scholarly journals A Gut Reaction to SIV and SHIV Infection: Lower Dysregulation of Mucosal T Cells during Acute Infection Is Associated with Greater Viral Suppression during cART

Viruses ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1609
Author(s):  
Megan A. O’Connor ◽  
Paul V. Munson ◽  
Sandra E. Dross ◽  
Hillary C. Tunggal ◽  
Thomas B. Lewis ◽  
...  
Keyword(s):  
T Cell ◽  
Viral Suppression ◽  
Acute Infection ◽  
Therapeutic Vaccine ◽  
Cell Subset ◽  
Hiv Treatment ◽  
Viral Control ◽  
Viral Kinetics ◽  
Shiv Infection ◽  
Selection Of

Selection of a pre-clinical non-human primate (NHP) model is essential when evaluating therapeutic vaccine and treatment strategies for HIV. SIV and SHIV-infected NHPs exhibit a range of viral burdens, pathologies, and responses to combinatorial antiretroviral therapy (cART) regimens and the choice of the NHP model for AIDS could influence outcomes in studies investigating interventions. Previously, in rhesus macaques (RMs) we showed that maintenance of mucosal Th17/Treg homeostasis during SIV infection correlated with a better virological response to cART. Here, in RMs we compared viral kinetics and dysregulation of gut homeostasis, defined by T cell subset disruption, during highly pathogenic SIVΔB670 compared to SHIV-1157ipd3N4 infection. SHIV infection resulted in lower acute viremia and less disruption to gut CD4 T-cell homeostasis. Additionally, 24/24 SHIV-infected versus 10/19 SIV-infected animals had sustained viral suppression <100 copies/mL of plasma after 5 months of cART. Significantly, the more profound viral suppression during cART in a subset of SIV and all SHIV-infected RMs corresponded with less gut immune dysregulation during acute SIV/SHIV infection, defined by maintenance of the Th17/Treg ratio. These results highlight significant differences in viral control during cART and gut dysregulation in NHP AIDS models and suggest that selection of a model may impact the evaluation of candidate therapeutic interventions for HIV treatment and cure strategies.

scholarly journals Better Viral Control despite Higher CD4+ T Cell Activation during Acute HIV-1 Infection in Zambian Women Is Linked to the Sex Hormone Estradiol

2020 ◽  
Vol 94 (16) ◽  
Author(s):  
Elina El-Badry ◽  
Gladys Macharia ◽  
Daniel Claiborne ◽  
Kelsie Brooks ◽  
Darío A. Dilernia ◽  
...  
Keyword(s):  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Acute Infection ◽  
Chronic Phase ◽  
Cell Loss ◽  
Viral Control ◽  
Acute Hiv ◽  
17Β Estradiol ◽  
Hiv 1

ABSTRACT The influence of biological sex on disease progression in HIV-1-infected individuals has been focused on the chronic stage of infection, but little is known about how sex differences influence acute HIV-1 infection. We observed profound differences in viral load and CD4+ T cell activation from the earliest time points in men and women in a Zambian heterosexual acute infection cohort. Women exhibited a >2-fold higher rate of CD4+ T cell loss despite significantly lower viral loads (VL) than men. The importance of studying acute infection was highlighted by the observation that very early in infection, women exhibited significantly higher levels of CD4+ T cell activation, a difference that was lost over the first 3 years of infection as activation in men increased. In women, activation of CD4+ T cells in the acute phase was significantly correlated with plasma levels of 17β-estradiol (E2). However, unlike in men, higher CD4+ T cell activation in women was not associated with higher VL. In contrast, a higher E2 level in early infection was associated with lower early and set-point VL in women. We attribute this to an inhibitory effect of estradiol on virus replication, which we were able to observe with relevant transmitted/founder viruses in vitro. Thus, estradiol plays a key role in defining major differences between men and women during early HIV-1 infection by contributing to both viral control and CD4+ T cell loss, an effect that extends into the chronic phase of the disease. IMPORTANCE Previous studies have identified sex-specific differences during chronic HIV-1 infection, but little is known about sex differences in the acute phase, or how disparities in the initial response to the virus may affect disease. We demonstrate that restriction of viral load in women begins during acute infection and is maintained into chronic infection. Despite this, women exhibit more rapid CD4+ T cell loss than men. These profound differences are influenced by 17β-estradiol, which contributes both to T cell activation and to reduced viral replication. Thus, we conclude that estradiol plays a key role in shaping responses to early HIV-1 infection that influence the chronic phase of disease.

