Dietetics and Clinical Nutrition Commons^™

Methods For Quantifying T Cell Receptor Binding Affinities And Thermodynamics, Kurt H. Piepenbrink, Brian E. Gloor, Kathryn M. Armstrong, Brian M. Baker

Food for Health: Publications

αβ T cell receptors (TCRs) recognize peptide antigens bound and presented by class I or class II major histocompatibility complex (MHC) proteins. Recognition of a peptide/MHC complex is required for initiation and propagation of a cellular immune response, as well as the development and maintenance of the T cell repertoire. Here we discuss methods to quantify the affinities and thermodynamics of interactions between soluble ectodomains of TCRs and their peptide/MHC ligands, focusing on titration calorimetry, surface plasmon resonance, and fluorescence anisotropy. As TCRs typically bind ligand with weak-to-moderate affinities, we focus the discussion on means to enhance the accuracy and …

Holobiont Nutrition: Considering The Role Of The Gastrointestinal Microbiota In The Health Benefits Of Whole Grains, Jens Walter, Ines Martinez, Devin J. Rose

Food for Health: Publications

Intake of whole grains and other food products high in dietary fiber have long been linked to the prevention of chronic diseases associated with inflammation. A contribution of the gastrointestinal microbiota to these effects has been suggested, but little is known on how whole grains interact with gut bacteria. We have recently published the first human trial that made use of next-generation sequencing to determine the effect of whole grains (whole grain barley, brown rice or a mixture of the two) on fecal microbiota structure and tested for associations between the gut microbiota and blood markers of inflammation, glucose and …

Eating Behaviors Of Older Adults Participating In Government-Sponsored Programs With Different Demographic Backgrounds, Yeon Bai, Shahla M. Wunderlich, Joseph Brusca, Johnson-Austin Marti, Michelle O'Malley

Department of Nutrition and Food Studies Scholarship and Creative Works

The purpose of this study was to determine the food behaviors of nutritionally high-risk seniors as a function of their racial background, gender, marital status, and education level. A total of 69 seniors were identified to be at high nutritional risk using the Nutrition Screening Initiative (NSI) checklist. A supplemental questionnaire (SQ) was created to examine the risk factors in relation to the participant’s demographic background. Key results indicated that Asians practiced healthy food behaviors and women were more likely to eat alone (p≤0.05). Married participants (90.9%) were most likely to consume 2 meals or more each day. College educated …

Gut Microbiome Composition Is Linked To Whole Grain-Induced Immunological Improvements, Ines Martinez, James M. Lattimer, Kelcie L. Hubach, Jennifer A. Case, Junyi Yang, Casey G. Weber, Julie A. Louk, Devin J. Rose, Gayaneh Kyureghian, Daniel A. Peterson, Mark D. Haub, Jens Walter

Food for Health: Publications

The involvement of the gut microbiota in metabolic disorders, and the ability of whole grains to affect both host metabolism and gut microbial ecology, suggest that some benefits of whole grains are mediated through their effects on the gut microbiome. Nutritional studies that assess the effect of whole grains on both the gut microbiome and human physiology are needed. We conducted a randomized cross-over trial with four-week treatments in which 28 healthy humans consumed a daily dose of 60 g of whole-grain barley (WGB), brown rice (BR), or an equal mixture of the two (BR+WGB), and characterized their impact on …

Single-Chain Vαvβ T Cell Receptors Function Without Mispairing With Endogenous Tcr Chains1, David H. Aggen, Adam S. Chervin, Thomas M. Schmitt, Boris Engels, Jennifer D. Stone, Sarah A. Richman, Kurt H. Piepenbrink, Brian M. Baker, Philip D. Greenberg, Hans Schreiber, David M. Kranz

Food for Health: Publications

Transduction of exogenous T cell receptor (TCR) genes into patients’ activated peripheral blood T cells is a potent strategy to generate large numbers of specific T cells for adoptive therapy of cancer and viral diseases. However, the remarkable clinical promise of this powerful approach is still being overshadowed by a serious potential consequence: mispairing of the exogenous TCR chains with endogenous TCR chains. These “mixed” heterodimers can generate new specificities that result in graft-versus-host reactions. Engineering TCR constant regions of the exogenous chains with a cysteine promotes proper pairing and reduces the mispairing, but, as we show here, does not …

