Worse outcomes occur in aged compared with young populations after infections with respiratory viruses, including pathogenic coronaviruses (SARS-CoV, MERS-CoV, and SARS-CoV-2), and are associated with a suboptimal lung milieu (“inflammaging”). We previously showed that a single inducible phospholipase, PLA2G2D, is associated with a proresolving/antiinflammatory response in the lungs, and increases with age. Survival was increased in naive Pla2g2d–/– mice infected with SARS-CoV resulting from augmented respiratory dendritic cell (rDC) activation and enhanced priming of virus-specific T cells. Here, in contrast, we show that intranasal immunization provided no additional protection in middle-aged Pla2g2d–/– mice infected with any of the 3 pathogenic human coronaviruses because virtually no virus-specific antibodies or follicular helper CD4+ T (Tfh) cells were produced. Using MERS-CoV–infected mice, we found that these effects did not result from T or B cell intrinsic factors. Rather, they resulted from enhanced, and ultimately, pathogenic rDC activation, as manifested most prominently by enhanced IL-1β expression. Wild-type rDC transfer to Pla2g2d–/– mice in conjunction with partial IL-1β blockade reversed this defect and resulted in increased virus-specific antibody and Tfh responses. Together, these results indicate that PLA2G2D has an unexpected role in the lungs, serving as an important modulator of rDC activation, with protective and pathogenic effects in respiratory coronavirus infections and immunization, respectively.
Jian Zheng, David Meyerholz, Lok-Yin Roy Wong, Michael Gelb, Makoto Murakami, Stanley Perlman
The four serotypes of dengue virus (DENV1-4) are mosquito-borne flaviviruses that infect humans. Live attenuated tetravalent DENV vaccines are at different phases of clinical testing. DENV vaccine developers have relied on neutralizing antibodies (NAbs) as a correlate of protection. A leading tetravalent vaccine (Dengvaxia) stimulated NAbs to the 4 DENV serotypes, yet overall vaccine efficacy was low in children who were DENV seronegative at baseline before vaccination. We compared the properties of 1) NAbs induced by wild type DENV1 or 3 infections, which are strongly correlated with protection from repeat infections, and 2) NAbs induced by Dengvaxia in individuals who subsequently experienced DENV1 or DENV3 breakthrough infections. Wild type infections induced NAbs that recognized epitopes unique (type-specific) to each serotype, whereas the vaccine stimulated qualitatively different NAbs that recognized epitopes conserved (cross-reactive) between serotypes. Our results indicate that among children who were DENV seronegative at baseline, unbalanced replication of the DENV type 4 vaccine component in the tetravalent vaccine stimulates Abs capable of cross neutralizing DENV1 and 3 in vitro but not protect in vivo. In DENV seronegative individuals who are vaccinated, we propose that type specific NAbs are a better correlate of protection than total levels of NAbs.
Sandra Henein, Cameron Adams, Matthew Bonaparte, Janice M. Moser, Alina Munteanu, Ralph Baric, Aravinda M. Desilva
Human cytomegalovirus (HCMV) is a ubiquitous pathogen that causes severe disease following congenital infection and in immunocompromised individuals. No vaccines are licensed, and there are limited treatment options. We now show that the addition of anti-HCMV antibodies (Abs) can activate NK cells prior to the production of new virions, through Ab-dependent cellular cytotoxicity (ADCC), overcoming viral immune evasins. Quantitative proteomics defined the most abundant HCMV proteins on the cell surface, and we screened these targets to identify the viral antigens responsible for activating ADCC. Surprisingly, these were not structural glycoproteins; instead, the immune evasins US28, RL11, UL5, UL141, and UL16 each individually primed ADCC. We isolated human monoclonal Abs (mAbs) specific for UL16 or UL141 from a seropositive donor and optimized them for ADCC. Cloned Abs targeting a single antigen (UL141) were sufficient to mediate ADCC against HCMV-infected cells, even at low concentrations. Collectively, these findings validated an unbiased methodological approach to the identification of immunodominant viral antigens, providing a pathway toward an immunotherapeutic strategy against HCMV and potentially other pathogens.
