Modification of the HLA-A*24:02 Peptide Binding Pocket Enhances Cognate Peptide-Binding Capacity and Antigen-Specific T Cell Activation.

The immunogenicity of a T cell Ag is correlated with the ability of its antigenic epitope to bind HLA and be stably presented to T cells. This presents a challenge for the development of effective cancer immunotherapies, as many self-derived tumor-associated epitopes elicit weak T cell responses, in part due to weak binding affinity to HLA. Traditional methods to increase peptide-HLA binding affinity involve modifying the peptide to reflect HLA allele binding preferences. Using a different approach, we sought to analyze whether the immunogenicity of wild-type peptides could be altered through modification of the HLA binding pocket. After analyzing HLA class I peptide binding pocket alignments, we identified an alanine 81 to leucine (A81L) modification within the F binding pocket of HLA-A*24:02 that was found to heighten the ability of artificial APCs to retain and present HLA-A*24:02-restricted peptides, resulting in increased T cell responses while retaining Ag specificity. This modification led to increased peptide exchange efficiencies for enhanced detection of low-avidity T cells and, when expressed on artificial APCs, resulted in greater expansion of Ag-specific T cells from melanoma-derived tumor-infiltrating lymphocytes. Our study provides an example of how modifications to the HLA binding pocket can enhance wild-type cognate peptide presentation to heighten T cell activation.

Lifestyle behaviors and intervention preferences of early-stage lung cancer survivors and their family caregivers.

PURPOSE: Lung cancer (LC) is a highly prevalent disease with more survivors diagnosed and treated at earlier stages. There is a need to understand psychological and lifestyle behavior needs to design interventions for this population. Furthermore, understanding the needs and role of family caregivers, especially given the risks associated with second-hand smoke, is needed. METHODS: Thirty-one early-stage (stages I or IIA) LC survivors of (52% men) and 22 (50% women) caregivers (N = 53 total) completed surveys after surgery (baseline) and at 3- and 6-month follow-ups. Participants reported on psychological functioning, smoking, and physical activity (PA) as well as intervention preferences. RESULTS: Survivors reported low levels of psychological distress and 3% were current smokers during the study. Approximately 79% were sedentary and not meeting national PA guidelines. Caregivers also reported minimal psychological distress and were sedentary (62% not meeting guidelines), but a larger proportion continued to smoke following the survivor's cancer diagnosis (14%). Both survivors and caregivers expressed interest in home-based PA interventions but differed regarding preferred format for delivery. Most (64%) caregivers preferred a dyadic format, where survivors and caregivers participate in the intervention together. However, most survivors preferred an individual or group format (57%) for intervention delivery. CONCLUSION: Both LC survivors and family caregivers could benefit from PA interventions, and flexible, dyadic interventions could additionally support smoking cessation for family caregivers.

The electronic cigarette epidemic in youth and young adults: A practical review.

Electronic cigarettes are the most common form of nicotine delivery used by youth and young adults, and in 2018, the US Surgeon General declared this to be an epidemic. The developing adolescent brain is vulnerable to nicotine exposure, which can lead to long-lasting cognitive and mood disorders. Screening rates for vaping are low and lack of knowledge by adolescents, clinicians, parents, and caregivers is high. This article reviews the components of vaping, prevalence, adverse reactions, regulation, treatment, and prevention strategies related to vaping in youth and young adults.

The adaptor protein VEPH1 interacts with the kinase domain of ERBB2 and impacts EGF signaling in ovarian cancer cells.

