Read by QxMD icon Read


Melanie A Gasper, Anneke C Hesseling, Isaac Mohar, Landon Myer, Tali Azenkot, Jo-Ann S Passmore, Willem Hanekom, Mark F Cotton, I Nicholas Crispe, Donald L Sodora, Heather B Jaspan
BACKGROUND. Bacillus Calmette-Guérin (BCG) vaccine is administered at birth to protect infants against tuberculosis throughout Africa, where most perinatal HIV-1 transmission occurs. We examined whether BCG vaccination alters the levels of activated HIV target T cells in HIV-exposed South African infants. METHODS. HIV-exposed infants were randomized to receive routine (at birth) or delayed (at 8 weeks) BCG vaccination. Activated and CCR5-expressing peripheral blood CD4(+) T cell, monocyte, and NK cell frequencies were evaluated by flow cytometry and immune gene expression via PCR using Biomark (Fluidigm)...
April 6, 2017: JCI Insight
Phillip Pymm, Patricia T Illing, Sri H Ramarathinam, Geraldine M O'Connor, Victoria A Hughes, Corinne Hitchen, David A Price, Bosco K Ho, Daniel W McVicar, Andrew G Brooks, Anthony W Purcell, Jamie Rossjohn, Julian P Vivian
Major histocompatibility complex class I (MHC-I) molecules play a crucial role in immunity by capturing peptides for presentation to T cells and natural killer (NK) cells. The peptide termini are tethered within the MHC-I antigen-binding groove, but it is unknown whether other presentation modes occur. Here we show that 20% of the HLA-B*57:01 peptide repertoire comprises N-terminally extended sets characterized by a common motif at position 1 (P1) to P2. Structures of HLA-B*57:01 presenting N-terminally extended peptides, including the immunodominant HIV-1 Gag epitope TW10 (TSTLQEQIGW), showed that the N terminus protrudes from the peptide-binding groove...
April 2017: Nature Structural & Molecular Biology
Enrique Martin-Gayo, Xu G Yu
PURPOSE OF REVIEW: Robust HIV-1-specific CD8 T cell responses are currently regarded as the main correlate of immune defense in rare individuals who achieve natural, drug-free control of HIV-1; however, the mechanisms that support evolution of such powerful immune responses are not well understood. Dendritic cells (DCs) are specialized innate immune cells critical for immune recognition, immune regulation, and immune induction, but their possible contribution to HIV-1 immune defense in controllers remains ill-defined...
January 21, 2017: Current HIV/AIDS Reports
Faatima Laher, Srinika Ranasinghe, Filippos Porichis, Nikoshia Mewalal, Karyn Pretorius, Nasreen Ismail, Søren Buus, Anette Stryhn, Mary Carrington, Bruce D Walker, Thumbi Ndung'u, Zaza M Ndhlovu
Immune control of viral infections is heavily dependent on helper CD4(+) T cell function. However, the understanding of the contribution of HIV-specific CD4(+) T cell responses to immune protection against HIV-1, particularly in clade C infection, remains incomplete. Recently, major histocompatibility complex (MHC) class II tetramers have emerged as a powerful tool for interrogating antigen-specific CD4(+) T cells without relying on effector functions. Here, we defined the MHC class II alleles for immunodominant Gag CD4(+) T cell epitopes in clade C virus infection, constructed MHC class II tetramers, and then used these to define the magnitude, function, and relation to the viral load of HIV-specific CD4(+) T cell responses in a cohort of untreated HIV clade C-infected persons...
April 1, 2017: Journal of Virology
Nina C Flerin, Huabiao Chen, Tynisha D Glover, Pedro A Lamothe, Jian Hua Zheng, Justin W Fang, Zaza M Ndhlovu, Evan W Newell, Mark M Davis, Bruce D Walker, Harris Goldstein
Functional analysis of T-cell responses in HIV-infected individuals has indicated that virus-specific CD8(+) T cells with superior antiviral efficacy are well represented in HIV-1 controllers but are rare or absent in HIV-1 progressors. To define the role of individual T-cell receptor (TCR) clonotypes in differential antiviral CD8(+) T-cell function, we performed detailed functional and mass cytometric cluster analysis of multiple CD8(+) T-cell clones recognizing the identical HLA-B*2705-restricted HIV-1 epitope KK10 (KRWIILGLNK)...