Virginia-Maria Vlahava, Isa Murrell, Lihui Zhuang, Rebecca J. Aicheler, Eleanor Lim, Kelly L. Miners, Kristin Ladell, Nicolás M. Suárez, David A. Price, Andrew J. Davison, Gavin W.G. Wilkinson, Mark R. Wills, Michael P. Weekes, Eddie C.Y. Wang, Richard J. Stanton
Background: SARS-CoV-2-specific antibodies may protect from reinfection and disease, providing rationale for administration of plasma containing SARS-CoV-2 neutralizing antibodies (nAb) as a treatment for COVID-19. Clinical factors and laboratory assays to streamline plasma donor selection, and the durability of nAb responses, are incompletely understood. Methods: Potential convalescent plasma donors with virologically-documented SARS-CoV-2 infection were tested for serum IgG to SARS-CoV-2 spike protein S1 domain, nucleoprotein (NP), and for nAb. Results: Amongst 250 consecutive persons, including 27 (11%) requiring hospitalization, studied a median of 67 days since symptom onset, 97% were seropositive on one or more assays. Sixty percent of donors had nAb titers ≥1:80. Correlates of higher nAb titer included older age (adjusted odds ratio [AOR] 1.03/year of age, 95% CI 1.00-1.06), male sex (AOR 2.08, 95% CI 1.13-3.82), fever during acute illness (AOR 2.73, 95% CI 1.25-5.97), and disease severity represented by hospitalization (AOR 6.59, 95% CI 1.32-32.96). Receiver operating characteristic (ROC) analyses of anti-S1 and anti-NP antibody results yielded cutoffs that corresponded well with nAb titers, with the anti-S1 assay being slightly more predictive. NAb titers declined in 37 of 41 paired specimens collected a median of 98 days (range, 77-120) apart (P<0.001). Seven individuals (2.8%) were persistently seronegative and lacked T cell responses. Conclusions: Nab titers correlated with COVID-19 severity, age, and sex. Standard commercially available SARS-CoV-2 IgG results can serve as useful surrogates for nAb testing. Functional nAb levels were found to decline and a small proportion of persons recovered from COVID-19 lack adaptive immune responses.
Jim Boonyaratanakornkit, Chihiro Morishima, Stacy Selke, Danniel Zamora, Sarah A. McGuffin, Adrienne E. Shapiro, Victoria L. Campbell, Christopher L. McClurkan, Lichen Jing, Robin Gross, Janie Liang, Elena Postnikova, Steven Mazur, Vladimir V. Lukin, Anu Chaudhary, Marie K. Das, Susan L. Fink, Andrew Bryan, Alexander L. Greninger, Keith R. Jerome, Michael R. Holbrook, Terry B. Gernsheimer, Mark H. Wener, Anna Wald, David M. Koelle
Human T cell leukemia virus type 1 (HTLV-1) is mainly transmitted vertically through breast milk. The rate of mother-to-child transmission (MTCT) through formula feeding, although significantly lower than through breastfeeding, is approximately 2.4%–3.6%, suggesting the possibility of alternative transmission routes. MTCT of HTLV-1 might occur through the uterus, birth canal, or placental tissues; the latter is known as transplacental transmission. Here, we found that HTLV-1 proviral DNA was present in the placental villous tissues of the fetuses of nearly half of pregnant carriers and in a small number of cord blood samples. An RNA ISH assay showed that HTLV-1–expressing cells were present in nearly all subjects with HTLV-1–positive placental villous tissues, and their frequency was significantly higher in subjects with HTLV-1–positive cord blood samples. Furthermore, placental villous trophoblasts expressed HTLV-1 receptors and showed increased susceptibility to HTLV-1 infection. In addition, HTLV-1–infected trophoblasts expressed high levels of viral antigens and promoted the de novo infection of target T cells in a humanized mouse model. In summary, during pregnancy of HTLV-1 carriers, HTLV-1 was highly expressed in placental villous tissues, and villous trophoblasts showed high HTLV-1 sensitivity, suggesting that MTCT of HTLV-1 occurs through the placenta.
