37 results found
Hayes P, Fernandez N, Ochsenbauer C, et al., 2021, Breadth of CD8 T-cell mediated inhibition of replication of diverse HIV-1 transmitted-founder isolates correlates with the breadth of recognition within a comprehensive HIV-1 Gag, Nef, Env and Pol potential T-cell epitope (PTE) peptide set., PLoS One, Vol: 16, Pages: 1-24, ISSN: 1932-6203
Full characterisation of functional HIV-1-specific T-cell responses, including identification of recognised epitopes linked with functional antiviral responses, would aid development of effective vaccines but is hampered by HIV-1 sequence diversity. Typical approaches to identify T-cell epitopes utilising extensive peptide sets require subjects' cell numbers that exceed feasible sample volumes. To address this, CD8 T-cells were polyclonally expanded from PBMC from 13 anti-retroviral naïve subjects living with HIV using CD3/CD4 bi-specific antibody. Assessment of recognition of individual peptides within a set of 1408 HIV-1 Gag, Nef, Pol and Env potential T-cell epitope peptides was achieved by sequential IFNγ ELISpot assays using peptides pooled in 3-D matrices followed by confirmation with single peptides. A Renilla reniformis luciferase viral inhibition assay assessed CD8 T-cell-mediated inhibition of replication of a cross-clade panel of 10 HIV-1 isolates, including 9 transmitted-founder isolates. Polyclonal expansion from one frozen PBMC vial provided sufficient CD8 T-cells for both ELISpot steps in 12 of 13 subjects. A median of 33 peptides in 16 epitope regions were recognised including peptides located in previously characterised HIV-1 epitope-rich regions. There was no significant difference between ELISpot magnitudes for in vitro expanded CD8 T-cells and CD8 T-cells directly isolated from PBMCs. CD8 T-cells from all subjects inhibited a median of 7 HIV-1 isolates (range 4 to 10). The breadth of CD8 T-cell mediated HIV-1 inhibition was significantly positively correlated with CD8 T-cell breadth of peptide recognition. Polyclonal CD8 T-cell expansion allowed identification of HIV-1 isolates inhibited and peptides recognised within a large peptide set spanning the major HIV-1 proteins. This approach overcomes limitations associated with obtaining sufficient cell numbers to fully characterise HIV-1-specific CD8 T-cell responses by different functiona
Dalel J, Ung SK, Hayes P, et al., 2021, HIV-1 infection and the lack of viral control are associated with greater expression of interleukin-21 receptor on CD8(+) T cells, AIDS, Vol: 35, Pages: 1167-1177, ISSN: 0269-9370
Objectives: Interleukin-21 (IL-21) has been linked with the generation of virus-specific memory CD8+ T cells following acute infection with HIV-1 and reduced exhaustion of CD8+ T cells. IL-21 has also been implicated in the promotion of CD8+ T-cell effector functions during viral infection. Little is known about the expression of interleukin-21 receptor (IL-21R) during HIV-1 infection or its role in HIV-1-specific CD8+ T-cell maintenance and subsequent viral control.Methods: We compared levels of IL-21R expression on total and memory subsets of CD8+ T cells from HIV-1-negative and HIV-1-positive donors. We also measured IL-21R on antigen-specific CD8+ T cells in volunteers who were positive for HIV-1 and had cytomegalovirus-responding T cells. Finally, we quantified plasma IL-21 in treatment-naive HIV-1-positive individuals and compared this with IL-21R expression.Results: IL-21R expression was significantly higher on CD8+ T cells (P = 0.0256), and on central memory (P = 0.0055) and effector memory (P = 0.0487) CD8+ T-cell subsets from HIV-1-positive individuals relative to HIV-1-negative individuals. For those infected with HIV-1, the levels of IL-21R expression on HIV-1-specific CD8+ T cells correlated significantly with visit viral load (r = 0.6667, P = 0.0152, n = 13) and inversely correlated with plasma IL-21 (r = −0.6273, P = 0.0440, n = 11). Lastly, CD8+ T cells from individuals with lower set point viral load who demonstrated better viral control had the lowest levels of IL-21R expression and highest levels of plasma IL-21.Conclusion: Our data demonstrates significant associations between IL-21R expression on peripheral CD8+ T cells and viral load, as well as disease trajectory. This suggests that the IL-21 receptor could be a novel marker of CD8+ T-cell dysfunction during HIV-1 infection.