Upregulation of ERBB2 and activating mutations in downstream KRAS/BRAF and PIK3CA are found in several ovarian cancer histotypes. ERBB2 enhances signaling by the ERBB family of EGF receptors, and contains docking positions for proteins that transduce signaling through multiple pathways. We identified the adaptor protein ventricular zone-expressed pleckstrin homology domain-containing protein 1 (VEPH1) as a potential interacting partner of ERBB2 in a screen of proteins co-immunoprecipitated with VEPH1. In this study, we confirm a VEPH1 - ERBB2 interaction by co-immunoprecipitation and biotin proximity labelling and show that VEPH1 interacts with the juxtamembrane-kinase domain of ERBB2. In SKOV3 ovarian cancer cells, which bear a PIK3CA mutation and ERBB2 overexpression, ectopic VEPH1 expression enhanced EGF activation of ERK1/2, and mTORC2 activation of AKT. In contrast, in ES2 ovarian cancer cells, which bear a BRAFV600E mutation with VEPH1 amplification but low ERBB2 expression, loss of VEPH1 expression enabled further activation of ERK1/2 by EGF and enhanced EGF activation of AKT. VEPH1 expression in SKOV3 cells enhanced EGF-induced cell migration consistent with increased Snail2 and decreased E-cadherin levels. In comparison, loss of VEPH1 expression in ES2 cells led to decreased cell motility independent of EGF treatment despite higher levels of N-cadherin and Snail2. Importantly, we found that loss of VEPH1 expression rendered ES2 cells less sensitive to BRAF and MEK inhibition. This study extends the range of adaptor function of VEPH1 to ERBB2, and indicates VEPH1 has differential effects on EGF signaling in ovarian cancer cells that may be influenced by driver gene mutations.

Changing the landscape of tumor immunology: novel tools to examine T cell specificity.

Immunotherapy has established itself as a stalwart arm in patient care and with precision medicine forms the new paradigm in cancer treatment. T cells are an important group of immune cells capable of potent cancer immune surveillance and immunity. The advent of bioinformatics, particularly more recent advances incorporating algorithms employing machine learning, provide a seemingly limitless ability for T cell analysis and hypothesis generation. Such endeavors have become indispensable to research efforts accelerating and evolving to such an extent that there exists an appreciable gap between knowledge and proof of function and application. Exciting new technologies such as DNA barcoding, cytometry by time-of-flight (CyTOF), and peptide-exchangeable pHLA multimers inclusive of rare and difficult HLA alleles offer high-throughput cell-by-cell analytical capabilities. These outstanding recent contributions to T cell research will help close this gap and potentially bring practical benefit to patients.

Affinity-matured HLA class II dimers for robust staining of antigen-specific CD4+ T cells.

Peptide-major histocompatibility complex (pMHC) multimers enable the detection of antigen-specific T cells in studies ranging from vaccine efficacy to cancer immunotherapy. However, this technology is unreliable when applied to pMHC class II for the detection of CD4+ T cells. Here, using a combination of molecular biological and immunological techniques, we cloned sequences encoding human leukocyte antigen (HLA)-DP, HLA-DQ and HLA-DR molecules with enhanced CD4 binding affinity (with a Kd of 8.9 ± 1.1 µM between CD4 and affinity-matured HLA-DP4) and produced affinity-matured class II dimers that stain antigen-specific T cells better than conventional multimers in both in vitro and ex vivo analyses. Using a comprehensive library of dimers for HLA-DP4, which is the most frequent HLA allele in many ancestry groups, we mapped 103 HLA-DP4-restricted epitopes derived from diverse tumor-associated antigens and cloned the cognate T-cell antigen receptor (TCR) genes from in vitro-stimulated CD4+ T cells. The availability of affinity-matured class II dimers across HLA-DP, HLA-DQ and HLA-DR alleles will aid in the investigation of human CD4+ T-cell responses.

Landscape mapping of shared antigenic epitopes and their cognate TCRs of tumor-infiltrating T lymphocytes in melanoma.

HLA-restricted T cell responses can induce antitumor effects in cancer patients. Previous human T cell research has largely focused on the few HLA alleles prevalent in a subset of ethnic groups. Here, using a panel of newly developed peptide-exchangeable peptide/HLA multimers and artificial antigen-presenting cells for 25 different class I alleles and greater than 800 peptides, we systematically and comprehensively mapped shared antigenic epitopes recognized by tumor-infiltrating T lymphocytes (TILs) from eight melanoma patients for all their class I alleles. We were able to determine the specificity, on average, of 12.2% of the TILs recognizing a mean of 3.1 shared antigen-derived epitopes across HLA-A, B, and C. Furthermore, we isolated a number of cognate T cell receptor genes with tumor reactivity. Our novel strategy allows for a more complete examination of the immune response and development of novel cancer immunotherapy not limited by HLA allele prevalence or tumor mutation burden.

