The combined molecular adjuvant CASAC enhances the CD8+ T cell response to a tumor-associated self-antigen in aged, immunosenescent mice.

BACKGROUND: Ineffective induction of T cell mediated immunity in older individuals remains a persistent challenge for vaccine development. Thus, there is a need for more efficient and sophisticated adjuvants that will complement novel vaccine strategies for the elderly. To this end, we have investigated a previously optimized, combined molecular adjuvant, CASAC (Combined Adjuvant for Synergistic Activation of Cellular immunity), incorporating two complementary Toll-like receptor agonists, CpG and polyI:C, a class-II epitope, and interferon (IFN)-γ in aged mice. FINDINGS: In aged mice with typical features of immunosenescence, antigen specific CD8+ T cell responses were stimulated after serial vaccinations with CASAC or Complete/Incomplete Freund's Adjuvant (CFA/IFA) and a class I epitope, deriving either from ovalbumin (SIINFEKL, SIL) or the melanoma-associated self-antigen, tyrosinase-related protein-2 (SVYDFFVWL, SVL). Pentamer analysis revealed that aged, CASAC/SIL-vaccinated animals had substantially higher frequencies of H-2K(b)/SIL-specific CD8+ T cells compared to the CFA/IFA-vaccinated groups. Similarly, higher frequencies of H-2K(b)/SVL-pentamer+ and IFN-γ+ CD8+ T cells were detected in the aged, CASAC + SVL-vaccinated mice than in their CFA/IFA-vaccinated counterparts. In both antigen settings, CASAC promoted significantly better functional CD8+ T cell activity. CONCLUSION: These studies demonstrate that functional CD8+ T cells, specific for both foreign and tumour-associated self-antigens, can be effectively induced in aged immunosenescent mice using the novel multi-factorial adjuvant CASAC.

Impact of changes to invite methodology on equality of access to the National Breast Screening Programme in the South of England.

In response to the COVID-19 pandemic, a temporary change in policy was implemented in 2020. Breast screening services in England were advised to change from timed appointments to an open invitation for invitees to contact the service and arrange an appointment. This change to invitation methodology had potential benefits and risks including impacting inequalities in uptake. Qualitative data were collected by online questionnaire from 23 service providers and routinely collected quantitative uptake data were analysed to investigate the impact of open invitations on the National Programme in the South of England. Office for National Statistics and general practitioner (GP) practice profile data enabled the modelling of sociodemographic characteristics of breast screening invitees at each GP practice. Most services changed to open invitations (17/23), 82% of which altered administrative capacity and/or procedures to accommodate this change. Logistic benefits were reported including a more consistent flow of participants, fewer long gaps and fewer wasted slots. The change to open invitations was associated with a 7.2% reduction in the percentage of participants screened, accounting for participant sociodemographics and historical screening provider uptake. The inequality in screening uptake experienced by participants of minority ethnic background was exacerbated by the change to open invitations. Open invitations, whilst affording logistic benefits in an unprecedented pandemic era, were associated with reduced overall uptake and exacerbation of existing health inequality experienced by women of minority ethnic background. The broader impact on services highlighted the need for sustainability of measures taken to accommodate such operational changes.

Trends in coagulase-negative staphylococci (CoNS), England, 2010-2021.

Objective: To review the epidemiology of coagulase-negative staphylococci (CoNS) in England over the recent 12 year period. Methods: Laboratory-confirmed CoNS reported from sterile sites in patients in England to the UK Health Security Agency (UKHSA) between 2010 and 2021 were extracted from the national laboratory database and analysed. Results: Overall, 668 857 episodes of CoNS were reported. Unspeciated CoNS accounted for 56 % (374 228) of episodes, followed by Staphylococcus epidermidis (26 %; 174 050), S. hominis (6.5 %; 43 501) and S. capitis (3.9 %; 25 773). Unspeciated CoNS increased by 8.2 % (95 % CI, 7.1-9.3) annually between 2010 and 2016, then decreased annually by 6.4 % (95 % CI: -4.8 to -7.9) until 2021. Speciated CoNS increased by 47.6 % (95 % CI, 44.5-50.9) annually between 2010 and 2016 and increased annually by 8.9 % (95 % CI: 5.1 to 12.8) until 2021. Antimicrobial susceptibility profiles differed by species. Conclusions: Reports of CoNS from normally sterile body sites in patients in England increased between 2010 and 2016 and remained stable between 2017 and 2021. There has been a striking improvement in species-level identification of CoNS in recent years. Monitoring trends in CoNS epidemiology is crucial for development of observational and clinical intervention studies on individual species.

