Rusert P, Magnus C, Weber J, Böni J, Günthard HF, Regoes RR, Trkola A. Partial rescue of V1V2 mutant infectivity by HIV-1 cell-cell transmission supports the domain's exceptional capacity for sequence variation. Retrovirology 2014; 11:75. [PMID: 25287422 PMCID: PMC4190450 DOI: 10.1186/s12977-014-0075-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2014] [Accepted: 08/13/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Variable loops 1 and 2 (V1V2) of the HIV-1 envelope glycoprotein gp120 perform two key functions: ensuring envelope trimer entry competence and shielding against neutralizing antibodies. While preserving entry functionality would suggest a high need for V1V2 sequence optimization and conservation, shielding efficacy is known to depend on a high flexibility of V1V2 giving rise to its substantial sequence variability. How entry competence of the trimer is maintained despite the continuous emergence of antibody escape mutations within V1V2 has not been resolved. Since HIV cell-cell transmission is considered a highly effective means of virus dissemination, we investigated whether cell-cell transmission may serve to enhance infectivity of V1V2 variants with debilitated free virus entry. RESULTS In a detailed comparison of wt and V1V2 mutant envelopes, V1V2 proved to be a key factor in ascertaining free virus infectivity, with V1V2 mutants displaying significantly reduced trimer integrity. Despite these defects, cell-cell transmission was able to partially rescue infectivity of V1V2 mutant viruses. We identified two regions, encompassing amino acids 156 to 160 (targeted by broadly neutralizing antibodies) and 175 to 180 (encompassing the α4β7 binding site) which were particularly prone to free virus infectivity loss upon mutation but maintained infectivity in cell-cell transmission. Of note, V1V2 antibody shielding proved important during both free virus infection and cell-cell transmission. CONCLUSIONS Based on our data we propose a model for V1V2 evolution that centers on cell-cell transmission as a salvage pathway for virus replication. Escape from antibody neutralization may frequently result in V1V2 mutations that reduce free virus infectivity. Cell-cell transmission could provide these escape viruses with sufficiently high replication levels that enable selection of compensatory mutations, thereby restoring free virus infectivity while ensuring antibody escape. Thus, our study highlights the need to factor in cell-cell transmission when considering neutralization escape pathways of HIV-1.
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208
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HIV-1 entry in SupT1-R5, CEM-ss, and primary CD4+ T cells occurs at the plasma membrane and does not require endocytosis. J Virol 2014; 88:13956-70. [PMID: 25253335 DOI: 10.1128/jvi.01543-14] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
UNLABELLED Cytoplasmic entry of HIV-1 requires binding of the viral glycoproteins to the cellular receptor and coreceptor, leading to fusion of viral and cellular membranes. Early studies suggested that productive HIV-1 infection occurs by direct fusion at the plasma membrane. Endocytotic uptake of HIV-1 was frequently observed but was considered to constitute an unspecific dead-end pathway. More recent evidence suggested that endocytosis contributes to productive HIV-1 entry and may even represent the predominant or exclusive route of infection. We have analyzed HIV-1 binding, endocytosis, cytoplasmic entry, and infection in T-cell lines and in primary CD4(+) T cells. Efficient cell binding and endocytosis required viral glycoproteins and CD4, but not the coreceptor. The contribution of endocytosis to cytoplasmic entry and infection was assessed by two strategies: (i) expression of dominant negative dynamin-2 was measured and was found to efficiently block HIV-1 endocytosis but to not affect fusion or productive infection. (ii) Making use of the fact that HIV-1 fusion is blocked at temperatures below 23 °C, cells were incubated with HIV-1 at 22 °C for various times, and endocytosis was quantified by parallel analysis of transferrin and fluorescent HIV-1 uptake. Subsequently, entry at the plasma membrane was blocked by high concentrations of the peptidic fusion inhibitor T-20, which does not reach previously endocytosed particles. HIV-1 infection was scored after cells were shifted to 37 °C in the presence of T-20. These experiments revealed that productive HIV-1 entry occurs predominantly at the plasma membrane in SupT1-R5, CEM-ss, and primary CD4(+) T cells, with little, if any, contribution coming from endocytosed virions. IMPORTANCE HIV-1, like all enveloped viruses, reaches the cytoplasm by fusion of the viral and cellular membranes. Many viruses enter the cytoplasm by endosomal uptake and fusion from the endosome, while cell entry can also occur by direct fusion at the plasma membrane in some cases. Conflicting evidence regarding the site of HIV-1 fusion has been reported, with some studies claiming that fusion occurs predominantly at the plasma membrane, while others have suggested predominant or even exclusive fusion from the endosome. We have revisited HIV-1 entry using a T-cell line that exhibits HIV-1 endocytosis dependent on the viral glycoproteins and the cellular CD4 receptor; results with this cell line were confirmed for another T-cell line and primary CD4(+) T cells. Our studies show that fusion and productive entry occur predominantly at the plasma membrane, and we conclude that endocytosis is dispensable for HIV-1 infectivity in these T-cell lines and in primary CD4(+) T cells.
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209
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Hayashi Y, Nemoto-Sasaki Y, Tanikawa T, Oka S, Tsuchiya K, Zama K, Mitsutake S, Sugiura T, Yamashita A. Sphingomyelin synthase 2, but not sphingomyelin synthase 1, is involved in HIV-1 envelope-mediated membrane fusion. J Biol Chem 2014; 289:30842-30856. [PMID: 25231990 DOI: 10.1074/jbc.m114.574285] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Membrane fusion between the viral envelope and plasma membranes of target cells has previously been correlated with HIV-1 infection. Lipids in the plasma membrane, including sphingomyelin, may be crucially involved in HIV-1 infection; however, the role of lipid-metabolic enzymes in membrane fusion remains unclear. In this study, we examined the roles of sphingomyelin synthase (SMS) in HIV-1 Env-mediated membrane fusion using a cell-cell fusion assay with HIV-1 mimetics and their target cells. We employed reconstituted cells as target cells that stably express Sms1 or Sms2 in Sms-deficient cells. Fusion susceptibility was ∼5-fold higher in Sms2-expressing cells (not in Sms1-expressing cells) than in Sms-deficient cells. The enhancement of fusion susceptibility observed in Sms2-expressing cells was reversed and reduced by Sms2 knockdown. We also found that catalytically nonactive Sms2 promoted membrane fusion susceptibility. Moreover, SMS2 co-localized and was constitutively associated with the HIV receptor·co-receptor complex in the plasma membrane. In addition, HIV-1 Env treatment resulted in a transient increase in nonreceptor tyrosine kinase (Pyk2) phosphorylation in Sms2-expressing and catalytically nonactive Sms2-expressing cells. We observed that F-actin polymerization in the region of membrane fusion was more prominent in Sms2-expressing cells than Sms-deficient cells. Taken together, our research provides insight into a novel function of SMS2 which is the regulation of HIV-1 Env-mediated membrane fusion via actin rearrangement.
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Affiliation(s)
- Yasuhiro Hayashi
- Faculty of Pharma-Sciences, Teikyo University, 2-11-1 Kaga, Itabashi-ku, Tokyo 173-8605
| | - Yoko Nemoto-Sasaki
- Faculty of Pharma-Sciences, Teikyo University, 2-11-1 Kaga, Itabashi-ku, Tokyo 173-8605
| | - Takashi Tanikawa
- Faculty of Pharma-Sciences, Teikyo University, 2-11-1 Kaga, Itabashi-ku, Tokyo 173-8605
| | - Saori Oka
- Faculty of Pharma-Sciences, Teikyo University, 2-11-1 Kaga, Itabashi-ku, Tokyo 173-8605
| | - Kiyoto Tsuchiya
- AIDS Clinical Center, National Center for Global Health and Medicine, 1-21-1 Toyama, Shinjuku-ku, Tokyo 162-8655
| | - Kouta Zama
- Departments of Biomembrane and Biofunctional Chemistry, Faculty of Advanced Life Science, Hokkaido University, Sapporo 001-0021, and
| | - Susumu Mitsutake
- Department of Applied Biochemistry and Food Science, Faculty of Agriculture, Saga University, Honjo-machi 1, Saga 840-8502, Japan
| | - Takayuki Sugiura
- Faculty of Pharma-Sciences, Teikyo University, 2-11-1 Kaga, Itabashi-ku, Tokyo 173-8605
| | - Atsushi Yamashita
- Faculty of Pharma-Sciences, Teikyo University, 2-11-1 Kaga, Itabashi-ku, Tokyo 173-8605,.
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210
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Mucosal immunity in the female genital tract, HIV/AIDS. BIOMED RESEARCH INTERNATIONAL 2014; 2014:350195. [PMID: 25313360 PMCID: PMC4181941 DOI: 10.1155/2014/350195] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 06/26/2014] [Revised: 08/27/2014] [Accepted: 08/28/2014] [Indexed: 01/15/2023]
Abstract
Mucosal immunity consists of innate and adaptive immune responses which can be influenced by systemic immunity. Despite having been the subject of intensive studies, it is not fully elucidated what exactly occurs after HIV contact with the female genital tract mucosa. The sexual route is the main route of HIV transmission, with an increased risk of infection in women compared to men. Several characteristics of the female genital tract make it suitable for inoculation, establishment of infection, and systemic spread of the virus, which causes local changes that may favor the development of infections by other pathogens, often called sexually transmitted diseases (STDs). The relationship of these STDs with HIV infection has been widely studied. Here we review the characteristics of mucosal immunity of the female genital tract, its alterations due to HIV/AIDS, and the characteristics of coinfections between HIV/AIDS and the most prevalent STDs.
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211
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Preferential infection of human Ad5-specific CD4 T cells by HIV in Ad5 naturally exposed and recombinant Ad5-HIV vaccinated individuals. Proc Natl Acad Sci U S A 2014; 111:13439-44. [PMID: 25197078 DOI: 10.1073/pnas.1400446111] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Efficacy trials of adenovirus 5-vectored candidate HIV vaccines [recombinant Ad5 (rAd5)-HIV] were halted for futility due to lack of vaccine efficacy and unexpected excess HIV infections in the vaccine recipients. The potential immunologic basis for these observations is unclear. We comparatively evaluated the HIV susceptibility and phenotypes of human CD4 T cells specific to Ad5 and CMV, two viruses that have been used as HIV vaccine vectors. We show that Ad5-specific CD4 T cells, either induced by natural Ad5 exposure or expanded by rAd5 vaccination, are highly susceptible to HIV in vitro and are preferentially lost in HIV-infected individuals compared with CMV-specific CD4 T cells. Further investigation demonstrated that Ad5-specific CD4 T cells selectively display a proinflammatory Th17-like phenotype and express macrophage inflammatory protein 3α and α4β7 integrin, suggestive of gut mucosa homing potential of these cells. Analysis of HIV p24 and cytokine coexpression using flow cytometry revealed preferential infection of IL-17- and IL-2-producing, Ad5-specific CD4 T cells by HIV in vitro. Our data suggest a potential mechanism explaining the excess HIV infections in vaccine recipients after rAd5-HIV vaccination and highlight the importance of testing the HIV susceptibility of vaccine-generated, vector and insert-specific CD4 T cells in future HIV vaccine studies.
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212
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O'Connell RJ, Kim JH, Excler JL. The HIV-1 gp120 V1V2 loop: structure, function and importance for vaccine development. Expert Rev Vaccines 2014; 13:1489-500. [PMID: 25163695 DOI: 10.1586/14760584.2014.951335] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Although the second variable loop (V2) of the HIV-1 gp120 envelope glycoprotein shows substantial sequence diversity between strains, its functional importance imposes critical conservation of structure, and within particular microdomains, of sequence. V2 influences HIV-1 viral entry by contributing to trimer stabilization and co-receptor binding. It is one of 4 key domains targeted by the broadly neutralizing antibodies that arise during HIV-1 infection. HIV-1 uses V1V2 sequence variation and glycosylation to escape neutralizing antibody. In the Thai Phase III HIV-1 vaccine trial, RV144, vaccine-induced IgG against V1V2 inversely correlated with the risk of HIV-1 acquisition, and HIV-1 strains infecting RV144 vaccine recipients differed from those infecting placebo recipients in the V2 domain. Similarly, non-human primate challenge studies demonstrated an inverse correlation between vaccine-induced anti-V2 responses and simian immunodeficiency virus acquisition. We hypothesize that increased magnitude, frequency and duration of vaccine-induced anti-V2 antibody responses should improve efficacy afforded by pox-protein prime-boost HIV vaccine strategies.
