Association between SARS-CoV-2 RNAemia, skewed T cell responses, inflammation, and severity in hospitalized COVID-19 people living with HIV.

Severe COVID-19 outcomes have been reported in people living with HIV (PLWH), yet the underlying pathogenetic factors are largely unknown. We therefore aimed to assess SARS-CoV-2 RNAemia and plasma cytokines in PLWH hospitalized for COVID-19 pneumonia, exploring associations with magnitude and functionality of SARS-CoV-2-specific immune responses. Eighteen unvaccinated PLWH (16/18 on cART; median CD4 T cell count 361.5/µL; HIV-RNA<50 cp/mL in 15/18) and 18 age/sex-matched people without HIV were consecutively recruited at a median time of 10 days from symptoms onset. PLWH showed greater SARS-CoV-2 RNAemia, a distinct plasma cytokine profile, and worse respiratory function (lower PaO2/FiO2nadir), all correlating with skewed T cell responses (higher perforin production by cytotoxic T cells as well as fewer and less polyfunctional SARS-CoV-2-specific T cells), despite preserved humoral immunity. In conclusion, these data suggest a link between HIV-related T cell dysfunction and poor control over SARS-CoV-2 replication/dissemination that may in turn influence COVID-19 severity in PLWH.

Six-month immune responses to mRNA-1273 vaccine in combination antiretroviral therapy treated late presenter people with HIV according to previous SARS-CoV-2 infection.

OBJECTIVE: Immune responses to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) mRNA vaccines in people with HIV (PWH) with a history of late presentation (LP) and their durability have not been fully characterized. DESIGN: In this prospective, longitudinal study, we sought to assess T-cell and humoral responses to SARS-CoV-2 mRNA vaccination up to 6 months in LP-PWH on effective combination antiretroviral therapy (cART) as compared to HIV-negative healthcare workers (HCWs), and to evaluate whether previous SARS-CoV-2 infection modulates immune responses to vaccine. METHODS: SARS-CoV-2 spike (S)-specific T-cell responses were determined by two complementary flow cytometry methodologies, namely activation-induced marker (AIM) assay and intracellular cytokine staining (ICS), whereas humoral responses were measured by ELISA [anti-receptor binding domain (RBD) antibodies) and receptor-binding inhibition assay (spike-ACE2 binding inhibition activity), before vaccination (T0), 1 month (T1) and 5 months (T2) after the second dose. RESULTS: LP-PWH showed at T1 and T2 significant increase of: S-specific memory and circulating T follicular helper (cTfh) CD4 + T cells; polyfunctional Th1-cytokine (IFN-γ, TNF-α, IL-2)- and Th2-cytokine (IL-4)-producing S-specific CD4 + T cells; anti-RBD antibodies and spike-ACE2 binding inhibition activity. Immune responses to vaccine in LP-PWH were not inferior to HCWs overall, yet S-specific CD8 + T cells and spike-ACE2 binding inhibition activity correlated negatively with markers of immune recovery on cART. Interestingly, natural SARS-CoV-2 infection, while able to sustain S-specific antibody response, seems less efficacious in inducing a T-cell memory and in boosting immune responses to vaccine, possibly reflecting an enduring partial immunodeficiency. CONCLUSIONS: Altogether, these findings support the need for additional vaccine doses in PWH with a history of advanced immune depression and poor immune recovery on effective cART.

Immunologic Interplay Between HIV/AIDS and COVID-19: Adding Fuel to the Flames?

PURPOSE OF REVIEW: HIV/AIDS and COVID-19 have been the major pandemics overwhelming our times. Given the enduring immune disfunction featuring people living with HIV (PLWH) despite combination antiretroviral therapy (cART), concerns for higher incidence and severity of SARS-CoV-2 infection as well as for suboptimal responses to the newly developed vaccines in this population arose early during the pandemics. Herein, we discuss the complex interplay between HIV and SARS-CoV-2, with a special focus on the immune responses to SARS-CoV-2 natural infection and vaccination in PLWH. RECENT FINDINGS: Overall, current literature shows that COVID-19 severity and outcomes may be worse and immune responses to infection or vaccination lower in PLWH with poor CD4 + T-cell counts and/or uncontrolled HIV viremia. Data regarding the risk of post-acute sequelae of SARS-CoV-2 infection (PASC) among PLWH are extremely scarce, yet they seem to suggest a higher incidence of such condition. Scarce immunovirological control appears to be the major driver of weak immune responses to SARS-CoV-2 infection/vaccination and worse COVID-19 outcomes in PLWH. Therefore, such individuals should be prioritized for vaccination and should receive additional vaccine doses. Furthermore, given the potentially higher risk of developing long-term sequelae, PLWH who experienced COVID-19 should be ensured a more careful and prolonged follow-up.