CCR5 antagonism impacts vaccination response and immune profile in HIV-1 infection.

Maraviroc (MVC) is the first licensed antiretroviral therapeutic agent to target a host cell surface molecule, and successful HIV-1 entry blockade by this C-C chemokine receptor type 5 (CCR5)-antagonist potentiates immunomodulation. We hypothesized that MVC intensification impacts immunization responses, T-cell phenotype, function and delayed type hypersensitivity (DTH) in HIV-1(+) subjects. A 24-wk, double-blinded, placebo-controlled study of the addition of MVC to suppressive antiretroviral therapy in HIV-1(+) persons was performed. Subjects received DTH tests, intramuscular tetanus, meningococcal and oral cholera immunizations. Antibody titers, T-cell function and phenotype were assessed. Of 157 patients referred, 47 were randomized 1:1; MVC:placebo. MVC enhanced meningococcal neo-immunization, blunted cholera response and expedited lymphoproliferation to tetanus boost, without affecting recall humoral response. Anti-HIV-1 group-specific antigen (Gag) and tetanus toxoid (TTox) function improved significantly, HIV-1-associated CD8 T-cell skewing normalized, and the percentage of late-stage and major histocompatibility complex (MHC) class II expressing CD4 T-cells increased. Activated CD4(+) CD38(+) human leukocyte antigen (HLA)-DR(+) T-cells declined, and costimulation shifted to coinhibition. DTH was unchanged. Maraviroc intensification, through antagonism of the cell surface molecule CCR5, favorably influences immune profiles of HIV-1(+) patients, supporting its immunomodulatory use in HIV-1 infection and potentially in other immunologically relevant settings.

Real-world data on immune responses following heterologous prime-boost COVID-19 vaccination schedule with Pfizer and AstraZeneca vaccines in England.

BACKGROUND: There are limited data on immune responses to heterologous COVID-19 immunisation schedules, especially following an extended ≥12-week interval between doses. METHODS: SARS-CoV-2 infection-naïve and previously-infected adults receiving ChAd-BNT (ChAdOx1 nCoV-19, AstraZeneca followed by BNT162b2, Pfizer-BioNTech) or BNT-ChAd as part of the UK national immunisation programme provided blood samples at 30 days and 12 weeks after their second dose. Geometric mean concentrations (GMC) of anti-SARS-CoV-2 spike (S-antibody) and nucleoprotein (N-antibody) IgG antibodies and geometric mean ratios (GMR) were compared with a contemporaneous cohort receiving homologous ChAd-ChAd or BNT-BNT. RESULTS: During March-October 2021, 75,827 individuals were identified as having received heterologous vaccination, 9,489 invited to participate, 1,836 responded (19.3%) and 656 were eligible. In previously-uninfected adults, S-antibody GMC at 30 days post-second dose were lowest for ChAd-ChAd (862 [95% CI, 694 - 1069]) and significantly higher for ChAd-BNT (6233 [5522-7035]; GMR 6.29; [5.04-7.85]; p<0.001), BNT-ChAd (4776 [4066-5610]; GMR 4.55 [3.56-5.81]; p<0.001) and BNT-BNT (5377 [4596-6289]; GMR 5.66 [4.49-7.15]; p<0.001). By 12 weeks after dose two, S-antibody GMC had declined in all groups and remained significantly lower for ChAd-ChAd compared to ChAd-BNT (GMR 5.12 [3.79-6.92]; p<0.001), BNT-ChAd (GMR 4.1 [2.96-5.69]; p<0.001) and BNT-BNT (GMR 6.06 [4.32-8.50]; p<0.001). Previously infected adults had higher S-antibody GMC compared to infection-naïve adults at all time-points and with all vaccine schedules. CONCLUSIONS: These real-world findings demonstrate heterologous schedules with adenoviral-vector and mRNA vaccines are highly immunogenic and may be recommended after a serious adverse reaction to one vaccine product, or to increase programmatic flexibility where vaccine supplies are constrained.

