Attention for sex in COVID-19 trials: a review of regulatory dossiers.

An under-representation of women and a lack of sex-specific analyses in COVID-19 trials has been suggested. However, the higher number of men than women who are severely affected by COVID-19 and the restricted information in scientific publications may have biased these suggestions. Therefore, we evaluated sex proportionality and sex-specific efficacy and safety data in trials of COVID-19 treatments and vaccines using both publicly available regulatory documents and confidential documents used by regulators in their review of medicinal products.

Protective HLA Alleles Recruit Biased and Largely Similar Antigen-Specific T Cell Repertoires across Different Outcomes in HIV Infection.

CD8 T cells play an important role in the control of untreated HIV infection. Several studies have suggested a decisive role of TCRs involved in anti-HIV immunity. HLA-B*27 and B*57 are often associated with a delayed HIV disease progression, but the exact correlates that provide superior immunity against HIV are not known.

Immune activation correlates with and predicts CXCR4 co-receptor tropism switch in HIV-1 infection.

HIV-1 cell entry is mediated by binding to the CD4-receptor and chemokine co-receptors CCR5 (R5) or CXCR4 (X4). R5-tropic viruses are predominantly detected during early infection. A switch to X4-tropism often occurs during the course of infection.

Rapid reconstitution of CD4 T cells and NK cells protects against CMV-reactivation after allogeneic stem cell transplantation.

Background: Epstein-Barr virus and Cytomegalovirus reactivations frequently occur after allogeneic stem cell transplantation (SCT).

Methods: Here we investigated the role of immune cell reconstitution in the onset and subsequent severity of EBV- and CMV-reactivation. To this end, 116 patients were prospectively sampled for absolute T cell (CD4 and CD8), B-cell (CD19) and NK-cell (CD16 and CD56) numbers weekly post-SCT during the first 3 months and thereafter monthly until 6 months post-SCT.

The presence of protective cytotoxic T lymphocytes does not correlate with shorter lifespans of productively infected cells in HIV-1 infection.

Objectives And Design: CD8+ cytotoxic T lymphocytes (CTL) are important in the control of HIV infection. Although CTL are thought to reduce the lifespan of productively infected cells, CD8+ T-cell depletion in simian immunodeficiency virus-infected rhesus-macaques showed no effect on the lifespan of productively infected cells. As CD8+ T-cell responses that successfully delay HIV disease progression occur only in a minority of HIV-infected individuals, we studied the hypothesis that the ability of CTL to reduce the lifespan of productively infected cells is limited to protective CTL responses only.

Measles Virus Epitope Presentation by HLA: Novel Insights into Epitope Selection, Dominance, and Microvariation.

Immunity to infections with measles virus (MV) can involve vigorous human leukocyte antigen (HLA) class I-restricted CD8(+) cytotoxic T cell (CTL) responses. MV, albeit regarded monotypic, is known to undergo molecular evolution across its RNA genome. To address which regions of the MV proteome are eligible for recognition by CD8(+) CTLs and how different HLA class I loci contribute to the epitope display, we interrogated the naturally processed and presented MV peptidome extracted from cell lines expressing in total a broad panel of 16 different common HLA-A, -B, and -C molecules.

Comprehensive Analysis of the Naturally Processed Peptide Repertoire: Differences between HLA-A and B in the Immunopeptidome.

The cytotoxic T cell (CTL) response is determined by the peptide repertoire presented by the HLA class I molecules of an individual. We performed an in-depth analysis of the peptide repertoire presented by a broad panel of common HLA class I molecules on four B lymphoblastoid cell-lines (BLCL). Peptide elution and mass spectrometry analysis were utilised to investigate the number and abundance of self-peptides.

A lower viral set point but little immunological impact after early treatment during primary HIV infection.

The Primo-SHM trial, a multicenter randomized trial comparing no treatment with 24 or 60 weeks of combination antiretroviral therapy (cART) during primary human immunodeficiency virus (HIV) infection (PHI), recently demonstrated that temporary early cART lowered the viral set point and deferred the need for re-initiation of cART during chronic HIV infection. This study examined whether the beneficial effect of early treatment was caused by preservation of immunological responses. Twenty-seven treated and 20 untreated PHI individuals participating in the Primo-SHM trial were compared at viral set point, that is, 36 weeks after baseline or after treatment interruption, respectively, for a diverse set of immunological parameters.

