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Tuberculosis (TB) is one of the deadliest diseases, causing ∼2 million deaths annually worldwide. bacillus Calmette-Guérin (BCG), the only TB vaccine in common use, is effective against disseminated and meningeal TB in young children but is not effective against adult pulmonary TB. T helper 1 (Th1) cells producing interferon gamma (IFN-γ) and Th17 cells producing interleukin-17 (IL-17) play key roles in host protection against TB, whereas Th2 cells producing IL-4 and regulatory T cells (Tregs) facilitate TB disease progression by inhibiting protective Th1 and Th17 responses. Furthermore, the longevity of vaccine efficacy critically depends on the magnitude of long-lasting central memory T (T) cell responses. Hence, immunomodulators that promote T responses of the Th1 and Th17 cell lineages may improve BCG vaccine efficacy. Here, we show that curcumin nanoparticles enhance various antigen-presenting cell (APC) functions, including autophagy, costimulatory activity, and the production of inflammatory cytokines and other mediators. We further show that curcumin nanoparticles enhance the capacity of BCG to induce T cells of the Th1 and Th17 lineages, which augments host protection against TB infection. Thus, curcumin nanoparticles hold promise for enhancing the efficacy of TB vaccines.
Copyright © 2019 Ahmad et al.
T cell help in humoral immunity includes interactions of B cells with activated extrafollicular CD4 and follicular T helper (Tfh) cells. Each can promote antibody responses but Tfh cells play critical roles during germinal center (GC) reactions. After restimulation of their antigen receptor (TCR) by B cells, helper T cells act on B cells via CD40 ligand and secreted cytokines that guide Ig class switching. Hypoxia is a normal feature of GC, raising questions about molecular mechanisms governing the relationship between hypoxia response mechanisms and T cell help to antibody responses. Hypoxia-inducible factors (HIF) are prominent among mechanisms that mediate cellular responses to limited oxygen but also are induced by lymphocyte activation. We now show that loss of HIF-1α or of both HIF-1α and HIF-2α in CD4 T cells compromised essential functions in help during antibody responses. HIF-1α depletion from CD4 T cells reduced frequencies of antigen-specific GC B cells, Tfh cells, and overall antigen-specific Ab after immunization with sheep red blood cells. Compound deficiency of HIF-1α and HIF-2α led to humoral defects after hapten-carrier immunization. Further, HIF promoted CD40L expression while restraining the FoxP3-positive CD4 cells in the CXCR5 follicular regulatory population. Glycolysis increases T helper cytokine expression, and HIF promoted glycolysis in T helper cells via TCR or cytokine stimulation, as well as their production of cytokines that direct antibody class switching. Indeed, IFN-γ elaboration by HIF-deficient in vivo-generated Tfh cells was impaired. Collectively, the results indicate that HIF transcription factors are vital components of the mechanisms of help during humoral responses.
BACKGROUND - Acute invasive fungal sinusitis (AIFS) is a rare, aggressive infection occurring in immunocompromised patients. In this study we examined factors that affect survival in AIFS, and whether immune-stimulating therapies (IST) improve survival.
METHODS - Pathology records of biopsy-proven AIFS were reviewed from 3 academic institutions from 1995 to 2016. Univariate and multivariate Cox regressions were performed at 1 and 3 months from diagnosis.
RESULTS - One hundred fourteen patients were included; 45 received IST. In the univariate analysis, the following factors were associated with worse survival: hematologic malignancy (3-month hazard ratio [HR], 3.7; p = 0.01); recent chemotherapy (within 1 month of AIFS diagnosis) (3-month HR, 2.3; p = 0.02); recent bone marrow transplant (BMT) (3-month HR, 2.5; p = 0.02); and infection with atypical fungi (1-month HR, 3.1; p = 0.04). The following were associated with improved survival in univariate analysis: increasing A1c% (1-month HR, 0.7; p = 0.01) and surgical debridement (1-month HR, 0.1; p = 0.001). One third of patients with a hematologic malignancy had an absolute neutrophil count (ANC) >1000 at the time of diagnosis. ANC was not associated with prognosis in these patients. The following were associated with worse survival in multivariate analyses: hematologic malignancy; recent chemotherapy; atypical organisms; and cavernous sinus extension. In multivariate analyses, IST was associated with a 70% reduction in mortality at 1 month (p = 0.02).
