Characterization of "Off-Target" Immune Modulation Induced by Live Attenuated Yellow Fever Vaccine.

BACKGROUND: Live attenuated vaccines alter immune functions and are associated with beneficial outcomes. We previously demonstrated that live attenuated yellow fever virus (YFV) vaccine (LA-YF-Vax) dampens T-cell receptor (TCR) signaling in vitro via an RNA-based mechanism. We examined study participants before and after LA-YF-Vax to assess TCR-mediated functions in vivo. METHODS: Serum samples and peripheral blood mononuclear cells (PBMCs) were obtained before and after LA-YF-Vax (with or without additional vaccines) or quadrivalent influenza vaccine. TCR-mediated activation was determined by interleukin 2 release or phosphorylation of the lymphocyte-specific Src kinase. TCR-regulating phosphatase (protein tyrosine phosphatase receptor type E [PTPRE]) expression was also measured. RESULTS: Compared with prevaccination findings, LA-YF-Vax recipient PBMCs demonstrated transient reduction in interleukin 2 release after TCR stimulation and PTPRE levels, unlike in control participants who received quadrivalent influenza vaccine. YFV was detected in 8 of 14 participants after LA-YF-Vax. After incubation of healthy donor PBMCs in serum-derived extracellular vesicles prepared from LA-YF-Vax recipients, TCR signaling and PTPRE levels were reduced after vaccination, even in participants without detectable YFV RNA. CONCLUSIONS: LA-YF-Vax reduces TCR functions and PTPRE levels after vaccination. Extracellular vesicles from serum recapitulated this effect in healthy cells. This likely contributes to the reduced immunogenicity for heterologous vaccines after LA-YF-Vax administration. Identification of specific immune mechanisms related to vaccines should contribute to understanding of the "off-target," beneficial effects of live vaccines.

Immunogenicity and safety of varying dosages of a fifth-wave influenza A/H7N9 inactivated vaccine given with and without AS03 adjuvant in healthy adults.

BACKGROUND: Human infections with the avian influenza A(H7N9) virus were first reported in China in 2013 and continued to occur in annual waves. In the 2016/2017 fifth wave, Yangtze River Delta (YRD) lineage viruses, which differed antigenically from those of earlier waves, predominated. METHODS: In this phase 2 double-blinded trial we randomized 720 adults ≥ 19 years of age to receive two injections of a YRD lineage inactivated A/Hong Kong/125/2017 fifth-wave H7N9 vaccine, given 21 days apart, at doses of 3.75, 7.5, and 15 µg of hemagglutinin (HA) with AS03A adjuvant and at doses of 15 and 45 µg of HA without adjuvant. RESULTS: Two doses of adjuvanted vaccine were required to induce HA inhibition (HI) antibody titers ≥ 40 in most participants. After two doses of the 15 µg H7N9 formulation, given with or without AS03 adjuvant, the proportion achieving a HI titer ≥ 40 against the vaccine strain at 21 days after the second vaccination was 65 % (95 % CI, 57 %-73 %) and 0 % (95 % CI, 0 %-4%), respectively. Among those who received two doses of the 15 µg adjuvanted formulation the proportion with HI titer ≥ 40 at 21 days after the second vaccination was 76 % (95 % CI, 66 %-84 %) in those 19-64 years of age and 49 % (95 % CI, 37 %-62 %) in those ≥ 65 years of age. Responses to the adjuvanted vaccine formulations did not vary by HA content. Antibody responses declined over time and responses against drifted H7N9 strains were diminished. Overall, the vaccines were well tolerated but, as expected, adjuvanted vaccines were associated with more frequent solicited systemic and local adverse events. CONCLUSIONS: AS03 adjuvant improved the immune responses to an inactivated fifth-wave H7N9 influenza vaccine, particularly in younger adults, but invoked lower responses to drifted H7N9 strains. These findings may inform future influenza pandemic preparedness strategies.

Renaming of the genus Flavivirus to Orthoflavivirus and extension of binomial species names within the family Flaviviridae.