Kenta Tezuka, Naoki Fuchi, Kazu Okuma, Takashi Tsukiyama, Shoko Miura, Yuri Hasegawa, Ai Nagata, Nahoko Komatsu, Hiroo Hasegawa, Daisuke Sasaki, Eita Sasaki, Takuo Mizukami, Madoka Kuramitsu, Sahoko Matsuoka, Katsunori Yanagihara, Kiyonori Miura, Isao Hamaguchi
BACKGROUND HIV-1 viremia that is not suppressed by combination antiretroviral therapy (ART) is generally attributed to incomplete medication adherence and/or drug resistance. We evaluated individuals referred by clinicians for nonsuppressible viremia (plasma HIV-1 RNA above 40 copies/mL) despite reported adherence to ART and the absence of drug resistance to the current ART regimen.METHODS Samples were collected from at least 2 time points from 8 donors who had nonsuppressible viremia for more than 6 months. Single templates of HIV-1 RNA obtained from plasma and viral outgrowth of cultured cells and from proviral DNA were amplified by PCR and sequenced for evidence of clones of cells that produced infectious viruses. Clones were confirmed by host-proviral integration site analysis.RESULTS HIV-1 genomic RNA with identical sequences were identified in plasma samples from all 8 donors. The identical viral RNA sequences did not change over time and did not evolve resistance to the ART regimen. In 4 of the donors, viral RNA sequences obtained from plasma matched those sequences from viral outgrowth cultures, indicating that the viruses were replication competent. Integration sites for infectious proviruses from those 4 donors were mapped to the introns of the MATR3, ZNF268, ZNF721/ABCA11P, and ABCA11P genes. The sizes of the clones were estimated to be from 50 million to 350 million cells.CONCLUSION These findings show that clones of HIV-1–infected cells producing virus can cause failure of ART to suppress viremia. The mechanisms involved in clonal expansion and persistence need to be defined to effectively target viremia and the HIV-1 reservoir.FUNDING National Cancer Institute, NIH; Howard Hughes Medical Research Fellows Program, Howard Hughes Medical Institute; Bill and Melinda Gates Foundation; Office of AIDS Research; American Cancer Society; National Cancer Institute through a Leidos subcontract; National Institute for Allergy and Infectious Diseases, NIH, to the I4C Martin Delaney Collaboratory; University of Rochester Center for AIDS Research and University of Rochester HIV/AIDS Clinical Trials Unit.
Elias K. Halvas, Kevin W. Joseph, Leah D. Brandt, Shuang Guo, Michele D. Sobolewski, Jana L. Jacobs, Camille Tumiotto, John K. Bui, Joshua C. Cyktor, Brandon F. Keele, Gene D. Morse, Michael J. Bale, Wei Shao, Mary F. Kearney, John M. Coffin, Jason W. Rausch, Xiaolin Wu, Stephen H. Hughes, John W. Mellors
Chronic viral infections are often established by the exploitation of immune regulatory mechanisms that result in non-functional T cell responses. Viruses that establish persistent infections remain a serious threat to human health. Sphingosine kinase (SphK) 2 generates sphingosine 1-phosphate, which is a molecule known to regulate multiple cellular processes. However, little is known about SphK2’s role during the host immune responses to viral infection. Here, we demonstrate that SphK2 functions during lymphocytic choriomeningitis virus Cl 13 (LCMV Cl 13) infection to limit T cell immune pathology, which subsequently aids in the establishment of virus-induced immunosuppression and the resultant viral persistence. The infection of Sphk2-deficient (Sphk2-/-) mice with LCMV Cl 13 led to the development of nephropathy and mortality via T cell-mediated immunopathology. Following LCMV infection, Sphk2-/- CD4+ T cells displayed increased activity and proliferation, and these cells promoted overactive LCMV Cl 13-specific CD8+ T cell responses. Notably, oral instillation of an SphK2-selective inhibitor promoted protective T cell responses and accelerated the termination of LCMV Cl 13 persistence in mice. Thus, SphK2 is indicated as an immunotherapeutic target for the control of persistent viral infections.
Caleb J. Studstill, Curtis J. Pritzl, Young-Jin Seo, Dae Young Kim, Chuan Xia, Jennifer J. Wolf, Ravi Nistala, Madhuvanthi Vijayan, Yong-Bin Cho, Kyung Won Kang, Sang-Myeong Lee, Bumsuk Hahm
The development of broadly neutralizing antibodies (BNAbs) in HIV infection is a result of long-term co-evolutionary interaction between viruses and antibodies. Understanding how this interaction promotes the increase of neutralization breadth during infection will improve the way in which we design AIDS vaccine strategies. In this paper, we used SIV-infected rhesus macaques as a model to study the development of neutralization breadth by infecting rhesus macaques with longitudinal NAb escape variants and evaluating the kinetics of NAb response and viral evolution. We found that the infected macaques developed a stepwise NAb response against escape variants and increased neutralization breadth during the course of infection. Furthermore, the increase of neutralization breadth correlated with the duration of infection but was independent of properties of the inoculum, viral loads or viral diversity during infection. These results imply that the duration of infection was the main factor driving the development of BNabs. These data suggest the importance of novel immunization strategies to induce effective NAb response against HIV infection by mimicking long-term infection.