March 15, 2017: Journal of Virology
Michela Serena, Francesca Parolini, Priscilla Biswas, Francesca Sironi, Almudena Blanco Miranda, Elisa Zoratti, Maria Teresa Scupoli, Serena Ziglio, Agustin Valenzuela-Fernandez, Davide Gibellini, Maria Grazia Romanelli, Antonio Siccardi, Mauro Malnati, Alberto Beretta, Donato Zipeto
HLA-C has been demonstrated to associate with HIV-1 envelope glycoprotein (Env). Virions lacking HLA-C have reduced infectivity and increased susceptibility to neutralizing antibodies. Like all others MHC-I molecules, HLA-C requires β2-microglobulin (β2m) for appropriate folding and expression on the cell membrane but this association is weaker, thus generating HLA-C free-chains on the cell surface. In this study, we deepen the understanding of HLA-C and Env association by showing that HIV-1 specifically increases the amount of HLA-C free chains, not bound to β2m, on the membrane of infected cells...
January 4, 2017: Scientific Reports
Srinika Ranasinghe, Pedro A Lamothe, Damien Z Soghoian, Samuel W Kazer, Michael B Cole, Alex K Shalek, Nir Yosef, R Brad Jones, Faith Donaghey, Chioma Nwonu, Priya Jani, Gina M Clayton, Frances Crawford, Janice White, Alana Montoya, Karen Power, Todd M Allen, Hendrik Streeck, Daniel E Kaufmann, Louis J Picker, John W Kappler, Bruce D Walker
CD8(+) T cell recognition of virus-infected cells is characteristically restricted by major histocompatibility complex (MHC) class I, although rare examples of MHC class II restriction have been reported in Cd4-deficient mice and a macaque SIV vaccine trial using a recombinant cytomegalovirus vector. Here, we demonstrate the presence of human leukocyte antigen (HLA) class II-restricted CD8(+) T cell responses with antiviral properties in a small subset of HIV-infected individuals. In these individuals, T cell receptor β (TCRβ) analysis revealed that class II-restricted CD8(+) T cells underwent clonal expansion and mediated killing of HIV-infected cells...
October 18, 2016: Immunity
Joseph S Murray, Elaina H Murray
Genes of the major histocompatibility complex (MHC; also called HLA in human) are polymorphic elements in the genomes of sharks to humans. Class-I and class-II MHC loci appear responsible for much of the genetic linkage to myriad disease states via the capacity to bind short (~8-15 a.a.) peptides of a given pathogen's proteome, or in some cases, the altered proteomes of cancerous cells, and even (in autoimmunity) certain nominal 'self' peptides (Janeway, 2004).(1) Unfortunately, little is known about how the canonical structure of the MHC-I/-II peptide-presenting gene evolved, particularly since beyond ~500 Mya (sharks) no paralogs exist...
May 2016: Mobile Genetic Elements
Marijana Rucevic, Georgio Kourjian, Julie Boucau, Renata Blatnik, Wilfredo Garcia Bertran, Matthew J Berberich, Bruce D Walker, Angelika B Riemer, Sylvie Le Gall
UNLABELLED: Despite the critical role of epitope presentation for immune recognition, we still lack a comprehensive definition of HIV peptides presented by HIV-infected cells. Here we identified 107 major histocompatibility complex (MHC)-bound HIV peptides directly from the surface of live HIV-transfected 293T cells, HIV-infected B cells, and primary CD4 T cells expressing a variety of HLAs. The majority of peptides were 8 to 12 amino acids (aa) long and mostly derived from Gag and Pol...
October 1, 2016: Journal of Virology
Xiaoming Sun, Yi Shi, Tomohiro Akahoshi, Mamoru Fujiwara, Hiroyuki Gatanaga, Christian Schönbach, Nozomi Kuse, Victor Appay, George F Gao, Shinichi Oka, Masafumi Takiguchi
The mechanistic basis for the progressive accumulation of Y(135)F Nef mutant viruses in the HIV-1-infected population remains poorly understood. Y(135)F viruses carry the 2F mutation within RW8 and RF10, which are two HLA-A(∗)24:02-restricted superimposed Nef epitopes recognized by distinct and adaptable CD8(+) T cell responses. We combined comprehensive analysis of the T cell receptor repertoire and cross-reactive potential of wild-type or 2F RW8- and RF10-specific CD8(+) T cells with peptide-MHC complex stability and crystal structure studies...