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Affiliation(s)
- Robert J O'Connell
- Armed Forces Research Institute of Medical Sciences (AFRIMS), 315/6 Rajvithi Road, Bangkok 10400, Thailand
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213
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Distinct mechanisms regulate exposure of neutralizing epitopes in the V2 and V3 loops of HIV-1 envelope. J Virol 2014; 88:12853-65. [PMID: 25165106 DOI: 10.1128/jvi.02125-14] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED Broadly neutralizing antibodies targeting the HIV-1 envelope (Env) are key components for protection against HIV-1. However, many cross-reactive epitopes are often occluded. This study investigates the mechanisms contributing to the masking of V2i (variable loop V2 integrin) epitopes compared to the accessibility of V3 epitopes. V2i are conformation-dependent epitopes encompassing the integrin α4β7-binding motif on the V1V2 loop of HIV-1 Env gp120. The V2i monoclonal antibodies (MAbs) display extensive cross-reactivity with gp120 monomers from many subtypes but neutralize only few viruses, indicating V2i's cryptic nature. First, we asked whether CD4-induced Env conformational changes affect V2i epitopes similarly to V3. CD4 treatment of BaL and JRFL pseudoviruses increased their neutralization sensitivity to V3 MAbs but not to the V2i MAbs. Second, the contribution of N-glycans in masking V2i versus V3 epitopes was evaluated by testing the neutralization of pseudoviruses produced in the presence of a glycosidase inhibitor, kifunensine. Viruses grown in kifunensine were more sensitive to neutralization by V3 but not V2i MAbs. Finally, we evaluated the time-dependent dynamics of the V2i and V3 epitopes. Extending the time of virus-MAb interaction to 18 h before adding target cells increased virus neutralization by some V2i MAbs and all V3 MAbs tested. Consistent with this, V2i MAb binding to Env on the surface of transfected cells also increased in a time-dependent manner. Hence, V2i and V3 epitopes are highly dynamic, but distinct factors modulate the antibody accessibility of these epitopes. The study reveals the importance of the structural dynamics of V2i and V3 epitopes in determining HIV-1 neutralization by antibodies targeting these sites. IMPORTANCE Conserved neutralizing epitopes are present in the V1V2 and V3 regions of HIV-1 Env, but these epitopes are often occluded from Abs. This study reveals that distinct mechanisms contribute to the masking of V3 epitopes and V2i epitopes in the V1V2 domain. Importantly, V3 MAbs and some V2i MAbs display greater neutralization against relatively resistant HIV-1 isolates when the MAbs interact with the virus for a prolonged period of time. Given their highly immunogenic nature, V3 and V2i epitopes are valuable targets that would augment the efficacy of HIV vaccines.
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214
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Raska M, Czernekova L, Moldoveanu Z, Zachova K, Elliott MC, Novak Z, Hall S, Hoelscher M, Maboko L, Brown R, Smith PD, Mestecky J, Novak J. Differential glycosylation of envelope gp120 is associated with differential recognition of HIV-1 by virus-specific antibodies and cell infection. AIDS Res Ther 2014; 11:23. [PMID: 25120578 PMCID: PMC4130436 DOI: 10.1186/1742-6405-11-23] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Accepted: 07/26/2014] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND HIV-1 entry into host cells is mediated by interactions between the virus envelope glycoprotein (gp120/gp41) and host-cell receptors. N-glycans represent approximately 50% of the molecular mass of gp120 and serve as potential antigenic determinants and/or as a shield against immune recognition. We previously reported that N-glycosylation of recombinant gp120 varied, depending on the producer cells, and the glycosylation variability affected gp120 recognition by serum antibodies from persons infected with HIV-1 subtype B. However, the impact of gp120 differential glycosylation on recognition by broadly neutralizing monoclonal antibodies or by polyclonal antibodies of individuals infected with other HIV-1 subtypes is unknown. METHODS Recombinant multimerizing gp120 antigens were expressed in different cells, HEK 293T, T-cell, rhabdomyosarcoma, hepatocellular carcinoma, and Chinese hamster ovary cell lines. Binding of broadly neutralizing monoclonal antibodies and polyclonal antibodies from sera of subtype A/C HIV-1-infected subjects with individual gp120 glycoforms was assessed by ELISA. In addition, immunodetection was performed using Western and dot blot assays. Recombinant gp120 glycoforms were tested for inhibition of infection of reporter cells by SF162 and YU.2 Env-pseudotyped R5 viruses. RESULTS We demonstrated, using ELISA, that gp120 glycans sterically adjacent to the V3 loop only moderately contribute to differential recognition of a short apex motif GPGRA and GPGR by monoclonal antibodies F425 B4e8 and 447-52D, respectively. The binding of antibodies recognizing longer peptide motifs overlapping with GPGR epitope (268 D4, 257 D4, 19b) was significantly altered. Recognition of gp120 glycoforms by monoclonal antibodies specific for other than V3-loop epitopes was significantly affected by cell types used for gp120 expression. These epitopes included CD4-binding site (VRC03, VRC01, b12), discontinuous epitope involving V1/V2 loop with the associated glycans (PG9, PG16), and an epitope including V3-base-, N332 oligomannose-, and surrounding glycans-containing epitope (PGT 121). Moreover, the different gp120 glycoforms variably inhibited HIV-1 infection of reporter cells. CONCLUSION Our data support the hypothesis that the glycosylation machinery of different cells shapes gp120 glycosylation and, consequently, impacts envelope recognition by specific antibodies as well as the interaction of HIV-1 gp120 with cellular receptors. These findings underscore the importance of selection of appropriately glycosylated HIV-1 envelope as a vaccine antigen.
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Morales JF, Morin TJ, Yu B, Tatsuno GP, O'Rourke SM, Theolis R, Mesa KA, Berman PW. HIV-1 envelope proteins and V1/V2 domain scaffolds with mannose-5 to improve the magnitude and quality of protective antibody responses to HIV-1. J Biol Chem 2014; 289:20526-42. [PMID: 24872420 PMCID: PMC4110267 DOI: 10.1074/jbc.m114.554089] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2014] [Revised: 05/07/2014] [Indexed: 01/15/2023] Open
Abstract
Two lines of investigation have highlighted the importance of antibodies to the V1/V2 domain of gp120 in providing protection from HIV-1 infection. First, the recent RV144 HIV-1 vaccine trial documented a correlation between non-neutralizing antibodies to the V2 domain and protection. Second, multiple broadly neutralizing monoclonal antibodies to the V1/V2 domain (e.g. PG9) have been isolated from rare infected individuals, termed elite neutralizers. Interestingly, the binding of both types of antibodies appears to depend on the same cluster of amino acids (positions 167–171) adjacent to the junction of the B and C strands of the four-stranded V1/V2 domain β-sheet structure. However, the broadly neutralizing mAb, PG9, additionally depends on mannose-5 glycans at positions 156 and 160 for binding. Because the gp120 vaccine immunogens used in previous HIV-1 vaccine trials were enriched for complex sialic acid-containing glycans, and lacked the high mannose structures required for the binding of PG9-like mAbs, we wondered if these immunogens could be improved by limiting glycosylation to mannose-5 glycans. Here, we describe the PG9 binding activity of monomeric gp120s from multiple strains of HIV-1 produced with mannose-5 glycans. We also describe the properties of glycopeptide scaffolds from the V1/V2 domain also expressed with mannose-5 glycans. The V1/V2 scaffold from the A244 isolate was able to bind the PG9, CH01, and CH03 mAbs with high affinity provided that the proper glycans were present. We further show that immunization with A244 V1/V2 fragments alone, or in a prime/boost regimen with gp120, enhanced the antibody response to sequences in the V1/V2 domain associated with protection in the RV144 trial.
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Affiliation(s)
- Javier F. Morales
- From the Department of Biomolecular Engineering, Baskin School of Engineering, University of California at Santa Cruz, Santa Cruz, California 95064
| | - Trevor J. Morin
- From the Department of Biomolecular Engineering, Baskin School of Engineering, University of California at Santa Cruz, Santa Cruz, California 95064
| | - Bin Yu
- From the Department of Biomolecular Engineering, Baskin School of Engineering, University of California at Santa Cruz, Santa Cruz, California 95064
| | - Gwen P. Tatsuno
- From the Department of Biomolecular Engineering, Baskin School of Engineering, University of California at Santa Cruz, Santa Cruz, California 95064
| | - Sara M. O'Rourke
- From the Department of Biomolecular Engineering, Baskin School of Engineering, University of California at Santa Cruz, Santa Cruz, California 95064
| | - Richard Theolis
- From the Department of Biomolecular Engineering, Baskin School of Engineering, University of California at Santa Cruz, Santa Cruz, California 95064
| | - Kathryn A. Mesa
- From the Department of Biomolecular Engineering, Baskin School of Engineering, University of California at Santa Cruz, Santa Cruz, California 95064
| | - Phillip W. Berman
- From the Department of Biomolecular Engineering, Baskin School of Engineering, University of California at Santa Cruz, Santa Cruz, California 95064
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Envelope glycoprotein binding to the integrin α4β7 is not a general property of most HIV-1 strains. J Virol 2014; 88:10767-77. [PMID: 25008916 DOI: 10.1128/jvi.03296-13] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED The HIV-1 surface glycoprotein gp120 has been reported to bind and signal through α4β7 by means of a tripeptide motif in the V2 loop that mimics structures present in the natural ligands for α4β7, suggesting that α4β7 may facilitate HIV-1 infection of CD4(+) T cells in the gut. Furthermore, immune correlates in the RV144 vaccine efficacy trial generated the hypothesis that V1V2 antibodies to an epitope near the putative α4β7 binding motif may play a role in protection against HIV-1 infection. In the interest of developing an assay to detect antibodies that block gp120 binding to α4β7, we used retinoic acid (RA)-activated human peripheral blood mononuclear cells (PBMCs) and transfected HEK293T (293T) cells expressing the integrin complex to study the α4β7 binding properties of 16 HIV-1 envelope glycoproteins. The natural ligand for α4β7, mucosal addressin cell adhesion molecule-1 (MAdCAM-1), bound efficiently to RA-activated PBMCs and transfected 293T cells, and this binding was blocked by antibodies to α4. gp120 from multiple HIV-1 subtypes bound to RA-activated PBMCs from three donors in a CD4-dependent manner, but little or no α4β7 binding was detected. Similarly, little or no binding to α4β7 on transfected 293T cells was detected with multiple gp120s and gp140s, including gp120s from transmitted/founder strains, or when gp120 was produced in CHO, 293T, and 293S/GnT1(-/-) cells. Finally, we found no evidence that infectious HIV-1 virions produced in either PBMCs or 293T cells could bind α4β7 on transfected 293T cells. Infectious HIV-1 virions and most gp120s/gp140s appear to be poor ligands for the α4β7 integrin complex under the conditions tested here. IMPORTANCE Certain HIV-1 gp120 envelope glycoproteins have been shown to bind the gut-homing receptor α4β7, and it has been suggested that this binding facilitates mucosal transmission and virus replication in the gut mucosa. Additional evidence has generated the hypothesis that antibodies that bind near the putative α4β7 binding motif in the V2 loop of gp120, possibly disrupting gp120-α4β7 binding, may be important for HIV-1 vaccines. Our evidence indicates that infectious HIV-1 virions and many gp120s lack detectable α4β7 binding activity, suggesting that this homing receptor may play a limited role in direct HIV-1 infection of cells.
