Publications by authors named "Jacob D Estes"

148 Publications

CD8+ T cells fail to limit SIV reactivation following ART withdrawal until after viral amplification.

J Clin Invest 2021 Feb 25. Epub 2021 Feb 25.

Vaccine and Gene Therapy Institute, Oregon Health & Science University, Beaverton, United States of America.

To define the contribution of CD8+ T cell responses to control of SIV reactivation during and following antiretroviral therapy (ART), we determined the effect of long-term CD8+ T cell depletion using a rhesusized anti-CD8β monoclonal antibody (mAb) on barcoded SIVmac239 dynamics on stable ART and after ART cessation in Rhesus Macaques (RMs). Among the RMs with full CD8+ T cell depletion in both blood and tissue, there were no significant differences in the frequency of viral blips in plasma, the number of SIV RNA+ cells and the average number of RNA copies/infected cell in tissue, and levels of cell-associated SIV RNA and DNA in blood and tissue relative to control-treated RM during ART. Upon ART cessation, both CD8+ T cell-depleted and control RMs rebounded in <12 days with no difference in the time to viral rebound, or in either the number or growth rate of rebounding SIVmac239M barcode clonotypes. However, effectively CD8+ T cell-depleted RMs showed a stable ~2-log increase in post-ART plasma viremia relative to controls. These results indicate that while potent anti-viral CD8+ T cell responses can develop during ART-suppressed SIV infection, these responses effectively intercept post-ART SIV rebound only after systemic viral replication, too late to limit reactivation frequency or the early spread of reactivating SIV reservoirs.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1172/JCI141677DOI Listing
February 2021

Evaluating a New Class of AKT/mTOR Activators for HIV Latency Reversing Activity .

J Virol 2021 Feb 3. Epub 2021 Feb 3.

Gladstone Institute of Virology, Gladstone Institutes, San Francisco, California, USA

An ability to activate latent HIV-1 expression could benefit many HIV cure strategies, but the first generation of latency reversing agents (LRAs) has proven disappointing. We evaluated AKT/mTOR activators as a potential new class of LRAs. Two glycogen synthase kinase-3 inhibitors (GSK-3i's), SB-216763 and tideglusib (the latter already in phase II clinical trials) that activate AKT/mTOR signaling were tested. These GSK-3i's reactivated latent HIV-1 present in blood samples from aviremic individuals on antiretroviral therapy (ART) in the absence of T cell activation, release of inflammatory cytokines, cell toxicity, or impaired effector function of cytotoxic T lymphocytes or NK cells. However, when administered to SIV-infected rhesus macaques on suppressive ART, tideglusib exhibited poor pharmacodynamic properties and resulted in no clear evidence of significant SIV latency reversal. Whether alternative pharmacological formulations or combinations of this drug with other classes of LRAs will lead to an effective latency-reversing strategy remains to be determined. If combined with immune therapeutics, latency reversing agents (LRAs) have the potential to reduce the size of the reservoir sufficiently that an engineered immune response can control the virus in the absence of antiretroviral therapy. We have identified a new class of LRAs that do not induce T-cell activation and that are able to potentiate, rather than inhibit, CD8+ T and NK cell cytotoxic effector functions. This new class of LRAs corresponds to inhibitors of glycogen synthase kinase-3. In this work, we have also studied the effects of one member of this drug class, tideglusib, in SIV-infected rhesus monkeys. When tested in vivo, however, tideglusib showed unfavorable pharmacokinetic properties, which resulted in lack of SIV latency reversal. The disconnect between our ex vivo and in vivo results highlights the importance of developing next generation LRAs with pharmacological properties that allow systemic drug delivery in relevant anatomical compartments harboring latent reservoirs.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1128/JVI.02393-20DOI Listing
February 2021

Prolonged Posttreatment Virologic Control and Complete Seroreversion After Advanced Human Immunodeficiency Virus-1 Infection.

Open Forum Infect Dis 2021 Jan 15;8(1):ofaa613. Epub 2020 Dec 15.

Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA.

Background: Possible human immunodeficiency virus (HIV)-1 clearance has rarely been reported. In this study, we describe a unique case of an HIV-positive, combination antiretroviral therapy (cART)-experienced woman with prior acquired immunodeficiency syndrome (AIDS) who has not experienced viral rebound for over 12 years since discontinuing cART.

Methods: Leukapheresis, colonoscopy, and lymph node excision were performed for detailed examination of virologic (including HIV reservoir) and immunologic features. Comparisons were made with chronically infected patients and healthy controls.

Results: No HIV-specific antibodies were detected in serum. Plasma HIV ribonucleic acid (RNA) levels were <0.2 copies/mL, and, except for low-frequency HIV deoxyribonucleic acid (DNA) cells in lymph node tissue (1 copy/3 × 10 cells), HIV antigen could not be detected by quantitative virus outgrowth (<0.0025 infectious units/10 CD4 T cells) or by most measurements of HIV RNA or DNA in blood, lymph node, or gut-associated mononuclear cells. Human immunodeficiency virus-specific T-cell responses were detectable but low. Brain imaging revealed a prior biopsy site and persistent white matter disease since 1996. Human immunodeficiency virus DNA cells in the 1996 brain biopsy specimen confirmed her identity and initial HIV diagnosis.

Conclusions: This represents the first report of complete seroreversion, prolonged posttreatment virus suppression, a profoundly small HIV reservoir, and persistent HIV-specific T cells in an adult with prior AIDS.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/ofid/ofaa613DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7824876PMC
January 2021

Antibody-mediated depletion of viral reservoirs is limited in SIV-infected macaques treated early with antiretroviral therapy.

J Clin Invest 2021 Jan 19. Epub 2021 Jan 19.

AIDS and Cancer Virus Program, Frederick National Laboratory for Cancer Research, Frederick, United States of America.