June 7, 2016: Cell Reports
Daniela Benati, Moran Galperin, Olivier Lambotte, Stéphanie Gras, Annick Lim, Madhura Mukhopadhyay, Alexandre Nouël, Kristy-Anne Campbell, Brigitte Lemercier, Mathieu Claireaux, Samia Hendou, Pierre Lechat, Pierre de Truchis, Faroudy Boufassa, Jamie Rossjohn, Jean-François Delfraissy, Fernando Arenzana-Seisdedos, Lisa A Chakrabarti
The rare patients who are able to spontaneously control HIV replication in the absence of therapy show signs of a particularly efficient cellular immune response. To identify the molecular determinants that underlie this response, we characterized the T cell receptor (TCR) repertoire directed at Gag293, the most immunoprevalent CD4 epitope in the HIV-1 capsid. HIV controllers from the ANRS CODEX cohort showed a highly skewed TCR repertoire that was characterized by a predominance of TRAV24 and TRBV2 variable genes, shared CDR3 motifs, and a high frequency of public clonotypes...
June 1, 2016: Journal of Clinical Investigation
Greta Forlani, Filippo Turrini, Silvia Ghezzi, Alessandra Tedeschi, Guido Poli, Roberto S Accolla, Giovanna Tosi
BACKGROUND: We previously demonstrated that the HLA class II transactivator CIITA inhibits HIV-1 replication in T cells by competing with the viral transactivator Tat for the binding to Cyclin T1 subunit of the P-TEFb complex. Here, we analyzed the anti-viral function of CIITA in myeloid cells, another relevant HIV-1 target cell type. We sinvestigated clones of the U937 promonocytic cell line, either permissive (Plus) or non-permissive (Minus) to HIV-1 replication. This different phenotype has been associated with the expression of TRIM22 in U937 Minus but not in Plus cells...
April 18, 2016: Journal of Translational Medicine
Zachary B Davis, Andrew Cogswell, Hamish Scott, Amanda Mertsching, Julie Boucau, Daniel Wambua, Sylvie Le Gall, Vicente Planelles, Kerry S Campbell, Edward Barker
Major histocompatibility class I (MHC-I)-specific inhibitory receptors on natural killer (NK) cells (iNKRs) tolerize mature NK cell responses toward normal cells. NK cells generate cytolytic responses to virus-infected or malignant target cells with altered or decreased MHC-I surface expression due to the loss of tolerizing ligands. The NKG2A/CD94 iNKR suppresses NK cell responses through recognition of the non-classical MHC-I, HLA-E. We used HIV-infected primary T-cells as targets in an in vitro cytolytic assay with autologous NK cells from healthy donors...
February 2016: PLoS Pathogens
Miguel Marcilla, Iñaki Alvarez, Antonio Ramos-Fernández, Manuel Lombardía, Alberto Paradela, Juan Pablo Albar
Indian rhesus macaques are arguably the most reliable animal models in AIDS research. In this species the MHC class I allele Mamu-B*08, among others, is associated with elite control of SIV replication. A similar scenario is observed in humans where the expression of HLA-B*27 or HLA-B*57 has been linked to slow or no progression to AIDS after HIV infection. Despite having large differences in their primary structure, it has been reported that HLA-B*27 and Mamu-B*08 display peptides with sequence similarity...
March 4, 2016: Journal of Proteome Research
S L Gooneratne, R J Center, S J Kent, M S Parsons
Evidence from the RV144 HIV-1 vaccine trial implicates anti-HIV-1 antibody-dependent cellular cytotoxicity (ADCC) in vaccine-conferred protection from infection. Among effector cells that mediate ADCC are natural killer (NK) cells. The ability of NK cells to be activated in an antibody-dependent manner is reliant upon several factors. In general, NK cell-mediated antibody-dependent activation is most robust in terminally differentiated CD57(+) NK cells, as well as NK cells educated through ontological interactions between inhibitory killer immunoglobulin-like receptors (KIR) and their major histocompatibility complex class I [MHC-I or human leucocyte antigen (HLA-I)] ligands...
