Infectious disease
Abstract
Nontuberculous mycobacteria (NTM) are an increasingly common cause of respiratory infection in people with cystic fibrosis (PwCF). Relative to those with no history of NTM infection (CF-NTMNEG), PwCF and a history of NTM infection (CF-NTMPOS) are more likely to develop severe lung disease and experience complications over the course of treatment. In other mycobacterial infections (e.g. tuberculosis), an overexuberant immune response causes pathology and compromises organ function; however, since the immune profiles of CF-NTMPOS and CF-NTMNEG airways are largely unexplored, it is unknown which if any immune responses distinguish these cohorts or concentrate in damaged tissues. Here we evaluated lung lobe-specific immune profiles of three cohorts (CF-NTMPOS, CF-NTMNEG, and non-CF adults) and found that CF-NTMPOS airways are distinguished by a hyper-inflammatory cytokine profile. Importantly, the CF-NTMPOS airway immune profile was dominated by B cells, classical macrophages and the cytokines which support their accumulation. These and other immunological differences between cohorts, including the near absence of NK cells and complement pathway members, were enriched in the most damaged lung lobes. The implications of these findings for our understanding of lung disease in PwCF are discussed, as are how they may inform the development of host-directed therapies to improve NTM disease treatment.
Authors
Don Hayes, Jr., Rajni Kant Shukla, Yizi Cheng, Emrah Gecili, Marlena R. Merling, Rhonda D. Szczesniak, Assem G Ziady, Jason C. Woods, Luanne Hall-Stoodley, Namal P.M. Liyanage, Richard T. Robinson
Abstract
Studies have demonstrated the phenotypic heterogeneity of vascular endothelial cells (ECs) within a vascular bed; however, little is known about how distinct endothelial subpopulations in a particular organ respond to an inflammatory stimulus. We performed single cell RNA-sequencing of 35,973 lung ECs obtained during the baseline state as well as post-injury time points following inflammatory lung injury induced by lipopolysaccharide. Seurat clustering and gene expression pathway analysis identified two major subpopulations in the lung microvascular endothelium, a subpopulation enriched for expression of immune response genes such as major histocompatibility complex genes (immuneEC) and another defined by increased expression of vascular development genes such as Sox17 (devEC). The presence of immuneEC and devEC subpopulations was also observed in non-human primate lungs infected with SARS-CoV-2 and murine lungs infected with H1N1 influenza virus. Following the peak of inflammatory injury, we observed the emergence of a proliferative lung EC subpopulation. Overexpression of Sox17 prevented inflammatory activation in ECs. Thus, there appears to be a” division of labor” within the lung microvascular endothelium with some ECs showing propensity for inflammatory signaling and others for endothelial regeneration. These results provide underpinnings for the development of targeted therapies to limit inflammatory lung injury and promote regeneration.
Authors
Lianghui Zhang, Shang Gao, Zachary White, Yang Dai, Asrar B. Malik, Jalees Rehman
Abstract
Understanding the immune response to dengue virus (DENV) is essential for developing a dengue vaccine that is protective against all four DENV serotypes. We evaluated the immune response post-vaccination (live attenuated tetravalent dengue vaccine TV005 or trivalent admixture) and post-challenge with DEN2Δ30 (Tonga/74) to better understand the importance of homotypic immunity in vaccine protection. Significant increases in IP-10 expression were observed following receipt of either the trivalent or tetravalent vaccine. After challenge, a large increase in IP-10 expression was observed in the placebo (FCH = 4.5) and trivalent admixture groups (FCH = 2.3) but not in the tetravalent vaccine group (FCH = 1.1). MCP-1, IL-1RA, and MIP-1β exhibit a similar pattern as IP-10. These results demonstrate protective effects of trivalent and tetravalent vaccines against DENV, but suggest a better protective effect with the tetravalent vaccine compared to the trivalent admixture. We also explored the post-vaccination and post-challenge immune response differences between black participants and white participants. White participants respond to vaccine differently from black participants, with black participants receiving trivalent and tetravalent vaccines respond strongly and white participants only transiently in trivalent group. In response to challenge, white participants elicit a stronger response than black participants. These results may explain why white participants may have a more vigorous DENV immune response than black participants reported in literature.