The immune system is the body's way of defending itself, offering protection against diseases such as cancer. But to remove the cancer cells, the immune system must be able to identify them as different from the rest of the body. All cells break down proteins into shorter fragments, known as peptides, that are displayed on the cell surface by a protein called human leukocyte antigen, HLA for short. Cancer cells display distinctive peptides on their surface as they generate different proteins to those of healthy cells. Immune cells called T cells use these abnormal peptides to identify the cancer so that it can be destroyed. Sometimes T cells can lack the right equipment to detect abnormal peptides, allowing cancer cells to hide from the immune system. However, T cells can be trained through a treatment called immunotherapy, which provides T cells with new tools so that they can spot the peptides displayed by HLA on the previously 'hidden' cancer cells. There are many different forms of HLA, each of which can display different peptides. Current research in immunotherapy commonly targets only a subset of HLA forms, and not all cancer patients have these types. This means that immunotherapy research is only likely to be of most benefit to a limited number of patients. Immunotherapy could be made effective for more people if new cancer peptides that are displayed by the other 'under-represented' forms of HLA were identified. Murata, Nakatsugawa et al. have now used T cells that were taken from tumors in eight patients with melanoma, which is a type of skin cancer. A library of fluorescent HLA-peptides was generated ­ using a new, simplified methodology ­ with 25 forms of HLA that displayed over 800 peptides. T cells were then mixed with the library to identify which HLA-peptides they can target. As a result, Murata, Nakatsugawa et al. found the cancer targets of around 12% of the tumor-infiltrating T cells tested, including those from under-represented forms of HLA. Consequently, these findings could be used to develop new immunotherapies that can treat more patients.

Fluoride ingestion is related to fluid consumption patterns.

OBJECTIVES: There have been few reports regarding variations of fluoride intake by fluid consumption patterns. The purpose of this study was to estimate fluoride intake among children in the United States based on their fluid consumption patterns. METHODS: Fluid intakes of children aged 1-10 years from plain water, beverages, and water from foods were assessed in a 24-hour recall diet survey as a part of the third National Health and Nutritional Examination Survey (NHANES III, 1988-1994). The amount of fluoride ingested from fluids in NHANES III was estimated from several assumptions about the concentration of fluoride in drinking water and beverages. Logistic regression analysis was conducted using SAS and SUDAAN. RESULTS: Children at the 75th percentile or higher of F intake from fluids (not including water used in cooking) ingested 0.05 mg F/kg/day or more, and children at the 90th percentile or higher ingested 0.07 mg F/kg/day or more. This finding held across all age groups. There was substantial variation in the estimated amount of fluoride ingestion depending on the children's fluid consumption patterns as well as age, gender, and race/ethnicity. African-American children ingested significantly more fluoride than White children in bivariate analysis. This association remained significant after accounting for fluid consumption pattern and other confounding factors in the model. CONCLUSION: Our results raise concerns that some children are ingesting significantly more fluoride than others depending on sociodemographic factors and fluid consumption patterns. Additional research is warranted to investigate the variation in the amounts of fluoride ingestion by these factors and its impact on fluorosis prevalence in different population groups.

The association between antibiotics usage in early childhood and early childhood caries.

PURPOSE: The objectives of this study were to learn if the intake of systemic antibiotics during the first year of age (period of primary teeth development) was associated with an increased risk for early childhood caries during the following years; and after the first year of age (following the formation of primary teeth) was associated with a lower risk for early childhood caries during the following years. CONCLUSIONS: Children who used systemic antibiotics during the first year of age had a significantly greater risk for early childhood caries (ECC) during follow-up compared to children who did not use antibiotics. After the first year of life, only children who used systemic antibiotics at 13 to 18 months old showed a significant increase in the risk of ECC. A child's racial background was a determining factor in the association between antibiotic intake and ECC.

Social factors and periodontitis in an older population.

OBJECTIVES: We assessed the prevalences of periodontitis by education and income levels among US adults with data from the third National Health and Nutrition Examination Survey. METHODS: The study was limited to non-Hispanic Blacks, Mexican Americans, and non-Hispanic Whites 50 years of age or older with a complete periodontal assessment during the dental examination. RESULTS: Blacks with higher education and income levels had a significantly higher prevalence of periodontitis than their White and Mexican-American counterparts. The relationship between income level and periodontitis was modified by race/ethnicity. High-income Blacks exhibited a higher prevalence of periodontitis than did low-income Blacks and high-income Whites. CONCLUSIONS: Our findings call attention to the importance of recognizing socioeconomic status-related health differences across racial/ethnic groups within the social, political, and historical context.