This review provides a summary of the recently ratified changes to genus and species nomenclature within the virus family Flaviviridae along with reasons for these changes. First, it was considered that the vernacular terms "flaviviral", "flavivirus", and "flaviviruses" could under certain circumstances be ambiguous due to the same word stem "flavi" in the taxon names Flaviviridae and Flavivirus; these terms could either have referred to all viruses classified in the family Flaviviridae or only to viruses classified in the included genus Flavivirus. To remove this ambiguity, the genus name Flavivirus was changed to Orthoflavivirus by the International Committee on Taxonomy of Viruses (ICTV). Second, all species names in the family were changed to adhere to a newly ICTV-mandated binomial format (e.g., Orthoflavivirus zikaense, Hepacivirus hominis) similar to nomenclature conventions used for species elsewhere in biology. It is important to note, however, that virus names remain unchanged. Here we outline the revised taxonomy of the family Flaviviridae as approved by the ICTV in April 2023.

Coronary Artery Plaque Composition and Severity Relate to the Inflammasome in People With Treated Human Immunodeficiency Virus.

Background: Inflammasome activation is increased in people with human immunodeficiency virus (PWH), but its relationship with coronary plaque is poorly understood in this setting. Methods: In a large human immunodeficiency virus cardiovascular prevention cohort, relationships between caspase-1, interleukin (IL)-1ß, and IL-18 and coronary plaque indices were assessed by multivariate logistic regression. Results: Higher IL-18 and IL-1ß were associated with Leaman score, an integrative measure of plaque burden and composition. Conclusions: As Leaman score >5 is associated with cardiovascular events in the general population, future work is needed to determine how the inflammasome relates to events and whether strategies to reduce its activation affect events or plaque progression among PWH.

Clinical Features and Treatment Outcomes of Pulmonary Mycobacterium avium-intracellulare Complex With and Without Coinfections.

Coinfections are more common in patients with cystic fibrosis and bronchiectasis. Infiltrates on imaging studies are seen more commonly in patients with coinfections, but coinfections did not affect treatment outcomes of pulmonary Mycobacterium avium complex.

Human Pegivirus Type 1: A Common Human Virus That Is Beneficial in Immune-Mediated Disease?

Two groups identified a novel human flavivirus in the mid-1990s. One group named the virus hepatitis G virus (HGV) and the other named it GB Virus type C (GBV-C). Sequence analyses found these two isolates to be the same virus, and subsequent studies found that the virus does not cause hepatitis despite sharing genome organization with hepatitis C virus. Although HGV/GBV-C infection is common and may cause persistent infection in humans, the virus does not appear to directly cause any other known disease state. Thus, the virus was renamed "human pegivirus 1" (HPgV-1) for "persistent G" virus. HPgV-1 is found primarily in lymphocytes and not hepatocytes, and several studies found HPgV-1 infection associated with prolonged survival in people living with HIV. Co-infection of human lymphocytes with HPgV-1 and HIV inhibits HIV replication. Although three viral proteins directly inhibit HIV replication in vitro, the major effects of HPgV-1 leading to reduced HIV-related mortality appear to result from a global reduction in immune activation. HPgV-1 specifically interferes with T cell receptor signaling (TCR) by reducing proximal activation of the lymphocyte specific Src kinase LCK. Although TCR signaling is reduced, T cell activation is not abolished and with sufficient stimulus, T cell functions are enabled. Consequently, HPgV-1 is not associated with immune suppression. The HPgV-1 immunomodulatory effects are associated with beneficial outcomes in other diseases including Ebola virus infection and possibly graft-versus-host-disease following stem cell transplantation. Better understanding of HPgV-1 immune escape and mechanisms of inflammation may identify novel therapies for immune-based diseases.

Urban Particulate Matter Impairment of Airway Surface Liquid-Mediated Coronavirus Inactivation.

