Carter Center

A deeper understanding of how tissue-localized immune cells arise and function is critical for developing mucosal vaccines. Currently, there are no murine models that specifically target tissue T cells while leaving their lymphoid counterparts untouched. Here, we leverage the observation that during influenza infection, HIF-1α regulatory activity is higher in the lung compared with lymph node CD4+ T cells. Inducible deletion of Hif1a in CD4+ T cells, at the onset of its activity in the lung, reduces the tissue-resident T cell compartment with minimal impact on peripheral immunity. HIF-1α-active CD4+ T cells occupy the border of tertiary lymphoid structures, where they coordinate an interleukin 21 (IL-21)-dependent network of spatially colocalized immune cells including macrophages, natural killer (NK) cells, and immunoglobulin A-positive (IgA+) B cells. A similar HIF-1α-dependent network is engaged in a lung adenocarcinoma model, highlighting a broader role for HIF-1α+ CD4+ T cells in integrating protective immunity during infection and cancer.

Vaccines targeting melanoma antigens can elicit CD8+ T cell responses, but a growing body of work suggests CD4+ T cells also play a role in tumor control. Induction of CD4+ cells may also support B cells in producing tumor antigen-specific antibodies (Abs). We investigated Abs induced by vaccination with a cocktail of six class II MHC-restricted melanoma peptides (6MHP) and the effect of adjuvant type on Ab isotypes. We hypothesized that the vaccines would induce Abs that respond to different epitopes on individual peptides and that IgG isotype distribution varies with different vaccine adjuvants. Sera from patients who received a 6MHP vaccine were evaluated with enzyme-linked immunosorbent assays to map epitopes for polyclonal Ab responses to synthetic melanoma peptides. IgG isotypes of Ab responses to 6MHP were assessed in patients who received one of four adjuvants (Incomplete Freund's Adjuvant (IFA) alone, IFA + polyICLC, IFA + systemic metronomic cyclophosphamide (mCy), or IFA + polyICLC + systemic mCy) to characterize IgG isotype distribution. Epitope mapping revealed that at least 50% of patients had responses to two or more epitopes on the same peptide, suggesting polyclonal Ab responses. Serum evaluation for IgG isotypes showed predominant induction of IgG1 and IgG3. Mean total IgG was highest when IFA and polyICLC were used in combination. Patients who received TLR3 agonist polyICLC had significantly higher concentrations of total IgG, IgG1, and IgG3 compared to patients who did not receive polyICLC. Vaccine-induced Abs may respond to multiple epitopes within the same peptide, warranting further studies into their ability to facilitate antigen uptake and presentation through the formation of large immune complexes. The findings also show that adding polyICLC to IFA can significantly enhance Ab responses. Collectively, this work underscores the immunologic potential of peptide-induced Abs and the importance of adjuvant selection in cancer vaccine design.

This article presents a caregiver-centered framework that categorizes the experiences of caregivers to align unmet caregiver needs with relevant supports. The study applied a partner-engaged, qualitative, mixed-methods approach. Using findings from a qualitative evidence synthesis, facilitated data sorting, and caregiver focus groups, the team developed and refined a conceptual model comprised of four key components: phases, goals, stressors, and multilevel contextual factors. This model was simplified into a framework of ten categories of caregiving experiences that are widely applicable to the US caregiving context. This framework is a tool for healthcare and social service professionals to target caregiver supports.

Gene editing strategies that do not rely on viral vectors are being explored for their potential to support durable biologics production. While clinical trials have shown that adeno-associated virus encoding broadly neutralizing antibodies can protect against HIV, these interventions often yield limited, short-lived responses. The development of non-viral gene editing approaches in hematopoietic stem and progenitor cells holds promise for long-term antibody production. In this study, we evaluated CRISPR/Cas9 and CRISPR/Cas12a for gene knock-in at the immunoglobulin heavy chain locus in non-human primate (NHP) hematopoietic stem and progenitor cells (HSPCs). Delivering the nuclease as a protein alongside a custom DNA template, we optimized editing with Cas12a and demonstrated higher knock-in efficiency and fewer non-specific edits than Cas9. Transplantation of edited NHP HSPCs into MISTRG mice led to engraftment, B cell differentiation, and transgene expression of a reporter transgene or anti-HIV antibody after gp120 antigen immunization with detectable titers in circulation. These findings demonstrate the feasibility of using non-viral knock-in in HSPCs as a potential strategy for sustained biologics production in the treatment of chronic diseases. Future work will assess the efficacy of this approach in a NHP model of HIV infection.