Fan Wu, Ilnour Ourmanov, Andrea Kirmaier, Sivan Leviyang, Celia LaBranche, Jinghe Huang, Sonya Whitted, Kenta Matsuda, David Montefiori, Vanessa M. Hirsch
The SARS-CoV-2 is the causative agent for COVID-19 pneumonia. Little is known about the kinetics, tissue distribution, cross-reactivity and neutralization antibody response in COVID-19 patients. Two groups of RT-PCR confirmed COVID-19 patients were enrolled in this study, including 12 severe patients in ICUs who needed mechanical ventilation and 11 mild patients in isolation wards. Serial clinical samples were collected for laboratory detection. Results showed that most of the severe patients had viral shedding in a variety of tissues for 20~40 days post onset of disease (8/12, 66.7%); while the majority of mild patients had viral shedding restricted to the respiratory tract and had no detectable virus RNA after 10 days post-onset (9/11, 81.8%). Mild patients showed significantly lower IgM response compared with that of the severe group. IgG responses were detected in most patients in both severe and mild groups at 9 days post onset and remained high level throughout the study. Antibodies cross-reactive to SARS-CoV and SARS-CoV-2 were detected in COVID-19 patients but not in MERS patients. High-levels of neutralizing antibodies were induced after about 10 days post onset in both severe and mild patients which were higher in the severe group. SARS-CoV-2 pseudotype neutralization test and focus reduction neutralization test with authentic virus showed consistent results. Sera from COVID-19 patients, but not convalescent SARS and MERS patients inhibited SARS-CoV-2 entry. Anti-SARS-CoV-2 S and N IgG level exhibited moderate correlation with neutralization titers in patients’ plasma. This study improves our understanding of immune response in human after SARS-CoV-2 infection.
Yanqun Wang, Lu Zhang, Ling Sang, Feng Ye, Shicong Ruan, Bei Zhong, Tie Song, Abeer N. Alshukairi, Rongchang Chen, Zhaoyong Zhang, Mian Gan, Airu Zhu, Yongbo Huang, Ling Luo, Chris KP Mok, Manal M. Al Gethamy, Haitao Tan, Zhengtu Li, Xiaofang Huang, Fang Li, Jing Sun, Yanjun Zhang, Liyan Wen, Yuming Li, Zhao Chen, Zhen Zhuang, Jianfen Zhuo, Chunke Chen, Lijun Kuang, Junxiang Wang, Huibin Lv, Yongliang Jiang, Min Li, Yimin Lin, Ying Deng, Lan Tang, Jieling Liang, Jicheng Huang, Stanley Perlman, Nanshan Zhong, Jingxian Zhao, J.S. Malik Peiris, Yimin Li, Jincun Zhao
In patients with HBV and HCV coinfection, HBV reactivation leading to severe hepatitis has been reported with the use of direct-acting antivirals (DAAs) to treat HCV infection. Here we study the molecular mechanisms behind this viral interaction. In coinfected cell culture and humanized mice, HBV replication was suppressed by HCV coinfection. In vitro, HBV suppression was attenuated when interferon signaling was blocked. In vivo, HBV viremia, after initial suppression by HCV super-infection, rebounded following HCV clearance by DAA treatment that was accompanied by a reduced hepatic interferon response. Using blood samples of coinfected patients, interferon-stimulated gene products including C-X-C motif chemokine 10 (CXCL10) and C-C motif chemokine ligand 5 (CCL5), and alanine aminotransferase (ALT) were identified to have predictive value for HBV reactivation after HCV clearance. Taken together, our data suggest that HBV reactivation is a result of diminished hepatic interferon response following HCV clearance and identifies serologic markers that can predict HBV reactivation in DAA-treated HBV-HCV coinfected persons.
Xiaoming Cheng, Takuro Uchida, Yuchen Xia, Regina Umarova, Chun-Jen Liu, Pei-Jer Chen, Anuj Gaggar, Vithika Suri, Marcus Maximilian Mücke, Johannes Vermehren, Stefan Zeuzem, Yuji Teraoka, Mitsutaka Osawa, Hiroshi Aikata, Keiji Tsuji, Nami Mori, Shuhei Hige, Yoshiyasu Karino, Michio Imamura, Kazuaki Chayama, T. Jake Liang
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