The association between IgG and IgM antibodies against cardiolipin, β2-glycoprotein I and Domain I of β2-glycoprotein I with disease profile in patients with multiple sclerosis

Antiphospholipid antibodies (aPL) occur in patients with multiple sclerosis (MS) with a number of studies reporting elevated levels; their exact prevalence and pathogenic role remain unclear. Epidemiological studies associate MS with an increased risk of deep venous thromboembolism and stroke; overlapping clinical features with APS. Antibodies against the first domain – Domain I (DI) – of β2glycoprotein I (β2GPI), show the most clinical significance and evidence for pathogenicity in the antiphospholipid syndrome (APS), but have not yet been investigated in MS. Serum from a well-defined cohort of 127 MS patients and 92 healthy controls were tested for IgM and IgG antibodies against cardiolipin (CL), β2GPI and DI. Higher frequency of IgM and IgG anti-CL were found in MS patients (18.1% and 21.3%), compared to controls (1.1% in both cases, p < 0.0001). We report that anti-DI antibodies were associated with MS patients, with 6.3% and 7.1% positive for IgM and IgG, respectively, compared to controls, 1.1% (p < 0.05). IgM anti-CL antibodies were elevated in secondary progressive MS and primary progressive MS compared to relapse-remitting MS, (p < 0.005). This study enrolled the largest number of patients with definite MS for studying the association with aPL. Although we confirmed IgM and IgG anti-CL antibodies occur in patients with MS, this is the first study that identified anti-DI antibodies in MS patients. This new finding may prove valuable and future studies are required to evaluate its role as a potential risk factor of thromboembolic phenomena in MS

Phase I Randomised Clinical Trial of an HIV-1CN54, Clade C, Trimeric Envelope Vaccine Candidate Delivered Vaginally

We conducted a phase 1 double-blind randomised controlled trial (RCT) of a HIV-1 envelope protein (CN54 gp140) candidate vaccine delivered vaginally to assess immunogenicity and safety. It was hypothesised that repeated delivery of gp140 may facilitate antigen uptake and presentation at this mucosal surface. Twenty two healthy female volunteers aged 18–45 years were entered into the trial, the first receiving open-label active product. Subsequently, 16 women were randomised to receive 9 doses of 100 µg of gp140 in 3 ml of a Carbopol 974P based gel, 5 were randomised to placebo solution in the same gel, delivered vaginally via an applicator. Participants delivered the vaccine three times a week over three weeks during one menstrual cycle, and were followed up for two further months. There were no serious adverse events, and the vaccine was well tolerated. No sustained systemic or local IgG, IgA, or T cell responses to the gp140 were detected following vaginal immunisations. Repeated vaginal immunisation with a HIV-1 envelope protein alone formulated in Carbopol gel was safe, but did not induce local or systemic immune responses in healthy women

Geographical and temporal distribution of SARS-CoV-2 clades in the WHO European Region, January to June 2020

We show the distribution of SARS-CoV-2 genetic clades over time and between countries and outline potential genomic surveillance objectives. We applied three available genomic nomenclature systems for SARS-CoV-2 to all sequence data from the WHO European Region available during the COVID-19 pandemic until 10 July 2020. We highlight the importance of real-time sequencing and data dissemination in a pandemic situation. We provide a comparison of the nomenclatures and lay a foundation for future European genomic surveillance of SARS-CoV-2.Peer reviewe

Geographical and temporal distribution of SARS-CoV-2 clades in the WHO European Region, January to June 2020

We show the distribution of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) genetic clades over time and between countries and outline potential genomic surveillance objectives. We applied three genomic nomenclature systems to all sequence data from the World Health Organization European Region available until 10 July 2020. We highlight the importance of real-time sequencing and data dissemination in a pandemic situation, compare the nomenclatures and lay a foundation for future European genomic surveillance of SARS-CoV-2

Analysis of the relationship between cytokine secretion and proliferative capacity in hepatitis C virus infection.