Makinde J, Nduati EW, Freni-Sterrantino A, et al., 2021, A novel sample selection approach to aid the identification of factors that correlate wth the control of HIV-1 infection, Frontiers in Immunology, Vol: 12, Pages: 1-12, ISSN: 1664-3224
Individuals infected with HIV display varying rates of viral control and disease progression, with a small percentage of individuals being able to spontaneously control infection in the absence of treatment. In attempting to define the correlates associated with natural protection against HIV, extreme heterogeneity in the datasets generated from systems methodologies can be further complicated by the inherent variability encountered at the population, individual, cellular and molecular levels. Furthermore, such studies have been limited by the paucity of well-characterised samples and linked epidemiological data, including duration of infection and clinical outcomes. To address this, we selected 10 volunteers who rapidly and persistently controlled HIV, and 10 volunteers each, from two control groups who failed to control (based on set point viral loads) from an acute and early HIV prospective cohort from East and Southern Africa. A propensity score matching approach was applied to control for the influence of five factors (age, risk group, virus subtype, gender, and country) known to influence disease progression on causal observations. Fifty-two plasma proteins were assessed at two timepoints in the 1st year of infection. We independently confirmed factors known to influence disease progression such as the B*57 HLA Class I allele, and infecting virus Subtype. We demonstrated associations between circulating levels of MIP-1α and IL-17C, and the ability to control infection. IL-17C has not been described previously within the context of HIV control, making it an interesting target for future studies to understand HIV infection and transmission. An in-depth systems analysis is now underway to fully characterise host, viral and immunological factors contributing to control.
Makinde J, Fernandez N, Hayes P, et al., 2021, Spontaneous in vivo control of HIV replication is underpinned by the cross-clade antiviral potency of HIV-specific CD8 T cells, Publisher: JOHN WILEY & SONS LTD
Boelen L, Debebe B, Silveira M, et al., 2018, Inhibitory killer-cell immunoglobulin-like receptors strengthen CD8+ T cell-mediated control of HIV-1, HCV and HTLV-1, Science Immunology, Vol: 3, Pages: 1-16, ISSN: 2470-9468
Killer cell immunoglobulin-like receptors (KIRs) are expressed predominantly on natural killer cells, where they play a key role in the regulation of innate immune responses. Recent studies show that inhibitory KIRs can also affect adaptive T cell–mediated immunity. In mice and in human T cells in vitro, inhibitory KIR ligation enhanced CD8+ T cell survival. To investigate the clinical relevance of these observations, we conducted an extensive immunogenetic analysis of multiple independent cohorts of HIV-1–, hepatitis C virus (HCV)–, and human T cell leukemia virus type 1 (HTLV-1)–infected individuals in conjunction with in vitro assays of T cell survival, analysis of ex vivo KIR expression, and mathematical modeling of host-virus dynamics. Our data suggest that functional engagement of inhibitory KIRs enhances the CD8+ T cell response against HIV-1, HCV, and HTLV-1 and is a significant determinant of clinical outcome in all three viral infections.