Conformational Melding Permits A Conserved Binding Geometry In Tcr Recognition Of Foreign And Self Molecular Mimics, Oleg Y. Borbulevych, Kurt H. Piepenbrink, Brian M. Baker

Food for Health: Publications

Molecular mimicry between foreign and self antigens is a mechanism of T cell receptor cross reactivity and is thought to contribute to the development of autoimmunity. The αβ TCR A6 recognizes the foreign antigen Tax from the virus HTLV-1 when presented by the class I MHC HLA-A2. In a possible link with the autoimmune disease HAM/TSP, A6 also recognizes a self peptide from the neuronal protein HuD in the context of HLA-A2. We found here that the complexes of the HuD and Tax epitopes with HLA-A2 are close but imperfect structural mimics, and that in contrast with other recent structures …

Disparate Degrees Of Hypervariable Loop Flexibility Control T Cell Receptor Cross-Reactivity, Specificity, And Binding Mechanism, Daniel R. Scott, Oleg Y. Borbulevych, Kurt H. Piepenbrink, Steven A. Corcelli, Brian M. Baker

Food for Health: Publications

αβ T cell receptors recognize multiple antigenic peptides bound and presented by major histocompatibility complex molecules. TCR cross-reactivity has been attributed in part to flexibility of the complementarity-determining region loops, yet there have been limited direct studies of loop dynamics to determine the extent of its role. Here we studied the flexibility of the binding loops of the αβ TCR A6 utilizing crystallographic, spectroscopic, and computational methods. A significant role for flexibility in binding and cross-reactivity was indicated only for the CDR3α and CDR3β hypervariable loops. Examination of the energy landscapes of these two loops indicated that CDR3β possesses a …

Identification And Engineering Of Human Variable Regions That Allow Expression Of Stable Single-Chain T Cell Receptors, David H. Aggen, Adam S. Chervin, Francis K. Insaidoo, Kurt H. Piepenbrink, Brian M. Baker, David M. Kranz

Food for Health: Publications

Single-chain antibody fragments (scFv), consisting of two linked variable regions (V_H and V_L), are a versatile format for engineering and as potential antigen-specific therapeutics. Although the analogous format for T cell receptors (TCRs), consisting of two linked V regions (Vα and Vβ; referred to here as scTv), could provide similar opportunities, all wild-type scTv proteins examined to date are unstable. This obstacle has prevented scTv fragments from being widely used for engineering or therapeutics. To further explore whether some stable human scTv fragments could be expressed, we used a yeast system in which display of properly folded …

Fluorine Substitutions In An Antigenic Peptide Selectively Modulate T Cell Receptor Binding In A Minimally Perturbing Manner, Kurt H. Piepenbrink, Oleg Y. Borbulevych, Ruth F. Sommese, John Clemens, Kathrynq M. Armstrong, Clare Desmond, Priscilla Do, Brian M. Baker

Food for Health: Publications

T cell receptor (TCR) recognition of antigenic peptides bound and presented by major histocompatibility complex (MHC) molecules forms the basis of the cellular immune response to pathogens and cancer. TCRs bind peptide/MHC molecules weakly and with fast kinetics, features which have hindered detailed biophysical studies of these interactions. Modified peptides resulting in enhanced TCR binding could help overcome these challenges. Further, there is considerable interest in using modified peptides with enhanced TCR binding as the basis for clinical vaccines. Here, we studied how fluorine substitutions in an antigenic peptide can selectively impact TCR recognition. Using a structure-guided design approach, we …

Probiotic Therapy - Recruiting Old Friends To Fight New Foes, Roy D. Sleator

Department of Biological Sciences Publications

Against a backdrop of increasing antibiotic resistance, and the emergence of new and evolving pathogens, clinicians are increasingly forced to consider alternative therapies - probiotics are one such alternative.