CD4(+) T-cell responses are important for the outcome of hepatitis C virus (HCV) infection. However, the functional status of HCV-specific CD4(+) T cells in persistent infection is poorly understood. It is generally recognized that proliferative capacity of HCV-specific CD4(+) T cells is weak or absent in persistent infection, but whether this results from deletion of antigen-specific cells or represents maintenance of antigen-specific but poorly proliferative populations is not defined. We used a set of ex vivo assays to evaluate the functionality of HCV specific CD4(+) T cells in persistent and resolved infection. Peripheral blood mononuclear cells (PBMC) from 24 prospectively recruited HCV polymerase chain reaction (PCR) positive individuals, 12 spontaneously resolved individuals (i.e. anti-HCV+, PCR-) and 11 healthy controls were analysed for interferon-gamma (IFN-gamma) and interleukin 2 (IL-2) secretion by enzyme linked immunospot assays (ELISpot). HCV-specific CD4(+) proliferative responses of carboxy fluorescein succinimidyl ester-labelled PBMC were assessed using a sensitive single cell flow cytometric assay. Sustained IFN-gamma ELISpot responses were observed in the PCR+ group. However, proliferation of HCV-specific CD4(+) T cells in the PCR+ group was substantially reduced on a per cell basis, in parallel to IL-2 secretion, compared with responses in the PCR- group. In PCR- individuals, a strong relationship between cytokine secretion and proliferative capacity was seen. However, in PCR+ individuals, IFN-gamma secretion far exceeded proliferative capacity. During persistent HCV infection, some CD4(+) T-cell specificities appear to be lost, as measured using a range of techniques, but others, potentially important, are maintained as IFN-gamma secretors but with low proliferative capacity even using a highly sensitive assay. Such subsets may yet play a significant role in vivo and also provide a template for modulation in immunotherapeutic interventions

Maintenance of HCV-specific T-cell responses in antibody-deficient patients a decade after early therapy.

Early therapy for hepatitis C virus (HCV) is associated with a high rate of viral clearance, but the long-term effects on immune responses remain controversial. The role of antibodies, both acutely and in the long term, is not clearly defined. We investigated these issues in a unique cohort of 7 individuals with primary antibody failure, who had received early interferon therapy after infection through contaminated immunoglobulin therapy a decade previously

Contribution of redox status to hepatitis C virus E2 envelope protein function and antigenicity

Disulfide bonding contributes to the function and antigenicity of many viral envelope glycoproteins. We assessed here its significance for the hepatitis C virus E2 envelope protein and a counterpart deleted for hypervariable region-1 (HVR1). All 18 cysteine residues of the antigens were involved in disulfides. Chemical reduction of up to half of these disulfides was compatible with anti-E2 monoclonal antibody reaction, CD81 receptor binding, and viral entry, whereas complete reduction abrogated these properties. The addition of 5,5'-dithiobis-2-nitrobenzoic acid had no effect on viral entry. Thus, E2 function is only weakly dependent on its redox status, and cell entry does not require redox catalysts, in contrast to a number of enveloped viruses. Because E2 is a major neutralizing antibody target, we examined the effect of disulfide bonding on E2 antigenicity. We show that reduction of three disulfides, as well as deletion of HVR1, improved antibody binding for half of the patient sera tested, whereas it had no effect on the remainder. Small scale immunization of mice with reduced E2 antigens greatly improved serum reactivity with reduced forms of E2 when compared with immunization using native E2, whereas deletion of HVR1 only marginally affected the ability of the serum to bind the redox intermediates. Immunization with reduced E2 also showed an improved neutralizing antibody response, suggesting that potential epitopes are masked on the disulfide-bonded antigen and that mild reduction may increase the breadth of the antibody response. Although E2 function is surprisingly independent of its redox status, its disulfide bonds mask antigenic domains. E2 redox manipulation may contribute to improved vaccine design

Sterile inflammation induced by Carbopol elicits robust adaptive immune responses in the absence of pathogen-associated molecular patterns

Carbopol is a polyanionic carbomer used in man for topical application and drug delivery purposes. However parenteral administration of Carbopol in animal models results in systemic adjuvant activity including strong pro-inflammatory type-1 T-cell (Th1) polarization. Here we investigated potential pathways of immune activation by Carbopol by comparison with other well-characterized adjuvants. Carbopol administration triggered rapid and robust leukocyte recruitment, pro-inflammatory cytokine secretion and antigen capture largely by inflammatory monocytes. The induction of antigen specific Th1 cells by Carbopol was found to occur via a non-canonical pathway, independent of MyD88/TRIF signaling and in the absence of pattern-recognition-receptor (PRR) activation typically associated with Th1/Ig2a induction. Using multispectral fluorescence imaging (Imagestream) and electron microscopy we demonstrated that phagocytic uptake of Carbopol particles followed by entry into the phagosomal/lysosomal pathway elicited conformational changes to the polymer and reactive oxygen species (ROS) production. We therefore conclude that Carbopol may mediate its adjuvant activity via novel mechanisms of antigen presenting cell activation and Th1 induction, leading to enhanced IgG2a responses independent of microbial pattern recognition