CONCLUSION - We presented the largest series of AIFS. Further studies are needed to examine the importance of ANC in diagnosis and prognosis. Patients diagnosed with atypical organisms may be at higher risk of death. IST likely improves short-term survival, but prospective studies are needed.
© 2018 ARS-AAOA, LLC.
OBJECTIVES - When examining vaccination coverage, researchers must make decisions about how to define outcome measures based on many factors, including the timing of doses. Different operationalizations of the same outcome can often lead to different findings and can affect the ability to make comparisons across studies. This methodological article aimed to illustrate the implications of two options for operationalizing human papillomavirus (HPV) vaccination based on timing: initiation of the first dose at any age vs before the 13th birthday (on time).
STUDY DESIGN - Cross-sectional observational design.
METHODS - The 2014 National Immunization Survey for Teens (N = 16,439 adolescents aged 13-17 years) was analyzed using multivariate logistic regression for each outcome measure and effect modification by gender.
RESULTS - Age was positively associated with initiation at any age but negatively associated with on-time initiation. Gender modified the effect of race/ethnicity for both measures of initiation, but the pattern across groups was different for the two outcomes. Gender modified the effect of provider recommendation for initiation at any age, while gender modified the effects of age and region for on-time initiation.
CONCLUSION - Decisions of how to operationalize outcomes of HPV vaccine initiation among adolescents can lead to different conclusions about the role of age and gender differences for several predictive variables. To inform the development of public health efforts that promote on-time HPV vaccination among male and female adolescents, researchers should consider the importance of dose timing when operationalizing outcome measures. We recommend including on-time receipt of the HPV vaccine as an outcome measure.
Copyright © 2018 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.
The events required for the induction of broad neutralizing antibodies (bnAbs) following HIV-1 envelope (Env) vaccination are unknown, and their induction in animal models as proof of concept would be critical. Here, we describe the induction of plasma antibodies capable of neutralizing heterologous primary (tier 2) HIV-1 strains in one macaque and two rabbits. Env immunogens were designed to induce CD4 binding site (CD4bs) bnAbs, but surprisingly, the macaque developed V1V2-glycan bnAbs. Env immunization of CD4bs bnAb heavy chain rearrangement (VDJ) knockin mice similarly induced V1V2-glycan neutralizing antibodies (nAbs), wherein the human CD4bs V chains were replaced with mouse rearrangements bearing diversity region (D)-D fusions, creating antibodies with long, tyrosine-rich HCDR3s. Our results show that Env vaccination can elicit broad neutralization of tier 2 HIV-1, demonstrate that V1V2-glycan bnAbs are more readily induced than CD4bs bnAbs, and define V replacement and diversity region fusion as potential mechanisms for generating V1V2-glycan bnAb site antibodies.
Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.