Cariogenicity of soft drinks, milk and fruit juice in low-income african-american children: a longitudinal study.

BACKGROUND: The authors conducted a study to test the hypothesis that high consumption of soft drinks, relative to milk and 100 percent fruit juice, is a risk factor for dental caries in low-income African-American children in Detroit. METHODS: Trained dentists and interviewers examined a representative sample of 369 children, aged 3 to 5 years, in 2002-2003 and again two years later. The authors used the 2000 Block Kids Food Frequency Questionnaire (NutritionQuest, Berkeley, Calif.) to collect dietary information. They assessed caries by using the International Caries Detection and Assessment System. RESULTS: Soft drinks, 100 percent fruit juice and milk represented the sugared beverages consumed by the cohort. A cluster analysis of the relative proportion of each drink at baseline and follow-up revealed four consumption patterns. Using zero-inflated negative binomial models, the authors found that children who changed from being low consumers of soft drinks at baseline to high consumers after two years had a 1.75 times higher mean number of new decayed, missing and filled tooth surfaces compared with low consumers of soft drinks at both time points. CONCLUSION: Children who consumed more soft drinks, relative to milk and 100 percent fruit juice, as they grew older were at a greater risk of developing dental caries. CLINICAL IMPLICATIONS: Health promotion programs and health care providers should emphasize to patients and caregivers the caries risk associated with consumption of soft drinks.

Middle ear and respiratory infections in early childhood and their association with early childhood caries.

PURPOSE: The purpose of this study was to examine the risk of early childhood caries (ECC) in children who had middle ear infections (MEI) or respiratory tract infections (RTI) during early childhood. METHODS: Medicaid data from Michigan were analyzed for all continuously enrolled children born in 2001 for whom enrollment, medical, and dental claims were filed during 2001-2004. Proportional hazards survival models were used to assess the risk of ECC in children who had MEl or RTI during the first year of life. RESULTS: Included in the study were 29,485 children (51% males and 49% females). By first year of life, 47% and 69% of children had a claim for MEI and RTI, respectively. Children with at least one claim for MEI or RTI were at 29% higher risk for developing ECC compared to those with no claims (P < .001). Hispanic children with 8 or more claims showed 91% greater risk for developing ECC than those with less than 8 claims (P = .01). CONCLUSIONS: The occurrence of middle ear infections or respiratory tract infections during the first year of life is associated with a significantly increased risk for developing early childhood caries during subsequent years. Race and ethnicity are possible predictors for ECC in the studied models.

Dental caries and dietary patterns in low-income African American children.

PURPOSE: The purpose of this study was to assess the relationship between dietary patterns and dental caries severity in low-income African American children. METHODS: The participants were 3- to 5-year-old African American children in Detroit, Mich, with household incomes below 250% of the 2000 federal poverty level (N=436). Dietary intakes were obtained using the Block Kids Food Questionnaire. Dental caries in primary teeth were measured by the International Caries Detection and Assessment System criteria. The mean number of decoyed surfaces (noncavitated and cavitated, missing, and filled surfaces [dmfs]) for each child was estimated. Factor analysis was carried out to identify the patterns of solid food consumption. The resulting factor scores and drink variables were then used as covariates in multinomial logistic regression, with 4 levels of dmfs as the outcome. Statistical analyses were conducted using SAS and SUDAAN. RESULTS: Multinomial regression models found that age, soda consumption, and powdered/sport drink consumption were positively associated with dmfs scores. Milk and real juice (not orange) were associated with lower dmfs levels. CONCLUSIONS: Children frequently consume sugared drinks, which is associated with the prevalence of dental caries. Intervention programs that promote the adoption of noncariogenic dietary alternatives for children are needed.

The role of individual and neighborhood social factors on periodontitis: the third National Health and Nutrition Examination Survey.

