UTMB Health SHARED

UTMB Health SHARED is an online community space for Scholarship, Historical Archives, Repository, & Electronic Dissertations. This digital service is an important tool for preserving the organization’s legacy and facilitating scholarly communication.

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Ernst Karl Abbé
(Mücchen, J.F. Lehmann, 1905)
Portrait of Ernst Abbé, 1840-1905.
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Yellow Fever: Role of Heterologous Flavivirus Immunity on Urban Emergence
(2024-08) Shinde, Divya Pratik 1993-; Weaver, Scott (sweaver@utmb.edu); Plante, Kenneth (ksplante@utmb.edu); Vasilakis, Nikos (nivasila@utmb.edu); Beasley, David (dwbeasle@utmb.edu); Drumond, Betania (betaniadrumond@gmail.com); Weiskopf, Daniela (dweiskopf@lji.org)
During the recent yellow fever (YF) epidemics in Brazil, human cases were attributed only to spillover infections via sylvatic mosquito transmission. Despite YF virus (YFV) transmission in major urban centers with insufficient vaccination coverage and abundant populations of the domestic vector, Aedes aegypti, there was no evidence of human-amplified transmission. Furthermore, the complete historic absence of YF in Asia, despite abundant Ae. aegypti and a completely immunologically naive human population represents a longstanding epidemiological enigma. We tested the hypothesis that pre-existing, heterologous flavivirus immunity, specifically from dengue (DENV) and Zika (ZIKV) viruses, limits YFV viremia and transmission by Ae. aegypti. We infected cynomolgus macaques with DENV or ZIKV, then challenged them 6-9 months later with YFV. We then measured viremia and disease, and allowed Ae. aegypti mosquitoes to feed during peak macaque viremia. Although prior heterologous immunity had variable effects on disease, DENV and ZIKV immunity consistently suppressed YFV viremia, leading to a significant reduction in Ae. aegypti infection and a lack of transmission potential. Next, we utilized an interferon α/β receptor knock-out mouse model to determine the role of pre-existing DENV-2 and ZIKV immunity in YF virus infection, and to determine mechanisms of cross-protection. We utilized African and Brazilian YF strains and found that DENV-2 and ZIKV immunity significantly suppresses YFV viremia in mice but did not consistently protect against disease outcome. Cross-protection appears to be mediated mainly by humoral immune responses. These studies underscore the importance to re-assess the risk of YF outbreak accounting for prior immunity from flaviviruses that are endemic.
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HUMAN GENETIC VARIANTS IN ESSENTIAL SPLICING FACTORS AND THEIR IMPACT ON IMMUNE PATHOLOGY
(2024-08) Nagasawa, Chloe Kazue; Garcia-Blanco, Mariano (rxh8rw@virginia.edu); Ward, Michelle (miward@utmb.edu); Lincoln, John; Abbott, Robert; Sheetz, Michael
Pre-mRNA splicing is critical for proper gene expression, and its dysregulation has been implicated in many human diseases including neurodegenerative disorders, cancers and autoimmune diseases. Splicing is a multi-step process executed by the spliceosome, which is composed of five small nuclear ribonucleoproteins (snRNPs) and hundreds of proteins that are generally referred to as splicing factors (SFs). Here we present two unique cases in which genetic variations in two essential SFs, DExD-box polypeptide 39B (DDX39B) and U2 small nuclear RNA auxiliary factor 1 (U2AF1), contribute to altered splicing of Forkhead box P3 (FOXP3) – an immunoregulatory gene critical for regulatory T (Treg) cell function and homeostasis. Mutations in FOXP3 cause immunodysregulation polyendocrinopathy enteropathy X-linked (IPEX) syndrome, and aberrant expression of FOXP3 has been associated with other diseases such as multiple sclerosis (MS) and non-small cell lung cancer (NSCLC). We previously described a single nucleotide polymorphism (SNP) in DDX39B, rs2523506, which is associated with increased risk of MS. The population homozygous for the risk allele had ~50% less DDX39B protein expression. Furthermore, we demonstrated that DDX39B expression is critical for proper splicing, expression and function of FOXP3. Here we describe the mechanism underlying the exquisite dependence of FOXP3 introns on DDX39B and the potential impact of rs2523506 in DDX39B on FOXP3 expression and autoimmunity. Additionally, we highlight splicing alterations in a patient with a complex immune phenotype and a de novo in-frame deletion in U2AF1. Moreover, we discuss the potential implications of these splicing alterations in the disease pathogenesis of the patient. These two examples of genetic variations in SFs showcase the importance of splicing and how its dysregulation can contribute to immune pathology.