Air pollution particulate matter (PM) is associated with SARS-CoV-2 infection and severity, although mechanistic studies are lacking. We tested whether airway surface liquid (ASL) from primary human airway epithelial cells is antiviral against SARS-CoV-2 and human alphacoronavirus 229E (CoV-229E) (responsible for common colds), and whether PM (urban, indoor air pollution [IAP], volcanic ash) affected ASL antiviral activity. ASL inactivated SARS-CoV-2 and CoV-229E. Independently, urban PM also decreased SARS-CoV-2 and CoV-229E infection, and IAP PM decreased CoV-229E infection. However, in combination, urban PM impaired ASL's antiviral activity against both viruses, and the same effect occurred for IAP PM and ash against SARS-CoV-2, suggesting that PM may enhance SARS-CoV-2 infection.

A short hepatitis C virus NS5A peptide expression by AAV vector modulates human T cell activation and reduces vector immunogenicity.

Viral vector-mediated gene therapies have the potential to treat many human diseases; however, host immune responses against the vector and/or the transgene pose a safety risk to the patients and can negatively impact product efficacy. Thus, novel strategies to reduce vector immunogenicity are critical for the advancement of these therapies. T cell activation (TCA) is required for the development of immune responses during gene therapy. We hypothesized that modulation of TCA by incorporating a novel viral immunomodulatory factor into a viral vector may reduce unwanted TCA and immune responses during gene therapy. To test this hypothesis, we identified an immunomodulatory domain of the hepatitis C virus (HCV) NS protein 5A (NS5A) protein and studied the effect of viral vectors expressing NS5A peptide on TCA. Lentiviral vector-mediated expression of a short 20-mer peptide derived from the NS5A protein in human T cells was sufficient to inhibit TCA. Synthetic 20-mer NS5A peptide also inhibited TCA in primary human T cells. Mechanistically, the NS5A protein interacted with Lck and inhibited proximal TCR signaling. Importantly, NS5A peptide expression did not cause global T cell signaling dysfunction as distal T cell signaling was not inhibited. Finally, recombinant adeno-associated virus (AAV) vector expressing the 20-mer NS5A peptide reduced both the recall antigen and the TCR-mediated activation of human T cells and did not cause global T cell signaling dysfunction. Together, these data suggest that expression of a 20-mer NS5A peptide by an AAV vector may reduce unwanted TCA and may contribute to lower vector immunogenicity during gene therapy.

T-Cell Expression of Angiotensin-Converting Enzyme 2 and Binding of Severe Acute Respiratory Coronavirus 2.

The pathogenesis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is not completely understood. SARS-CoV-2 infection frequently causes significant immune function consequences including reduced T cell numbers and enhanced T cell exhaustion that contribute to disease severity. The extent to which T cell effects are directly mediated through infection or indirectly result from infection of respiratory-associated cells is unclear. We show that primary human T cells express sufficient levels of angiotensin converting enzyme 2 (ACE-2), the SARS-CoV-2 receptor, to mediate viral binding and entry into T cells. We further show that T cells exposed to SARS-CoV-2 particles demonstrate reduced proliferation and apoptosis compared to uninfected controls, indicating that direct interaction of SARS-CoV-2 with T cells may alter T cell growth, activation, and survival. Regulation of T cell activation and/or turnover by SARS-CoV-2 may contribute to impaired T cell function observed in patients with severe disease.

HIV-infection and cocaine use regulate semen extracellular vesicles proteome and miRNAome in a manner that mediates strategic monocyte haptotaxis governed by miR-128 network.