The effectiveness of virus-specific strategies, including administered HIV-specific mAbs, to target cells that persistently harbor latent, rebound competent HIV genomes during combination antiretroviral therapy (cART) has been limited by inefficient induction of viral protein expression. To examine antibody-mediated viral reservoir targeting without a need for viral induction, we used an anti-CD4 mAb to deplete both infected and uninfected CD4+ T cells. Ten rhesus macaques infected with barcoded SIVmac239M received cART for 93 weeks starting 4 days post-infection. During cART, five animals received 5-6 anti-CD4 antibody administrations and CD4+ T cell populations were then allowed one year on cART to recover. Despite profound CD4+ T cell depletion in blood and lymph nodes, time to viral rebound following cART cessation was not significantly delayed in anti-CD4 treated animals compared with controls. Viral reactivation rates, determined based on rebounding SIVmac239M clonotype proportions, also were not significantly different in CD4 depleted animals. Notably, antibody-mediated depletion was limited in rectal tissue and negligible in lymphoid follicles. These results suggest that even if robust viral reactivation can be achieved, antibody-mediated viral reservoir depletion may be limited in key tissue sites.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1172/JCI142421DOI Listing
January 2021

Baricitinib treatment resolves lower-airway macrophage inflammation and neutrophil recruitment in SARS-CoV-2-infected rhesus macaques.

Cell 2021 01 10;184(2):460-475.e21. Epub 2020 Nov 10.

Division of Microbiology and Immunology, Yerkes National Primate Research Center, Emory University, Atlanta, GA 30329, USA; Department of Pathology and Laboratory Medicine, School of Medicine, Emory University, Atlanta, GA 30322, USA. Electronic address:

SARS-CoV-2-induced hypercytokinemia and inflammation are critically associated with COVID-19 severity. Baricitinib, a clinically approved JAK1/JAK2 inhibitor, is currently being investigated in COVID-19 clinical trials. Here, we investigated the immunologic and virologic efficacy of baricitinib in a rhesus macaque model of SARS-CoV-2 infection. Viral shedding measured from nasal and throat swabs, bronchoalveolar lavages, and tissues was not reduced with baricitinib. Type I interferon (IFN) antiviral responses and SARS-CoV-2-specific T cell responses remained similar between the two groups. Animals treated with baricitinib showed reduced inflammation, decreased lung infiltration of inflammatory cells, reduced NETosis activity, and more limited lung pathology. Importantly, baricitinib-treated animals had a rapid and remarkably potent suppression of lung macrophage production of cytokines and chemokines responsible for inflammation and neutrophil recruitment. These data support a beneficial role for, and elucidate the immunological mechanisms underlying, the use of baricitinib as a frontline treatment for inflammation induced by SARS-CoV-2 infection.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.cell.2020.11.007DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7654323PMC
January 2021

In vitro and in vivo characterization of a recombinant rhesus cytomegalovirus containing a complete genome.

PLoS Pathog 2020 11 24;16(11):e1008666. Epub 2020 Nov 24.

Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon, United States of America.

Cytomegaloviruses (CMVs) are highly adapted to their host species resulting in strict species specificity. Hence, in vivo examination of all aspects of CMV biology employs animal models using host-specific CMVs. Infection of rhesus macaques (RM) with rhesus CMV (RhCMV) has been established as a representative model for infection of humans with HCMV due to the close evolutionary relationships of both host and virus. However, the only available RhCMV clone that permits genetic modifications is based on the 68-1 strain which has been passaged in fibroblasts for decades resulting in multiple genomic changes due to tissue culture adaptations. As a result, 68-1 displays reduced viremia in RhCMV-naïve animals and limited shedding compared to non-clonal, low passage isolates. To overcome this limitation, we used sequence information from primary RhCMV isolates to construct a full-length (FL) RhCMV by repairing all mutations affecting open reading frames (ORFs) in the 68-1 bacterial artificial chromosome (BAC). Inoculation of adult, immunocompetent, RhCMV-naïve RM with the reconstituted virus resulted in significant viremia in the blood similar to primary isolates of RhCMV and furthermore led to high viral genome copy numbers in many tissues at day 14 post infection. In contrast, viral dissemination was greatly reduced upon deletion of genes also lacking in 68-1. Transcriptome analysis of infected tissues further revealed that chemokine-like genes deleted in 68-1 are among the most highly expressed viral transcripts both in vitro and in vivo consistent with an important immunomodulatory function of the respective proteins. We conclude that FL-RhCMV displays in vitro and in vivo characteristics of a wildtype virus while being amenable to genetic modifications through BAC recombineering techniques.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1371/journal.ppat.1008666DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7723282PMC
November 2020

Vascular Disease and Thrombosis in SARS-CoV-2-Infected Rhesus Macaques.

Cell 2020 11 9;183(5):1354-1366.e13. Epub 2020 Oct 9.

Center for Virology and Vaccine Research, Beth Israel Deaconess Medical Center, Boston, MA 02215, USA; Ragon Institute of MGH, MIT, and Harvard, Cambridge, MA 02139, USA. Electronic address:

The COVID-19 pandemic has led to extensive morbidity and mortality throughout the world. Clinical features that drive SARS-CoV-2 pathogenesis in humans include inflammation and thrombosis, but the mechanistic details underlying these processes remain to be determined. In this study, we demonstrate endothelial disruption and vascular thrombosis in histopathologic sections of lungs from both humans and rhesus macaques infected with SARS-CoV-2. To define key molecular pathways associated with SARS-CoV-2 pathogenesis in macaques, we performed transcriptomic analyses of bronchoalveolar lavage and peripheral blood and proteomic analyses of serum. We observed macrophage infiltrates in lung and upregulation of macrophage, complement, platelet activation, thrombosis, and proinflammatory markers, including C-reactive protein, MX1, IL-6, IL-1, IL-8, TNFα, and NF-κB. These results suggest a model in which critical interactions between inflammatory and thrombosis pathways lead to SARS-CoV-2-induced vascular disease. Our findings suggest potential therapeutic targets for COVID-19.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.cell.2020.10.005DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7546181PMC
November 2020

Baricitinib treatment resolves lower airway inflammation and neutrophil recruitment in SARS-CoV-2-infected rhesus macaques.

bioRxiv 2020 Sep 16. Epub 2020 Sep 16.