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The Impact of An Innovative Online Orientation Program on Graduation among Graduate Nursing Students: A Secondary Analysis
(2024-08) Letz, Lisa Kye 1978-; Nguyen, Hoang T./hnguyen@UTMB.EDU; Jupiter, Daniel/dajupite@utmb.edu; Lorenzo, Elizabeth/ellorenz@utmb.edu; Leger, Michael/jmleger@utmb.edu; Kapaale, Chaluza/chaluza.kapaale@simmons.edu
The current shortage of Advanced Practice Registered Nurses (APRN) in the United States requires innovative programs to increase on-time graduation and decrease attrition. The Master of Science in Nursing (MSN) Online Orientation for Retention Excellence (MORE) Program is one such program. However, the program’s impact on on-time graduation and attrition is not known. The purpose of this study was to examine the impact of the MORE Program on student’s on-time graduation and attrition. Tinto’s Theoretical Model of Student Departure (1993) was used as the guiding theoretical framework. A retrospective secondary analysis was conducted on all 608 MSN students who enrolled in the Fall 2016 to Fall 2018 at one nursing school located in the southern United States. Logistic regression models were used to examine the association between the MORE Program and the on-time graduation rate and the attrition rate. The models adjusted for the effect of age, sex, program track, and admission GPA. The study found no statistical difference in the odds of graduating on-time between students who did and did not participate in the MORE Program. However, age, program track, and admission GPA were significant predictors of on-time graduation. For attrition, students who never or only partially participated in the MORE Program had 2 to 3 times higher odds of attrition compared to students who fully participated. Age and program track were also significant predictors of attrition. Online orientation programs should be used in online graduate nursing programs to decrease attrition. Findings from this study could inform nursing educators about establishing online orientation programs and resources to support at-risk students to better prepare online graduate nursing students for successful graduation.
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Interferons in Influenza A Virus and Streptococcus Pneumoniae Co-Pathogenesis
(2024-08) Palani, Sunil 1992-; Sun, Keer Ph.D. (kesun@utmb.edu); Xiaoyong Bao, Ph.D.; Yingzi Cong, Ph.D.; Parimal Samir, Ph.D.; Victor Huber, Ph.D.
Secondary pneumococcal pneumonia postinfluenza significantly increases the disease burden associated with influenza A virus (IAV) infection. IAV induced interferons (IFN) play a crucial role in antiviral immunity. However, recent reports have indicated that influenza-induced IFN-I and IFN- γ signaling suppress innate antibacterial immunity by distinct mechanisms, thereby increasing host susceptibility to secondary bacterial pneumonia. Despite their detrimental role, the interplay between them remains poorly understood. In this dissertation, we have investigated the relative importance of IFN-I and IFN-γ pathways in the pathogenesis of IAV/ Streptococcus Pneumoniae (SPn) coinfection. Using gene knock-out models and neutralizing in vivo antibodies, we demonstrated that IFN-I and IFN-γ inhibit acute bacterial clearance post-IAV infection. However, IFN-γ plays a more critical role. Additionally, we found that IFN-I signaling is essential for preventing IFN-γ hyperproduction and animal death during coinfection, indicating the dual role of IFN-I, which was novel. Moreover, we show that both IFN-I and IFN-γ employ distinct mechanisms to regulate inflammatory cytokine response and immune cell recruitment during copathogenesis. Given the dominant role of IFN-γ in the progression of coinfection, we further investigated the effect of immune predisposition on susceptibility to coinfection. To that end, we demonstrated that pathogenicity to coinfection remains distinct between BALB/c and C57BL/6 (B6) mice that recapitulate Th2- and Th1-biased responses, respectively. Prior infection with a low-virulent IAV strain (X31) renders B6 mice extremely susceptible to superinfection compared to the resistant BALB/c mice. We found that neither the viral nor the bacterial infection alone induced IFN-γ response in both strains of mice. However, the coinfection resulted in a robust IFN-γ response in the B6 mice, not the BALB/c mice. Furthermore, this IFN-γ response in the B6 mice inhibited neutrophil recruitment and innate bacterial clearance. Additionally, we also demonstrated that neutrophils in BALB/c mice are required for effective bacterial control. Collectively, our results indicate that Th1-biased immune predisposition plays an important role in determining the outcome during IAV/ SPn coinfection. Altogether, our work has demonstrated the relative importance and the regulation between IFN-I and IFN-γ during the coinfection pathogenesis, which is imperative for understanding the complex pathogenic mechanisms.