BACKGROUND: Extracellular vesicles (EVs) are regulators of cell-cell interactions and mediators of horizontal transfer of bioactive molecules between cells. EV-mediated cell-cell interactions play roles in physiological and pathophysiological processes, which maybe modulated by exposure to pathogens and cocaine use. However, the effect of pathogens and cocaine use on EV composition and function are not fully understood. RESULTS: Here, we used systems biology and multi-omics analysis to show that HIV infection (HIV +) and cocaine (COC) use (COC +) promote the release of semen-derived EVs (SEV) with dysregulated extracellular proteome (exProtein), miRNAome (exmiR), and exmiR networks. Integrating SEV proteome and miRNAome revealed a significant decrease in the enrichment of disease-associated, brain-enriched, and HIV-associated miR-128-3p (miR-128) in HIV + COC + SEV with a concomitant increase in miR-128 targets-PEAK1 and RND3/RhoE. Using two-dimensional-substrate single cell haptotaxis, we observed that in the presence of HIV + COC + SEV, contact guidance provided by the extracellular matrix (ECM, collagen type 1) network facilitated far-ranging haptotactic cues that guided monocytes over longer distances. Functionalizing SEV with a miR-128 mimic revealed that the strategic changes in monocyte haptotaxis are in large part the result of SEV-associated miR-128. CONCLUSIONS: We propose that compositionally and functionally distinct HIV + COC + and HIV-COC- SEVs and their exmiR networks may provide cells relevant but divergent haptotactic guidance in the absence of chemotactic cues, under both physiological and pathophysiological conditions.

Characterization of performance and disinfection resilience of nonwoven filter materials for use in 3D-printed N95 respirators.

The COVID-19 pandemic has caused a high demand for respiratory protection among health care workers in hospitals, especially surgical N95 filtering facepiece respirators (FFRs). To aid in alleviating that demand, a survey of commercially available filter media was conducted to determine whether any could serve as a substitute for an N95 FFR while held in a 3D-printed mask (Stopgap Surgical Face Mask from the NIH 3D Print Exchange). Fourteen filter media types and eight combinations were evaluated for filtration efficiency, breathing resistance (pressure drop), and liquid penetration. Additional testing was conducted to evaluate two filter media disinfection methods in the event that the filters were reused in a hospital setting. Efficiency testing was conducted in accordance with the procedures established for approving an N95 FFR. One apparatus used a filter-holding device and another apparatus employed a manikin head to which the 3D-printed mask could be sealed. The filter media and combinations exhibited collection efficiencies varied between 3.9% and 98.8% when tested with a face velocity comparable to that of a standard N95 FFR at the 85 L min-1 used in the approval procedure. Breathing resistance varied between 10.8 to >637 Pa (1.1 to > 65 mm H2O). When applied to the 3D-printed mask efficiency decreased by an average of 13% and breathing resistance increased 4-fold as a result of the smaller surface area of the filter media when held in that mask compared to that of an N95 FFR. Disinfection by dry heat, even after 25 cycles, did not significantly affect filter efficiency and reduced viral infectivity by > 99.9%. However, 10 cycles of 59% vaporized H2O2 significantly (p < 0.001) reduced filter efficiency of the media tested. Several commercially available filter media were found to be potential replacements for the media used to construct the typical cup-like N95 FFR. However, their use in the 3D-printed mask demonstrated reduced efficiency and increased breathing resistance at 85 L min-1.

Human Antibody Responses Following Vaccinia Immunization Using Protein Microarrays and Correlation With Cell-Mediated Immunity and Antibody-Dependent Cellular Cytotoxicity Responses.

BACKGROUND: There are limited data regarding immunological correlates of protection for the modified vaccinia Ankara (MVA) smallpox vaccine. METHODS: A total of 523 vaccinia-naive subjects were randomized to receive 2 vaccine doses, as lyophilized MVA given subcutaneously, liquid MVA given subcutaneously (liquid-SC group), or liquid MVA given intradermally (liquid-ID group) 28 days apart. For a subset of subjects, antibody-dependent cellular cytotoxicity (ADCC), interferon-γ release enzyme-linked immunospot (ELISPOT), and protein microarray antibody-binding assays were conducted. Protein microarray responses were assessed for correlations with plaque reduction neutralization titer (PRNT), enzyme-linked immunosorbent assay, ADCC, and ELISPOT results. RESULTS: MVA elicited significant microarray antibody responses to 15 of 224 antigens, mostly virion membrane proteins, at day 28 or 42, particularly WR113/D8L and WR101H3L. In the liquid-SC group, responses to 9 antigens, including WR113/D8L and WR101/H3L, correlated with PRNT results. Three were correlated in the liquid-ID group. No significant correlations were observed with ELISPOT responses. In the liquid-ID group, WR052/F13L, a membrane glycoprotein, correlated with ADCC responses. CONCLUSIONS: MVA elicited antibodies to 15 vaccinia strain antigens representing virion membrane. Antibody responses to 2 proteins strongly increased and significantly correlated with increases in PRNT. Responses to these proteins are potential correlates of protection and may serve as immunogens for future vaccine development. CLINICAL TRIALS REGISTRATION: NCT00914732.