Division of Microbiology and Immunology, Yerkes National Primate Research Center, Emory University, Atlanta, Georgia, USA.

Effective therapeutics aimed at mitigating COVID-19 symptoms are urgently needed. SARS-CoV-2 induced hypercytokinemia and systemic inflammation are associated with disease severity. Baricitinib, a clinically approved JAK1/2 inhibitor with potent anti-inflammatory properties is currently being investigated in COVID-19 human clinical trials. Recent reports suggest that baricitinib may also have antiviral activity in limiting viral endocytosis. Here, we investigated the immunologic and virologic efficacy of baricitinib in a rhesus macaque model of SARS-CoV-2 infection. Viral shedding measured from nasal and throat swabs, bronchoalveolar lavages and tissues was not reduced with baricitinib. Type I IFN antiviral responses and SARS-CoV-2 specific T cell responses remained similar between the two groups. Importantly, however, animals treated with baricitinib showed reduced immune activation, decreased infiltration of neutrophils into the lung, reduced NETosis activity, and more limited lung pathology. Moreover, baricitinib treated animals had a rapid and remarkably potent suppression of alveolar macrophage derived production of cytokines and chemokines responsible for inflammation and neutrophil recruitment. These data support a beneficial role for, and elucidate the immunological mechanisms underlying, the use of baricitinib as a frontline treatment for severe inflammation induced by SARS-CoV-2 infection.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1101/2020.09.16.300277DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7523106PMC
September 2020

Feasibility and safety of ultrasound-guided minimally invasive autopsy in COVID-19 patients.

Abdom Radiol (NY) 2020 Sep 17. Epub 2020 Sep 17.

Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA.

Objectives: To determine the feasibility and safety of ultrasound-guided minimally invasive autopsy in COVID-19 patients.

Methods: 60 patients who expired between 04/22/2020-05/06/2020 due to COVID-19 were considered for inclusion in the study, based on availability of study staff. Minimally invasive ultrasound-guided autopsy was performed with 14G core biopsies through a 13G coaxial needle. The protocol required 20 cores of the liver, 30 of lung, 12 of spleen, 20 of heart, 20 of kidney, 4 of breast, 4 of testis, 2 of skeletal muscle, and 4 of fat with total of 112 cores per patient. Quality of the samples was evaluated by number, size, histology, immunohistochemistry, and in situ hybridization for COVID-19 and PCR-measured viral loads for SARS-CoV-2.

Results: Five (5/60, 8%) patients were included. All approached families gave their consent for the minimally invasive autopsy. All organs for biopsy were successfully targeted with ultrasound guidance obtaining all required samples, apart from 2 patients where renal samples were not obtained due to atrophic kidneys. The number, size, and weight of the tissue cores met expectation of the research group and tissue histology quality was excellent. Pathology findings were concordant with previously reported autopsy findings for COVID-19. Highest SARS-CoV-2 viral load was detected in the lung, liver, and spleen that had small to moderate amount, and low viral load in was detected in the heart in 2/5 (40%). No virus was detected in the kidney (0/3, 0%).

Conclusions: Ultrasound-guided percutaneous post-mortem core biopsies can safely provide adequate tissue. Highest SARS-CoV-2 viral load was seen in the lung, followed by liver and spleen with small amount in the myocardium.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00261-020-02753-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7494380PMC
September 2020

Intrahepatic CXCL10 is strongly associated with liver fibrosis in HIV-Hepatitis B co-infection.

PLoS Pathog 2020 09 8;16(9):e1008744. Epub 2020 Sep 8.

The Peter Doherty Institute for Infection and Immunity, The University of Melbourne and Royal Melbourne Hospital, Melbourne, Victoria, Australia.

In HIV-hepatitis B virus (HBV) co-infection, adverse liver outcomes including liver fibrosis occur at higher frequency than in HBV-mono-infection, even following antiretroviral therapy (ART) that suppresses both HIV and HBV replication. To determine whether liver disease was associated with intrahepatic or circulating markers of inflammation or burden of HIV or HBV, liver biopsies and blood were collected from HIV-HBV co-infected individuals (n = 39) living in Bangkok, Thailand and naïve to ART. Transient elastography (TE) was performed. Intrahepatic and circulating markers of inflammation and microbial translocation were quantified by ELISA and bead arrays and HIV and HBV infection quantified by PCR. Liver fibrosis (measured by both transient elastography and liver biopsy) was statistically significantly associated with intrahepatic mRNA for CXCL10 and CXCR3 using linear and logistic regression analyses adjusted for CD4 T-cell count. There was no evidence of a relationship between liver fibrosis and circulating HBV DNA, qHBsAg, plasma HIV RNA or circulating cell-associated HIV RNA or DNA. Using immunohistochemistry of liver biopsies from this cohort, intrahepatic CXCL10 was detected in hepatocytes associated with inflammatory liver infiltrates in the portal tracts. In an in vitro model, we infected an HBV-infected hepatocyte cell line with HIV, followed by interferon-γ stimulation. HBV-infected cells lines produced significantly more CXCL10 than uninfected cells lines and this significantly increased in the presence of an increasing multiplicity of HIV infection. Conclusion: Enhanced production of CXCL10 following co-infection of hepatocytes with both HIV and HBV may contribute to accelerated liver disease in the setting of HIV-HBV co-infection.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1371/journal.ppat.1008744DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7521747PMC
September 2020

Recommendations for measuring HIV reservoir size in cure-directed clinical trials.

Nat Med 2020 09 7;26(9):1339-1350. Epub 2020 Sep 7.

The Wistar Institute, Philadelphia, PA, USA.

