Vaccines for COVID-19.

Since the emergence of COVID-19, caused by the SARS-CoV-2 virus at the end of 2019, there has been an explosion of vaccine development. By 24 September 2020, a staggering number of vaccines (more than 200) had started preclinical development, of which 43 had entered clinical trials, including some approaches that have not previously been licensed for human vaccines. Vaccines have been widely considered as part of the exit strategy to enable the return to previous patterns of working, schooling and socializing. Importantly, to effectively control the COVID-19 pandemic, production needs to be scaled-up from a small number of preclinical doses to enough filled vials to immunize the world's population, which requires close engagement with manufacturers and regulators. It will require a global effort to control the virus, necessitating equitable access for all countries to effective vaccines. This review explores the immune responses required to protect against SARS-CoV-2 and the potential for vaccine-induced immunopathology. We describe the profile of the different platforms and the advantages and disadvantages of each approach. The review also addresses the critical steps between promising preclinical leads and manufacturing at scale. The issues faced during this pandemic and the platforms being developed to address it will be invaluable for future outbreak control. Nine months after the outbreak began we are at a point where preclinical and early clinical data are being generated for the vaccines; an overview of this important area will help our understanding of the next phases.

Compromised CD4:CD8 ratio recovery in people living with HIV aged over 50 years: an observational study.

OBJECTIVES: Persistent CD4:CD8 ratio inversion (< 1) is associated with mortality in older people. We investigated the interaction of the effects of baseline CD8 count and age at HIV diagnosis on CD4:CD8 ratio recovery with antiretroviral therapy (ART). METHODS: An observational study (1 January 2007 to 31 December 2016) was carried out using routinely collected data from the HIV outpatient services at Imperial College Healthcare NHS Trust, London, UK. CD4 and CD8 counts, prior to and during ART, treatment during primary HIV infection (PHI) and HIV-1 viral load were included in univariate and multivariate analyses using Cox proportional hazard regression. RESULTS: Data were included for 876 patients starting ART, where HIV suppression was achieved. Of these patients, 741 of 876 (84.6%) were male and 507 of 876 (57.9%) were Caucasian. The median time on ART was 38 [interquartile range (IQR) 17-66] months. CD8 count change on ART was bidirectional; low CD8 counts (≤ 600 cells/µL) increased and high CD8 counts (> 900 cells/µL) decreased. The median pre-ART CD4:CD8 ratio was 0.41 (IQR 0.24-0.63), and recovery (≥ 1) occurred in 274 of 876 patients (31.3%). Pre- and post-ART CD4:CD8 ratios were lower in those aged > 50 years compared with young adults aged 18-30 years (P < 0.001 and P = 0.002, respectively). After adjustment, younger age at HIV diagnosis (P < 0.001) and treatment during PHI (P < 0.001) were favourable for CD4:CD8 ratio normalization. CONCLUSIONS: Older age (> 50 years) at HIV diagnosis was associated with persistent CD4:CD8 ratio inversion, whereas treatment of PHI was protective. These findings confirm the need for testing and early treatment of people aged > 50 years, and could be used in a risk management algorithm for enhanced surveillance.

Exercise in treating depression: broadening the psychotherapist's role.

Research findings over the past two decades strongly indicate that moderate exercise can have a beneficial effect upon depression, yet suggestions to depressed patients that they exercise rarely are followed. Despite the research, few psychotherapists employ exercise promotion and maintenance as part of their treatment. An approach to integrating exercise promotion into psychotherapy treatment is presented. It incorporates a therapist-patient collaborative process involving joint assessment of biopsychosocial barriers and facilitators for exercise initiation and maintenance that are unique to the patient. Based upon the assessment, a collaborative exercise plan is developed and implemented.

Cocaine differentially regulates activator protein-1 mRNA levels and DNA-binding complexes in the rat striatum and cerebellum.

Cocaine is a psychomotor stimulant that exerts many of its behavioral and physiological effects through alteration of catecholamine reuptake systems. One early cellular response to cocaine administration is a brain region-specific alteration in the transcriptional pattern of immediate early genes belonging to the Fos/Jun family of nucleotide sequence-specific [activator protein-1 (AP-1)] DNA-binding proteins. The work described here compares cocaine-induced transcriptional regulation of immediate early gene mRNA levels, as well as AP-1 DNA-binding activity, within the striatum and cerebellum. In the striatum, acute cocaine administration increases cellular levels of c-fos and jun-B mRNA, whereas transcriptional effects in the cerebellum are limited to c-fos mRNA. After chronic cocaine treatment a desensitization of c-fos mRNA induction is observed in the striatum, with sensitization of the same transcriptional effect occurring in the cerebellum. Pharmacological studies further reveal that the dopamine D1, dopamine D2, gamma-aminobutyric acid type B, and N-methyl-D-aspartate receptor systems mediate the effects of cocaine on cerebellar neurons, whereas striatal effects are modulated through D1 and N-methyl-D-aspartate receptors. Gel retention analysis using antibodies to the various Fos and Jun proteins was used to characterize cocaine-dependent alterations in the composition of striatal and cerebellar AP-1 DNA-binding complexes. In striatum, cocaine increases the relative levels of c-Fos, Fos-B, Jun-B, and Jun-D proteins that bind the AP-1 DNA sequence element, whereas in the cerebellum only c-Fos and Jun-D binding activities are increased. These data suggest two possible neuroanatomical sites where tolerance and sensitization to cocaine can be examined at the genomic level.

Identification of multiple DNA elements regulating basal and protein kinase A-induced transcriptional expression of the rat prodynorphin gene.