Complex T-cell receptor repertoire dynamics underlie the CD8+ T-cell response to HIV-1.

Unlabelled: Although CD8(+) T cells are important for the control of HIV-1 in vivo, the precise correlates of immune efficacy remain unclear. In this study, we conducted a comprehensive analysis of viral sequence variation and T-cell receptor (TCR) repertoire composition across multiple epitope specificities in a group of antiretroviral treatment-naive individuals chronically infected with HIV-1. A negative correlation was detected between changes in antigen-specific TCR repertoire diversity and CD8(+) T-cell response magnitude, reflecting clonotypic expansions and contractions related to alterations in cognate viral epitope sequences.

Differential characteristics of cytotoxic T lymphocytes restricted by the protective HLA alleles B*27 and B*57 in HIV-1 infection.

Objective: HLA-B*27 and B*57 are associated with relatively slow progression to AIDS. Mechanisms held responsible for this protective effect include the immunodominance and high magnitude, breadth, and affinity of the cytotoxic T lymphocytes (CTL) response restricted by these HLA molecules, as well as superior maintenance of CTL responses during HIV-1 disease progression.

Design: We examined CTL responses from HIV-1-infected individuals restricted through protective and nonprotective HLA alleles within the same host, thereby excluding any effects of slow or rapid progression on the CTL response.

Elevated granzyme M-expressing lymphocytes during cytomegalovirus latency and reactivation after allogeneic stem cell transplantation.

Human cytomegalovirus (HCMV) reactivation can cause serious complications in allogeneic stem cell transplantation (SCT) patients. HCMV is controlled by cytotoxic lymphocytes that release antiviral granzymes. Recently, we have demonstrated that granzyme M (GrM) inhibits HCMV replication in vitro, however the physiological role of GrM and its cellular distribution during HCMV infection remains unknown.

CD8+ TCR repertoire formation is guided primarily by the peptide component of the antigenic complex.

CD8(+) T cells recognize infected or dysregulated cells via the clonotypically expressed αβ TCR, which engages Ag in the form of peptide bound to MHC class I (MHC I) on the target cell surface. Previous studies have indicated that a diverse Ag-specific TCR repertoire can be beneficial to the host, yet the determinants of clonotypic diversity are poorly defined. To better understand the factors that govern TCR repertoire formation, we conducted a comprehensive clonotypic analysis of CD8(+) T cell populations directed against epitopes derived from EBV and CMV.

Pegylated interferon-α monotherapy leads to low response rates in HIV-infected patients with acute hepatitis C.

Background: Despite a rising incidence of acute HCV in patients infected with HIV, the optimal therapeutic strategy (pegylated interferon-α [PEG-IFN-α] monotherapy or in combination with ribavirin) is still under debate.

Methods: A total of 23 HIV-infected patients were prospectively diagnosed with acute HCV and treated with PEG-IFN-α2a monotherapy (180 μg/week) for 24 or 48 weeks. Add-on ribavirin was allowed from week 4 of therapy onwards.

Influence of HIV infection on cytomegalovirus-specific immunity: T-cell responses to pp65 and IE1 before and after HAART may reflect altered cytomegalovirus biology.

Background: Data are inconclusive whether treatment with HAART induces functional recovery of HIV-specific T-cells. Since the introduction of HAART, a marked decrease of cytomegalovirus (CMV) disease - for which untreated HIV-infected individuals are at increased risk - is observed, suggesting that this treatment influences CMV-specific T-cell immunity.

Methods: To study potential functional recovery of HIV- and CMV-specific T-cells, CD4(+) and CD8(+) T-cell responses were measured longitudinally after in vitro expansion using gag, pp65 and IE1 peptide pools, during HIV infection and after long-term HAART.

Loss of HIV-1-derived cytotoxic T lymphocyte epitopes restricted by protective HLA-B alleles during the HIV-1 epidemic.

Objective And Design: HIV-1 is known to adapt to the human immune system, leading to accumulation of escape mutations during the course of infection within an individual. Cross-sectional studies have shown an inverse correlation between the prevalence of human leukocyte antigen (HLA) alleles in a population and the number of cytotoxic T lymphocyte (CTL) escape mutations in epitopes restricted by those HLA alleles. Recently, it was demonstrated that at a population level HIV-1 is adapting to the humoral immune response, which is reflected in an increase in resistance to neutralizing antibodies over time.