Therapeutic strategies are being clinically tested either to eradicate latent HIV reservoirs or to achieve virologic control in the absence of antiretroviral therapy. Attaining this goal will require a consensus on how best to measure the numbers of persistently infected cells with the potential to cause viral rebound after antiretroviral-therapy cessation in assessing the results of cure-directed strategies in vivo. Current measurements assess various aspects of the HIV provirus and its functionality and produce divergent results. Here, we provide recommendations from the BEAT-HIV Martin Delaney Collaboratory on which viral measurements should be prioritized in HIV-cure-directed clinical trials.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41591-020-1022-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7703694PMC
September 2020

Ad26 vaccine protects against SARS-CoV-2 severe clinical disease in hamsters.

Nat Med 2020 11 3;26(11):1694-1700. Epub 2020 Sep 3.

Center for Virology and Vaccine Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA.

Coronavirus disease 2019 (COVID-19) in humans is often a clinically mild illness, but some individuals develop severe pneumonia, respiratory failure and death. Studies of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in hamsters and nonhuman primates have generally reported mild clinical disease, and preclinical SARS-CoV-2 vaccine studies have demonstrated reduction of viral replication in the upper and lower respiratory tracts in nonhuman primates. Here we show that high-dose intranasal SARS-CoV-2 infection in hamsters results in severe clinical disease, including high levels of virus replication in tissues, extensive pneumonia, weight loss and mortality in a subset of animals. A single immunization with an adenovirus serotype 26 vector-based vaccine expressing a stabilized SARS-CoV-2 spike protein elicited binding and neutralizing antibody responses and protected against SARS-CoV-2-induced weight loss, pneumonia and mortality. These data demonstrate vaccine protection against SARS-CoV-2 clinical disease. This model should prove useful for preclinical studies of SARS-CoV-2 vaccines, therapeutics and pathogenesis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41591-020-1070-6DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7671939PMC
November 2020

Adjuvanted HIV-1 vaccine promotes antibody-dependent phagocytic responses and protects against heterologous SHIV challenge.

PLoS Pathog 2020 09 3;16(9):e1008764. Epub 2020 Sep 3.

US Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, Maryland, United States of America.

To augment HIV-1 pox-protein vaccine immunogenicity using a next generation adjuvant, a prime-boost strategy of recombinant modified vaccinia virus Ankara and multimeric Env gp145 was evaluated in macaques with either aluminum (alum) or a novel liposomal monophosphoryl lipid A (MPLA) formulation adsorbed to alum, ALFA. Binding antibody responses were robust and comparable between arms, while antibody-dependent neutrophil and monocyte phagocytotic responses were greatly enhanced by ALFA. Per-exposure vaccine efficacy against heterologous tier 2 SHIV mucosal challenge was 90% in ALFA-adjuvanted males (P = 0.002), while alum conferred no protection. Half of the ALFA-adjuvanted males remained uninfected after the full challenge series, which spanned seven months after the last vaccination. Antibody-dependent monocyte and neutrophil phagocytic responses both strongly correlated with protection. Significant sex differences in infection risk were observed, with much lower infection rates in females than males. In humans, MPLA-liposome-alum adjuvanted gp120 also increased HIV-1-specific phagocytic responses relative to alum. Thus, next-generation liposome-based adjuvants can drive vaccine elicited antibody effector activity towards potent phagocytic responses in both macaques and humans and these responses correlate with protection. Future protein vaccination strategies aiming to improve functional humoral responses may benefit from such adjuvants.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1371/journal.ppat.1008764DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7505435PMC
September 2020

Application of a Scavenger Receptor A1-Targeted Polymeric Prodrug Platform for Lymphatic Drug Delivery in HIV.

Mol Pharm 2020 10 9;17(10):3794-3812. Epub 2020 Sep 9.

Nanotechnology Characterization Lab, Frederick National Laboratory for Cancer Research sponsored by the National Cancer Institute, Frederick, Maryland 21702-1201, United States.

We have developed a macromolecular prodrug platform based on poly(l-lysine succinylated) (PLS) that targets scavenger receptor A1 (SR-A1), a receptor expressed by myeloid and endothelial cells. We demonstrate the selective uptake of PLS by murine macrophage, RAW 264.7 cells, which was eliminated upon cotreatment with the SR-A inhibitor polyinosinic acid (poly I). Further, we observed no uptake of PLS in an SR-A1-deficient RAW 264.7 cell line, even after 24 h incubation. In mice, PLS distributed to lymphatic organs following i.v. injection, as observed by fluorescent imaging, and accumulated in lymph nodes following both i.v. and i.d. administrations, based on immunohistochemical analysis with high-resolution microscopy. As a proof-of-concept, the HIV antiviral emtricitabine (FTC) was conjugated to the polymer's succinyl groups via ester bonds, with a drug loading of 14.2% (wt/wt). The prodrug (PLS-FTC) demonstrated controlled release properties with a release half-life of 15 h in human plasma and 29 h in esterase-inhibited plasma, indicating that drug release occurs through both enzymatic and nonenzymatic mechanisms. Upon incubation of PLS-FTC with human peripheral blood mononuclear cells (PBMCs), the released drug was converted to the active metabolite FTC triphosphate. In a pharmacokinetic study in rats, the prodrug achieved ∼7-19-fold higher concentrations in lymphatic tissues compared to those in FTC control, supporting lymphatic-targeted drug delivery. We believe that the SR-A1-targeted macromolecular PLS prodrug platform has extraordinary potential for the treatment of infectious diseases.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/acs.molpharmaceut.0c00562DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7861197PMC
October 2020

SARS-CoV-2 infection protects against rechallenge in rhesus macaques.

Science 2020 08 20;369(6505):812-817. Epub 2020 May 20.

Center for Virology and Vaccine Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA.