Growth Differentiation Factor 15 (GDF-15) Levels Associate with Lower Survival in Chronic Kidney Disease Patients with COVID-19.

A cytokine storm drives the pathogenesis of severe COVID-19 infection and several biomarkers have been linked to mortality. Chronic kidney disease (CKD) emerged as a risk factor for severe COVID-19. We investigated the association between selected biomarkers and mortality in 77 patients hospitalized for COVID-19, and whether they differ in patients with eGFR higher and lower than 45 mL/min. The association between patients' characteristics, plasma biomarkers and mortality was conducted by univariate logistic regression models and independent predictors of mortality were then used to create a multivariate prediction model through Cox regression. Patients with lower eGFR had a significant increase of GDF-15, CD-25 and RAGE, with higher plasma levels in non-survivors and in patients who needed ventilation. At univariate analysis, low and mid-low GDF-15 quartiles (<4.45 ng/mL) were associated with lower mortality risk, while mid-high and high quartiles (>4.45 ng/mL) were associated with higher mortality risk. Independent association between GDF-15 quartiles and mortality risk was confirmed in the Cox model and adjusted for eGFR, age, fever and dyspnea (HR 2.28, CI 1.53−3.39, p < 0.0001). The strength of the association between GDF-15 quartiles and mortality risk increased in patients with lower compared to higher eGFR (HR 2.53, CI 1.34−4.79 versus HR 1.99, CI 1.17−3.39). Our findings may suggest a further investigation of the effect of GDF-15 signaling pathway inhibition in CKD.

Association between SARS-CoV-2 RNAemia and dysregulated immune response in acutely ill hospitalized COVID-19 patients.

Severe/critical COVID-19 is associated with immune dysregulation and plasmatic SARS-CoV-2 detection (i.e. RNAemia). We detailed the association of SARS-CoV-2 RNAemia with immune responses in COVID-19 patients at the end of the first week of disease. We enrolled patients hospitalized in acute phase of ascertained SARS-CoV-2 pneumonia, and evaluated SARS-CoV-2 RNAemia, plasmatic cytokines, activated/pro-cytolytic T-cells phenotypes, SARS-CoV-2-specific cytokine-producing T-cells (IL-2, IFN-γ, TNF-α, IL-4, IL-17A), simultaneous Th1-cytokines production (polyfunctionality) and amount (iMFI). The humoral responses were assessed with anti-S1/S2 IgG, anti-RBD total-Ig, IgM, IgA, IgG1 and IgG3, neutralization and antibody-dependent cellular cytotoxicity (ADCC). Out of 54 patients, 27 had detectable viremia (viremic). Albeit comparable age and co-morbidities, viremic more frequently required ventilatory support, with a trend to higher death. Viremic displayed higher pro-inflammatory cytokines (IFN-α, IL-6), lower activated T-cells (HLA-DR+CD38+), lower functional SARS-CoV-2-specific T-cells (IFN-γ+CD4+, TNF-α+CD8+, IL-4+CD8+, IL-2+TNF-α+CD4+, and IL-2+TNF-α+CD4+ iMFI) and SARS-CoV-2-specific Abs (anti-S IgG, anti-RBD total-Ig, IgM, IgG1, IgG3; ID50, %ADCC). These data suggest a link between SARS-CoV-2 RNAemia at the end of the first stage of disease and immune dysregulation. Whether high ab initium viral burden and/or intrinsic host factors contribute to immune dysregulation in severe COVID-19 remains to be elucidated, to further inform strategies of targeted therapeutic interventions.

Gamma-Delta T-Cell Phenotype and Function in DAA-Treated HIV-HCV Co-Infected and HCV-Mono-Infected Subjects.