There has been discussion regarding the definition of the clinical sign trachomatous trichiasis (TT) for the purposes of determining elimination of trachoma as a public health problem, and whether the definition should include the presence of trachomatous scarring (TS). A multi-country observational study was conducted in Ethiopia, Uganda and Nigeria to assess whether TS grading by field graders using the WHO simplified system in trachoma surveys are comparable with expert grading of tarsal conjunctival scarring (TCS) using a detailed system. The primary outcome was the proportion of eyes graded as "No TS" in the surveys but with TCS from expert photographic grading (the negative predictive value, NPV). In Ethiopia, Uganda and Nigeria, 545 (438 trichiasis cases and 107 comparisons), 256 (156 trichiasis cases and 100 comparisons), and 468 (352 trichiasis cases and 116 comparisons) participants, respectively, were enrolled. In Ethiopia, among 111 trichiatic eyes graded "No TS" in the surveys, 103 (92.8%) had TCS in expert photo grading, NPV 7.2% (95% CI 3.2%-13.7%). In Uganda, among 28 trichiatic eyes graded "No TS" in the surveys, 19 (67.9%) had TCS in expert photo grading, NPV 32.1% (95% CI 15.9%-52.4%). In Nigeria, among 111 trichiatic eyes graded "No TS" in the surveys, 100 (90.1%) had TCS in expert photo grading, NPV 9.9% (95% CI 5.0%-17.0%). Across settings, among eyes misdiagnosed as "No TS" in the survey, 174/250 (69.6%) had extensive TCS (patches of scarring occupying ≥1/3 of the upper tarsal conjunctiva). Trichiatic eyes with TCS had more severe entropion, trichiasis, conjunctival inflammation, and corneal opacity than those without TCS. In all three settings, including TS to define a trichiasis "trachomatous" in a survey could result in the underestimation of the burden of TT. However, TCS can be effectively used to determine TT severity and management.

SummaryBackgroundRoutine surveillance is a pillar of malaria programmes, and the primary source of data used for decision making. However, any inference when relying on routine data to inform decision making is limited by how effective the system is at measuring the actual malaria burden. Here, we aimed to extend the Freedom From Infection (FFI) framework to produce species-specific estimates of surveillance system sensitivity and probability of freedom from malaria, combine multiple surveillance components including community case management and active case detection, and apply the FFI model in five malaria eliminating settings.MethodsMonthly routine data on Plasmodium falciparum and Plasmodium vivax and health system factors were collected from 1515 facilities across five countries. Additionally, data from 12 community health workers and from 10 767 individuals from cross-sectional surveys (active case detection) were available. The data were analysed using FFI models accounting for multiple malaria species and surveillance components. The primary outcomes were the sensitivity of the surveillance system and the probability of malaria freedom.FindingsStrong surveillance systems were characterised by access to testing and treatment supplies, training on diagnostics and case management within the previous 12 months, and shorter estimated travel times to facilities. Only half of the facilities (841 of 1515 facilities for P falciparum and 771 of 1455 facilities for P vivax) had sufficient sensitivity to achieve and maintain a high probability of freedom, consistent with having achieved malaria elimination, with either passive case detection data alone or when combined with active case detection.InterpretationApplying the FFI model framework to malaria surveillance data can provide programmes with information to support decision making, specific to malaria species. When routine malaria surveillance systems are strong, they are sufficient to achieve and maintain a high probability of freedom. Including additional surveillance components such as community case management and active case detection with multiple diagnostic tools can help improve estimates for which routine malaria data alone are not sufficient to ensure confidence in elimination.FundingThe Bill and Melinda Gates Foundation, the Global Institute for Disease Elimination, and the Carter Center.