Authors
Ruixue Hou, Lewis E. Tomalin, Jessica Pintado Silva, Seunghee Kim-Schulze, Stephen S. Whitehead, Ana Fernandez-Sesma, Anna P. Durbin, Mayte Suárez-Fariñas
Abstract
Preterm infants are susceptible to bloodstream infection by coagulase-negative staphylococci (CONS) that can lead to sepsis. High parenteral glucose supplement is commonly used to support their growth and energy expenditure, but may exceed endogenous regulation during infection, causing dysregulated immune response and clinical deterioration. Using a preterm piglet model of neonatal CONS sepsis induced by Staphylococcus epidermidis infection, we demonstrate the delicate interplay between immunity and glucose metabolism to regulate the host infection response. Circulating glucose levels, glycolysis and inflammatory response to infection are closely connected across the states of tolerance, resistance and immunoparalysis. Further, high parenteral glucose provision during infection induces hyperglycemia, elevated glycolysis and inflammation, leading to metabolic acidosis and sepsis, whereas glucose restricted individuals are clinically unaffected with increased gluconeogenesis to maintain moderate hypoglycemia. Finally, standard glucose supply maintaining normoglycemia or pharmacological glycolysis inhibition enhances bacterial clearance and dampens inflammation but fails to prevent sepsis. Our results uncover how blood glucose and glycolysis controls circulating immune responses, in turn determining the clinical fate of CONS infected preterm individuals. This questions the current practice of parenteral glucose supply for preterm infants during infection.
Authors
Tik Muk, Anders Brunse, Nicole L. Henriksen, Karoline Aasmul-Olsen, Duc Ninh Nguyen
Abstract
Secondary infections are frequent complications of viral respiratory infections but the potential consequence of SARS-CoV-2 co-infection with common pulmonary pathogens is poorly understood. We report that co-infection of human ACE2 transgenic mice with sublethal doses of SARS-CoV-2 and Streptococcus pneumoniae results in synergistic lung inflammation and lethality. Mortality was observed regardless of whether SARS-CoV-2 challenge occurred before or after establishment of sublethal pneumococcal infection. Increased bacterial levels following co-infection were associated with alveolar macrophage depletion and treatment with murine GM-CSF reduced lung bacteria numbers and pathology, and partially protected from death. However, therapeutic targeting of interferons, an approach that is effective against influenza co-infections, failed to increase survival. Combined vaccination against both SARS-CoV-2 and pneumococci resulted in 100% protection against subsequent co-infection. The results indicate that when seasonal respiratory infections return to pre-pandemic levels, they could lead to an increased incidence of lethal COVID-19 superinfections, especially among the unvaccinated population.
Authors
Tarani Kanta Barman, Amit K. Singh, Jesse L. Bonin, Tanvir N. Nafiz, Sharon L. Salmon, Dennis W. Metzger
Abstract
Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a chronic, debilitating multisystem illness of unknown etiology for which there is no cure and no diagnostic tests available. Despite increasing evidence implicating EBV and human herpesvirus-6A (HHV-6A) as potential causative infectious agents in a subset of ME/CFS patients, there are few mechanistic studies to address a causal relationship. In this study we examined a large ME/CFS cohort (n=351) and 77 controls and demonstrate a significant increase in activin A and IL-21serum levels, which correlated with seropositivity for antibodies to the EBV and HHV-6 protein deoxyuridine-triphosphate nucleotidohydrolase (dUTPase), but not CXCL13. These cytokines are critical for T follicular helper (TFH) cell differentiation, generation of high-affinity antibodies and long-lived plasma cells. Notably, ME/CFS serum was sufficient to drive TFH cell differentiation via an activin A-dependent mechanism. The lack of simultaneous CXCL13 increase with IL-21 indicates impaired TFH-function in ME/CFS. In vitro studies revealed that virus-dUTPases strongly induced activin A secretion while in vivo, EBV-dUTPase induced the formation of splenic marginal zone B and invariant NKTFH cells. Altogether, our data indicate abnormal germinal center (GC) activity in ME/CFS subjects and highlight a mechanism by which EBV and HHV6-dUTPases may alter GC and extrafollicular Ab responses.