Makinde J, Hayes P, Black SL, et al., 2018, A Rapid Protocol for Enriching Peptide-specific CD8 T Cell Lines to Determine Their Contribution to Viral Inhibition, HIV Research for Prevention Meeting (HIVR4P) - AIDS Vaccine, Microbicide and ARV-Based Prevention Science, Publisher: MARY ANN LIEBERT, INC, Pages: 246-246, ISSN: 0889-2229
Fernandez N, Makinde J, Black SL, et al., 2018, The Generation and Validation of Autologous CD8 and CD4 T Cell Lines for Use as Assay Controls in HIV Viral Inhibition Assays, HIV Research for Prevention Meeting (HIVR4P) - AIDS Vaccine, Microbicide and ARV-Based Prevention Science, Publisher: MARY ANN LIEBERT, INC, Pages: 247-247, ISSN: 0889-2229
Makinde J, Nduati EW, Kibirige C, et al., 2018, Classification of HIV Controllers in an Acute Infection Cohort to Enable Systems Investigation of Signatures Associated With Control of Infection, HIV Research for Prevention Meeting (HIVR4P) - AIDS Vaccine, Microbicide and ARV-Based Prevention Science, Publisher: MARY ANN LIEBERT, INC, Pages: 377-377, ISSN: 0889-2229
Kvirkvelia N, Chikadze N, Makinde J, et al., 2018, Investigation of factors influencing the immunogenicity of hCG as a potential cancer vaccine, CLINICAL AND EXPERIMENTAL IMMUNOLOGY, Vol: 193, Pages: 73-83, ISSN: 0009-9104
Miles JJ, Tan MP, Dolton G, et al., 2018, Peptide mimic for influenza vaccination using nonnatural combinatorial chemistry, JOURNAL OF CLINICAL INVESTIGATION, Vol: 128, Pages: 1569-1580, ISSN: 0021-9738
Polypeptide vaccines effectively activate human T cells but suffer from poor biological stability, which confines both transport logistics and in vivo therapeutic activity. Synthetic biology has the potential to address these limitations through the generation of highly stable antigenic “mimics” using subunits that do not exist in the natural world. We developed a platform based on D–amino acid combinatorial chemistry and used this platform to reverse engineer a fully artificial CD8+ T cell agonist that mirrored the immunogenicity profile of a native epitope blueprint from influenza virus. This nonnatural peptide was highly stable in human serum and gastric acid, reflecting an intrinsic resistance to physical and enzymatic degradation. In vitro, the synthetic agonist stimulated and expanded an archetypal repertoire of polyfunctional human influenza virus–specific CD8+ T cells. In vivo, specific responses were elicited in naive humanized mice by subcutaneous vaccination, conferring protection from subsequent lethal influenza challenge. Moreover, the synthetic agonist was immunogenic after oral administration. This proof-of-concept study highlights the power of synthetic biology to expand the horizons of vaccine design and therapeutic delivery.
Makinde J, Jones C, Bartolf A, et al., 2018, Localized cyclical variations in immunoproteins in the female genital tract and the implications on the design and assessment of mucosal infection and therapies, AMERICAN JOURNAL OF REPRODUCTIVE IMMUNOLOGY, Vol: 79, ISSN: 1046-7408
ProblemFluctuating hormones regulate reproductive processes in the female genital tract. Consequent changes in the local immunological environment are likely to affect cellular interaction with infectious agents and the assessment of therapies that target mucosal infections.Method of studyWe compared Softcup and Weck‐Cel sampling protocols and assessed the changes in the concentrations of 39 soluble proteins with menstrual cycle progression in the mucosal and peripheral compartments.ResultsWe demonstrate that the mucosal immunological profile is distinct from serum with inflammatory and migratory signatures that are localized throughout the cycle. The analytes highlighted in the mucosal compartment were generally highest at the follicular phase with a tendency to fall as the cycle progressed through ovulation to the luteal phase.ConclusionOur results underscore the need to consider these localized cyclical differences in studies aimed at assessing the outcome of disease and the efficacy of mucosal vaccines and other therapies.
Wooldridge L, Morgan D, Pearson JA, et al., 2017, Autoreactive CD8(+) T-cells are highly dependent on CD8 for activation and as such targeting CD8 is an effective way of blocking autoreactive CD8(+) T-cell activation, Annual Meeting of the American-Association-of-Immunologists (AAI), Publisher: AMER ASSOC IMMUNOLOGISTS, ISSN: 0022-1767
Cole DK, van den Berg HA, Lloyd A, et al., 2016, Structural Mechanism Underpinning Cross-reactivity of a CD8(+) T-cell Clone That Recognizes a Peptide Derived from Human Telomerase Reverse Transcriptase, Journal of Biological Chemistry, Vol: 292, Pages: 802-813, ISSN: 0021-9258
T-cell cross-reactivity is essential for effective immune surveillance but has also been implicated as a pathway to autoimmunity. Previous studies have demonstrated that T-cell receptors (TCRs) that focus on a minimal motif within the peptide are able to facilitate a high level of T-cell cross-reactivity. However, the structural database shows that most TCRs exhibit less focused antigen binding involving contact with more peptide residues. To further explore the structural features that allow the clonally expressed TCR to functionally engage with multiple peptide-major histocompatibility complexes (pMHCs), we examined the ILA1 CD8+ T-cell clone that responds to a peptide sequence derived from human telomerase reverse transcriptase. The ILA1 TCR contacted its pMHC with a broad peptide binding footprint encompassing spatially distant peptide residues. Despite the lack of focused TCR-peptide binding, the ILA1 T-cell clone was still cross-reactive. Overall, the TCR-peptide contacts apparent in the structure correlated well with the level of degeneracy at different peptide positions. Thus, the ILA1 TCR was less tolerant of changes at peptide residues that were at, or adjacent to, key contact sites. This study provides new insights into the molecular mechanisms that control T-cell cross-reactivity with important implications for pathogen surveillance, autoimmunity, and transplant rejection.