T Cell Receptor Cross-Reactivity Directed By Antigen-Dependent Tuning Of Peptide-Mhc Molecular Flexibility, Oleg Y. Borbulevych, Kurt H. Piepenbrink, Brian E. Gloor, Daniel R. Scott, Ruth F. Sommese, David K. Cole, Andrew K. Sewell, Brian M. Baker

Food for Health: Publications

Tell mediated immunity requires T cell receptor (TCR) cross-reactivity, the mechanisms behind which remain incompletely elucidated. The αβ TCR A6 recognizes both the Tax (LLFGYPVYV) and Tel1p (MLWGYLQYV) peptides presented by the human class I MHC molecule HLA-A2. Here we found that although the two ligands are ideal structural mimics, they form substantially different interfaces with A6, with conformational differences in the peptide, the TCR, and unexpectedly, the MHC molecule. The differences between the Tax and Tel1p ternary complexes could not be predicted from the free peptide-MHC structures and are inconsistent with a traditional induced-fit mechanism. Instead, the differences were …

Field Testing Adolescent Females For Cardiovascular Disease Risk, C. Jayne Brahler, Wesley R. Stephens, Betsy Donahoe Fillmore

Physical Therapy Faculty Publications

Over-fatness and poor cardiovascular (CV) fitness are well-documented risk factors for cardiovascular disease (CVD) in adults, but less is known about their association with disease risk in adolescents. This study aimed to determine the relationship between anthropometrics, fitness, and CVD risk.

Six anthropometric indicators of body fatness, seven measures of fitness, and seven metabolic and hemodynamic CVD risk factors were measured in a convenience sample of 28 female high school students (15-18 years of age). A tally was made of the number of factors for which each subject was outside the normal reference range (CVD risk).

Correlation analyses were completed …

Conformational Changes And Flexibility In T-Cell Receptor Recognition Of Peptide–Mhc Complexes, Kathryn M. Armstrong, Kurt H. Piepenbrink, Brian M. Baker

Food for Health: Publications

A necessary feature of the immune system, TCR (T-cell receptor) cross-reactivity has been implicated in numerous autoimmune pathologies and is an underlying cause of transplant rejection. Early studies of the interactions of αβ TCRs (T-cell receptors) with their peptide–MHC ligands suggested that conformational plasticity in the TCR CDR (complementarity determining region) loops is a dominant contributor to T-cell cross-reactivity. Since these initial studies, the database of TCRs whose structures have been solved both bound and free is now large enough to permit general conclusions to be drawn about the extent of TCR plasticity and the types and locations of motion …

Residency Program At Michael E Debakey Department Of Surgery, Baylor College Of Medicine, F Charles Brunicardi

Faculty, Staff and Students Publications

No abstract provided.

The Effect Of A Pufa Diet On Human Red Blood Cell Levels Of 2, 3-Dpg, Sandra A. Dassenko

Loma Linda University Electronic Theses, Dissertations & Projects

Fasting blood was collected at weekly intervals and the level of 2,3-DPG of the red blood cell was determined in 15 male subjects age 28 to 57 with serum cholesterol levels greater than 250 mg%. A lactovegetarian diet containing no cholesterol, a high level of dietary fiber and a P/S ratio of 4.0 was provided for 28 days.

During the course of the experimental period the 2,3-DPG increased by an average of 0.83> «moles/ml red blood cell which was highly significant (p^.001). This significant increase of 2,3-DPG which relates to an increased oxygen delivery capability of the red blood cells …

Effect Of Isocaloric Unsaturated Fats On Serum Cholesterol Of Patients Treated With Hypocholesterolemic Agents, Yvonne Marie Hatley

Loma Linda University Electronic Theses, Dissertations & Projects

The effect of a high unsaturated-low saturated fat diet on serum cholesterol levels were studied. Subjects were clinic patients receiving the following hypocholesterolmeic agents: triparanol (MER-29), diildothyroacetic acid (Diac), dextrothyroxine (d-T₄) and 3-methoxy-16, alpha-methyl-1,3,5, (10)-estratriene-16 beta, 17 beta-diol (Manvene or Anvene).

Fifteen hypercholesterolemic patients, eleven of whom were diabetic, were placed on diets with prescribed amounts of unsaturated fat. The caloric distribution was 40 per cent carbohydrate, 20 per cent protein, and 40 per cent fat. The level of unsaturated fat was 70 per cent of the total fat.

Seventy-one per cent of the patients on the hypocholesterolemic …