BACKGROUND: This study investigates whether race/ethnicity, individual income, education, and neighborhood socioeconomic characteristics are independently associated with periodontitis in adults>or=18 years of age who participated in the third National Health and Nutrition Examination Survey (NHANES III). METHODS: Analyses were limited to participants in NHANES III who self-identified as non-Hispanic black, non-Hispanic white, or Mexican American, received a periodontal examination, and whose records were linked to the 1990 U.S. Census data (N=13,090). Periodontitis was investigated using a combination of clinical attachment loss and probing depth. Marginal logistic regression models were used to assess the association of race/ethnicity, individual income, education, and neighborhood socioeconomic characteristics with periodontitis before and after adjusting for selected covariates. A survey program was used to account for the survey sampling design and for the intraneighborhood correlation of outcomes of participants selected from the same neighborhood. RESULTS: Race/ethnicity, education, and neighborhood socioeconomic conditions were associated with periodontitis before and after controlling for selected covariates. After adjustment, blacks were twice (1.58 to 2.53) as likely to have periodontitis as whites. Compared to those with more than a high school education, those with less than a high school diploma were twice (1.48 to 2.89) as likely to have periodontitis. Individuals living in a neighborhood in the lowest tertile of the socioeconomic score were 1.81 times (1.36 to 2.41) more likely to have periodontitis than those living in a neighborhood in the highest tertile of the socioeconomic score. CONCLUSION: This study indicates that race/ethnicity, individual education, and neighborhood socioeconomic circumstances are important for periodontal health.

Lead levels in blood and saliva in a low-income population of Detroit, Michigan.

The relationships between blood lead (PbB) and saliva lead (PbSa) concentrations and the determinants of PbB and PbSa status in 970 low-income adults in the city of Detroit, Michigan were explored. Average PbB and PbSa values in the sample population were found to be 2.7+/-0.1 microg/dl and 2.4+/-0.13 microg/l (equivalent to 0.24+/-0.13 microg/dl), respectively, and a weak but statistically significant association was found between the lead levels in the two types of body fluid samples. The average PbB level for men (4.0+/-0.56 microg/dl) was higher than that for women (2.7+/-0.11 microg/dl); other significant predictors of PbB included age, level of education, being employed, income level, the presence of peeling paint on the wall at home and smoking. There was no gender- or age-dependent difference in blood saliva values but statistically significant correlations were found between PbSa and level of education, employment, income level and smoking. Dental caries was severe in this population. Only 0.5% of the participants had no clinical signs of caries, over 80% had cavitated carious lesions (i.e., lesions that had progressed into dentin), and the number of lost teeth and carious lesions averaged 3.4 and 30, respectively. Weak but significant associations were found between PbB as well as PbSa and measures of dental caries in the study population. The positive associations are believed to be a reflection of the fact that the risk factors for dental caries, especially in low-income populations of the US, overlap extensively with those of lead poisoning and may not have a causal significance.

Assessment of the relationship between neighborhood characteristics and dental caries severity among low-income African-Americans: a multilevel approach.

OBJECTIVES: To assess the relationship between neighborhood effects and the severity of dental caries among low-income African-Americans. METHODS: A multistage probability sample of African-American families living in the poorest 39 census tracts in Detroit was drawn. During 2002-03, cross-sectional data of a cohort that includes 1021 caregivers were collected in the first of three waves of interviews and examinations. Multilevel analyses focused on 27 neighborhood clusters and involved a combination of individual (Level-1) and neighborhood (Level-2) data including census and geocoded (address matching to census geographic areas) information. RESULTS: There is significant variation in the severity of caries between low-income neighborhood clusters. Caries severity decreases with a higher number of churches, while it increases with a higher number of grocery stores in the clusters after accounting for individual characteristics. Only 14% of the inter-individual variability in caries was explained by classical individual risk factors for this condition. CONCLUSION: Neighborhoods contribute something unique to caregivers' oral health, beyond socioeconomic position and individual risk factors. Multilevel interventions are necessary to reduce disparities among African-Americans and churches may offer a promising venue from which to conduct them.

The use of sorbitol- and xylitol-sweetened chewing gum in caries control.