Anti-Leukemia Activity of Alloreactive NK Cells in Haploidentical HSCT in Pediatric Patients: Re-Defining the Role of Activating and Inhibitory KIR

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 3002-3002 ◽  
Author(s):  
Daniela Pende ◽  
Stefania Marcenaro ◽  
Michela Falco ◽  
Stefania Martini ◽  
Maria Ester Bernardo ◽  
...  
Keyword(s):  
T Cell ◽  
Nk Cells ◽  
Nk Cell ◽  
Cell Subset ◽  
Hla Class I ◽  
Class I ◽  
Leukemia Cells ◽  
Hla Alleles ◽  
Time Points ◽  
Selection Of

Abstract T-cell depleted hematopoietic stem cell transplantation from haploidentical donors (haplo-HSCT) has been reported to benefit from the graft-versus-leukemia effect mediated by natural killer (NK) cells when donor displays NK alloreactivity versus the recipient. NK alloreactivity is mediated by NK receptors, namely Killer Ig-like receptors (KIR) which are specific for allotypic determinants that are shared by different HLA-class I alleles (referred to as KIR ligands). It is known that KIR2DL1 recognizes HLA-C alleles characterized by Lys at position 80 (C2 group), KIR2DL2/3 recognize HLA-C alleles characterized by Asn at position 80 (C1 group), KIR3DL1 recognizes HLA-B alleles sharing the Bw4 supertypic specificity (Bw4 group) and KIR3DL2 recognizes HLA-A3 and –A11 alleles. KIR2D/3DL are inhibitory receptors that, upon engagement with the cognate ligand, inhibit lysis. Activating KIRs, highly homologous in the extracellular domain to the inhibitory counterparts, are KIR2DS1, KIR2DS2 and KIR3DS1, but only KIR2DS1 has been shown to specifically recognize C2 group of alleles expressed on B-EBV cells. We analyzed 21 children with leukemia receiving haplo-HSCT from a relative after a myeloablative conditioning regimen; in all pairs, the expression of a given KIR ligand (HLA class I allele) of the donor was missing in the patient (i.e. KIR ligand-mismatched haplo-HSCT). T-cell depletion was performed through positive selection of CD34+ cells; no pharmacological immune suppression was employed after HSCT. KIR genotype of all donors was evaluated to detect the presence of the various inhibitory and activating KIR genes. Phenotypic analyses were performed on NK cells derived from the donor and the patient at different time points after HSCT. Thanks to the availability of new mAbs able to discriminate between the inhibitory and the activating forms of a certain KIR, we could identify the alloreactive NK cell subset at the population level. These alloreactive NK cells express the KIR specific for the KIR ligand-mismatch (permissive inhibitory KIR) and the activating KIR (if present), while they do not express all inhibitory KIR specific for the patient HLA alleles and NKG2A. Thus, in most instances, we could precisely identify the size of the alloreactive NK cell subset in the donor and in the reconstituted repertoire of the recipient. Functional assays were performed to assess alloreactivity, using appropriate B-EBV cell lines and, if available, patient’s leukemia blasts. In some cases, also NK cell clones were extensively studied, for phenotype and receptor involvement in killing activity. We found that, in most transplanted patients, variable proportions of donor-derived alloreactive NK cells displaying anti-leukemia activity were generated and maintained even at late time-points after transplantation. Donor-derived KIR2DL1+ NK cells isolated from the recipient displayed the expected capability of selectively killing C1/C1 target cells, including patient leukemia blasts. Differently, KIR2DL2/3+ NK cells displayed poor alloreactivity against leukemia cells carrying HLA alleles belonging to the C2 specificity. Unexpectedly, this was due to recognition of C2 by KIR2DL2/3, as revealed by receptor blocking experiments and by binding assays of soluble KIR to HLA-C transfectants. Remarkably, however, C2/C2 leukemia blasts were killed by KIR2DL2/3+ (or by NKG2A+) NK cells that co-expressed KIR2DS1. This could be explained by the ability of KIR2DS1 to directly recognize C2 on leukemia cells. A role for the KIR2DS2 activating receptor in leukemia cell lysis could not be established. Taken together, these findings provide new information on NK alloreactivity in haplo-HSCT that may greatly impact on the selection of the optimal donor.