The integration of inflammatory signals is paramount in controlling the intensity and duration of immune responses. Eicosanoids, particularly PGE, are critical molecules in the initiation and resolution of inflammation and in the transition from innate to acquired immune responses. Microsomal PGE synthase 1 (mPGES1) is an integral membrane enzyme whose regulated expression controls PGE levels and is highly expressed at sites of inflammation. PGE is also associated with modulation of autoimmunity through altering the IL-23/IL-17 axis and regulatory T cell (Treg) development. During a type II collagen-CFA immunization response, lack of mPGES1 impaired the numbers of CD4 regulatory (Treg) and Th17 cells in the draining lymph nodes. Ag-experienced mPGES1 CD4 cells showed impaired IL-17A, IFN-γ, and IL-6 production when rechallenged ex vivo with their cognate Ag compared with their wild-type counterparts. Additionally, production of PGE by cocultured APCs synergized with that of Ag-experienced CD4 T cells, with mPGES1 competence in the APC compartment enhancing CD4 IL-17A and IFN-γ responses. However, in contrast with CD4 cells that were Ag primed in vivo, exogenous PGE inhibited proliferation and skewed IL-17A to IFN-γ production under Th17 polarization of naive T cells in vitro. We conclude that mPGES1 is necessary in vivo to mount optimal Treg and Th17 responses during an Ag-driven primary immune response. Furthermore, we uncover a coordination of autocrine and paracrine mPGES1-driven PGE production that impacts effector T cell IL-17A and IFN-γ responses.
Copyright © 2018 by The American Association of Immunologists, Inc.
While the HIV-1-glycan shield is known to shelter Env from the humoral immune response, its quantitative impact on antibody elicitation has been unclear. Here, we use targeted deglycosylation to measure the impact of the glycan shield on elicitation of antibodies against the CD4 supersite. We engineered diverse Env trimers with select glycans removed proximal to the CD4 supersite, characterized their structures and glycosylation, and immunized guinea pigs and rhesus macaques. Immunizations yielded little neutralization against wild-type viruses but potent CD4-supersite neutralization (titers 1: >1,000,000 against four-glycan-deleted autologous viruses with over 90% breadth against four-glycan-deleted heterologous strains exhibiting tier 2 neutralization character). To a first approximation, the immunogenicity of the glycan-shielded protein surface was negligible, with Env-elicited neutralization (ID) proportional to the exponential of the protein-surface area accessible to antibody. Based on these high titers and exponential relationship, we propose site-selective deglycosylated trimers as priming immunogens to increase the frequency of site-targeting antibodies.
Published by Elsevier Inc.
The present study investigated the immunoenhancing property of our newly designed nanovaccine, that is, its ability to induce antigen-specific immunity. This study also evaluated the synergistic effect of a novel compound PBS-44, an α-galactosylceramide analog, in boosting the immune response induced by our nanovaccine. The nanovaccine was prepared by encapsulating ovalbumin (ova) and an adjuvant within the poly(lactic-co-glycolic acid) nanoparticles. Quantitative analysis of our study data showed that the encapsulated vaccine was physically and biologically stable; the core content of our nanovaccine was found to be released steadily and slowly, and nearly 90% of the core content was slowly released over the course of 25 days. The in vivo immunization studies exhibited that the nanovaccine induced stronger and longer immune responses compared to its soluble counterpart. Similarly, intranasal inhalation of the nanovaccine induced more robust antigen-specific CD8 T cell response than intraperitoneal injection of nanovaccine.
The design of immunogens that elicit broadly reactive neutralizing antibodies (bnAbs) has been a major obstacle to HIV-1 vaccine development. One approach to assess potential immunogens is to use mice expressing precursors of human bnAbs as vaccination models. The bnAbs of the VRC01-class derive from the IGHV1-2 immunoglobulin heavy chain and neutralize a wide spectrum of HIV-1 strains via targeting the CD4 binding site of the envelope glycoprotein gp120. We now describe a mouse vaccination model that allows a germline human IGHV1-2(∗)02 segment to undergo normal V(D)J recombination and, thereby, leads to the generation of peripheral B cells that express a highly diverse repertoire of VRC01-related receptors. When sequentially immunized with modified gp120 glycoproteins designed to engage VRC01 germline and intermediate antibodies, IGHV1-2(∗)02-rearranging mice, which also express a VRC01-antibody precursor light chain, can support the affinity maturation of VRC01 precursor antibodies into HIV-neutralizing antibody lineages.
Copyright © 2016 Elsevier Inc. All rights reserved.