Makinde J, 2016, Eradicating polio amidst insurgency in Nigeria, Eradicating polio amidst insurgency in Nigeria
Speed read:Nigeria is now striving for polio eradication following four new cases.The new cases have led to unconventional strategies for vaccine coverage.But dealing decisively with Boko Haram insurgency could help achieve eradication.
Clement M, Pearson JA, Gras S, et al., 2016, Targeted suppression of autoreactive CD8(+) T-cell activation using blocking anti-CD8 antibodies, Scientific Reports, Vol: 6, ISSN: 2045-2322
CD8+ T-cells play a role in the pathogenesis of autoimmune diseases such as multiple sclerosis and type 1 diabetes. However, drugs that target the entire CD8+ T-cell population are not desirable because the associated lack of specificity can lead to unwanted consequences, most notably an enhanced susceptibility to infection. Here, we show that autoreactive CD8+ T-cells are highly dependent on CD8 for ligand-induced activation via the T-cell receptor (TCR). In contrast, pathogen-specific CD8+ T-cells are relatively CD8-independent. These generic differences relate to an intrinsic dichotomy that segregates self-derived and exogenous antigen-specific TCRs according to the monomeric interaction affinity with cognate peptide-major histocompatibility complex class I (pMHCI). As a consequence, “blocking” anti-CD8 antibodies can suppress autoreactive CD8+ T-cell activation in a relatively selective manner. These findings provide a rational basis for the development and in vivo assessment of novel therapeutic strategies that preferentially target disease-relevant autoimmune responses within the CD8+ T-cell compartment.
Ekeruche-Makinde J, Herrera C, Evans A, et al., 2016, Targeting Cellular Drug Transporters to Boost Antiretroviral Drug Activity at Mucosal Sites, Conference on HIV Research for Prevention (HIV R4P), Publisher: MARY ANN LIEBERT, INC, Pages: 221-221, ISSN: 0889-2229
Szomolay B, Liu J, Brown PE, et al., 2016, Identification of human viral protein-derived ligands recognized by individual MHCI-restricted T-cell receptors, IMMUNOLOGY AND CELL BIOLOGY, Vol: 94, Pages: 573-582, ISSN: 0818-9641
McDonald JU, Ekeruche-Makinde J, Ho MM, et al., 2016, Development of a custom pentaplex sandwich immunoassay using Protein-G coupled beads for the Luminex® xMAP® platform., Journal of Immunological Methods, Vol: 433, Pages: 6-16, ISSN: 1872-7905
Multiplex bead-based assays have many advantages over ELISA, particularly for the analyses of large quantities of samples and/or precious samples of limited volume. Although many commercial arrays covering multitudes of biologically significant analytes are available, occasionally the development of custom arrays is necessary. Here, the development of a custom pentaplex sandwich immunoassay using Protein G-coupled beads, for analysis using the Luminex® xMAP® platform, is described. This array was required for the measurement of candidate biomarkers of vaccine safety in small volumes of mouse sera. Optimisation of this assay required a stepwise approach: testing cross-reactivity of the antibody pairs, the development of an in-house serum diluent buffer as well as heat-inactivation of serum samples to prevent interference from matrix effects. We then demonstrate the use of this array to analyse inflammatory mediators in mouse serum after immunisation. The work described here exemplifies how Protein G-coupled beads offer a flexible and robust approach to develop custom multiplex immunoassays, which can be applied to a range of analytes from multiple species.