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Nonneutralizing functional antibodies: a new "old" paradigm for HIV vaccines. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2014; 21:1023-36. [PMID: 24920599 DOI: 10.1128/cvi.00230-14] [Citation(s) in RCA: 96] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Animal and human data from various viral infections and vaccine studies suggest that nonneutralizing antibodies (nNAb) without neutralizing activity in vitro may play an important role in protection against viral infection in vivo. This was illustrated by the recent human immunodeficiency virus (HIV) RV144 vaccine efficacy trial, which demonstrated that HIV-specific IgG-mediated nNAb directed against the V2 loop of HIV type 1 envelope (Env) were inversely correlated with risk for HIV acquisition, while Env-specific plasma IgA-mediated antibodies were directly correlated with risk. However, tier 1 NAb in the subset of responders with a low level of plasma Env-specific IgA correlated with decreased risk. Nonhuman primate simian immunodeficiency virus (SIV) and simian-human immunodeficiency virus (SHIV) challenge studies suggest that Env-mediated antibodies are essential and sufficient for protection. A comparison of immune responses generated in human efficacy trials reveals subtle differences in the fine specificities of the antibody responses, in particular in HIV-specific IgG subclasses. The underlying mechanisms that may have contributed to protection against HIV acquisition in humans, although not fully understood, are possibly mediated by antibody-dependent cell-mediated cytotoxicity (ADCC) and/or other nonneutralizing humoral effector functions, such as antibody-mediated phagocytosis. The presence of such functional nNAb in mucosal tissues and cervico-vaginal and rectal secretions challenges the paradigm that NAb are the predominant immune response conferring protection, although this does not negate the desirability of evoking neutralizing antibodies through vaccination. Instead, NAb and nNAb should be looked upon as complementary or synergistic humoral effector functions. Several HIV vaccine clinical trials to study these antibody responses in various prime-boost modalities in the systemic and mucosal compartments are ongoing. The induction of high-frequency HIV-specific functional nNAb at high titers may represent an attractive hypothesis-testing strategy in future HIV vaccine efficacy trials.
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Rao M, Peachman KK, Kim J, Gao G, Alving CR, Michael NL, Rao VB. HIV-1 variable loop 2 and its importance in HIV-1 infection and vaccine development. Curr HIV Res 2014; 11:427-38. [PMID: 24191938 DOI: 10.2174/1570162x113116660064] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2013] [Revised: 05/24/2013] [Accepted: 06/13/2013] [Indexed: 12/30/2022]
Abstract
A vaccine that can prevent the transmission of HIV-1 at the site of exposure to the host is one of the best hopes to control the HIV-1 pandemic. The trimeric envelope spike consisting of heterodimers, gp120 and gp41, is essential for virus entry and thus has been a key target for HIV-1 vaccine development. However, it has been extremely difficult to identify the types of antibodies required to block the transmission of various HIV-1 strains and the immunogens that can elicit such antibodies due to the high genetic diversity of the HIV-1 envelope. The modest efficacy of the gp120 HIV-1 vaccine used in the RV144 Thai trial, including the studies on the immune correlates of protection, and the discovery of vaccine-induced immune responses to certain signature regions of the envelope have shown that the gp120 variable loop 2 (V2) is an important region. Since there is evidence that the V2 region interacts with the integrin α4β7 receptor of the host cell, and that this interaction might be important for virus capture, induction of antibodies against V2 loop could be postulated as one of the mechanisms to prevent the acquisition of HIV-1. Immunogens that can induce these antibodies should therefore be taken into consideration when designing HIV-1 vaccine formulations.
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Affiliation(s)
- Mangala Rao
- Laboratory of Adjuvant and Antigen Research, USMHRP at the Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Rm 2A08, Sliver Spring, MD 20910, USA.
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Goode D, Aravantinou M, Jarl S, Truong R, Derby N, Guerra-Perez N, Kenney J, Blanchard J, Gettie A, Robbiani M, Martinelli E. Sex hormones selectively impact the endocervical mucosal microenvironment: implications for HIV transmission. PLoS One 2014; 9:e97767. [PMID: 24830732 PMCID: PMC4022654 DOI: 10.1371/journal.pone.0097767] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2014] [Accepted: 04/22/2014] [Indexed: 12/29/2022] Open
Abstract
Several studies suggest that progesterone and estrogens may affect HIV transmission in different, possibly opposing ways. Nonetheless, a direct comparison of their effects on the mucosal immune system has never been done. We hypothesize that sex hormones might impact the availability of cells and immune factors important in early stages of mucosal transmission, and, in doing so influence the risk of HIV acquisition. To test this hypothesis, we employed 15 ovarectomized rhesus macaques: 5 were treated with Depot Medroxy Progesterone Acetate (DMPA), 6 with 17-β estradiol (E2) and 4 were left untreated. All animals were euthanized 5 weeks after the initiation of hormone treatment, a time post-DMPA injection associated with high susceptibility to SIV infection. We found that DMPA-treated macaques exhibited higher expression of integrin α4β7 (α4β7) on CD4+ T cells, the gut homing receptor and a marker of cells highly susceptible to HIV, in the endocervix than did the E2-treated animals. In contrast, the frequency of CCR5+ CD4+ T cells in DMPA-treated macaques was higher than in the E2-treated group in vaginal tissue, but lower in endocervix. α4β7 expression on dendritic cells (DCs) was higher in the DMPA-treated group in the endocervical tissue, but lower in vaginal tissue and on blood DCs compared with the E2-treated animals. Soluble MAdCAM-1, the α4β7 ligand, was present in the vaginal fluids of the control and E2-treated groups, but absent in the fluids from DMPA-treated animals. Both hormones modulated the expression and release of inflammatory factors and modified the distribution of sialomucins in the endocervix. In summary, we found that sex hormones profoundly impact mucosal immune factors that are directly implicated in HIV transmission. The effect is particularly significant in the endocervix. This may increase our understanding of the potential hormone-driven modulation of HIV susceptibility and potentially guide contraceptive policies in high-risk settings.
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Affiliation(s)
- Diana Goode
- Center for Biomedical Research, Population Council, New York, New York, United States of America
| | - Meropi Aravantinou
- Center for Biomedical Research, Population Council, New York, New York, United States of America
| | - Sebastian Jarl
- Center for Biomedical Research, Population Council, New York, New York, United States of America
| | - Rosaline Truong
- Center for Biomedical Research, Population Council, New York, New York, United States of America
| | - Nina Derby
- Center for Biomedical Research, Population Council, New York, New York, United States of America
| | - Natalia Guerra-Perez
- Center for Biomedical Research, Population Council, New York, New York, United States of America
| | - Jessica Kenney
- Center for Biomedical Research, Population Council, New York, New York, United States of America
| | - James Blanchard
- Tulane National Primate Research Center, Tulane University Sciences Center, Covington, Louisiana, United States of America
| | - Agegnehu Gettie
- Aaron Diamond AIDS Research Center, Rockefeller University, New York, New York, United States of America
| | - Melissa Robbiani
- Center for Biomedical Research, Population Council, New York, New York, United States of America
| | - Elena Martinelli
- Center for Biomedical Research, Population Council, New York, New York, United States of America
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221
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Hait SH, Darc M, Machado ES, Soares EA, Sprinz E, Soares MA. Conservation of the α4β7 lymphocyte homing receptor in HIV-infected patients with distinct transmission routes and disease progression profiles. AIDS Res Hum Retroviruses 2014; 30:493-7. [PMID: 24387749 DOI: 10.1089/aid.2013.0248] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The α4β7 is a lymphocyte homing receptor to the gut-associated lymphoid tissue (GALT). HIV-1 gp120 binds to α4β7 integrin through a mimetic tripeptide in V2 and ensures successful infection of GALT. In the present report, we investigated the presence of polymorphisms in the α4β7 cytoplasmic and α4 N-terminal binding domains and their potential association with susceptibility to HIV infection or disease progression. Subjects displaying distinct categories of disease progression or transmission routes (HIV-positive adults, vertically infected infants, and seronegative subjects) had their ITGA4 and ITGB7 gene segments corresponding to virus binding sites and C-terminal domains PCR amplified and sequenced. An absolute conservation of the studied regions was observed in all patients and controls. Albeit polymorphisms in α4β7 may exist in other regions not tracked in this study, α4β7 activation and binding domains do not seem to be polymorphic and are not correlated with distinct patterns of HIV transmission or disease progression.
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Affiliation(s)
- Sabrina H. Hait
- Departamento de Genética, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
- Programa de Genética, Instituto Nacional de Câncer, Rio de Janeiro, RJ, Brazil
| | - Mirela Darc
- Departamento de Genética, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
- Programa de Genética, Instituto Nacional de Câncer, Rio de Janeiro, RJ, Brazil
| | - Elizabeth S. Machado
- Departamento de Genética, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
- Hospital Universitário Clementino Fraga Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Esmeralda A. Soares
- Programa de Genética, Instituto Nacional de Câncer, Rio de Janeiro, RJ, Brazil
| | - Eduardo Sprinz
- Hospital de Clínicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Marcelo A. Soares
- Departamento de Genética, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
- Programa de Genética, Instituto Nacional de Câncer, Rio de Janeiro, RJ, Brazil
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Shannon B, Yi TJ, Thomas-Pavanel J, Chieza L, Janakiram P, Saunders M, Tharao W, Huibner S, Remis R, Rebbapragada A, Kaul R. Impact of asymptomatic herpes simplex virus type 2 infection on mucosal homing and immune cell subsets in the blood and female genital tract. THE JOURNAL OF IMMUNOLOGY 2014; 192:5074-82. [PMID: 24760150 DOI: 10.4049/jimmunol.1302916] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
HSV-2 infection is common and generally asymptomatic, but it is associated with increased HIV susceptibility and disease progression. This may relate to herpes-mediated changes in genital and systemic immunology. Cervical cytobrushes and blood were collected from HIV-uninfected African/Caribbean women in Toronto, and immune cell subsets were enumerated blindly by flow cytometry. Immune differences between groups were assessed by univariate analysis and confirmed using a multivariate model. Study participants consisted of 46 women, of whom 54% were infected with HSV-2. T cell activation and expression of the mucosal homing integrin α4β7 (19.60 versus 8.76%; p < 0.001) were increased in the blood of HSV-2-infected women. Furthermore, expression of α4β7 on blood T cells correlated with increased numbers of activated (coexpressing CD38/HLA-DR; p = 0.004) and CCR5(+) (p = 0.005) cervical CD4(+) T cells. HSV-2-infected women exhibited an increase in the number of cervical CD4(+) T cells (715 versus 262 cells/cytobrush; p = 0.016), as well as an increase in the number and proportion of cervical CD4(+) T cells that expressed CCR5(+) (406 versus 131 cells, p = 0.001; and 50.70 versus 34.90%, p = 0.004) and were activated (112 versus 13 cells, p < 0.001; and 9.84 versus 4.86%, p = 0.009). Mannose receptor expression also was increased on cervical dendritic cell subsets. In conclusion, asymptomatic HSV-2 infection was associated with significant systemic and genital immune changes, including increased immune activation and systemic α4β7 expression; correlation of the latter with highly HIV-susceptible CD4(+) T cell subsets in the cervix may provide a mechanism for the increased HIV susceptibility observed in asymptomatic HSV-2-infected women.