HIV-HCV co-infected subjects are at risk of liver fibrosis which may be linked to immune imbalances. Direct-acting antivirals (DAAs) represent the mainstay of HCV treatment in co-infected individuals, yet their effects on immune cell populations playing a role in fibrogenesis is unknown. We assessed γδ T-cell phenotype and function, Treg and Th17 frequencies, as well as γ-globulins and B-cell activation in 47 HIV-HCV co-infected and 35 HCV mono-infected individuals prior to and following DAA treatment (SVR12). Γδ T-cell activation decreased in both groups yet persisted at higher levels in the HIV-HCV co-infected subjects. No differences were registered in terms of γδT-cell function. Of note, the Vδ2/Th17 ratio, inversely linked to liver damage, increased significantly in the two groups upon treatment, yet a negative correlation between the Vδ2/Th17 ratio and liver function enzymes was found in the co-infected subjects alone. B-cell activation and γ-globulin levels decreased in both settings, yet B-cell activation remained higher in the HIV-HCV co-infected individuals. In HIV-HCV co-infected and HCV mono-infected participants, the effect of DAA was limited to γδ T- and B-cell activation as well as γ-globulin concentrations and the Vδ2/Th17 ratio, with no changes in γδ T-cell function and Treg frequencies. Importantly, γδ T- and B-cell activation remained at higher levels in the co-infected individuals than in those with HCV mono-infection alone. The persistence of such alterations within these cell subsets may be associated with the risk of hepatic and extrahepatic complications.

Hallmarks of Severe COVID-19 Pathogenesis: A Pas de Deux Between Viral and Host Factors.

Two years into Coronavirus Disease 2019 (COVID-19) pandemic, a comprehensive characterization of the pathogenesis of severe and critical forms of COVID-19 is still missing. While a deep dysregulation of both the magnitude and functionality of innate and adaptive immune responses have been described in severe COVID-19, the mechanisms underlying such dysregulations are still a matter of scientific debate, in turn hampering the identification of new therapies and of subgroups of patients that would most benefit from individual clinical interventions. Here we review the current understanding of viral and host factors that contribute to immune dysregulation associated with COVID-19 severity in the attempt to unfold and broaden the comprehension of COVID-19 pathogenesis and to define correlates of protection to further inform strategies of targeted therapeutic interventions.

Strong humoral immune responses against SARS-CoV-2 Spike after BNT162b2 mRNA vaccination with a 16-week interval between doses.

The standard regimen of the BNT162b2 mRNA vaccine for SARS-CoV-2 includes two doses administered three weeks apart. However, some public health authorities spaced these doses, raising questions about efficacy. We analyzed longitudinal humoral responses against the D614G strain and variants of concern for SARS-CoV-2 in a cohort of SARS-CoV-2-naive and previously infected individuals who received the BNT162b2 mRNA vaccine with sixteen weeks between doses. While administering a second dose to previously infected individuals did not significantly improve humoral responses, these responses significantly increased in naive individuals after a 16-week spaced second dose, achieving similar levels as in previously infected individuals. Comparing these responses to those elicited in individuals receiving a short (4-week) dose interval showed that a 16-week interval induced more robust responses among naive vaccinees. These findings suggest that a longer interval between vaccine doses does not compromise efficacy and may allow greater flexibility in vaccine administration.

Patient-derived xenografts (PDXs) as model systems for human cancer.

Patient-derived xenografts (PDXs) are obtained by transplanting fragments of a patient's tumour into immunodeficient mice. Growth and propagation of PDXs allows correlating therapeutic response in vivo with extensive, multi-dimensional molecular annotation, leading to identification of predictive biomarkers. PDXs are increasingly recognised as clinically relevant models of cancer for several reasons, of which the main is the possibility of studying the behaviour of cancer cells in a natural microenvironment, where they interact with stromal components accrued from the mouse host. PDXs maintain close similarities with the tumour of origin, in terms of tissue architecture, molecular features and response to treatments. Indeed, preclinical trials in PDXs have been shown to match and also anticipate data obtained in patients. Exploration of more complex processes like metastatic evolution and antitumour immune responses is actively pursued with PDXs, as new generations of host models emerge on the horizon.

Impact of congenital cytomegalovirus infection on transcriptomes from archived dried blood spots in relation to long-term clinical outcome.