scholarly journals Profound metabolic, functional, and cytolytic differences characterize HIV-specific CD8 T cells in primary and chronic HIV infection

Blood ◽  
2012 ◽  
Vol 120 (17) ◽  
pp. 3466-3477 ◽  
Author(s):  
Lydie Trautmann ◽  
Florentin-Martial Mbitikon-Kobo ◽  
Jean-Philippe Goulet ◽  
Yoav Peretz ◽  
Yu Shi ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Hiv Infection ◽  
Cd8 T Cells ◽  
Primary Infection ◽  
Acute Infection ◽  
T Cell Response ◽  
Viral Control ◽  
Metabolic State ◽  
Host Virus Interactions

AbstractImmediate-early host-virus interactions that occur during the first weeks after HIV infection have a major impact on disease progression. The mechanisms underlying the failure of HIV-specific CD8 T-cell response to persist and control viral replication early in infection are yet to be characterized. In this study, we performed a thorough phenotypic, gene expression and functional analysis to compare HIV-specific CD8 T cells in acutely and chronically infected subjects. We showed that HIV-specific CD8 T cells in primary infection can be distinguished by their metabolic state, rate of proliferation, and susceptibility to apoptosis. HIV-specific CD8 T cells in acute/early HIV infection secreted less IFN-γ but were more cytotoxic than their counterparts in chronic infection. Importantly, we showed that the levels of IL-7R expression and the capacity of HIV-specific CD8 T cells to secrete IL-2 on antigenic restimulation during primary infection were inversely correlated with the viral set-point. Altogether, these data suggest an altered metabolic state of HIV-specific CD8 T cells in primary infection resulting from hyperproliferation and stress induced signals, demonstrate the discordant function of HIV-specific CD8 T cells during early/acute infection, and highlight the importance of T-cell maintenance for viral control.

scholarly journals MHC Class I Presented T Cell Epitopes as Potential Antigens for Therapeutic Vaccine against HBV Chronic Infection

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Joseph D. Comber ◽  
Aykan Karabudak ◽  
Vivekananda Shetty ◽  
James S. Testa ◽  
Xiaofang Huang ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Chronic Infection ◽  
Acute Infection ◽  
Therapeutic Vaccine ◽  
T Cell Responses ◽  
Hbv Infection ◽  
Mhc I ◽  
Cell Responses ◽  
Cell Immunity

Approximately 370 million people worldwide are chronically infected with hepatitis B virus (HBV). Despite the success of the prophylactic HBV vaccine, no therapeutic vaccine or other immunotherapy modality is available for treatment of chronically infected individuals. Clearance of HBV depends on robust, sustained CD8+ T activity; however, the limited numbers of therapeutic vaccines tested have not induced such a response. Most of these vaccines have relied on peptide prediction algorithms to identify MHC-I epitopes or characterization of T cell responses during acute infection. Here, we took an immunoproteomic approach to characterize MHC-I restricted epitopes from cells chronically infected with HBV and therefore more likely to represent the true targets of CD8+ T cells during chronic infection. In this study, we identified eight novel MHC-I restricted epitopes derived from a broad range of HBV proteins that were capable of activating CD8+ T cells. Furthermore, five of the eight epitopes were able to bind HLA-A2 and A24 alleles and activated HBV specific T cell responses. These epitopes also have potential as new tools to characterize T cell immunity in chronic HBV infection and may serve as candidate antigens for a therapeutic vaccine against HBV infection.

scholarly journals Perforin and Fas Cytolytic Pathways Coordinately Shape the Selection and Diversity of CD8+-T-Cell Escape Variants of Influenza Virus