An understanding of protective immunity to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is critical for vaccine and public health strategies aimed at ending the global coronavirus disease 2019 (COVID-19) pandemic. A key unanswered question is whether infection with SARS-CoV-2 results in protective immunity against reexposure. We developed a rhesus macaque model of SARS-CoV-2 infection and observed that macaques had high viral loads in the upper and lower respiratory tract, humoral and cellular immune responses, and pathologic evidence of viral pneumonia. After the initial viral clearance, animals were rechallenged with SARS-CoV-2 and showed 5 log reductions in median viral loads in bronchoalveolar lavage and nasal mucosa compared with after the primary infection. Anamnestic immune responses after rechallenge suggested that protection was mediated by immunologic control. These data show that SARS-CoV-2 infection induced protective immunity against reexposure in nonhuman primates.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1126/science.abc4776DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7243369PMC
August 2020

CTLA-4 and PD-1 dual blockade induces SIV reactivation without control of rebound after antiretroviral therapy interruption.

Nat Med 2020 04 16;26(4):519-528. Epub 2020 Mar 16.

Division of Microbiology and Immunology, Yerkes National Primate Research Center, Emory University, Atlanta, GA, USA.

The primary human immunodeficiency virus (HIV) reservoir is composed of resting memory CD4 T cells, which often express the immune checkpoint receptors programmed cell death protein 1 (PD-1) and cytotoxic T lymphocyte-associated protein 4 (CTLA-4), which limit T cell activation via synergistic mechanisms. Using simian immunodeficiency virus (SIV)-infected, long-term antiretroviral therapy (ART)-treated rhesus macaques, we demonstrate that PD-1, CTLA-4 and dual CTLA-4/PD-1 immune checkpoint blockade using monoclonal antibodies is well tolerated, with evidence of bioactivity in blood and lymph nodes. Dual blockade was remarkably more effective than PD-1 blockade alone in enhancing T cell cycling and differentiation, expanding effector-memory T cells and inducing robust viral reactivation in plasma and peripheral blood mononuclear cells. In lymph nodes, dual CTLA-4/PD-1 blockade, but not PD-1 alone, decreased the total and intact SIV-DNA in CD4 T cells, and SIV-DNA and SIV-RNA in B cell follicles, a major site of viral persistence during ART. None of the tested interventions enhanced SIV-specific CD8 T cell responses during ART or viral control after ART interruption. Thus, despite CTLA-4/PD-1 blockade inducing robust latency reversal and reducing total levels of integrated virus, the degree of reservoir clearance was still insufficient to achieve viral control. These results suggest that immune checkpoint blockade regimens targeting PD-1 and/or CTLA-4, if performed in people living with HIV with sustained aviremia, are unlikely to induce HIV remission in the absence of additional interventions.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41591-020-0782-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7790171PMC
April 2020

The human IL-15 superagonist N-803 promotes migration of virus-specific CD8+ T and NK cells to B cell follicles but does not reverse latency in ART-suppressed, SHIV-infected macaques.

PLoS Pathog 2020 03 12;16(3):e1008339. Epub 2020 Mar 12.

Vaccine & Gene Therapy Institute, Oregon Health & Science University, Beaverton, Oregon, United States of America.

Despite the success of antiretroviral therapy (ART) to halt viral replication and slow disease progression, this treatment is not curative and there remains an urgent need to develop approaches to clear the latent HIV reservoir. The human IL-15 superagonist N-803 (formerly ALT-803) is a promising anti-cancer biologic with potent immunostimulatory properties that has been extended into the field of HIV as a potential "shock and kill" therapeutic for HIV cure. However, the ability of N-803 to reactivate latent virus and modulate anti-viral immunity in vivo under the cover of ART remains undefined. Here, we show that in ART-suppressed, simian-human immunodeficiency virus (SHIV)SF162P3-infected rhesus macaques, subcutaneous administration of N-803 activates and mobilizes both NK cells and SHIV-specific CD8+ T cells from the peripheral blood to lymph node B cell follicles, a sanctuary site for latent virus that normally excludes such effector cells. We observed minimal activation of memory CD4+ T cells and no increase in viral RNA content in lymph node resident CD4+ T cells post N-803 administration. Accordingly, we found no difference in the number or magnitude of plasma viremia timepoints between treated and untreated animals during the N-803 administration period, and no difference in the size of the viral DNA cell-associated reservoir post N-803 treatment. These results substantiate N-803 as a potent immunotherapeutic candidate capable of activating and directing effector CD8+ T and NK cells to the B cell follicle during full ART suppression, and suggest N-803 must be paired with a bona fide latency reversing agent in vivo to facilitate immune-mediated modulation of the latent viral reservoir.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1371/journal.ppat.1008339DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7093032PMC
March 2020

African green monkeys avoid SIV disease progression by preventing intestinal dysfunction and maintaining mucosal barrier integrity.

PLoS Pathog 2020 03 2;16(3):e1008333. Epub 2020 Mar 2.

Department of Pathology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America.

Unlike HIV infection, SIV infection is generally nonpathogenic in natural hosts, such as African green monkeys (AGMs), despite life-long high viral replication. Lack of disease progression was reportedly based on the ability of SIV-infected AGMs to prevent gut dysfunction, avoiding microbial translocation and the associated systemic immune activation and chronic inflammation. Yet, the maintenance of gut integrity has never been documented, and the mechanism(s) by which gut integrity is preserved are unknown. We sought to investigate the early events of SIV infection in AGMs, specifically examining the impact of SIVsab infection on the gut mucosa. Twenty-nine adult male AGMs were intrarectally infected with SIVsab92018 and serially sacrificed at well-defined stages of SIV infection, preramp-up (1-3 days post-infection (dpi)), ramp-up (4-6 dpi), peak viremia (9-12 dpi), and early chronic SIV infection (46-55 dpi), to assess the levels of immune activation, apoptosis, epithelial damage and microbial translocation in the GI tract and peripheral lymph nodes. Tissue viral loads, plasma cytokines and plasma markers of gut dysfunction were also measured throughout the course of early infection. While a strong, but transient, interferon-based inflammatory response was observed, the levels of plasma markers linked to enteropathy did not increase. Accordingly, no significant increases in apoptosis of either mucosal enterocytes or lymphocytes, and no damage to the mucosal epithelium were documented during early SIVsab infection of AGMs. These findings were supported by RNAseq of the gut tissue, which found no significant alterations in gene expression that would indicate microbial translocation. Thus, for the first time, we confirmed that gut epithelial integrity is preserved, with no evidence of microbial translocation, in AGMs throughout early SIVsab infection. This might protect AGMs from developing intestinal dysfunction and the subsequent chronic inflammation that drives both HIV disease progression and HIV-associated comorbidities.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1371/journal.ppat.1008333DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7077871PMC
March 2020

HIV-1-induced cytokines deplete homeostatic innate lymphoid cells and expand TCF7-dependent memory NK cells.