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Affiliation(s)
- Brett Shannon
- Department of Medicine, University of Toronto, Toronto, Ontario M5G 2C4, Canada; Department of Immunology, University of Toronto, Toronto, Ontario M5S 1A8, Canada;
| | - Tae Joon Yi
- Department of Medicine, University of Toronto, Toronto, Ontario M5G 2C4, Canada; Department of Immunology, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Jamie Thomas-Pavanel
- Women's Health in Women's Hands Community Health Centre, Toronto M5B 7J3, Ontario, Canada
| | - Lisungu Chieza
- Women's Health in Women's Hands Community Health Centre, Toronto M5B 7J3, Ontario, Canada
| | - Praseedha Janakiram
- Women's Health in Women's Hands Community Health Centre, Toronto M5B 7J3, Ontario, Canada
| | - Megan Saunders
- Women's Health in Women's Hands Community Health Centre, Toronto M5B 7J3, Ontario, Canada
| | - Wangari Tharao
- Women's Health in Women's Hands Community Health Centre, Toronto M5B 7J3, Ontario, Canada
| | - Sanja Huibner
- Department of Medicine, University of Toronto, Toronto, Ontario M5G 2C4, Canada; Department of Immunology, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Robert Remis
- Department of Epidemiology, University of Toronto, Toronto, Ontario M5T 3M7, Canada; Public Health Ontario - Toronto Public Health Laboratory, Toronto, Ontario M9P 3T1, Canada; and
| | - Anu Rebbapragada
- Department of Medicine, University of Toronto, Toronto, Ontario M5G 2C4, Canada; Public Health Ontario - Toronto Public Health Laboratory, Toronto, Ontario M9P 3T1, Canada; and
| | - Rupert Kaul
- Department of Medicine, University of Toronto, Toronto, Ontario M5G 2C4, Canada; Department of Immunology, University of Toronto, Toronto, Ontario M5S 1A8, Canada; University Health Network, Toronto, Ontario M5G 2C4, Canada
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Penton PK, Blackard JT. Analysis of HIV quasispecies suggests compartmentalization in the liver. AIDS Res Hum Retroviruses 2014; 30:394-402. [PMID: 24074301 DOI: 10.1089/aid.2013.0146] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Liver disease is now a major cause of morbidity and mortality among persons infected with the human immunodeficiency virus (HIV). An increasing body of evidence suggests that HIV infection is associated with exacerbated liver fibrosis and that HIV has the ability to infect several hepatic cell types. Despite the recognized existence of genetically distinct subpopulations of HIV in the central nervous system and genital tract, viral diversity and compartmentalization in the liver have not been explored extensively. Therefore, phylogenetic analysis was performed on full-length env and nef sequences for four patients. Distinct clustering of viral variants was observed for all patients in both areas of the genome. Statistical evidence of HIV compartmentalization in the liver was demonstrated in 85.4% of comparisons. Signature sequence analysis identified several liver-specific amino acids in all patients. Thus, the current study demonstrates statistically significant evidence for HIV compartmentalization in the liver. Additionally, these data suggest that the hepatic microenvironment harbors unique selective pressures that drive viral adaptation.
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Affiliation(s)
- Patricia K. Penton
- Division of Digestive Diseases, Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio
| | - Jason T. Blackard
- Division of Digestive Diseases, Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio
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Loss of a conserved N-linked glycosylation site in the simian immunodeficiency virus envelope glycoprotein V2 region enhances macrophage tropism by increasing CD4-independent cell-to-cell transmission. J Virol 2014; 88:5014-28. [PMID: 24554659 DOI: 10.1128/jvi.02785-13] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
UNLABELLED Human immunodeficiency virus (HIV) and simian immunodeficiency virus (SIV) strains differ in their capacity to replicate in macrophages, but mechanisms underlying these differences are not fully understood. Here, we identify a highly conserved N-linked glycosylation site (N173 in SIV, corresponding to N160 in HIV) in the V2 region of the SIV envelope glycoprotein (Env) as a novel determinant of macrophage tropism and characterize mechanisms underlying this phenotype. Loss of the N173 glycosylation site in the non-macrophage-tropic SIVmac239 by introducing an N173Q mutation enhanced viral replication and multinucleated giant cell formation upon infection of rhesus macrophages, while the addition of N173 to SIVmac251 had the opposite effect. The removal of N173 in SIVmac239 enhanced CD4-independent cell-to-cell transmission to CCR5-expressing cells. SIVmac239 with N173Q mediated CD4-independent cell-cell fusion but could not infect CD4-negative cells in single-round infections. Thus, CD4-independent phenotypes were detected only in the context of cell-to-cell contact. Similar results were obtained in SIVmac251 with and without N173. N173 decreased the neutralization sensitivity of SIVmac251 but had no effect on the neutralization sensitivity of SIVmac239. The N173Q mutation had no effect on SIVmac239 binding to CD4 in Biacore assays, coimmunoprecipitation assays, and enzyme-linked immunosorbent assays (ELISAs). These findings suggest that the loss of the N173 N-linked glycosylation site increases SIVmac239 replication in macrophages by enhancing CD4-independent cell-to-cell virus transmission through CCR5-mediated fusion. This mechanism may facilitate the escape of macrophage-tropic viruses from neutralizing antibodies while promoting spreading infection by these viruses in vivo. IMPORTANCE In this study, we identify a genetic determinant in the viral envelope (N173) that increases replication and spreading infection of SIV strains in macrophages by enhancing cell-to-cell virus transmission. This effect is explained by a novel mechanism involving increased cell-to-cell fusion in the absence of CD4, the primary receptor that normally mediates virus entry. The same genetic determinant also affects the sensitivity of these viruses to inhibition by neutralizing antibodies. Most macrophage-tropic HIV/SIV strains are known to be neutralization sensitive. Together, these findings suggest that this efficient mode of virus transmission may facilitate the escape of macrophage-tropic viruses from neutralizing antibodies while promoting spreading infection by these viruses to cells expressing little or no CD4 in vivo.
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Kiene M, Rethi B, Jansson M, Dillon S, Lee E, Lantto R, Wilson C, Pöhlmann S, Chiodi F. Toll-like receptor 3 signalling up-regulates expression of the HIV co-receptor G-protein coupled receptor 15 on human CD4+ T cells. PLoS One 2014; 9:e88195. [PMID: 24558379 PMCID: PMC3928197 DOI: 10.1371/journal.pone.0088195] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Accepted: 01/03/2014] [Indexed: 11/19/2022] Open
Abstract
Background Many HIV-2 and SIV isolates, as well as some HIV-1 strains, can use the orphan 7-transmembrane receptor GPR15 as co-receptor for efficient entry into host cells. GPR15 is expressed on central memory and effector memory CD4+ T cells in healthy individuals and a subset of these cells is susceptible to HIV-1 and SIV infection. However, it has not been determined whether GPR15 expression is altered in the context of HIV-1 infection. Results Here, we show that GPR15 expression in CD4+ T cells is markedly up-regulated in some HIV-1 infected individuals compared to the rest of the infected patients and to healthy controls. Infection of the PM1 T cell line with primary HIV-1 isolates was found to up-regulate GPR15 expression on the infected cells, indicating that viral components can induce GPR15 expression. Up-regulation of GPR15 expression on CD4+ T cells was induced by activation of Toll-like receptor 3 signalling via TIR-domain-containing adapter-inducing interferon-β (TRIF) and was more prominent on gut-homing compared to lymph node-homing CD4+ T cells. Conclusion These results suggest that infection-induced up-regulation of GPR15 expression could increase susceptibility of CD4+ T cells to HIV infection and target cell availability in the gut in some infected individuals.
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Affiliation(s)
- Miriam Kiene
- Institute of Virology, Hannover Medical School, Hannover, Germany
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Bence Rethi
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Marianne Jansson
- Department of Laboratory Medicine, Lund University, Lund, Sweden
| | - Stephanie Dillon
- Division of Infectious Diseases, University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States of America
| | - Eric Lee
- Division of Infectious Diseases, University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States of America
| | - Rebecka Lantto
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Cara Wilson
- Division of Infectious Diseases, University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States of America
| | - Stefan Pöhlmann
- Infection Biology Unit, German Primate Center, Göttingen, Germany
| | - Francesca Chiodi
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
- * E-mail:
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Zolla-Pazner S, deCamp A, Gilbert PB, Williams C, Yates NL, Williams WT, Howington R, Fong Y, Morris DE, Soderberg KA, Irene C, Reichman C, Pinter A, Parks R, Pitisuttithum P, Kaewkungwal J, Rerks-Ngarm S, Nitayaphan S, Andrews C, O’Connell RJ, Yang ZY, Nabel GJ, Kim JH, Michael NL, Montefiori DC, Liao HX, Haynes BF, Tomaras GD. Vaccine-induced IgG antibodies to V1V2 regions of multiple HIV-1 subtypes correlate with decreased risk of HIV-1 infection. PLoS One 2014; 9:e87572. [PMID: 24504509 PMCID: PMC3913641 DOI: 10.1371/journal.pone.0087572] [Citation(s) in RCA: 221] [Impact Index Per Article: 22.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2013] [Accepted: 12/16/2013] [Indexed: 11/18/2022] Open
Abstract
UNLABELLED In the RV144 HIV-1 vaccine efficacy trial, IgG antibody (Ab) binding levels to variable regions 1 and 2 (V1V2) of the HIV-1 envelope glycoprotein gp120 were an inverse correlate of risk of HIV-1 infection. To determine if V1V2-specific Abs cross-react with V1V2 from different HIV-1 subtypes, if the nature of the V1V2 antigen used to asses cross-reactivity influenced infection risk, and to identify immune assays for upcoming HIV-1 vaccine efficacy trials, new V1V2-scaffold antigens were designed and tested. Protein scaffold antigens carrying the V1V2 regions from HIV-1 subtypes A, B, C, D or CRF01_AE were assayed in pilot studies, and six were selected to assess cross-reactive Abs in the plasma from the original RV144 case-control cohort (41 infected vaccinees, 205 frequency-matched uninfected vaccinees, and 40 placebo recipients) using ELISA and a binding Ab multiplex assay. IgG levels to these antigens were assessed as correlates of risk in vaccine recipients using weighted logistic regression models. Levels of Abs reactive with subtype A, B, C and CRF01_AE V1V2-scaffold antigens were all significant inverse correlates of risk (p-values of 0.0008-0.05; estimated odds ratios of 0.53-0.68 per 1 standard deviation increase). Thus, levels of vaccine-induced IgG Abs recognizing V1V2 regions from multiple HIV-1 subtypes, and presented on different scaffolds, constitute inverse correlates of risk for HIV-1 infection in the RV144 vaccine trial. The V1V2 antigens provide a link between RV144 and upcoming HIV-1 vaccine trials, and identify reagents and methods for evaluating V1V2 Abs as possible correlates of protection against HIV-1 infection. TRIAL REGISTRATION ClinicalTrials.gov NCT00223080.
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Affiliation(s)
- Susan Zolla-Pazner
- Department of Veterans Affairs New York Harbor Healthcare System, New York, New York, United States of America
- New York University School of Medicine, New York, New York, United States of America
- * E-mail:
| | - Allan deCamp
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
| | - Peter B. Gilbert
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
| | - Constance Williams
- New York University School of Medicine, New York, New York, United States of America
| | - Nicole L. Yates
- Duke University, Durham, North Carolina, United States of America
| | | | - Robert Howington
- Duke University, Durham, North Carolina, United States of America
| | - Youyi Fong
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
| | - Daryl E. Morris
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
| | | | - Carmela Irene
- Public Health Research Institute, University of Medicine and Dentistry, Newark, New Jersey, United States of America
| | - Charles Reichman
- Public Health Research Institute, University of Medicine and Dentistry, Newark, New Jersey, United States of America
| | - Abraham Pinter
- Public Health Research Institute, University of Medicine and Dentistry, Newark, New Jersey, United States of America
| | - Robert Parks
- Duke University, Durham, North Carolina, United States of America
| | | | | | | | | | - Charla Andrews
- Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, Maryland, United States of America
| | - Robert J. O’Connell
- Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, Maryland, United States of America
| | - Zhi-yong Yang
- Virology Laboratory, Vaccine Research Center, National Institute for Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Gary J. Nabel
- Virology Laboratory, Vaccine Research Center, National Institute for Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Jerome H. Kim
- Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, Maryland, United States of America
| | - Nelson L. Michael
- Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, Maryland, United States of America
| | | | - Hua-Xin Liao
- Duke University, Durham, North Carolina, United States of America
| | - Barton F. Haynes
- Duke University, Durham, North Carolina, United States of America
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Functional implications of the binding mode of a human conformation-dependent V2 monoclonal antibody against HIV. J Virol 2014; 88:4100-12. [PMID: 24478429 DOI: 10.1128/jvi.03153-13] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
UNLABELLED Data from the RV144 HIV vaccine trial indicated that gp120 V2 antibodies were associated with a lower risk of infection; thus, the mapping of V2 epitopes can contribute to the design of an effective HIV vaccine. We solved the crystal structure of human monoclonal antibody (MAb) 2158, which targets a conformational V2 epitope overlapping the α4β7 integrin binding site, and constructed a full-length model of V1V2. Comparison of computational energy stability to experimental enzyme-linked immunosorbent assay (ELISA) results identified a hydrophobic core that stabilizes the V2 region for optimal 2158 binding, as well as residues that directly mediate side chain interactions with MAb 2158. These data define the binding surface recognized by MAb 2158 and offer a structural explanation for why a mismatched mutation at position 181 (I181X) in the V2 loop was associated with a higher vaccine efficiency in the RV144 clinical vaccine trial. IMPORTANCE Correlate analysis of the RV144 HIV-1 vaccine trial suggested that the presence of antibodies to the second variable region (V2) of HIV-1 gp120 was responsible for the modest protection observed in the trial. V2 is a highly variable and immunogenic region, and structural information on its antigenic landscape will be important for rational design of an effective HIV-1 vaccine. Using X-ray crystallography, computational design tools, and mutagenesis assays, we carried out a detailed and systematic investigation of the epitope recognition of human V2 MAb 2158 and demonstrated that its epitope region overlaps the integrin binding site within V2. In addition, we propose a structure-based mechanism for mismatching of the isoleucine at position 181 and the increased vaccine efficacy seen in the RV144 vaccine trial.