Authors
Brandon S. Cox, Khaled Alharshawi, Irene Mena-Palomo, William P. Lafuse, Maria E. Ariza
Abstract
The RTS,S/AS01E vaccine targets the circumsporozoite protein (CSP) of the Plasmodium falciparum parasite. Using protein microarrays, levels of IgG to 1,000 P. falciparum antigens were measured in 2,138 infants (age 6-12 weeks) and children (age 5-17 months) from 6 African sites of the phase 3 trial, sampled before and at four longitudinal visits after vaccination. One month post-vaccination, IgG responses to 17% of all probed antigens showed differences between RTS,S/AS01E and comparator vaccination groups, whereas no prevaccination differences were found. A small subset of antigens presented IgG levels reaching 4- to 8 fold increases in the RTS,S/AS01E group, comparable in magnitude to anti-CSP IgG levels (~11-fold increase). They were strongly cross-correlated and correlated with anti CSP levels, waning similarly over time and re-increasing with the booster dose. Such an intriguing phenomenon may be due to cross-reactivity of anti-CSP antibodies with these antigens. RTS,S/AS01E vaccinees with strong off target IgG responses had an estimated lower clinical malaria incidence after adjusting for age group, site and post-vaccination anti-CSP levels. RTS,S/AS01E-induced IgG may bind strongly not only to CSP, but to unrelated malaria antigens, and this seems to either confer, or at least be a marker of, increased protection from clinical malaria.
Authors
Dídac Macià, Joseph J. Campo, Gemma Moncunill, Chenjerai Jairoce, Augusto J. Nhabomba, Maximilian Mpina, Hermann Sorgho, David Dosoo, Ousmane Traore, Kwadwo A. Kusi, Nana Aba Williams, Amit Oberai, Arlo Randall, Hector Sanz, Clarissa Valim, Kwaku P. Asante, Seth Owusu-Agyei, Halidou Tinto, Selidji T. Agnandji, Simon Kariuki, Ben Gyan, Claudia Daubenberger, Benjamin Mordmüller, Paula Petrone, Carlota Dobaño
Abstract
SARS-CoV-2 has resulted in over 450 million confirmed cases since 2019. Although several vaccines have been certified by World Health Organization and are being vaccinated on a global scale, it has been reported that multiple SARS-CoV-2 variants can escape neutralisation by antibodies, resulting in vaccine breakthrough infections. Bacillus Calmette-Guérin (BCG) is known to induce heterologous protection based on trained immune responses. Here, we investigated whether BCG-induced trained immunity protected against SARS-CoV-2 challenge in the K18-hACE2 mouse model. Our data demonstrates that intravenous BCG vaccination induces robust trained innate immune responses and provides protection against wild-type SARS-CoV-2 as well as the B.1.617.1 and B.1.617.2 variants. Further studies suggest that myeloid cell differentiation and activation of the glycolysis pathway are associated with BCG-induced training immunity in the K18-hACE2 mice. Overall, our study provides the experimental evidence that establishes a causal relationship between intravenous BCG vaccination and protection against SARS-CoV-2 challenge.