Novel approach to recognition of predicted HIV-1 Gag B3501-restricted CD8 T-cell epitopes by HLA-B3501(+) patients: confirmation by quantitative ELISpot analyses and characterisation using multimers.

Exploring the intricacies of CD8(+) T-cell epitope recognition using emerging technologies to combine assessment of affinity, phenotype and resulting polyfunctional efficacy advances our understanding of HIV-1 immunopathogenesis and disease progression. Complexities within T-cell antigen recognition, such as epitope:MHC binding, stability and affinity, appear to influence the distinction between protective and ineffective anti-HIV-1 immune responses, which are thought to govern rate of disease progression. This study utilises the novel ProImmune REVEAL and ProVE(R) technology of rapid peptide synthesis, binding and affinity assays, and pentamer synthesis in conjunction with flow cytometry and simultaneous assessment of multiple CD8(+) T-cell effector functions in response to HLA-B3501-restricted HIV-1 Gag peptides, to discover new T-cell epitopes. The predicted HLA-B3501-restricted peptides, HPVHAGPIA and YPLTSLRSL, and relevant pentamers were used in parallel to validate T-cell epitopes on clinical HIV-1(+) samples, confirming correlation between the expected superior immunogenicity of newly discovered epitopes and the ex vivo T-cell response. Such a platform should be employed in prophylactic and therapeutic vaccine settings.

Effects of recombinant human growth hormone on HIV-1-specific T-cell responses, thymic output and proviral DNA in patients on HAART: 48-week follow-up.

BACKGROUND: Efficacious immune-based therapy in treated chronic HIV-1 infection requires the induction of virus-specific CD4+ T cells and subsequent maturation and maintenance of specific memory CD8+ T cells. Concomitant daily administration of recombinant human growth hormone (rhGH) with highly active antiretroviral therapy (HAART) was used in chronically infected patients with lipodystrophy in an attempt to reconstitute these virus-specific T-cell responses. METHODS: Individuals with chronic HIV-1 infection on HAART were enrolled on a randomized, double-blinded, placebo-controlled study to receive rhGH therapy. We assessed HIV-1-specific proliferative CD4+ and interferon-gamma (IFN-gamma)-producing CD8+ T-cell responses, quantified thymic output and proviral HIV-1 DNA at the following time points: baseline; after 12 weeks of rhGH therapy; at 24 weeks, after randomization into three groups [placebo weeks 12-24 (Group A), alternate-day dosing weeks 12-24 (Group B), and twice-per-week dosing weeks 12-24 (Group C)]; and at 48 weeks after all patients had received HAART alone for the final 24 weeks. RESULTS: We found significant increases in both proliferative CD4+ and IFN-gamma-producing CD8+ HIV-1-specific T-cell responses after daily administration of rhGH. This increase was focused on HIV-1 Gag-specific T-cell responses. Following subsequent randomisation into different dosing regimens, HIV-1-specific proliferative CD4+ T-cell responses declined in patients receiving less frequent dosing of rhGH, while virus-specific IFN-gamma-producing CD8+ T-cell responses were maintained for longer periods of time. There was no significant change in thymic output and the cell-associated HIV-1 DNA remained stable in most patients. An increased anti-HIV-1 Nef-specific CD4+ T-cell proliferative response was correlated to a decrease in proviral load, and an increased HIV-1 Gag-specific IFN-gamma-producing CD8+ T-cell response correlated with an increase in proviral load. CONCLUSION: The implication of these data is that daily dosing of rhGH with HAART, in addition to improving HIV-1-associated lipodystrophy, may reverse some of the T-lymphocyte dysfunction seen in most treated HIV-1-positive patients, in a dose-dependent manner. Such immune-based therapeutic strategies used in treated, chronic HIV-1 infection may enable the induction of virus-specific CD4+ T cells essential for the subsequent 'kick-start' and expansion of virus-specific CD8+ T cells. TRIAL REGISTRATION: GH in Lipoatrophy IMP22350.