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228
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Reversible and efficient activation of HIV-1 cell entry by a tyrosine-sulfated peptide dissects endocytic entry and inhibitor mechanisms. J Virol 2014; 88:4304-18. [PMID: 24478426 DOI: 10.1128/jvi.03447-13] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED HIV-1 membranes contain gp120-gp41 trimers. Binding of gp120 to CD4 and a coreceptor (CCR5 or CXCR4) reduces the constraint on metastable gp41, enabling a series of conformational changes that cause membrane fusion. An analytic difficulty occurs because these steps occur slowly and asynchronously within cohorts of adsorbed virions. We previously isolated HIV-1JRCSF variants that efficiently use CCR5 mutants severely damaged in the tyrosine-sulfated amino terminus or extracellular loop 2. Surprisingly, both independent adaptations included gp120 mutations S298N, F313L, and N403S, supporting other evidence that they function by weakening gp120's grip on gp41 rather than by altering gp120 binding to specific CCR5 sites. Although several natural HIV-1 isolates reportedly use CCR5(Δ18) (CCR5 with a deletion of 18 N-terminal amino acids, including the tyrosine-sulfated region) when the soluble tyrosine-sulfated peptide is present, we show that HIV-1JRCSF with the adaptive mutations [HIV-1JRCSF(Ad)] functions approximately 100 times more efficiently and that coreceptor activation is reversible, enabling synchronous efficient entry control under physiological conditions. This system revealed that three-stranded gp41 folding intermediates susceptible to the inhibitor enfuvirtide form slowly and asynchronously on cell surface virions but resolve rapidly, with virions generally forming only one target. Adsorbed virions asynchronously and transiently become competent for entry at 37°C but are inactivated if the CCR5 peptide is absent during their window of opportunity. This competency is conferred by endocytosis, which results in inactivation if the peptide is absent. For both wild-type and adapted HIV-1 isolates, early gp41 refolding steps obligatorily occur on cell surfaces, whereas the final step(s) is endosomal. This system powerfully dissects HIV-1 entry and inhibitor mechanisms. IMPORTANCE We present a powerful means to reversibly and efficiently activate or terminate HIV-1 entry by adding or removing a tyrosine-sulfated CCR5 peptide from the culture medium. This system uses stable cell clones and a variant of HIV-1JRCSF with three adaptive mutations. It enabled us to show that CCR5 coreceptor activation is rapidly reversible and to dissect aspects of entry that had previously been relatively intractable. Our analyses elucidate enfuvirtide (T-20) function and suggest that HIV-1 virions form only one nonredundant membrane fusion complex on cell surfaces. Additionally, we obtained novel and conclusive evidence that HIV-1 entry occurs in an assembly line manner, with some steps obligatorily occurring on cell surfaces and with final membrane fusion occurring in endosomes. Our results were confirmed for wild-type HIV-1. Thus, our paper provides major methodological and mechanistic insights about HIV-1 infection.
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229
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Early infection HIV-1 envelope V1-V2 genotypes do not enhance binding or replication in cells expressing high levels of α4β7 integrin. J Acquir Immune Defic Syndr 2014; 64:249-53. [PMID: 23797693 DOI: 10.1097/qai.0b013e3182a06ddd] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
It has been postulated that HIV-1 envelope properties, such as shorter and less-glycosylated V1-V2 loops commonly observed among non-subtype B early-transmitted viruses, promote utilization of the gut homing integrin α4β7. This property potentially confers an advantage to some HIV-1 variants early after acquisition. We found that replication-competent recombinant viruses incorporating HIV-1 subtype A compact and less-glycosylated early versus chronic phase V1-V2 loops demonstrated no significant difference in binding to α4β7 high CD8⁺ T cells or replication in α4β7 high CD4⁺ T cells. Integrin α4β7 usage does not select for shorter less-glycosylated envelopes during transmission.
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230
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Klatt NR, Chomont N, Douek DC, Deeks SG. Immune activation and HIV persistence: implications for curative approaches to HIV infection. Immunol Rev 2014; 254:326-42. [PMID: 23772629 DOI: 10.1111/imr.12065] [Citation(s) in RCA: 303] [Impact Index Per Article: 30.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Despite complete or near-complete suppression of human immunodeficiency virus (HIV) replication with combination antiretroviral therapy, both HIV and chronic inflammation/immune dysfunction persist indefinitely. Untangling the association between the virus and the host immune environment during therapy might lead to novel interventions aimed at either curing the infection or preventing the development of inflammation-associated end-organ disease. Chronic inflammation and immune dysfunction might lead to HIV persistence by causing virus production, generating new target cells, enabling infecting of activated and resting target cells, altering the migration patterns of susceptible target cells, increasing the proliferation of infected cells, and preventing normal HIV-specific clearance mechanisms from function. Chronic HIV production or replication might contribute to persistent inflammation and immune dysfunction. The rapidly evolving data on these issues strongly suggest that a vicious cycle might exist in which HIV persistence causes inflammation that in turn contributes to HIV persistence.
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Affiliation(s)
- Nichole R Klatt
- Department of Pharmaceutics, Washington National Primate Research Center, University of Washington, Seattle, WA, USA
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231
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Kulpa DA, Brehm JH, Fromentin R, Cooper A, Cooper C, Ahlers J, Chomont N, Sékaly RP. The immunological synapse: the gateway to the HIV reservoir. Immunol Rev 2014; 254:305-25. [PMID: 23772628 PMCID: PMC3707302 DOI: 10.1111/imr.12080] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
A major challenge in the development of a cure for human immunodeficiency virus (HIV) has been the incomplete understanding of the basic mechanisms underlying HIV persistence during antiretroviral therapy. It is now realized that the establishment of a latently infected reservoir refractory to immune system recognition has thus far hindered eradication efforts. Recent investigation into the innate immune response has shed light on signaling pathways downstream of the immunological synapse critical for T-cell activation and establishment of T-cell memory. This has led to the understanding that the cell-to-cell contacts observed in an immunological synapse that involve the CD4+ T cell and antigen-presenting cell or T-cell–T-cell interactions enhance efficient viral spread and facilitate the induction and maintenance of latency in HIV-infected memory T cells. This review focuses on recent work characterizing the immunological synapse and the signaling pathways involved in T-cell activation and gene regulation in the context of HIV persistence.
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Affiliation(s)
- Deanna A Kulpa
- Division of Infectious Diseases, Vaccine and Gene Therapy Institute-Florida (VGTI-FL), Port Saint Lucie, FL 34987, USA
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232
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McKinnon LR, Hughes SM, De Rosa SC, Martinson JA, Plants J, Brady KE, Gumbi PP, Adams DJ, Vojtech L, Galloway CG, Fialkow M, Lentz G, Gao D, Shu Z, Nyanga B, Izulla P, Kimani J, Kimwaki S, Bere A, Moodie Z, Landay AL, Passmore JAS, Kaul R, Novak RM, McElrath MJ, Hladik F. Optimizing viable leukocyte sampling from the female genital tract for clinical trials: an international multi-site study. PLoS One 2014; 9:e85675. [PMID: 24454917 PMCID: PMC3893217 DOI: 10.1371/journal.pone.0085675] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2013] [Accepted: 12/06/2013] [Indexed: 11/18/2022] Open
Abstract
Background Functional analysis of mononuclear leukocytes in the female genital mucosa is essential for understanding the immunologic effects of HIV vaccines and microbicides at the site of HIV exposure. However, the best female genital tract sampling technique is unclear. Methods and Findings We enrolled women from four sites in Africa and the US to compare three genital leukocyte sampling methods: cervicovaginal lavages (CVL), endocervical cytobrushes, and ectocervical biopsies. Absolute yields of mononuclear leukocyte subpopulations were determined by flow cytometric bead-based cell counting. Of the non-invasive sampling types, two combined sequential cytobrushes yielded significantly more viable mononuclear leukocytes than a CVL (p<0.0001). In a subsequent comparison, two cytobrushes yielded as many leukocytes (∼10,000) as one biopsy, with macrophages/monocytes being more prominent in cytobrushes and T lymphocytes in biopsies. Sample yields were consistent between sites. In a subgroup analysis, we observed significant reproducibility between replicate same-day biopsies (r = 0.89, p = 0.0123). Visible red blood cells in cytobrushes increased leukocyte yields more than three-fold (p = 0.0078), but did not change their subpopulation profile, indicating that these leukocytes were still largely derived from the mucosa and not peripheral blood. We also confirmed that many CD4+ T cells in the female genital tract express the α4β7 integrin, an HIV envelope-binding mucosal homing receptor. Conclusions CVL sampling recovered the lowest number of viable mononuclear leukocytes. Two cervical cytobrushes yielded comparable total numbers of viable leukocytes to one biopsy, but cytobrushes and biopsies were biased toward macrophages and T lymphocytes, respectively. Our study also established the feasibility of obtaining consistent flow cytometric analyses of isolated genital cells from four study sites in the US and Africa. These data represent an important step towards implementing mucosal cell sampling in international clinical trials of HIV prevention.