Authors
Bao-Zhong Zhang, Huiping Shuai, Hua-rui Gong, Jing-Chu Hu, Bingpeng Yan, Terrence Tsz-Tai Yuen, Ye-Fan Hu, Chaemin Yoon, Xiao-Lei Wang, Yuxin Hou, Xuansheng Lin, Xiner Huang, Renhao Li, Yee Man Au-Yeung, Wenjun Li, Bingjie Hu, Yue Chai, Ming Yue, Jian-Piao Cai, Guang Sheng Ling, Ivan Fan-Ngai Hung, Kwok-Yung Yuen, Jasper Fuk-Woo Chan, Jian-Dong Huang, Hin Chu
Abstract
Bacteria have evolved to cope with the detrimental effects of reactive oxygen species (ROS) using their essential molecular components. Catalase, a heme-containing tetramer protein expressed universally in most of the aerobic bacteria, plays an indispensable role in scavenging excess hydrogen peroxide (H2O2). Here, through utilization of wild-type and catalase-deficient mutants, we identified catalase as an endogenous therapeutic target of 400-420 nm blue light. Catalase residing inside bacteria could be effectively inactivated by blue light, subsequently rendering the pathogens extremely vulnerable to H2O2 and H2O2-producing agents. As a result, photoinactivation of catalase and H2O2 synergistically eliminate a wide range of catalase-positive planktonic bacteria and P. aeruginosa inside biofilms. In addition, photoinactivation of catalase is shown to facilitate macrophages to defend against intracellular pathogens. The antimicrobial efficacy of catalase photoinactivation is further validated using a Pseudomonas aeruginosa-induced mice abrasion model. Taken together, our findings offer a catalase-targeting phototherapy approach against multidrug-resistant bacterial infections.
Authors
Pu-Ting Dong, Sebastian Jusuf, Jie Hui, Yuewei Zhan, Yifan Zhu, George Y. Liu, Ji-Xin Cheng
Abstract
BACKGROUND. Measuring the immune response to SARS-CoV-2 enables assessment of past infection and protective immunity. SARS-CoV-2 infection induces humoral and T-cell responses, but these responses vary with disease severity and individual characteristics. METHODS. A T-cell receptor (TCR) immunosequencing assay was conducted using small-volume blood samples from 302 individuals recovered from COVID-19. Correlations between the magnitude of the T-cell response and neutralizing antibody (nAb) titers or indicators of disease severity were evaluated. Sensitivity of T-cell testing was assessed and compared to serologic testing. RESULTS. SARS-CoV-2–specific T-cell responses were significantly correlated with nAb titers and clinical indicators of disease severity, including hospitalization, fever, and difficulty breathing. Despite modest declines in depth and breadth of T-cell responses during convalescence, high sensitivity was observed until at least 6 months after infection, with overall sensitivity ~5% greater than serology tests for identifying prior SARS-CoV-2 infection. Improved performance of T-cell testing was most apparent in recovered, non-hospitalized individuals sampled >150 days after initial illness, suggesting greater sensitivity than serology at later timepoints and in individuals with less severe disease. T-cell testing identified SARS-CoV-2 infection in 68% (55/81) of samples with undetectable nAb titers (<1:40) and in 37% (13/35) of samples negative by 3 antibody assays. CONCLUSION. These results support TCR-based testing as a scalable, reliable measure of past SARS-CoV-2 infection with clinical value beyond serology. FUNDING. Adaptive Biotechnologies, Frederick National Laboratory for Cancer Research, National Institutes of Allergy and Infectious Diseases, Fred Hutchinson Joel Meyers Endowment; Fast Grants, American Society for Transplantation and Cell Therapy.
Authors
Rebecca Elyanow, Thomas M. Snyder, Sudeb C. Dalai, Rachel M. Gittelman, Jim Boonyaratanakornkit, Anna Wald, Stacy Selke, Mark H. Wener, Chihiro Morishima, Alexander L. Greninger, Michael Gale Jr., Tien-Ying Hsiang, Lichen Jing, Michael R. Holbrook, Ian M. Kaplan, H. Jabran Zahid, Damon H. May, Jonathan M. Carlson, Lance Baldo, Thomas Manley, Harlan S. Robins, David M. Koelle
No posts were found with this tag.