Enrichment of HLA Types and Single-Nucleotide Polymorphism Associated With Non-progression in a Strictly Defined Cohort of HIV-1 Controllers.

HIV-1 controllers (HIC) are extremely rare patients with the ability to control viral replication, maintain unchanging CD4 T-cell count, and evade disease progression for extensive periods of time, in the absence of antiretroviral therapy. In order to establish the representation of key genetic correlates of atypical disease progression within a cohort of HIV-1+ individuals who control viral replication, we examine four-digit resolution HLA type and single-nucleotide polymorphisms (SNP) previously identified to be correlated to non-progressive infection, in strictly defined HIC. Clinical histories were examined to identify patients exhibiting HIC status. Genomic DNA was extracted, and high definition HLA typing and genome-wide SNP analysis was performed. Data were compared with frequencies of SNP in European long-term non-progressors (LTNP) and primary infection cohorts. HLA-B alleles associated with atypical disease progression were at very high frequencies in the group of five HIC studied. All four HIC of European ancestry were HLA-B*57+ and half were also HLA-B*27+. All HIC, including one of self-reported African ethnicity, had the HLA-Cw*0602 allele, and the HLA-DQ9 allele was present only in HIC of European ancestry. A median 95% of the top 19 SNP known to be associated with LTNP status was observed in European HIC (range 78-100%); 17/19 of the SNP considered mapped to chromosome 6 in the HLA region, whereas 2/19 mapped to chromosome 8. The HIC investigated here demonstrated high enrichment of HLA types and SNP previously associated with long-term non-progression. These findings suggest that the extreme non-progressive phenotype considered here is associated with a genetic signature characterized by a single-genetic unit centered around the HLA-B*57 haplotype and the possible additive effect of HLA-B*27.

Long-Term Non-Progression and Broad HIV-1-Specific Proliferative T-Cell Responses.

Complex mechanisms underlying the maintenance of fully functional, proliferative, HIV-1-specific T-cell responses involve processes from early T-cell development through to the final stages of T-cell differentiation and antigen recognition. Virus-specific proliferative CD4 and CD8 T-cell responses, important for the control of infection, are observed in some HIV-1(+) patients during early stages of disease, and are maintained in long-term non-progressing subjects. In the vast majority of HIV-1(+) patients, full immune functionality is lost when proliferative HIV-1-specific T-cell responses undergo a variable progressive decline throughout the course of chronic infection. This appears irreparable despite administration of potent combination antiretroviral therapy, which to date is non-curative, necessitating life-long administration and the development of effective, novel, therapeutic interventions. While a sterilizing cure, involving clearance of virus from the host, remains a primary aim, a "functional cure" may be a more feasible goal with considerable impact on worldwide HIV-1 infection. Such an approach would enable long-term co-existence of host and virus in the absence of toxic and costly drugs. Effective immune homeostasis coupled with a balanced response appropriately targeting conserved viral antigens, in a manner that avoids hyperactivation and exhaustion, may prove to be the strongest correlate of durable viral control. This review describes novel concepts underlying full immune functionality in the context of HIV-1 infection, which may be utilized in future strategies designed to improve upon existing therapy. The aim will be to induce long-term non-progressor or elite controller status in every infected host, through immune-mediated control of viremia and reduction of viral reservoirs, leading to lower HIV-1 transmission rates.