Nat Immunol 2020 03 17;21(3):274-286. Epub 2020 Feb 17.

Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA, USA.

Human immunodeficiency virus 1 (HIV-1) infection is associated with heightened inflammation and excess risk of cardiovascular disease, cancer and other complications. These pathologies persist despite antiretroviral therapy. In two independent cohorts, we found that innate lymphoid cells (ILCs) were depleted in the blood and gut of people with HIV-1, even with effective antiretroviral therapy. ILC depletion was associated with neutrophil infiltration of the gut lamina propria, type 1 interferon activation, increased microbial translocation and natural killer (NK) cell skewing towards an inflammatory state, with chromatin structure and phenotype typical of WNT transcription factor TCF7-dependent memory T cells. Cytokines that are elevated during acute HIV-1 infection reproduced the ILC and NK cell abnormalities ex vivo. These results show that inflammatory cytokines associated with HIV-1 infection irreversibly disrupt ILCs. This results in loss of gut epithelial integrity, microbial translocation and memory NK cells with heightened inflammatory potential, and explains the chronic inflammation in people with HIV-1.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41590-020-0593-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7044076PMC
March 2020

Robust and persistent reactivation of SIV and HIV by N-803 and depletion of CD8 cells.

Nature 2020 02 22;578(7793):154-159. Epub 2020 Jan 22.

Emory Vaccine Center and Yerkes National Primate Research Center, Emory University, Atlanta, GA, USA.

Human immunodeficiency virus (HIV) persists indefinitely in individuals with HIV who receive antiretroviral therapy (ART) owing to a reservoir of latently infected cells that contain replication-competent virus. Here, to better understand the mechanisms responsible for latency persistence and reversal, we used the interleukin-15 superagonist N-803 in conjunction with the depletion of CD8 lymphocytes in ART-treated macaques infected with simian immunodeficiency virus (SIV). Although N-803 alone did not reactivate virus production, its administration after the depletion of CD8 lymphocytes in conjunction with ART treatment induced robust and persistent reactivation of the virus in vivo. We found viraemia of more than 60 copies per ml in all macaques (n = 14; 100%) and in 41 out of a total of 56 samples (73.2%) that were collected each week after N-803 administration. Notably, concordant results were obtained in ART-treated HIV-infected humanized mice. In addition, we observed that co-culture with CD8 T cells blocked the in vitro latency-reversing effect of N-803 on primary human CD4 T cells that were latently infected with HIV. These results advance our understanding of the mechanisms responsible for latency reversal and lentivirus reactivation during ART-suppressed infection.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41586-020-1946-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7580846PMC
February 2020

Elite control of HIV is associated with distinct functional and transcriptional signatures in lymphoid tissue CD8 T cells.

Sci Transl Med 2019 12;11(523)

Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.

The functional properties of circulating CD8 T cells have been associated with immune control of HIV. However, viral replication occurs predominantly in secondary lymphoid tissues, such as lymph nodes (LNs). We used an integrated single-cell approach to characterize effective HIV-specific CD8 T cell responses in the LNs of elite controllers (ECs), defined as individuals who suppress viral replication in the absence of antiretroviral therapy (ART). Higher frequencies of total memory and follicle-homing HIV-specific CD8 T cells were detected in the LNs of ECs compared with the LNs of chronic progressors (CPs) who were not receiving ART. Moreover, HIV-specific CD8 T cells potently suppressed viral replication without demonstrable cytolytic activity in the LNs of ECs, which harbored substantially lower amounts of CD4 T cell-associated HIV DNA and RNA compared with the LNs of CPs. Single-cell RNA sequencing analyses further revealed a distinct transcriptional signature among HIV-specific CD8 T cells from the LNs of ECs, typified by the down-regulation of inhibitory receptors and cytolytic molecules and the up-regulation of multiple cytokines, predicted secreted factors, and components of the protein translation machinery. Collectively, these results provide a mechanistic framework to expedite the identification of novel antiviral factors, highlighting a potential role for the localized deployment of noncytolytic functions as a determinant of immune efficacy against HIV.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1126/scitranslmed.aax4077DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7265335PMC
December 2019

Fingolimod retains cytolytic T cells and limits T follicular helper cell infection in lymphoid sites of SIV persistence.

PLoS Pathog 2019 10 18;15(10):e1008081. Epub 2019 Oct 18.

Division of Microbiology and Immunology, Yerkes National Primate Research Center, Emory University, Atlanta, Georgia, United States of America.

Lymph nodes (LN) and their resident T follicular helper CD4+ T cells (Tfh) are a critical site for HIV replication and persistence. Therefore, optimizing antiviral activity in lymphoid tissues will be needed to reduce or eliminate the HIV reservoir. In this study, we retained effector immune cells in LN of cART-suppressed, SIV-infected rhesus macaques by treatment with the lysophospholipid sphingosine-1 phosphate receptor modulator FTY720 (fingolimod). FTY720 was remarkably effective in reducing circulating CD4+ and CD8+ T cells, including those with cytolytic potential, and in increasing the number of these T cells retained in LN, as determined directly in situ by histocytometry and immunohistochemistry. The FTY720-induced inhibition of T cell egress from LN resulted in a measurable decrease of SIV-DNA content in blood as well as in LN Tfh cells in most treated animals. In conclusion, FTY720 administration has the potential to limit viral persistence, including in the critical Tfh cellular reservoir. These findings provide rationale for strategies designed to retain antiviral T cells in lymphoid tissues to target HIV remission.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1371/journal.ppat.1008081DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6834281PMC
October 2019

Intestinal proteomic analysis of a novel non-human primate model of experimental colitis reveals signatures of mitochondrial and metabolic dysfunction.