Vaccine-related major cutaneous reaction size correlates with cellular-mediated immune responses after tularaemia immunisation.

OBJECTIVES: Francisella tularensis, the causative agent of tularaemia, is an exceptionally infectious bacterium, potentially fatal for humans if left untreated and with the potential to be developed as a bioweapon. Both natural infection and live-attenuated vaccine strain (LVS) confer good protection against tularaemia. LVS vaccination is traditionally administered by scarification, and the formation of a cutaneous reaction or take at the vaccination site is recognised as a clinical correlate of protection. Although previous studies have suggested that high antibody titres following vaccination might serve as a useful surrogate marker, the immunological correlates of protection remain unknown. METHODS: We investigated the host T-cell-mediated immune (T-CMI) responses elicited following immunisation with LVS vaccine formulated by the DynPort Vaccine Company (DVC-LVS) or the United States Army Medical Research Institute of Infectious Diseases (USAMRIID-LVS). We compared T-CMI responses prompted by these vaccines and correlated them with take size. RESULTS: We found that both LVS vaccines elicited similar T-CMI responses. Interestingly, take size associated with the T cells' ability to proliferate, secrete IFN-γ and mobilise degranulation, suggesting that these responses play an essential role in tularaemia protection. CONCLUSIONS: These results renew the appreciation for vaccination through the scarification as a prime route of inoculation to target pathogens driving specific T-CMI responses and provide further evidence that T-CMI plays a role in protection from tularaemia.

Role of human Pegivirus infections in whole Plasmodium falciparum sporozoite vaccination and controlled human malaria infection in African volunteers.

BACKGROUND: Diverse vaccination outcomes and protection levels among different populations pose a serious challenge to the development of an effective malaria vaccine. Co-infections are among many factors associated with immune dysfunction and sub-optimal vaccination outcomes. Chronic, asymptomatic viral infections can contribute to the modulation of vaccine efficacy through various mechanisms. Human Pegivirus-1 (HPgV-1) persists in immune cells thereby potentially modulating immune responses. We investigated whether Pegivirus infection influences vaccine-induced responses and protection in African volunteers undergoing whole P. falciparum sporozoites-based malaria vaccination and controlled human malaria infections (CHMI). METHODS: HPgV-1 prevalence was quantified by RT-qPCR in plasma samples of 96 individuals before, post vaccination with PfSPZ Vaccine and after CHMI in cohorts from Tanzania and Equatorial Guinea. The impact of HPgV-1 infection was evaluated on (1) systemic cytokine and chemokine levels measured by Luminex, (2) PfCSP-specific antibody titers quantified by ELISA, (3) asexual blood-stage parasitemia pre-patent periods and parasite multiplication rates, (4) HPgV-1 RNA levels upon asexual blood-stage parasitemia induced by CHMI. RESULTS: The prevalence of HPgV-1 was 29.2% (28/96) and sequence analysis of the 5' UTR and E2 regions revealed the predominance of genotypes 1, 2 and 5. HPgV-1 infection was associated with elevated systemic levels of IL-2 and IL-17A. Comparable vaccine-induced anti-PfCSP antibody titers, asexual blood-stage multiplication rates and pre-patent periods were observed in HPgV-1 positive and negative individuals. However, a tendency for higher protection levels was detected in the HPgV-1 positive group (62.5%) compared to the negative one (51.6%) following CHMI. HPgV-1 viremia levels were not significantly altered after CHMI. CONCLUSIONS: HPgV-1 infection did not alter PfSPZ Vaccine elicited levels of PfCSP-specific antibody responses and parasite multiplication rates. Ongoing HPgV-1 infection appears to improve to some degree protection against CHMI in PfSPZ-vaccinated individuals. This is likely through modulation of immune system activation and systemic cytokines as higher levels of IL-2 and IL17A were observed in HPgV-1 infected individuals. CHMI is safe and well tolerated in HPgV-1 infected individuals. Identification of cell types and mechanisms of both silent and productive infection in individuals will help to unravel the biology of this widely present but largely under-researched virus.