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Affiliation(s)
- Lyle R. McKinnon
- Department of Medicine, University of Toronto, Toronto, Canada
- Department of Medical Microbiology, University of Nairobi, Nairobi, Kenya
| | - Sean M. Hughes
- Department of Obstetrics and Gynecology, University of Washington, Seattle, Washington, United States of America
| | - Stephen C. De Rosa
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
- Department of Laboratory Medicine, University of Washington, Seattle, Washington, United States of America
| | - Jeffrey A. Martinson
- Department of Immunology and Microbiology, Rush University Medical Center, Chicago, Illinois, United States of America
| | - Jill Plants
- Department of Immunology and Microbiology, Rush University Medical Center, Chicago, Illinois, United States of America
| | - Kirsten E. Brady
- Department of Immunology and Microbiology, Rush University Medical Center, Chicago, Illinois, United States of America
| | - Pamela P. Gumbi
- Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town, South Africa
| | - Devin J. Adams
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
| | - Lucia Vojtech
- Department of Obstetrics and Gynecology, University of Washington, Seattle, Washington, United States of America
| | - Christine G. Galloway
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
| | - Michael Fialkow
- Department of Obstetrics and Gynecology, University of Washington, Seattle, Washington, United States of America
| | - Gretchen Lentz
- Department of Obstetrics and Gynecology, University of Washington, Seattle, Washington, United States of America
| | - Dayong Gao
- Department of Mechanical Engineering, University of Washington, Seattle, Washington, United States of America
| | - Zhiquan Shu
- Department of Mechanical Engineering, University of Washington, Seattle, Washington, United States of America
| | - Billy Nyanga
- Department of Medical Microbiology, University of Nairobi, Nairobi, Kenya
| | - Preston Izulla
- Department of Medical Microbiology, University of Nairobi, Nairobi, Kenya
| | - Joshua Kimani
- Department of Medical Microbiology, University of Nairobi, Nairobi, Kenya
| | - Steve Kimwaki
- Department of Medical Microbiology, University of Nairobi, Nairobi, Kenya
| | - Alfred Bere
- Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town, South Africa
| | - Zoe Moodie
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
| | - Alan L. Landay
- Department of Immunology and Microbiology, Rush University Medical Center, Chicago, Illinois, United States of America
| | - Jo-Ann S. Passmore
- Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town, South Africa
- National Health Laboratory Services, Cape Town, South Africa
| | - Rupert Kaul
- Department of Medicine, University of Toronto, Toronto, Canada
- Department of Medical Microbiology, University of Nairobi, Nairobi, Kenya
- Department of Medicine, University Health Network, Toronto, Canada
| | - Richard M. Novak
- College of Medicine, University of Illinois, Chicago, Illinois, United States of America
| | - M. Juliana McElrath
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
- Department of Medicine, University of Washington, Seattle, Washington, United States of America
- Department of Laboratory Medicine, University of Washington, Seattle, Washington, United States of America
- Department of Global Health, University of Washington, Seattle, Washington, United States of America
| | - Florian Hladik
- Department of Obstetrics and Gynecology, University of Washington, Seattle, Washington, United States of America
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
- Department of Medicine, University of Washington, Seattle, Washington, United States of America
- * E-mail:
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233
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Liu A, Yang Y, Liu L, Meng Z, Li L, Qiu C, Xu J, Zhang X. Differential compartmentalization of HIV-targeting immune cells in inner and outer foreskin tissue. PLoS One 2014; 9:e85176. [PMID: 24454812 PMCID: PMC3893184 DOI: 10.1371/journal.pone.0085176] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2013] [Accepted: 11/22/2013] [Indexed: 11/18/2022] Open
Abstract
Ex vivo foreskin models have demonstrated that inner foreskin is more susceptible to HIV-1 infection than outer foreskin. In the present study we characterized the compartition of HIV-1 target cells and quantified these cells in the epidermis and dermis of inner and outer foreskins using immunohistochemistry and flow cytometry. Our data showed that the epidermis of the inner foreskin was more enriched with CD4+ T cells and Langerhans cells (LCs), with the co-expression of CCR5 and α4β7 receptors, than the outer foreskin. Interestingly, the vast majority of CD4+ T cells and LCs expressed CCR5, but not CXCR4, indicating that the inner foreskin might capture and transmit R5-tropic HIV strains more efficiently. In addition, lymphoid aggregates, composed of T cells, macrophages and dendritic cells (DCs) in the dermis, were closer to the epithelial surface in the inner foreskin than in the outer foreskin. As dendritic cells are able to capture and pass HIV particles to susceptible target cells, HIV may be able to more efficiently infect the inner foreskin by hijacking the augmented immune communication pathways in this tissue. After the inoculation of HIV-1 particles in a foreskin explant culture model, the level of p24 antigen in the supernatant from the inner foreskin was slightly higher than that from the outer foreskin, although this difference was not significant. The present study is the first to employ both CCR5 and α4β7 to identify HIV target cells in the foreskin. Our data demonstrated that the inner foreskin was more enriched with HIV target immune cells than the outer foreskin, and this tissue was structured for efficient communication among immune cells that may promote HIV transmission and replication. In addition, our data suggests the R5-tropism of HIV sexual transmission is likely shaped through the inherent receptor composition on HIV target cells in the mucosa.
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Affiliation(s)
- Aiping Liu
- Shanghai Public Health Clinical Center and Institutes of Biomedical Sciences, Key Laboratory of Medical Molecular Virology, Shanghai Medical College of Fudan University, Shanghai, China
| | - Yu Yang
- Shanghai Public Health Clinical Center and Institutes of Biomedical Sciences, Key Laboratory of Medical Molecular Virology, Shanghai Medical College of Fudan University, Shanghai, China
| | - Lu Liu
- Shanghai Public Health Clinical Center and Institutes of Biomedical Sciences, Key Laboratory of Medical Molecular Virology, Shanghai Medical College of Fudan University, Shanghai, China
| | - Zhefeng Meng
- Shanghai Public Health Clinical Center and Institutes of Biomedical Sciences, Key Laboratory of Medical Molecular Virology, Shanghai Medical College of Fudan University, Shanghai, China
| | - Liangzhu Li
- Shanghai Public Health Clinical Center and Institutes of Biomedical Sciences, Key Laboratory of Medical Molecular Virology, Shanghai Medical College of Fudan University, Shanghai, China
| | - Chao Qiu
- Shanghai Public Health Clinical Center and Institutes of Biomedical Sciences, Key Laboratory of Medical Molecular Virology, Shanghai Medical College of Fudan University, Shanghai, China
| | - Jianqing Xu
- Shanghai Public Health Clinical Center and Institutes of Biomedical Sciences, Key Laboratory of Medical Molecular Virology, Shanghai Medical College of Fudan University, Shanghai, China
- * E-mail: (JX); (XZ)
| | - Xiaoyan Zhang
- Shanghai Public Health Clinical Center and Institutes of Biomedical Sciences, Key Laboratory of Medical Molecular Virology, Shanghai Medical College of Fudan University, Shanghai, China
- * E-mail: (JX); (XZ)
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234
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Li FJ, Won WJ, Becker EJ, Easlick JL, Tabengwa EM, Li R, Shakhmatov M, Honjo K, Burrows PD, Davis RS. Emerging roles for the FCRL family members in lymphocyte biology and disease. Curr Top Microbiol Immunol 2014; 382:29-50. [PMID: 25116094 DOI: 10.1007/978-3-319-07911-0_2] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Members of the extended Fc receptor-like (FCRL) family in humans and mice are preferentially expressed by B cells and possess tyrosine-based immunoregulatory function. Although the majority of these proteins repress B cell receptor-mediated activation, there is an emerging evidence for their bifunctionality and capacity to counter-regulate adaptive and innate signaling pathways. In light of these findings, the recent discovery of ligands for several of these molecules has begun to reveal exciting potential for them in normal lymphocyte biology and is launching a new phase of FCRL investigation. Importantly, these fundamental developments are also setting the stage for defining their altered roles in the pathogenesis of a growing number of immune-mediated diseases. Here we review recent advances in the FCRL field and highlight the significance of these intriguing receptors in normal and perturbed immunobiology.
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Affiliation(s)
- F J Li
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
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235
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Dürr R, Keppler O, Christ F, Crespan E, Garbelli A, Maga G, Dietrich U. Targeting Cellular Cofactors in HIV Therapy. TOPICS IN MEDICINAL CHEMISTRY 2014. [DOI: 10.1007/7355_2014_45] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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236
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Sereti I, Estes JD, Thompson WL, Morcock DR, Fischl MA, Croughs T, Beq S, Lafaye de Micheaux S, Yao MD, Ober A, Wilson EMP, Natarajan V, Imamichi H, Boulassel MR, Lederman MM, Routy JP. Decreases in colonic and systemic inflammation in chronic HIV infection after IL-7 administration. PLoS Pathog 2014; 10:e1003890. [PMID: 24497828 PMCID: PMC3907377 DOI: 10.1371/journal.ppat.1003890] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2013] [Accepted: 12/04/2013] [Indexed: 12/12/2022] Open
Abstract
Despite antiretroviral therapy (ART), some HIV-infected persons maintain lower than normal CD4(+) T-cell counts in peripheral blood and in the gut mucosa. This incomplete immune restoration is associated with higher levels of immune activation manifested by high systemic levels of biomarkers, including sCD14 and D-dimer, that are independent predictors of morbidity and mortality in HIV infection. In this 12-week, single-arm, open-label study, we tested the efficacy of IL-7 adjunctive therapy on T-cell reconstitution in peripheral blood and gut mucosa in 23 ART suppressed HIV-infected patients with incomplete CD4(+) T-cell recovery, using one cycle (consisting of three subcutaneous injections) of recombinant human IL-7 (r-hIL-7) at 20 µg/kg. IL-7 administration led to increases of both CD4(+) and CD8(+) T-cells in peripheral blood, and importantly an expansion of T-cells expressing the gut homing integrin α4β7. Participants who underwent rectosigmoid biopsies at study baseline and after treatment had T-cell increases in the gut mucosa measured by both flow cytometry and immunohistochemistry. IL-7 therapy also resulted in apparent improvement in gut barrier integrity as measured by decreased neutrophil infiltration in the rectosigmoid lamina propria 12 weeks after IL-7 administration. This was also accompanied by decreased TNF and increased FOXP3 expression in the lamina propria. Plasma levels of sCD14 and D-dimer, indicative of systemic inflammation, decreased after r-hIL-7. Increases of colonic mucosal T-cells correlated strongly with the decreased systemic levels of sCD14, the LPS coreceptor - a marker of monocyte activation. Furthermore, the proportion of inflammatory monocytes expressing CCR2 was decreased, as was the basal IL-1β production of peripheral blood monocytes. These data suggest that administration of r-hIL-7 improves the gut mucosal abnormalities of chronic HIV infection and attenuates the systemic inflammatory and coagulation abnormalities that have been linked to it.
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Affiliation(s)
- Irini Sereti
- National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Jacob D. Estes
- Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc, Frederick, Maryland, United States of America
| | - William L. Thompson
- National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - David R. Morcock
- Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc, Frederick, Maryland, United States of America
| | - Margaret A. Fischl
- University of Miami School of Medicine, Miami, Florida, United States of America
| | | | | | | | - Michael D. Yao
- National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Alexander Ober
- National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Eleanor M. P. Wilson
- National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Ven Natarajan
- Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc, Frederick, Maryland, United States of America
| | - Hiromi Imamichi
- National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
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Virion attachment and entry: HIV gp120 Env biotinylation, gp120 Env, or integrin ligand-binding assay. Methods Mol Biol 2014; 1087:3-12. [PMID: 24158809 DOI: 10.1007/978-1-62703-670-2_1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The HIV-1 entry receptors are CD4 and a chemokine receptor (CCR5 or CXCR4). In addition it has recently been demonstrated that HIV-1 gp120 binds to and signals through integrin α4β7, the gut-homing receptor (Arthos et al., Nat Immunol 9(3):301-309, 2008). Integrin α4β7 is not an entry receptor for HIV-1, although it can facilitate virion attachment to target cells (Arthos et al., Nat Immunol 9(3):301-309, 2008; Cicala et al., Proc Natl Acad Sci U S A 106:20877-20882, 2009). Recombinant HIV-1 gp120s bind to integrin α4β7 in a manner similar to its natural ligands (MAdCAM-1, V-CAM-1, fibronectin) (Andrew et al., J Immunol 153:3847-3861, 1994). gp120-α4β7 interactions are detected in a manner similar to assays developed for the natural ligands of α4β7. In this chapter we describe a method for the analysis of integrin-gp120 binding via a cell-based binding assay. In vitro ligand-integrin affinity can be modified by the presence of divalent cations (Mn(2+), Mg(2+), Ca(2+)) (Leitinger et al., Leitinger Biochim Biophys Acta 1498:91-98, 2000). Here we describe a protocol to detect biotinylated recombinant HIV-1 gp120 binding to integrin α4β7 in both primary cells and cell lines expressing the gut-homing receptor.