April 2016: Clinical and Experimental Immunology
Lutz Walter, Aftab A Ansari
Natural killer lymphocytes are essentially involved as the first line of defense against agents such as viruses and malignant cells. The activity of these cells is regulated via interaction of specific and diverse killer cell immunoglobulin-like receptors (KIR) with the highly polymorphic cognate MHC class I proteins on target cells. Genetic variability of both KIR and MHC-I ligands has been shown to be associated with resistance to many diseases, including infection with the immunodeficiency virus. Disease course and progression to AIDS after infection with human immunodeficiency virus-1 (HIV-1) is essentially influenced by the presence of the stimulatory KIR3DS1 receptor in combination with HLA-Bw4...
2015: Frontiers in Immunology
Yang Zeng, Tongtong Gao, Guangyu Zhao, Yuting Jiang, Yi Yang, Hong Yu, Zhihua Kou, Yuchun Lone, Shihui Sun, Yusen Zhou
The rapid occurrence of emerging infectious diseases demonstrates an urgent need for a new preclinical experimental model that reliably replicates human immune responses. Here, a new homozygous humanized human leukocyte antigen (HLA)-A11/DR1 transgenic mouse (HLA-A11(+/+)/DR01(+/+)/H-2-β2m(-/-)/IAβ(-/-)) was generated by crossing HLA-A11 transgenic (Tg) mice with HLA-A2(+/+)/DR01(+/+)/H-2-β2m(-/-)/IAβ(-/-) mice. The HLA-A11-restricted immune response of this mouse model was then examined. HLA-A11 Tg mice expressing a chimeric major histocompatibility complex (MHC) molecule comprising the α1, α2, and β2m domains of human HLA-A11 and the α3 transmembrane and cytoplasmic domains of murine H-2D(b) were generated...
March 3, 2016: Human Vaccines & Immunotherapeutics
Maja K Choma, Jennifer Lumb, Patrycja Kozik, Margaret S Robinson
The HIV-1-encoded protein, Nef, plays a key role in the development of AIDS. One of Nef's functions is to keep MHC class I off the surface of infected cells, a process that requires the host proteins clathrin and AP-1. To identify other proteins involved in this pathway, we carried out a genome-wide siRNA library screen on HeLa cells co-expressing HLA-A2 and an inducible form of Nef. Out of 21,121 siRNA pools, 100 were selected for further analysis, based on their ability to either inhibit or enhance downregulation of MHC-I by Nef...
2015: PloS One
Mauricio A Martins, Damien C Tully, Michael A Cruz, Karen A Power, Marlon G Veloso de Santana, David J Bean, Colin B Ogilvie, Rujuta Gadgil, Noemia S Lima, Diogo M Magnani, Keisuke Ejima, David B Allison, Michael Piatak, John D Altman, Christopher L Parks, Eva G Rakasz, Saverio Capuano, Ricardo Galler, Myrna C Bonaldo, Jeffrey D Lifson, Todd M Allen, David I Watkins
UNLABELLED: Certain major histocompatibility complex class I (MHC-I) alleles (e.g., HLA-B*27) are enriched among human immunodeficiency virus type 1 (HIV-1)-infected individuals who suppress viremia without treatment (termed "elite controllers" [ECs]). Likewise, Mamu-B*08 expression also predisposes rhesus macaques to control simian immunodeficiency virus (SIV) replication. Given the similarities between Mamu-B*08 and HLA-B*27, SIV-infected Mamu-B*08(+) animals provide a model to investigate HLA-B*27-mediated elite control...
November 2015: Journal of Virology
Daniela Santoro Rosa, Susan Pereira Ribeiro, Simone Gonçalves Fonseca, Rafael Ribeiro Almeida, Vinicius Canato Santana, Juliana de Souza Apostólico, Jorge Kalil, Edecio Cunha-Neto
The development of a highly effective vaccine against the human immunodeficiency virus (HIV) will likely be based on rational vaccine design, since traditional vaccine approaches have failed so far. In recent years, an understanding of what type of immune response is protective against infection and/or disease facilitated vaccine design. T cell-based vaccines against HIV have the goal of limiting both transmission and disease progression by inducing broad and functionally relevant T cell responses. In this context, CD4(+) T cells play a direct cytotoxic role and are also important for the generation and maintenance of functional CD8(+) T and B cell responses...
November 2015: AIDS Research and Human Retroviruses
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"