Mucosal Immunol 2019 11 3;12(6):1327-1335. Epub 2019 Sep 3.

Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, MB, Canada.

Animal models recapitulating features of chronic colitis, such as ulcerative colitis, Crohn's disease, or HIV infection, are critical to study disease pathogenesis and test novel therapeutics. In this study, we used a proteomics approach to explore the molecular intestinal response in two rhesus macaque (RM) animal models of experimentally induced colitis using dextran sulfate sodium (DSS) and simian immunodeficiency virus (SIV) infection. Proteomic analysis detected more than 2500 proteins in colonic tissue collected from 30 RMs. Differential protein expression analysis revealed a protein expression pattern in DSS-treated RMs resembling the proteome of human ulcerative colitis. In a group of 12 DSS-treated RMs compared to 6 with no treatment, decrease in expression of proteins related to mitochondrial energy metabolism, including fatty acid metabolism was noted, while innate immune activation pathways, including complement and coagulation proteins were upregulated. SIV infection of RMs resulted in increased innate immune responses related to viral defense. Proteomic signatures of barrier damage were apparent in both DSS treatment or SIV infection. These results demonstrate that DSS treatment in a non-human primate model resembles features of human ulcerative colitis, making this a promising tool to study important immunological mechanisms in inflammatory bowel disease.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41385-019-0200-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7673647PMC
November 2019

TLR9 agonist MGN1703 enhances B cell differentiation and function in lymph nodes.

EBioMedicine 2019 Jul 9;45:328-340. Epub 2019 Jul 9.

Department of Infectious Diseases, Aarhus University Hospital, Denmark; Department of Clinical Medicine, Aarhus University, Denmark. Electronic address:

Background: TLR9 agonists are being developed as immunotherapy against malignancies and infections. TLR9 is primarily expressed in B cells and plasmacytoid dendritic cells (pDCs). TLR9 signalling may be critically important for B cell activity in lymph nodes but little is known about the in vivo impact of TLR9 agonism on human lymph node B cells. As a pre-defined sub-study within our clinical trial investigating TLR9 agonist MGN1703 (lefitolimod) treatment in the context of developing HIV cure strategies (NCT02443935), we assessed TLR9 agonist-mediated effects in lymph nodes.

Methods: Participants received MGN1703 for 24 weeks concurrent with antiretroviral therapy. Seven participants completed the sub-study including lymph node resection at baseline and after 24 weeks of treatment. A variety of tissue-based immunologic and virologic parameters were assessed.

Findings: MGN1703 dosing increased B cell differentiation; activated pDCs, NK cells, and T cells; and induced a robust interferon response in lymph nodes. Expression of Activation-Induced cytidine Deaminase, an essential regulator of B cell diversification and somatic hypermutation, was highly elevated. During MGN1703 treatment IgG production increased and antibody glycosylation patterns were changed.

Interpretation: Our data present novel evidence that the TLR9 agonist MGN1703 modulates human lymph node B cells in vivo. These findings warrant further considerations in the development of TLR9 agonists as immunotherapy against cancers and infectious diseases. FUND: This work was supported by Aarhus University Research Foundation, the Danish Council for Independent Research and the NovoNordisk Foundation. Mologen AG provided study drug free of charge.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ebiom.2019.07.005DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6642412PMC
July 2019

Kynurenine 3-Monooxygenase Inhibition during Acute Simian Immunodeficiency Virus Infection Lowers PD-1 Expression and Improves Post-Combination Antiretroviral Therapy CD4 T Cell Counts and Body Weight.

J Immunol 2019 08 8;203(4):899-910. Epub 2019 Jul 8.

Division of Experimental Medicine, University of California San Francisco, San Francisco, CA 94110.

The kynurenine pathway (KP) is a key regulator of many important physiological processes and plays a harmful role in cancer, many neurologic conditions, and chronic viral infections. In HIV infection, KP activity is consistently associated with reduced CD4 T cell counts and elevated levels of T cell activation and viral load; it also independently predicts mortality and morbidity from non-AIDS events. Kynurenine 3-monooxygenase (KMO) is a therapeutically important target in the KP. Using the nonhuman primate model of SIV infection in rhesus macaques, we investigated whether KMO inhibition could slow the course of disease progression. We used a KMO inhibitor, CHDI-340246, to perturb the KP during early acute infection and followed the animals for 1 y to assess clinical outcomes and immune phenotype and function during pre-combination antiretroviral therapy acute infection and combination antiretroviral therapy-treated chronic infection. Inhibition of KMO in acute SIV infection disrupted the KP and prevented SIV-induced increases in downstream metabolites, improving clinical outcome as measured by both increased CD4 T cell counts and body weight. KMO inhibition increased naive T cell frequency and lowered PD-1 expression in naive and memory T cell subsets. Importantly, early PD-1 expression during acute SIV infection predicted clinical outcomes of body weight and CD4 T cell counts. Our data indicate that KMO inhibition in early acute SIV infection provides clinical benefit and suggest a rationale for testing KMO inhibition as an adjunctive treatment in SIV/HIV infection to slow the progression of the disease and improve immune reconstitution.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.4049/jimmunol.1801649DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6684450PMC
August 2019

Heterogeneous antiretroviral drug distribution and HIV/SHIV detection in the gut of three species.

Sci Transl Med 2019 07;11(499)

Division of Pharmacotherapy and Experimental Therapeutics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.