Congenital Cytomegalovirus infection (cCMV) is the leading infection in determining permanent long-term impairments (LTI), and its pathogenesis is largely unknown due to the complex interplay between viral, maternal, placental, and child factors. The cellular activity, considered to be the result of the response to exogenous and endogenous factors, is captured by the determination of gene expression profiles. In this study, we determined whole blood transcriptomes in relation to cCMV, CMV viral load and LTI development at 6 years of age by using RNA isolated from neonatal dried blood spots (DBS) stored at room temperature for 8 years. As DBS were assumed to mainly reflect the neonatal immune system, particular attention was given to the immune pathways using the global test. Additionally, differential expression of individual genes was performed using the voom/limma function packages. We demonstrated feasibility of RNA sequencing from archived neonatal DBS of children with cCMV, and non-infected controls, in relation to LTI and CMV viral load. Despite the lack of statistical power to detect individual genes differences, pathway analysis suggested the involvement of innate immune response with higher CMV viral loads, and of anti-inflammatory markers in infected children that did not develop LTI. Finally, the T cell exhaustion observed in infected neonates, in particular with higher viral load, did not correlate with LTI, therefore other mechanisms are likely to be involved in the long-term immune dysfunction. Despite these data demonstrate limitation in determining prognostic markers for LTI by means of transcriptome analysis, this exploratory study represents a first step in unraveling the pathogenesis of cCMV, and the aforementioned pathways certainly merit further evaluation.

Maternal and child human leukocyte antigens in congenital cytomegalovirus infection.

Congenital Cytomegalovirus infection (cCMV) is the most common cause of congenital infections worldwide causing permanent long-term impairment (LTI). cCMV immunopathogenesis remains largely unknown due to the complex interplay between viral, maternal, placental and child factors. The aim of this study was to determine the possible role of particular HLA antigens, of the number of HLA mismatches (mm) and non-inherited maternal antigens (NIMAs) in a large retrospective nation-wide cohort of children with cCMV and their mothers. HLA Class I (HLA-A, HLA-B and HLA-C) and HLA Class II (HLA-DR and HLA-DQ) were assessed in 96 mother-child pairs in relation to a control group of 5604 Dutch blood donors, but no significant differences were observed. Next, although these HLA antigens could not be assessed in relation to symptoms at birth, nor to LTI, due to the low number of cases, they could be evaluated in relation to CMV viral load. HLA-DRB1*04, and potentially HLA-B*51, was shown to have a protective role in the children as its frequency was increased in the low viral load group compared to the high viral load group, and this remained significant after correction. The number of HLA mm and of NIMAs were not associated to symptoms at birth nor to LTI or viral load. In conclusion, although none of the HLA alleles could be put forward as prognostic marker for long-term outcome, our findings give useful insights into cCMV pathogenesis, and identify potential HLAs that correlate with a better viral control.

Neonatal screening parameters in infants with congenital Cytomegalovirus infection.

Congenital Cytomegalovirus infection (cCMV) is the most common cause of congenital infections worldwide that can cause long-term impairment (LTI). The metabolic alterations due to cCMV are largely unknown. This study aims to assess the metabolites included in the neonatal screening in relation to cCMV and cCMV outcome, allowing the identification of prognostic markers for clinical outcome. Essential amino acids, hormones, carnitines and enzymes from Dried Blood Spots (DBS) were analyzed of 102 children with cCMV and 179 children without cCMV, and they were related to symptoms at birth and LTI at 6years of age. In this cohort, the neonatal screening parameters did not change in relation to cCMV, nor to symptoms at birth or LTI. However, metabolic changes were observed in children born preterm, with lower concentrations of essential amino acids in premature infants with cCMV compared to premature controls. Finally, a higher concentration of palmytoilcarnitine (C16) in the group with higher viral load was observed. Though these data demonstrate limitations in the use of neonatal screening data as predictors for long-term cCMV outcome, the metabolism of preterm neonates with cCMV merits further evaluation.

T and B Cell Markers in Dried Blood Spots of Neonates with Congenital Cytomegalovirus Infection: B Cell Numbers at Birth Are Associated with Long-Term Outcomes.