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238
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Pena-Cruz V, Etemad B, Chatziandreou N, Nyein PH, Stock S, Reynolds SJ, Laeyendecker O, Gray RH, Serwadda D, Lee SJ, Quinn TC, Sagar M. HIV-1 envelope replication and α4β7 utilization among newly infected subjects and their corresponding heterosexual partners. Retrovirology 2013; 10:162. [PMID: 24369910 PMCID: PMC3883469 DOI: 10.1186/1742-4690-10-162] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2013] [Accepted: 12/10/2013] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND Previous studies suggest that active selection limits the number of HIV-1 variants acquired by a newly infected individual from the diverse variants circulating in the transmitting partner. We compared HIV-1 envelopes from 9 newly infected subjects and their linked transmitting partner to explore potential mechanisms for selection. RESULTS Recipient virus envelopes had significant genotypic differences compared to those present in the transmitting partner. Recombinant viruses incorporating pools of recipient and transmitter envelopes showed no significant difference in their sensitivity to receptor and fusion inhibitors, suggesting they had relatively similar entry capacity in the presence of low CD4 and CCR5 levels. Aggregate results in primary cells from up to 4 different blood or skin donors showed that viruses with envelopes from the transmitting partner as compared to recipient envelopes replicated more efficiently in CD4+ T cells, monocyte derived dendritic cell (MDDC) - CD4+ T cell co-cultures, Langerhans cells (LCs) - CD4+ T cell co-cultures and CD4+ T cells expressing high levels of the gut homing receptor, α4β7, and demonstrated greater binding to α4β7 high / CD8+ T cells. These transmitter versus recipient envelope virus phenotypic differences, however, were not always consistent among the primary cells from all the different blood or skin donation volunteers. CONCLUSION Although genotypically unique variants are present in newly infected individuals compared to the diverse swarm circulating in the chronically infected transmitting partner, replication in potential early target cells and receptor utilization either do not completely dictate this genetic selection, or these potential transmission phenotypes are lost very soon after HIV-1 acquisition.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | - Manish Sagar
- Department of Medicine, Division of Infectious Diseases, Boston University, Boston, MA, USA.
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The frequency of α₄β₇(high) memory CD4⁺ T cells correlates with susceptibility to rectal simian immunodeficiency virus infection. J Acquir Immune Defic Syndr 2013; 64:325-31. [PMID: 23797688 DOI: 10.1097/qai.0b013e31829f6e1a] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
BACKGROUND Integrin α₄β₇(high) (α₄β₇(high)) mediates the homing of CD4⁺ T cells to gut-associated lymphoid tissues, which constitute a highly favorable environment for HIV expansion and dissemination. HIV and simian immunodeficiency virus (SIV) envelope proteins bind to and signal through α₄β₇(high) and during acute infection SIV preferentially infects α₄β₇(high) CD4⁺ T cells. We postulated that the availability of these cells at the time of challenge could influence mucosal SIV transmission and acute viral load (VL). METHODS We challenged 17 rhesus macaques with 3000 TCID50 of SIVmac239 rectally and followed the subsets of α₄β₇(high) T cells and dendritic cells (DCs) by flow cytometry in blood and tissues, before and after challenge. RESULTS We found that the frequency of memory CD4⁺ T cells that expressed high levels of α₄β₇(high) (α₄β₇(high) memory CD4⁺ T cells) in blood before challenge correlated strongly with susceptibility to infection and acute VL. Notably, not only at the time of challenge but also their frequency 3 weeks before challenge correlated with infection. This association extended to the rectal tissue as we observed a strong direct correlation between the frequency of α₄β₇(high) memory CD4⁺ T cells in blood and rectum before and after challenge. The frequency of α4β7 myeloid DCs and α₄β₇(high) CD80⁺ DCs also correlated with infection and acute VL, whereas blood CCR5⁺ and CD69⁺ CD4⁺ T cells could not be associated with infection. CONCLUSIONS Our results suggest that animals with higher frequency of α₄β₇(high) CD4⁺ T cells in circulation and in rectal tissue could be more susceptible to SIV rectal transmission.
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240
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Boasso A. Type I Interferon at the Interface of Antiviral Immunity and Immune Regulation: The Curious Case of HIV-1. SCIENTIFICA 2013; 2013:580968. [PMID: 24455433 PMCID: PMC3885208 DOI: 10.1155/2013/580968] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2013] [Accepted: 12/10/2013] [Indexed: 06/03/2023]
Abstract
Type I interferon (IFN-I) play a critical role in the innate immune response against viral infections. They actively participate in antiviral immunity by inducing molecular mechanisms of viral restriction and by limiting the spread of the infection, but they also orchestrate the initial phases of the adaptive immune response and influence the quality of T cell immunity. During infection with the human immunodeficiency virus type 1 (HIV-1), the production of and response to IFN-I may be severely altered by the lymphotropic nature of the virus. In this review I consider the different aspects of virus sensing, IFN-I production, signalling, and effects on target cells, with a particular focus on the alterations observed following HIV-1 infection.
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Affiliation(s)
- Adriano Boasso
- Immunology Section, Chelsea and Westminster Hospital, 369 Fulham Road, London SW10 9NH, UK
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241
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McLinden RJ, LaBranche CC, Chenine AL, Polonis VR, Eller MA, Wieczorek L, Ochsenbauer C, Kappes JC, Perfetto S, Montefiori DC, Michael NL, Kim JH. Detection of HIV-1 neutralizing antibodies in a human CD4⁺/CXCR4⁺/CCR5⁺ T-lymphoblastoid cell assay system. PLoS One 2013; 8:e77756. [PMID: 24312168 PMCID: PMC3842913 DOI: 10.1371/journal.pone.0077756] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2013] [Accepted: 09/09/2013] [Indexed: 11/18/2022] Open
Abstract
Sensitive assays are needed to meaningfully assess low levels of neutralizing antibodies (NAbs) that may be important for protection against the acquisition of HIV-1 infection in vaccine recipients. The current assay of choice uses a non-lymphoid cell line (TZM-bl) that may lack sensitivity owing to over expression of CD4 and CCR5. We used transfection of a human CD4+/CXCR4+/α4β7+ T-lymphoblastoid cell line (A3.01) with a CMV IE promoter-driven CCR5neo vector to stably express CCR5. The resulting line, designated A3R5, is permissive to a wide range of CCR5-tropic circulating strains of HIV-1, including HIV-1 molecular clones containing a Tat-inducible Renilla luciferase reporter gene and expressing multiple Env subtypes. Flow cytometric analysis found CCR5 surface expression on A3R5 cells to be markedly less than TZM-bl but similar to CD3.8 stimulated PBMC. More importantly, neutralization mediated by a diverse panel of monoclonal antibodies, HIV-1 positive polyclonal sera and sCD4 was consistently greater in A3R5 compared to TZM-bl cells. The A3R5 cell line provides a novel approach to guide the development and qualification of promising new HIV-1 vaccine immunogens.
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Affiliation(s)
- Robert J. McLinden
- Military HIV- Research Program, WRAIR, Silver Spring, Maryland, United States of America
- * E-mail:
| | - Celia C. LaBranche
- Department of Surgery, Duke U. Medical Center, Durham, North Carolina, United States of America
| | - Agnès-Laurence Chenine
- Military HIV- Research Program, WRAIR, Silver Spring, Maryland, United States of America
| | - Victoria R. Polonis
- Military HIV- Research Program, WRAIR, Silver Spring, Maryland, United States of America
| | - Michael A. Eller
- Military HIV- Research Program, WRAIR, Silver Spring, Maryland, United States of America
| | - Lindsay Wieczorek
- Military HIV- Research Program, WRAIR, Silver Spring, Maryland, United States of America
| | - Christina Ochsenbauer
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - John C. Kappes
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
- Birmingham Veterans Affairs Medical Center, Research Service, Birmingham, Alabama, United States of America
| | - Stephen Perfetto
- Vaccine Research Center, NIH, Bethesda, Maryland, United States of America
| | - David C. Montefiori
- Department of Surgery, Duke U. Medical Center, Durham, North Carolina, United States of America
| | - Nelson L. Michael
- Military HIV- Research Program, WRAIR, Silver Spring, Maryland, United States of America
| | - Jerome H. Kim
- Military HIV- Research Program, WRAIR, Silver Spring, Maryland, United States of America
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242
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Imbalances of gut-homing CD4+ T-cell subsets in HIV-1-infected Chinese patients. J Acquir Immune Defic Syndr 2013; 64:25-31. [PMID: 23572009 DOI: 10.1097/qai.0b013e318293a114] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
BACKGROUND Full reconstitution of CD4 T cells in both peripheral blood and mucosal tissues is a desirable goal of treating AIDS patients. To date, few studies have investigated the potential role of gut-homing CD4 T-cell subsets as biomarkers in assisting Asian populations infected with HIV-1. METHODS A large cross-sectional study was conducted among Chinese patients with focus on the frequency, absolute number, and ratio of gut-homing Th1, Th17, and Treg subsets in 3 groups of age- and gender-matched study subjects: healthy donors, untreated AIDS patients, and antiretroviral therapy (ART)-treated patients with sustained undetectable viral load. RESULTS HIV-1 chronic infection resulted in positively correlated loss of total and gut-homing CD4 T cells (P < 0.001) among patients compared with healthy controls. Profiles of T-cell subsets, however, were different between total and gut-homing CD4 T cells in terms of frequency and absolute number. ART partially restored the frequencies of gut-homing Th1, Th17, and Treg cells but the lost number of gut-homing Th17 cells was found not easily reversible. These changes together with an increased frequency of gut-homing CD4 Treg cells led to dual imbalances of gut-homing Th1/Treg and Th17/Treg ratios, which were negatively correlated with viral load (P = 0.014 and P < 0.001) and hardly restored even by prolonged ART. CONCLUSIONS Our findings provide new insights into the investigation of gut-homing Th1/Treg and Th17/Treg imbalances in AIDS patients, which may have potential implications on the reconstitution of mucosal CD4 T cells.
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243
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Jelicic K, Cimbro R, Nawaz F, Huang DW, Zheng X, Yang J, Lempicki RA, Pascuccio M, Van Ryk D, Schwing C, Hiatt J, Okwara N, Wei D, Roby G, David A, Hwang IY, Kehrl JH, Arthos J, Cicala C, Fauci AS. The HIV-1 envelope protein gp120 impairs B cell proliferation by inducing TGF-β1 production and FcRL4 expression. Nat Immunol 2013; 14:1256-65. [PMID: 24162774 PMCID: PMC3870659 DOI: 10.1038/ni.2746] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2013] [Accepted: 09/25/2013] [Indexed: 01/08/2023]
Abstract
The humoral immune response after acute infection with HIV-1 is delayed and ineffective. The HIV-1 envelope protein gp120 binds to and signals through integrin α4β7 on T cells. We found that gp120 also bound to and signaled through α4β7 on naive B cells, which resulted in an abortive proliferative response. In primary B cells, signaling by gp120 through α4β7 resulted in increased expression of the immunosuppressive cytokine TGF-β1 and FcRL4, an inhibitory receptor expressed on B cells. Coculture of B cells with HIV-1-infected autologous CD4(+) T cells also increased the expression of FcRL4 by B cells. Our findings indicated that in addition to mediating chronic activation of the immune system, viral proteins contributed directly to HIV-1-associated B cell dysfunction. Our studies identify a mechanism whereby the virus may subvert the early HIV-1-specific humoral immune response.
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Affiliation(s)
- Katija Jelicic
- Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
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244
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Usami Y, Göttlinger H. HIV-1 Nef responsiveness is determined by Env variable regions involved in trimer association and correlates with neutralization sensitivity. Cell Rep 2013; 5:802-12. [PMID: 24209751 DOI: 10.1016/j.celrep.2013.09.028] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2013] [Revised: 08/19/2013] [Accepted: 09/20/2013] [Indexed: 11/26/2022] Open
Abstract
HIV-1 Nef and the unrelated murine leukemia virus glycoGag similarly enhance the infectivity of HIV-1 virions. We now show that the effects of Nef and glycoGag are similarly determined by variable regions of HIV-1 gp120 that control Env trimer association and neutralization sensitivity. Whereas neutralization-sensitive X4-tropic Env proteins conferred high responsiveness to Nef and glycoGag, particles bearing neutralization-resistant R5-tropic Envs were considerably less affected. The profoundly different Nef/glycoGag responsiveness of a neutralization-resistant and a neutralization-sensitive R5-tropic Env could be switched by exchanging their gp120 V1/V2 regions, which also switches their neutralization sensitivity. Within V1/V2, the same determinants governed Nef/glycoGag responsiveness and neutralization sensitivity, indicating that these phenotypes are mechanistically linked. The V1/V2 and V3 regions, which form an apical trimer-association domain, together determined the Nef and glycoGag responsiveness of an X4-tropic Env. Our results suggest that Nef and glycoGag counteract the inactivation of Env spikes with relatively unstable apical trimer-association domains.