HIV replication within tissues may increase in response to a reduced exposure to antiretroviral drugs. Traditional approaches to measuring drug concentrations in tissues are unable to characterize a heterogeneous drug distribution. Here, we used mass spectrometry imaging (MSI) to visualize the distribution of six HIV antiretroviral drugs in gut tissue sections from three species (two strains of humanized mice, macaques, and humans). We measured drug concentrations in proximity to CD3 T cells that are targeted by HIV, as well as expression of HIV or SHIV RNA and expression of the MDR1 drug efflux transporter in gut tissue from HIV-infected humanized mice, SHIV-infected macaques, and HIV-infected humans treated with combination antiretroviral drug therapy. Serial 10-μm sections of snap-frozen ileal and rectal tissue were analyzed by MSI for CD3 T cells and MDR1 efflux transporter expression by immunofluorescence and immunohistochemistry, respectively. The tissue slices were analyzed for HIV/SHIV RNA expression by in situ hybridization and for antiretroviral drug concentrations by liquid chromatography-mass spectrometry. The gastrointestinal tissue distribution of the six drugs was heterogeneous. Fifty percent to 60% of CD3 T cells did not colocalize with detectable drug concentrations in the gut tissue. In all three species, up to 90% of HIV/SHIV RNA was found to be expressed in gut tissue with no exposure to drug. These data suggest that there may be gut regions with little to no exposure to antiretroviral drugs, which may result in low-level HIV replication contributing to HIV persistence.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1126/scitranslmed.aap8758DOI Listing
July 2019

Identification of HIV transmitting CD11c human epidermal dendritic cells.

Nat Commun 2019 06 21;10(1):2759. Epub 2019 Jun 21.

Centre for Virus Research, The Westmead Institute for Medical Research, 176 Hawkesbury Road, Westmead, New South Wales, 2145, Australia.

Langerhans cells (LC) are thought to be the only mononuclear phagocyte population in the epidermis where they detect pathogens. Here, we show that CD11c dendritic cells (DCs) are also present. These cells are transcriptionally similar to dermal cDC2 but are more efficient antigen-presenting cells. Compared to LCs, epidermal CD11c DCs are enriched in anogenital tissues where they preferentially interact with HIV, express the higher levels of HIV entry receptor CCR5, support the higher levels of HIV uptake and replication and are more efficient at transmitting the virus to CD4 T cells. Importantly, these findings are observed using both a lab-adapted and transmitted/founder strain of HIV. We also describe a CD33 cell population, which is transcriptionally similar to LCs but does not appear to function as antigen-presenting cells or acts as HIV target cells. Our findings reveal that epidermal DCs in anogenital tissues potentially play a key role in sexual transmission of HIV.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41467-019-10697-wDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6588576PMC
June 2019

Autologous, Gene-Modified Hematopoietic Stem and Progenitor Cells Repopulate the Central Nervous System with Distinct Clonal Variants.

Stem Cell Reports 2019 07 13;13(1):91-104. Epub 2019 Jun 13.

Division of Clinical Research, Fred Hutchinson Cancer Research Center, 1100 Fairview Avenue N, Mail Stop D1-100, PO Box 19024, Seattle, WA 98109-1024, USA; Department of Medicine, University of Washington, Seattle WA 98195, USA; Department of Pathology, University of Washington, Seattle, WA 98195, USA. Electronic address:

Myeloid-differentiated hematopoietic stem cells (HSCs) have contributed to a number of novel treatment approaches for lysosomal storage diseases of the central nervous system (CNS), and may also be applied to patients infected with HIV. We quantified hematopoietic stem and progenitor cell (HSPC) trafficking to 20 tissues including lymph nodes, spleen, liver, gastrointestinal tract, CNS, and reproductive tissues. We observed efficient marking of multiple macrophage subsets, including CNS-associated myeloid cells, suggesting that HSPC-derived macrophages are a viable approach to target gene-modified cells to tissues. Gene-marked cells in the CNS were unique from gene-marked cells at any other physiological sites including peripheral blood. This novel finding suggests that these cells were derived from HSPCs, migrated to the brain, were compartmentalized, established myeloid progeny, and could be targeted for lifelong delivery of therapeutic molecules. Our findings have highly relevant implications for the development of novel therapies for genetic and infectious diseases of the CNS.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.stemcr.2019.05.016DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6626873PMC
July 2019

TLR7 agonist administration to SIV-infected macaques receiving early initiated cART does not induce plasma viremia.

JCI Insight 2019 06 6;4(11). Epub 2019 Jun 6.

AIDS and Cancer Virus Program.

Reduction/elimination of HIV-1 reservoirs that persist despite combination antiretroviral therapy (cART) will likely require induction of viral expression by residual infected cells and enhanced clearance of these cells. TLR7 agonists have potential to mediate these activities. We evaluated immunologic and virologic effects of repeated doses of the TLR7 agonist GS-9620 in SIV-infected rhesus macaques receiving cART, which was initiated at 13 days after infection and was continued for 75 weeks prior to GS-9620 administration. During cART, GS-9620 induced transient upregulation of IFN-stimulated genes in blood and tissues, increases in plasma cytokines, and changes in immune cell population activation and phenotypes but did not result in measurable increases in plasma viremia or viral RNA-to-viral DNA ratio in PBMCs or tissues nor decreases in viral DNA in PBMC or tissues. SIV-specific CD8+ T cell responses, negligible prior to GS-9620 treatment, were not measurably boosted by treatment; a second course of GS-9620 administration overlapping with later cART discontinuation was associated with increased CD8+ T cell responses during viral recrudescence. These results confirm and extend evidence for GS-9620-mediated enhancement of antiviral immune responses in SIV-infected macaques but suggest that GS-9620-mediated viral induction may depend critically on the timing of initiation and duration of cART and resulting characteristics of viral reservoirs.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1172/jci.insight.127717DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6629134PMC
June 2019