Variability in the Management of Adults With Pulmonary Nontuberculous Mycobacterial Disease.

BACKGROUND: The increasing global prevalence of pulmonary nontuberculous mycobacteria (NTM) disease has called attention to challenges in NTM diagnosis and management. This study was conducted to understand management and outcomes of patients with pulmonary NTM disease at diverse centers across the United States. METHODS: We conducted a 10-year (2005-2015) retrospective study at 7 Vaccine and Treatment Evaluation Units to evaluate pulmonary NTM treatment outcomes in human immunodeficiency virus-negative adults. Demographic and clinical information was abstracted through medical record review. Microbiologic and clinical cure were evaluated using previously defined criteria. RESULTS: Of 297 patients diagnosed with pulmonary NTM, the most frequent NTM species were Mycobacterium avium-intracellulare complex (83.2%), M. kansasii (7.7%), and M. abscessus (3.4%). Two hundred forty-five (82.5%) patients received treatment, while 45 (15.2%) were followed without treatment. Eighty-six patients had available drug susceptibility results; of these, >40% exhibited resistance to rifampin, ethambutol, or amikacin. Of the 138 patients with adequate outcome data, 78 (56.5%) experienced clinical and/or microbiologic cure. Adherence to the American Thoracic Society/Infectious Diseases Society of America (ATS/IDSA) treatment guidelines was significantly more common in patients who were cured (odds ratio, 4.5, 95% confidence interval, 2.0-10.4; P < .001). Overall mortality was 15.7%. CONCLUSIONS: Despite ATS/IDSA Guidelines, management of pulmonary NTM disease was heterogeneous and cure rates were relatively low. Further work is required to understand which patients are suitable for monitoring without treatment and the impact of antimicrobial therapy on pulmonary NTM morbidity and mortality.

Inactivation of Severe Acute Respiratory Coronavirus Virus 2 (SARS-CoV-2) and Diverse RNA and DNA Viruses on Three-Dimensionally Printed Surgical Mask Materials.

BACKGROUND: Personal protective equipment (PPE) is a critical need during the coronavirus disease 2019 (COVID-19) pandemic. Alternative sources of surgical masks, including 3-dimensionally (3D) printed approaches that may be reused, are urgently needed to prevent PPE shortages. Few data exist identifying decontamination strategies to inactivate viral pathogens and retain 3D-printing material integrity. OBJECTIVE: To test viral disinfection methods on 3D-printing materials. METHODS: The viricidal activity of common disinfectants (10% bleach, quaternary ammonium sanitizer, 3% hydrogen peroxide, or 70% isopropanol and exposure to heat (50°C, and 70°C) were tested on four 3D-printed materials used in the healthcare setting, including a surgical mask design developed by the Veterans' Health Administration. Inactivation was assessed for several clinically relevant RNA and DNA pathogenic viruses, including severe acute respiratory coronavirus virus 2 (SARS-CoV-2) and human immunodeficiency virus 1 (HIV-1). RESULTS: SARS-CoV-2 and all viruses tested were completely inactivated by a single application of bleach, ammonium quaternary compounds, or hydrogen peroxide. Similarly, exposure to dry heat (70°C) for 30 minutes completely inactivated all viruses tested. In contrast, 70% isopropanol reduced viral titers significantly less well following a single application. Inactivation did not interfere with material integrity of the 3D-printed materials. CONCLUSIONS: Several standard decontamination approaches effectively disinfected 3D-printed materials. These approaches were effective in the inactivation SARS-CoV-2, its surrogates, and other clinically relevant viral pathogens. The decontamination of 3D-printed surgical mask materials may be useful during crisis situations in which surgical mask supplies are limited.