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Affiliation(s)
- Yoshiko Usami
- Program in Gene Function and Expression, Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA
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245
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Lederman MM, Funderburg NT, Sekaly RP, Klatt NR, Hunt PW. Residual immune dysregulation syndrome in treated HIV infection. Adv Immunol 2013; 119:51-83. [PMID: 23886064 DOI: 10.1016/b978-0-12-407707-2.00002-3] [Citation(s) in RCA: 257] [Impact Index Per Article: 23.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Antiretroviral therapy has revolutionized the course of HIV infection, improving immune function and decreasing dramatically the mortality and morbidity due to the opportunistic complications of the disease. Nonetheless, even with sustained suppression of HIV replication, many HIV-infected persons experience a syndrome characterized by increased T cell activation and evidence of heightened inflammation and coagulation. This residual immune dysregulation syndrome or RIDS is more common in persons who fail to increase circulating CD4+ T cells to normal levels and in several epidemiologic studies it has been associated with increased morbidity and mortality. These morbid and fatal events are not the typical opportunistic infections and malignancies seen in the early AIDS era but rather comprise a spectrum of cardiovascular events, liver disease, metabolic disorders, kidney disease, bone disease, and a spectrum of malignant complications distinguishable from the opportunistic malignancies that characterized the earlier days of the AIDS epidemic. While immune activation, inflammation, and coagulopathy are characteristic of untreated HIV infection and improve with drug-induced control of HIV replication, the drivers of RIDS in treated HIV infection are incompletely understood. And while inflammation, immune activation, and coagulopathy are more common in treated persons who fail to restore circulating CD4+ T cells, it is not entirely clear how these two phenomena are linked.
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Affiliation(s)
- Michael M Lederman
- Division of Infectious Diseases and Center for AIDS Research, Case Western Reserve University and University Hospitals/Case Medical Center, Cleveland, Ohio, USA.
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246
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McBride K, Xu Y, Bailey M, Seddiki N, Suzuki K, Murray JM, Gao Y, Yan C, Cooper DA, Kelleher AD, Koelsch KK, Zaunders J. The majority of HIV type 1 DNA in circulating CD4+ T lymphocytes is present in non-gut-homing resting memory CD4+ T cells. AIDS Res Hum Retroviruses 2013; 29:1330-9. [PMID: 23971972 DOI: 10.1089/aid.2012.0351] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Memory CD4(+) T lymphocytes in peripheral blood that express integrins α4ß7 preferentially recirculate through gut-associated lymphoid tissue (GALT), a proposed site of significant HIV-1 replication. Tregs and activated CD4(+) T cells in GALT could also be particularly susceptible to infection. We therefore hypothesized that infection of these subsets of memory CD4(+) T cells may contribute disproportionately to the HIV-1 reservoir. A cross-sectional study of CD4(+) T cell subsets of memory CD45RO(+) cells in peripheral blood mononuclear cells (PBMCs) was conducted using leukapheresis from eight subjects with untreated chronic HIV-1 infection. Real-time polymerase chain reaction (PCR) was used to quantify total and integrated HIV-1 DNA levels from memory CD4(+) T cells sorted into integrin β7(+) vs. β7(-), CD25(+)CD127(low) Treg vs. CD127(high), and activated CD38(+) vs. CD38(-). More than 80% of total HIV-1 DNA was found to reside in the integrin β7-negative non-gut-homing subset of CD45RO(+) memory CD4(+) T cells. Less than 10% was found in highly purified Tregs or CD38(+) activated memory cells. Similarly, integrated HIV-1 DNA copies were found to be more abundant in resting non-gut-homing memory CD4(+) T cells (76%) than in their activated counterparts (23%). Our investigations showed that the majority of both total and integrated HIV-1 DNA was found within non-gut-homing resting CD4(+) T cells.
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Affiliation(s)
- Kristin McBride
- The Kirby Institute for Infection and Immunity in Society, University of New South Wales, Sydney, Australia
| | - Yin Xu
- The Kirby Institute for Infection and Immunity in Society, University of New South Wales, Sydney, Australia
| | - Michelle Bailey
- The Kirby Institute for Infection and Immunity in Society, University of New South Wales, Sydney, Australia
| | - Nabila Seddiki
- The Kirby Institute for Infection and Immunity in Society, University of New South Wales, Sydney, Australia
| | - Kazuo Suzuki
- St. Vincent's Centre for Applied Medical Research, St. Vincent's Hospital, Sydney, Australia
| | - John M. Murray
- Department of Mathematics, University of New South Wales, Sydney, Australia
| | - Yuan Gao
- St. Vincent's Centre for Applied Medical Research, St. Vincent's Hospital, Sydney, Australia
| | - Celine Yan
- St. Vincent's Centre for Applied Medical Research, St. Vincent's Hospital, Sydney, Australia
| | - David A. Cooper
- The Kirby Institute for Infection and Immunity in Society, University of New South Wales, Sydney, Australia
- St. Vincent's Centre for Applied Medical Research, St. Vincent's Hospital, Sydney, Australia
| | - Anthony D. Kelleher
- The Kirby Institute for Infection and Immunity in Society, University of New South Wales, Sydney, Australia
- St. Vincent's Centre for Applied Medical Research, St. Vincent's Hospital, Sydney, Australia
| | - Kersten K. Koelsch
- The Kirby Institute for Infection and Immunity in Society, University of New South Wales, Sydney, Australia
- St. Vincent's Centre for Applied Medical Research, St. Vincent's Hospital, Sydney, Australia
| | - John Zaunders
- St. Vincent's Centre for Applied Medical Research, St. Vincent's Hospital, Sydney, Australia
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Plasma IgG to linear epitopes in the V2 and V3 regions of HIV-1 gp120 correlate with a reduced risk of infection in the RV144 vaccine efficacy trial. PLoS One 2013; 8:e75665. [PMID: 24086607 PMCID: PMC3784573 DOI: 10.1371/journal.pone.0075665] [Citation(s) in RCA: 197] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2013] [Accepted: 08/19/2013] [Indexed: 11/26/2022] Open
Abstract
Neutralizing and non-neutralizing antibodies to linear epitopes on HIV-1 envelope glycoproteins have potential to mediate antiviral effector functions that could be beneficial to vaccine-induced protection. Here, plasma IgG responses were assessed in three HIV-1 gp120 vaccine efficacy trials (RV144, Vax003, Vax004) and in HIV-1-infected individuals by using arrays of overlapping peptides spanning the entire consensus gp160 of all major genetic subtypes and circulating recombinant forms (CRFs) of the virus. In RV144, where 31.2% efficacy against HIV-1 infection was seen, dominant responses targeted the C1, V2, V3 and C5 regions of gp120. An analysis of RV144 case-control samples showed that IgG to V2 CRF01_AE significantly inversely correlated with infection risk (OR= 0.54, p=0.0042), as did the response to other V2 subtypes (OR=0.60-0.63, p=0.016-0.025). The response to V3 CRF01_AE also inversely correlated with infection risk but only in vaccine recipients who had lower levels of other antibodies, especially Env-specific plasma IgA (OR=0.49, p=0.007) and neutralizing antibodies (OR=0.5, p=0.008). Responses to C1 and C5 showed no significant correlation with infection risk. In Vax003 and Vax004, where no significant protection was seen, serum IgG responses targeted the same epitopes as in RV144 with the exception of an additional C1 reactivity in Vax003 and infrequent V2 reactivity in Vax004. In HIV-1 infected subjects, dominant responses targeted the V3 and C5 regions of gp120, as well as the immunodominant domain, heptad repeat 1 (HR-1) and membrane proximal external region (MPER) of gp41. These results highlight the presence of several dominant linear B cell epitopes on the HIV-1 envelope glycoproteins. They also generate the hypothesis that IgG to linear epitopes in the V2 and V3 regions of gp120 are part of a complex interplay of immune responses that contributed to protection in RV144.
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Abstract
PURPOSE OF REVIEW Activation of the immune system only occurs when stimulated cells generate sufficient energy to support their growth and proliferation. Moreover, efficient HIV-1 infection requires that CD4(+) T cells meet the energy demands involved in completing the different steps of the virus life cycle. In this review, we highlight recent studies revealing the importance of nutrient fuels, nucleotide metabolism and the oxygen microenvironment in regulating HIV-1 infection, T-cell differentiation and the generation of HIV-1-specific immune responses. RECENT FINDINGS Glucose uptake via the Glut1 glucose transporter is required for efficient HIV-1 infection of CD4(+) lymphocytes. Other nutrients can also be used as sources of energy and their utilization conditions the differentiation of CD4(+) T cells to distinct effector fates. The conversion of ATP to adenosine inhibits HIV-specific effector cells and the hydrolysis of dNTPs by SAMHD1 restricts infection. Furthermore, oxygen concentration modulates metabolic status, thereby altering T-cell differentiation and potential to mediate a specific immune response. SUMMARY The availability and use of energy resources in fluctuating environments regulate T-cell function and susceptibility to HIV-1 infection. Identification of the targets coordinating the selected metabolic pathways will advance new strategic avenues for controlling HIV-1 disease progression.
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Abstract
OBJECTIVE To study the complex formed between Tat protein and Env soluble trimeric immunogen, and compare with previously determined structures of Env native trimers and Env-CD4m complexes. DESIGN The soluble Env trimer was used to mimic the spike glycoprotein on the virus surface for the study. To overcome limitations of other structural determination methods, cryoelectron microscopy was employed to image the complex, and single particle reconstruction was utilized to reconstruct the structure of the complex from collected micrographs. Molecular modeling of gp120-Tat was performed to provide atomic coordinates for docking. METHODS Images were preprocessed by multivariate statistical analysis to identify principal components of variation then submitted for reconstruction. Reconstructed structures were docked with modeled gp120-Tat atomic coordinates to study the positions of crucial epitopes. RESULTS Analysis of the Env-Tat complex demonstrated an intermediate structure between Env native trimers and Env-CD4m structures. Docking results indicate that the CD4-binding site and the V3 loop are exposed in the Env-Tat complex. The integrin-binding sequence in Tat was also exposed in Env-Tat docking. CONCLUSION The intermediate structure induced by Tat-interaction with Env could potentially provide an explanation for increased virus infection in the presence of Tat protein. Consequently, exposure of CD4-binding sites and a putative integrin-binding sequence on Tat in the complex may provide a new avenue for rational design of an effective HIV vaccine.
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250
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Effect of chronic morphine administration on circulating T cell population dynamics in rhesus macaques. J Neuroimmunol 2013; 265:43-50. [PMID: 24090653 DOI: 10.1016/j.jneuroim.2013.09.013] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2013] [Revised: 09/12/2013] [Accepted: 09/14/2013] [Indexed: 01/10/2023]
Abstract
Opioid receptor agonists modulate both innate and adaptive immune responses. In this study, we examined the impact of long-term chronic morphine administration on the circulating T cell population dynamics in rhesus macaques. We found that the numbers of circulating Treg cells, and the functional activity of Th17 cells, were significantly increased with chronic morphine exposure. Our results also show that T cell populations with surface markers characteristic of gut-homing (CD161 and CCR6) and HIV-1 susceptibility (CCR5 and β7 integrin) were increased. These results represent the first detailed report of the impact of chronic morphine administration on circulating T cell dynamics.
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