The prodynorphin gene encodes the precursor molecule from which the dynorphin family of opioid peptides is generated. The gene is transcriptionally active in a wide variety of brain regions and endocrine tissues. Much is known regarding the physiological and receptor-mediated events that regulate prodynorphin gene expression in vivo. However, the molecular mechanisms by which specific cis- and trans-acting factors control activity of the prodynorphin promoter are not as clearly defined. In the study described here, transient transfection of prodynorphin promoter-chloramphenicol acetyl transferase plasmid constructs into CV1 cells served to identify three nucleotide sequence elements conforming to cAMP regulatory element motifs which regulate both basal and protein kinase A (PKA)-induced transcription. The three elements are clustered at positions -1543, -1627, and -1659 relative to the RNA cap site. Site-specific mutagenesis further reveals that although the sites can act independently to positively regulate transcription from the prodynorphin promoter, they can also act combinatorially to produce maximal transcriptional efficacy. Gel retention analysis employing rat brain protein extracts also describes the ability of these sequence elements to form sequence-specific DNA/protein complexes.

Use of yeast artificial chromosome clones for mapping and walking within human chromosome segment 18q21.3.

Well-characterized large genomic clones obtained from yeast artificial chromosome (YAC) libraries provide the framework to localize genes and approach genetic disease. We developed universally applicable approaches to establish authenticity, localize and orient internal genes, map restriction sites, and rescue the distal ends of large human genomic DNA inserts. We selected human chromosome segment 18q21.3 as a model system. Molecular cloning of this segment was initiated by characterizing three plasminogen activator inhibitor type 2 (PAI-2) clones [290, 180, and 60 kilobases (kb)] isolated from a YAC library. Comparison of YAC and bacteriophage lambda genomic DNA clones confirmed the fidelity of the PAI-2 locus. Detailed rare cutting restriction maps were generated by ramped contour-clamped homogeneous electric field electrophoresis. The PAI-2 locus was located and oriented within the YACs, which span a distance 70 kb 5' to 220 kb 3' of PAI-2. Moreover, both left and right ends of the YAC genomic DNA inserts were rescued by amplifying circularized cloning sites with an inverted form of the polymerase chain reaction. These unique terminal genomic DNA fragments were used to rescreen the YAC library and isolate overlapping clones that extend the map. These approaches will enable neighboring loci to be definitively linked and establish the feasibility of using YAC technology to clone and map chromosomal segments.

The t(11;14)(p15;q11) in a T-cell acute lymphoblastic leukemia cell line activates multiple transcripts, including Ttg-1, a gene encoding a potential zinc finger protein.

Interchromosomal translocations within lymphoid neoplasms frequently involve the antigen receptor genes. We cloned the breakpoints of the t(11;14)(p15;q11) in a CD3-negative T-cell acute lymphoblastic leukemia cell line (RPMI 8402) in order to identify new genes potentially involved in T-cell neoplasia. An extensive comparison of both breakpoints and their germ line counterparts indicated that an inadvertant recombinase-mediated break at chromosome segment 11p15 recombined with the delta T-cell receptor at 14q11. The derivative 11 breakpoint resembles a coding joint in which 11p15 rather than a variable region was introduced 5' to a D delta 1 D delta 2 J delta 1 intermediate rearrangement. Conversely, the derivative 14 breakpoint corresponds to a signal joint between the 5' heptamer-spacer-nonamer recombinational signal of D delta 1 and an isolated heptamer at 11p15. Multiple, apparently distinct transcripts were found flanking both breakpoints of 8402. RNAs of 3.5, 4.4, 1.4, and 8.0 kilobases originating from either side of the derivative 14 breakpoint were highly expressed in 8402 compared with other cells. This suggests that this translocation deregulated multiple genes and provides the opportunity to assess any multifactorial contribution they may have to malignancy. We cloned and sequenced several cDNAs representing the 1.4-kilobase transcript (termed Ttg-1 [T-cell translocation gene 1]) from an 8402 library. The predicted protein of 156 amino acids contained two internal repeats which could potentially form zinc fingers.

Insulin-like growth factor gene expression during rat embryonic development.

The function of insulin-like growth factors I and II (IGF-I and IGF-II) in embryogenesis is unknown. To investigate the ontogeny of IGF gene expression during mammalian development we used a highly sensitive and specific solution-hybridization assay to determine the steady state levels of IGF mRNAs during midgestation in the rat. IGF-I mRNA can be detected as early as day 11 of embryonic development and rises 8.6-fold over the ensuing 48 h. By contrast IGF-II mRNA is relatively constant over days 11-14 of gestation. These observations suggest that both IGFs may play important roles in early fetal development.

Organization and sequence of the human insulin-like growth factor I gene. Alternative RNA processing produces two insulin-like growth factor I precursor peptides.

Insulin-like growth factor I (IGF-I), a 70-amino acid basic polypeptide, plays a fundamental role in postnatal mammalian growth as a major mediator through which growth hormone exerts its biological effects. We have recently identified two human IGF-I cDNAs which predict distinct peptide precursors of 153 and 195 amino acids. In the present study, both cDNAs were used to isolate and characterize the human IGF-I gene from genomic libraries. The IGF-I gene extends over at least 45 kilobase pairs and contains five exons interrupted by four introns. The DNA sequence of exons 1 through 4 encodes the 195-amino acid precursor, while exons 1, 2, 3, and 5 code for the 153-residue peptide, confirming the hypothesis that at least two IGF-I mRNAs are generated by alternative RNA processing of the primary gene transcript. The structure of the IGF-I gene resembles that of its companion somatomedin, IGF-II, as judged by the analogous location of two introns and considerable nucleotide and amino acid sequence similarity, but appears more distantly related to other members of the insulin gene family. Restriction endonuclease polymorphisms in the IGF-I gene, which map near exon 5 as determined by Southern blot analysis, will be useful in defining the genetics of familial growth failure.