Are long-term non-progressors very slow progressors? Insights from the Chelsea and Westminster HIV cohort, 1988-2010.

Define and identify long-term non-progressors (LTNP) and HIV controllers (HIC), and estimate time until disease progression. LTNP are HIV-1(+) patients who maintain stable CD4(+) T-cell counts, with no history of opportunistic infection or antiretroviral therapy (ART). HIC are a subset of LTNP who additionally have undetectable viraemia. These individuals may provide insights for prophylactic and therapeutic development. Records of HIV-1(+) individuals attending Chelsea and Westminster Hospital (1988-2010), were analysed. LTNP were defined as: HIV-1(+) for >7 years; ART-naïve; no history of opportunistic infection and normal, stable CD4(+) T-cell counts. MIXED procedure in SAS using random intercept model identified long-term stable CD4(+) T-cell counts. Survival analysis estimated time since diagnosis until disease progression. Subjects exhibiting long-term stable CD4(+) T-cell counts with history below the normal range (<450 cells/µl blood) were compared to LTNP whose CD4(+) T-cell count always remained normal. Within these two groups subjects with HIV-1 RNA load below limit of detection (BLD) were identified. Of 14,227 patients, 1,204 were diagnosed HIV-1(+) over 7 years ago and were ART-naïve. Estimated time until disease progression for the 20% (239) whose CD4(+) T-cell counts remained within the normal range, was 6.2 years (IQR: 2.0 to 9.6); significantly longer than 4.0 years (IQR: 1.0 to 7.3) for patients with historical CD4(+) T-cell count below normal (Logrank chi-squared = 21.26; p<0.001). Within a subpopulation of 312 asymptomatic patients, 50 exhibited long-term stable CD4(+) T-cell counts. Of these, 13 were LTNP, one of whom met HIC criteria. Of the remaining 37 patients with long-term stable low CD4(+) T-cell counts, 3 controlled HIV-1 RNA load BLD. Individuals with stable, normal CD4(+) T-cell counts progressed less rapidly than those with low CD4(+) T-cell counts. Few LTNP and HIC identified in this and other studies, endorse the need for universal definitions to facilitate comparison.

Transient nature of long-term nonprogression and broad virus-specific proliferative T-cell responses with sustained thymic output in HIV-1 controllers.

BACKGROUND: HIV-1(+) individuals who, without therapy, conserve cellular anti-HIV-1 responses, present with high, stable CD4(+) T-cell numbers, and control viral replication, facilitate analysis of atypical viro-immunopathology. In the absence of universal definition, immune function in such HIV controllers remains an indication of non-progression. METHODOLOGY/PRINCIPAL FINDINGS: CD4 T-cell responses to a number of HIV-1 proteins and peptide pools were assessed by IFN-gamma ELISpot and lymphoproliferative assays in HIV controllers and chronic progressors. Thymic output was assessed by sjTRECs levels. Follow-up of 41 HIV-1(+) individuals originally identified as "Long-term non-progressors" in 1996 according to clinical criteria, and longitudinal analysis of two HIV controllers over 22 years, was also performed. HIV controllers exhibited substantial IFN-gamma producing and proliferative HIV-1-specific CD4 T-cell responses to both recombinant proteins and peptide pools of Tat, Rev, Nef, Gag and Env, demonstrating functional processing and presentation. Conversely, HIV-specific T-cell responses were limited to IFN-gamma production in chronic progressors. Additionally, thymic output was approximately 19 fold higher in HIV controllers than in age-matched chronic progressors. Follow-up of 41 HIV-1(+) patients identified as LTNP in 1996 revealed the transitory characteristics of this status. IFN-gamma production and proliferative T-cell function also declines in 2 HIV controllers over 22 years. CONCLUSIONS: Although increased thymic output and anti-HIV-1 T-cell responses are observed in HIV controllers compared to chronic progressors, the nature of nonprogressor/controller status appears to be transitory.