Congenital CMV infection (cCMV) is the most common congenital infection that can cause long-term impairment (LTI). The pathogenesis of LTI is not completely understood. Fetal immunity may play a role in controlling the infection and preventing LTI, although immune activation may also contribute to fetal immunopathology. In this study, we analyzed various molecular markers of T and B cell numbers in neonatal dried blood spots of 99 children with cCMV and 54 children without cCMV: δRec-ψJα signal joints on TCR excision circles, intron recombination signal sequence k-deleting element signal joints on Igκ-deleting recombination excision circles, genomic intron recombination signal sequence k-deleting element coding joint, genomic Vδ1-Jδ1, and Vδ2-Jδ1 rearrangements. Of this cohort, clinical symptoms at birth and LTI at 6 y of age were recorded. Neonates with cCMV had fewer TCR excision circles in their blood than non-infected controls. Furthermore, cCMV infection was associated with increased numbers of γδ T cells and B cells, and these numbers were positively correlated with CMV viral load in the dried blood spots. Infected children with a better long-term outcome had higher numbers of B cells at birth than those who developed LTI; no difference in B cell replication was observed. The potential protective role of B cells in controlling cCMV-related disease and the clinical value of this marker as a predictor of long-term outcome merit further evaluation.

Congenital Cytomegalovirus Infection: Maternal-Child HLA-C, HLA-E, and HLA-G Affect Clinical Outcome.

Congenital CMV infection (cCMV) is the most common congenital infection causing permanent long-term impairments (LTI). cCMV immunopathogenesis is largely unknown due to the complex interplay between viral, maternal, placental, and child factors. In this study, a large retrospective nationwide cohort of children with cCMV and their mothers was used. HLA-C, HLA-E, and HLA-G were assessed in 96 mother-child pairs in relation to symptoms at birth and LTI at 6 years of age. The mothers were additionally typed for killer cell immunoglobulin-like receptors. The maternal HLA-G 14 bp deletion/deletion polymorphism was associated with a worse outcome, as the immunomodulation effect of higher protein levels may induce less CMV control, with a direct impact on placenta and fetus. The absence of maternal HLA-C belonging to the C2 group was associated with symptoms at birth, as activating signals on decidual NK may override inhibitory signals, contributing to a placental pro-inflammatory environment. Here, the increased HLA-E*0101 and HLA-C mismatches, which were associated with symptoms at birth, may enhance maternal allo-reactivity to fetal Ags, and cause suboptimal viral clearance. Finally, HLA-C non-inherited maternal antigens (NIMAs) were associated with LTI. The tolerance induced in the fetus toward NIMAs may indirectly induce a suboptimal CMV antiviral response throughout childhood. In light of our findings, the potential role of maternal-child HLA in controlling CMV infection and cCMV-related disease, and the clinical value as predictor for long-term outcome certainly deserve further evaluation.

In vitro anti-Herpes simplex virus activity of crude extract of the roots of Nauclea latifolia Smith (Rubiaceae).

BACKGROUND: Nauclea latifolia Smith, a shrub belonging to the family Rubiaceae is a very popular medicinal plant in Cameroon and neighboring countries where it is used to treat jaundice, yellow fever, rheumatism, abdominal pains, hepatitis, diarrhea, dysentery, hypertension, as well as diabetes. The ethno-medicinal use against yellow fever, jaundice and diarrhea prompted us to investigate on the antiviral activity of the root bark of N. latifolia. In this study, HSV-2 was chosen as a viral model because of its strong impact on HIV transmission and acquisition. METHODS: The crude extract under study was prepared by maceration of air-dried and powdered roots barks of N. latifolia in CH2Cl2/MeOH (50:50) mixture for 48 hours, then it was subjected to filtration and evaporation under vacuum. A phytochemical analysis of the crude extract was performed by High Performance Liquid Chromatography coupled with a photodiode array and mass spectrometry (HPLC-PDA-ESI-qMS). The anti-HSV-2 activity was assayed in vitro by plaque reduction and virus yield assays and the major mechanism of action was investigated by virucidal and time of addition assays. Data values were compared using the Extra sum of squares F test of program GraphPad PRISM 4. RESULTS: The main components detected in the extract belong to the class of indole alkaloids characteristic of Nauclea genus. Strictosamide, vincosamide and pumiloside were tentatively identified together with quinovic acid glycoside. N. latifolia crude extract inhibited both acyclovir sensitive and acyclovir resistant HSV-2 strains, with IC50 values of 5.38 µg/ml for the former and 7.17 µg/ml for the latter. The extract was found to be most active when added post-infection, with IC50 of 3.63 µg/ml. CONCLUSION: The results of this work partly justify the empirical use of N. latifolia in traditional medicine for the treatment of viral diseases. This extract could be a promising rough material for the development of a new and more effective modern anti-HSV-2 medication also active against acyclovir-resistant HSV-2 strains.