Immunological analysis of treatment interruption after early highly active antiretroviral therapy.

We longitudinally evaluated HIV-specific T-cell immunity after discontinuation of highly active antiretroviral therapy (HAART). After treatment interruption (TI), some individuals could maintain a low plasma viral load (<15,000 copies/mL), whereas others could not (>50,000 copies/mL). Before HAART was initiated, plasma viral load was similar.

Abundance of early functional HIV-specific CD8+ T cells does not predict AIDS-free survival time.

Background: T-cell immunity is thought to play an important role in controlling HIV infection, and is a main target for HIV vaccine development. HIV-specific central memory CD8(+) and CD4(+) T cells producing IFNgamma and IL-2 have been associated with control of viremia and are therefore hypothesized to be truly protective and determine subsequent clinical outcome. However, the cause-effect relationship between HIV-specific cellular immunity and disease progression is unknown.

A nonprogressive clinical course in HIV-infected individuals expressing human leukocyte antigen B57/5801 is associated with preserved CD8+ T lymphocyte responsiveness to the HW9 epitope in Nef.

The human leukocyte antigen (HLA) B57 allele and the closely related HLA-B5801 allele are overrepresented among human immunodeficiency virus type 1 (HIV-1)-infected individuals with a long-term nonprogressive clinical course of disease (known as "long-term nonprogressors" [LTNPs]). These alleles are, however, also present among individuals with normal disease progression (known as "progressors"). In a comparison of HLA-B57/5801-expressing progressors and LTNPs, we observed a similar prevalence of escape mutations in 4 Nef epitopes and a similar reactivity of CD8+ T cells against 3 of 4 of these epitopes and their autologous escape variants.

Statin synergizes with LPS to induce IL-1beta release by THP-1 cells through activation of caspase-1.

Mevalonate kinase deficiency (MKD) is a hereditary syndrome characterized by recurring episodes of fever and inflammation. Peripheral blood mononuclear cells from MKD patients secrete high levels of interleukin (IL)-1beta when stimulated with lipopolysaccharide (LPS), which is thought to be a primary cause of the inflammation. However, the link between a deficient mevalonate kinase and excessive IL-1beta release remains unclear.

An unanticipated lack of consensus cytotoxic T lymphocyte epitopes in HIV-1 databases: the contribution of prediction programs.

Background: Most consensus HIV-1-specific cytotoxic T lymphocytes epitopes presented via intensively studied HLA molecules are thought to be known

Objective: To identify possible novel HIV-1 epitopes for HLA-B27 and HLA-B57; two HLA types which are abundantly studied because of their correlation with slow HIV disease progression.

Methods: HIV-1 consensus subtype B sequences were analysed using peptide prediction programs based on major histocompatibility complex binding, proteasomal cleavage and TAP (transporter associated with antigen processing) transport. Recognition of the novel identified epitopes by cytotoxic T lymphocytes was tested using interferon-gamma ELISpot assay.

Viral replication capacity as a correlate of HLA B57/B5801-associated nonprogressive HIV-1 infection.

HLA B57 and the closely related HLA B5801 are over-represented among HIV-1 infected long-term nonprogressors (LTNPs). It has been suggested that this association between HLA B57/5801 and asymptomatic survival is a consequence of strong CTL responses against epitopes in the viral Gag protein. Moreover, CTL escape mutations in Gag would coincide with viral attenuation, resulting in low viral load despite evasion from immune control.

Efficient replication of pneumonia virus of mice (PVM) in a mouse macrophage cell line.

Pneumonia virus of mice (PVM; family Paramyxoviridae, subfamily Pneumovirinae) is a natural respiratory pathogen of rodent species and an important new model for the study of severe viral bronchiolitis and pneumonia. However, despite high virus titers typically detected in infected mouse lung tissue in vivo, cell lines used routinely for virus propagation in vitro are not highly susceptible to PVM infection. We have evaluated several rodent and primate cell lines for susceptibility to PVM infection, and detected highest virus titers from infection of the mouse monocyte-macrophage RAW 264.

Respiratory syncytial virus inhibits granulocyte apoptosis through a phosphatidylinositol 3-kinase and NF-kappaB-dependent mechanism.

Respiratory syncytial virus (RSV) is a common cause of lower respiratory tract disease in children. It is associated with increased neutrophil numbers in the airway. In this study, we assessed whether this ssRNA virus can directly influence granulocyte longevity.