2005 ◽  
Vol 79 (13) ◽  
pp. 8545-8559 ◽  
Author(s):  
Graeme E. Price ◽  
Lei Huang ◽  
Rong Ou ◽  
Menghua Zhang ◽  
Demetrius Moskophidis
Keyword(s):  
Influenza Virus ◽  
T Cell ◽  
Vaccine Development ◽  
Influenza Virus Infection ◽  
Influenza Viruses ◽  
Viral Escape ◽  
Viral Control ◽  
Ctl Escape ◽  
Selection Of

ABSTRACT Antigenic variation is a viral strategy exploited to promote survival in the face of the host immune response and represents a major challenge for efficient vaccine development. Influenza viruses are pathogens with high transmissibility and mutation rates, enabling viral escape from immunity induced by prior infection or vaccination. Intense selection from neutralizing antibody drives antigenic changes in the surface glycoproteins, resulting in emergence of new strains able to reinfect hosts immune to previously circulating viruses. CD8+ cytotoxic T cells (CTLs) also provide protective immunity from influenza virus infection and may contribute to the antigenic evolution of influenza viruses. Utilizing mice transgenic for an influenza virus NP366-374 peptide-specific T-cell receptor, we demonstrated that the respiratory tract is a suitable site for generation of escape variants of influenza virus selected by CTL in vivo. In this report the contributions of the perforin and Fas pathways utilized by influenza virus-specific CTLs in viral clearance and selection of CTL escape variants have been evaluated. While transgenic CTLs deficient in either perforin- or Fas-mediated pathways are efficient in initial pulmonary viral control, variant virus emergence was observed in all the mice studied, although the spectrum of viral CTL escape variants selected varied profoundly. Thus, a less-restricted repertoire of escape variants was observed in mice with an intact perforin cytotoxic pathway compared with a limited variant diversity in perforin pathway-deficient mice, although maximal variant diversity was observed in mice having both Fas and perforin pathways intact. We conclude that selection of viral CTL escape variants reflects coordinate action between the tightly controlled perforin/granzyme pathway and the more promiscuous Fas/FasL pathway.

scholarly journals CD8+ T Cells Participate in the Memory Immune Response to Mycobacterium tuberculosis

2001 ◽  
Vol 69 (7) ◽  
pp. 4320-4328 ◽  
Author(s):  
Natalya V. Serbina ◽  
JoAnne L. Flynn
Keyword(s):  
Immune Response ◽  
T Cells ◽  
Mycobacterium Tuberculosis ◽  
T Cell ◽  
Acute Infection ◽  
Cell Subset ◽  
Ifn Γ ◽  
Memory And Recall ◽  
Memory Immune Response ◽  
Activation Marker Cd69

ABSTRACT The contribution of CD8+ T cells to the control of tuberculosis has been studied primarily during acute infection in mouse models. Memory or recall responses in tuberculosis are less well characterized, particularly with respect to the CD8 T-cell subset. In fact, there are published reports that CD8+ T cells do not participate in the memory immune response to Mycobacterium tuberculosis. We examined the CD8+ T-cell memory and local recall response to M. tuberculosis. To establish a memory immunity model, C57BL/6 mice were infected with M. tuberculosis, followed by treatment with anti-mycobacterial drugs and prolonged rest. The lungs of memory immune mice contained CD4+ and CD8+ T cells with the cell surface phenotype characteristic of memory cells (CD69lowCD25low CD44high). At 1 week postchallenge withM. tuberculosis via aerosol, ≥30% of both CD4+ and CD8+ T cells in the lungs of immune mice expressed the activation marker CD69 and could be restimulated to produce gamma interferon (IFN-γ). In contrast, <6% of T cells in the lungs of naive challenged mice were CD69+ at 1 week postchallenge, and IFN-γ production was not observed at this time point. CD8+ T cells from the lungs of both naive and memory mice after challenge were cytotoxic toward M. tuberculosis-infected macrophages. Our data indicate that memory and recall immunity to M. tuberculosis is comprised of both CD4+ and CD8+ T lymphocytes and that there is a rapid response of both subsets in the lungs following challenge.

scholarly journals CD8lowCD100−T Cells Identify a Novel CD8 T Cell Subset Associated with Viral Control during Human Hantaan Virus Infection