Mukhopadhya I, Murray GI, Berry S, et al., 2016, Drug transporter gene expression in human colorectal tissue and cell lines: modulation with antiretrovirals for microbicide optimization, JOURNAL OF ANTIMICROBIAL CHEMOTHERAPY, Vol: 71, Pages: 372-386, ISSN: 0305-7453
Singanayagam A, Lamb L, Makinde JE, et al., 2015, Systemic cytokine storm in severe eosinophilic dermatitis, QJM-AN INTERNATIONAL JOURNAL OF MEDICINE, Vol: 108, Pages: 907-908, ISSN: 1460-2725
Hijazi K, Cuppone AM, Smith K, et al., 2015, Expression of Genes for Drug Transporters in the Human Female Genital Tract and Modulatory Effect of Antiretroviral Drugs, PLOS ONE, Vol: 10, ISSN: 1932-6203
Reynolds C, Goudet A, Jenjaroen K, et al., 2015, T cell immunity to the Alkyl Hydroperoxide Reductase of Burkholderia pseudomallei: A correlate of disease outcome in Acute Melioidosis., Journal of Immunology, Vol: 194, Pages: 4814-4824, ISSN: 0022-1767
There is an urgent need for a better understanding of adaptive immunity to Burkholderia pseudomallei, the causative agent of melioidosis that is frequently associated with sepsis or death in patients in Southeast Asia and Northern Australia. The imperative to identify vaccine targets is driven both by the public health agenda in these regions and biological threat concerns. In several intracellular bacterial pathogens, alkyl hydroperoxidase reductases are upregulated as part of the response to host oxidative stress, and they can stimulate strong adaptive immunity. We show that alkyl hydroperoxidase reductase (AhpC) of B. pseudomallei is strongly immunogenic for T cells of 'humanized' HLA transgenic mice and seropositive human donors. Some T cell epitopes, such as p6, are able to bind diverse HLA class II heterodimers and stimulate strong T cell immunity in mice and humans. Importantly, patients with acute melioidosis who survive infection show stronger T cell responses to AhpC relative to those who do not. Although the sequence of AhpC is virtually invariant among global B. pseudomallei clinical isolates, a Cambodian isolate varies only in C-terminal truncation of the p6 T cell epitope, raising the possibility of selection by host immunity. This variant peptide is virtually unable to stimulate T cell immunity. For an infection in which there has been debate about centrality of T cell immunity in defense, these observations support a role for T cell immunity to AhpC in disease protection.
Miles J, van den Berg H, Ekeruche-Makinde J, et al., 2013, The length of the peptide in the MHC groove compartmentalizes the CD8+T cell repertoire, 100th Annual Meeting of the American-Association-of-Immunologists, Publisher: AMER ASSOC IMMUNOLOGISTS, ISSN: 0022-1767
Ekeruche-Makinde J, Miles JJ, van den Berg HA, et al., 2013, Peptide length determines the outcome of TCR/peptide-MHCI engagement, BLOOD, Vol: 121, Pages: 1112-1123, ISSN: 0006-4971
Ekeruche-Makinde J, Clement M, Cole DK, et al., 2012, T-cell Receptor-optimized Peptide Skewing of the T-cell Repertoire Can Enhance Antigen Targeting, JOURNAL OF BIOLOGICAL CHEMISTRY, Vol: 287, Pages: 37269-37281
Wooldridge L, Ekeruche-Makinde J, Skowera A, et al., 2012, A single autoimmune T cell receptor recognizes more than a million different peptides, European Congress of Immunology, Publisher: WILEY-BLACKWELL, Pages: 101-101, ISSN: 0019-2805
Wooldridge L, Ekeruche-Makinde J, van den Berg HA, et al., 2012, A Single Autoimmune T Cell Receptor Recognizes More Than a Million Different Peptides, JOURNAL OF BIOLOGICAL CHEMISTRY, Vol: 287, Pages: 1168-1177
Cole DK, Bulek A, Rizkallah P, et al., 2011, Structural and biophysical binding parameters that govern T-cell antigen discrimination, Annual Congress of the British-Society-for-Immunology, Publisher: WILEY-BLACKWELL, Pages: 53-53, ISSN: 0019-2805
Pentier J, Dolton G, Ekeruche J, et al., 2011, Making tumour-associated antigens more immunogenic; lessons from positional scanning synthetic combinatorial libraries, Annual Congress of the British-Society-for-Immunology, Publisher: WILEY-BLACKWELL, Pages: 59-59, ISSN: 0019-2805
Clement M, Ladell K, Ekeruche-Makinde J, et al., 2011, Anti-CD8 Antibodies Can Trigger CD8(+) T Cell Effector Function in the Absence of TCR Engagement and Improve Peptide-MHCI Tetramer Staining, JOURNAL OF IMMUNOLOGY, Vol: 187, Pages: 654-663, ISSN: 0022-1767
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