BACKGROUND: The author compared the caries-inhibitory action of sorbitol- and xylitol-sweetened chewing gum and assessed the role of these products in caries prevention. TYPES OF STUDIES REVIEWED: The author reviewed studies including randomized field trials with substantial numbers of participants and observational studies. He did not review case studies. He found studies through a MEDLINE search and by hand searching. RESULTS: When compared with sugar-sweetened gum, sorbitol-sweetened gum had low cariogenicity [corrected] when it was chewed no more than three times per day. Xylitol-sweetened gum was noncariogenic in all of the protocols tested. Some studies claimed that xylitol-sweetened gum had an anticariogenic effect, though these claims need further study. There also is good evidence that when mothers of infants and young children chew xylitol-sweetened gum, it will block transmission of mutans streptococci from mother to child. CLINICAL IMPLICATIONS: The evidence is strong enough to support the regular use of xylitol-sweetened gum as a way to prevent caries, and it can be promoted as a public-health preventive measure. Chewing xylitol-sweetened gum, especially for patients who like chewing gum, can be fitted readily into a regimen that includes frequent fluoride exposure, good oral hygiene and regular dental appointments.

Concepts of risk in dental public health.

The purpose of this paper is to review the concepts of risk as we use them today in dental public health practice, and to suggest that we should broaden our view of risk. Use of terms like risk factor in the literature can be quite vague, and it is recommended that a clear definition of that and related terms be adhered to. A broader view of risk in dental research would take in the concepts of social determinants of health and population health. While some progress has been made in our understanding of these issues, better knowledge would give the public health administrator more readily available information to use in program planning. The skewed distribution of caries in the high-income countries has led to the emergence of targeted prevention programs toward those considered to be at high risk. In public health programs, targeting at the individual level is not practical: the risk assessment methods are not yet sufficiently precise, and even when individuals are identified there are practical problems with schools and with the children themselves. (For private practice, however, high-risk child patients can be identified as those with at least one approximal lesion in permanent teeth.) For public health purposes, an argument is made for geographic targeting, i.e. identification of areas of social deprivation where whole schools or school districts can be targeted. Geographic targeting is something between individual targeting and whole-population approaches. Ideally, geographic targeting would supplement population measures like water fluoridation and dental health education. Examples of geographic targeting from Ohio and New York are presented as illustrations.

Radiographic versus clinical extension of Class II carious lesions using an F-speed film.

This study investigated the difference in the apparent radiographic and true clinical extension of Class II carious lesions. Sixty-two lesions in both maxillary and mandibular premolars and molars were radiographed using Insight bitewing film. Class II lesions were scored independently by two masked examiners using an 8-point lesion severity scale. During the restoration process the lesions were dissected in a stepwise fashion from the occlusal aspect. Intraoperative photographs (2x) of the lesions were made, utilizing a novel measurement device in the field as a point of reference. Subsequently, the lesions were all given clinical scores using the same 8-point scale. Statistical analysis showed a significant difference between the true clinical extension of the lesions compared to the radiographic score. "Aggressive" and "Conservative" radiographic diagnoses underestimated the true clinical extent by 0.66 mm and 0.91 mm, respectively. No statistical difference was found between premolars and molars or maxillary and mandibular arches. The results of this study help to define the parameters for making restorative treatment decisions involving Class II carious lesions.

Is there homogeneity in periodontal health between African Americans and Mexican Americans?

OBJECTIVES: This study identified and contrasted prevalence and predictors of periodontitis among African Americans, Mexican Americans, and non-Hispanic Whites in the US adult population. DESIGN: Cross-sectional study. This study compared those with and without periodontitis in each racial/ethnic group. METHODS: This study was limited to records of US African-American, Mexican-American, and non-Hispanic White adults at least 17 years of age who received a complete periodontal assessment as part of the dental examination in the third National Health and Nutrition Examination Survey (1988-1994). RESULTS: Despite the findings that Mexican Americans were less educated, poorer, and had less insurance coverage than African Americans, Mexican Americans had a similar prevalence of periodontitis as non-Hispanic Whites. African Americans had the highest prevalence among all groups. A similar scenario was observed in the multiple logistic analyses. CONCLUSIONS: Mexican Americans had periodontal health profiles closer to non-Hispanic Whites than did African Americans, despite the shared "minority" status. Public health research and practice should explicitly recognize that while "minorities" are considered a homogeneous group, they do not necessarily share the same health profiles.