2015 ◽  
Vol 89 (23) ◽  
pp. 11834-11844 ◽  
Author(s):  
Bei Liu ◽  
Ying Ma ◽  
Yusi Zhang ◽  
Chunmei Zhang ◽  
Jing Yi ◽  
...  
Keyword(s):  
Immune Response ◽  
T Cells ◽  
Viral Load ◽  
T Cell ◽  
Early Phase ◽  
Late Phase ◽  
Cell Subset ◽  
T Cell Subsets ◽  
Hantaan Virus ◽  
Viral Control

ABSTRACTHantaan virus (HTNV) infection can cause a severe lethal hemorrhagic fever with renal syndrome (HFRS) in humans. CD8+T cells play a critical role in combating HTNV infections. However, the contributions of different CD8+T cell subsets to the immune response against viral infection are poorly understood. Here, we identified a novel subset of CD8+T cells characterized by the CD8lowCD100−phenotype in HFRS patients. The CD8lowCD100−subset accounted for a median of 14.3% of the total CD8+T cells in early phase of HFRS, and this percentage subsequently declined in the late phase of infection, whereas this subset was absent in healthy controls. Furthermore, the CD8lowCD100−cells were associated with high activation and expressed high levels of cytolytic effector molecules and exhibited a distinct expression profile of effector CD8+T cells (CCR7+/−CD45RA−CD127highCD27intCD28lowCD62L−). When stimulated with specific HTNV nucleocapsid protein-derived peptide pools, most responding CD8+cells (gamma interferon [IFN-γ] positive and/or tumor necrosis factor alpha [TNF-α] positive) were CD8lowCD100−cells. The frequency of CD8lowCD100−cells among HTNV-specific CD8+T cells was higher in milder cases than in more severe cases. Importantly, the proportion of the CD8lowCD100−subset among CD8+T cells in early phase of HFRS was negatively correlated with the HTNV viral load, suggesting that CD8lowCD100−cells may be associated with viral clearance. The contraction of the CD8lowCD100−subset in late phase of infection may be related to the consistently high expression levels of PD-1. These results may provide new insights into our understanding of CD8+T cell-mediated protective immunity as well as immune homeostasis after HTNV infection in humans.IMPORTANCECD8+T cells play important roles in the antiviral immune response. We found that the proportion of CD8lowCD100−cells among CD8+T cells from HFRS patients was negatively correlated with the HTNV viral load, and the frequency of CD8lowCD100−cells among virus-specific CD8+T cells was higher in milder HFRS cases than in more severe cases. These results imply a beneficial role for the CD8lowCD100−cell subset in viral control during human HTNV infection.

scholarly journals Integrated Single-Cell Analysis of Multicellular Immune Dynamics during Hyper-Acute HIV-1 Infection

2019 ◽  
Author(s):  
Samuel W. Kazer ◽  
Toby P. Aicher ◽  
Daniel M. Muema ◽  
Shaina L. Carroll ◽  
Jose Ordovas-Montanes ◽  
...  
Keyword(s):  
Single Cell ◽  
Single Cell Analysis ◽  
Nk Cell ◽  
Acute Infection ◽  
Cell Subset ◽  
Cell Types ◽  
Interferon Response ◽  
Unified Framework ◽  
Viral Control ◽  
Cellular Targets

ABSTRACTCellular immunity is critical for controlling intracellular pathogens, but the dynamics and cooperativity of the evolving host response to infection are not well defined. Here, we apply single-cell RNA-sequencing to longitudinally profile pre- and immediately post-HIV infection peripheral immune responses of multiple cell types in four untreated individuals. Onset of viremia induces a strong transcriptional interferon response integrated across most cell types, with subsequent pro-inflammatory T cell differentiation, monocyte MHC-II upregulation, and cytolytic killing. With longitudinal sampling, we nominate key intra- and extracellular drivers that induce these programs, and assign their multi-cellular targets, temporal ordering, and duration in acute infection. Two individuals studied developed spontaneous viral control, associated with initial elevated frequencies of proliferating cytotoxic cells, inclusive of a previously unappreciated proliferating natural killer (NK) cell subset. Our study presents a unified framework for characterizing immune evolution during a persistent human viral infection at single-cell resolution, and highlights programs that may drive response coordination and influence clinical trajectory.

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