Medicine and Health Sciences Commons^™

Competition For Antigen Selects T Cell Responses That Undergo Memory Inflation And Maintains Clonal Dominance During Mcmv Infection, Holly Turula, Lila A. Farrington, Corinne Smith, Ann B. Hill, Christopher M Snyder

Department of Microbiology and Immunology Faculty Papers

Cytomegalovirus (CMV) establishes a life-long, persistent/latent infection. Continuous immune surveillance by CMV-specific CD8+ T cells results in their accumulation over time, a process called “memory inflation”. These “inflationary” T cells migrate systemically and comprise the largest T cell populations in humans, making CMV-based vaccines attractive. Why T cells specific for only some CMV-derived epitopes undergo inflation is unclear. We found previously that recombinant murine (M)CMV expressing the SIINFEKL peptide only induced inflation of SIINFEKL-specific T cells, in contrast to wild-type MCMV infection. We show here that:

• Co-infecting mice with viruses expressing and lacking SIINFEKL enabled T cells with multiple specificities …

Competition For Antigen At The Level Of The Apc Is A Major Determinant Of Immunodominance During Memory Inflation In Murine Cytomegalovirus Infection., Lila A Farrington, Tameka A Smith, Finn Grey, Ann B Hill, Christopher M. Snyder

Department of Microbiology and Immunology Faculty Papers

The unique ability of CMV to drive the expansion of virus-specific T cell populations during the course of a lifelong, persistent infection has generated interest in the virus as a potential vaccine strategy. When designing CMV-based vaccine vectors to direct immune responses against HIV or tumor Ags, it becomes important to understand how and why certain CMV-specific populations are chosen to inflate over time. To investigate this, we designed recombinant murine CMVs (MCMVs) encoding a SIINFEKL-enhanced GFP fusion protein under the control of endogenous immediate early promoters. When mice were infected with these viruses, T cells specific for the SIINFEKL …

Two Coiled-Coil Domains Of Chlamydia Trachomatis Inca Affect Membrane Fusion Events During Infection., Erik Ronzone, Fabienne Paumet

Department of Microbiology and Immunology Faculty Papers

Chlamydia trachomatis replicates in a parasitophorous membrane-bound compartment called an inclusion. The inclusions corrupt host vesicle trafficking networks to avoid the degradative endolysosomal pathway but promote fusion with each other in order to sustain higher bacterial loads in a process known as homotypic fusion. The Chlamydia protein IncA (Inclusion protein A) appears to play central roles in both these processes as it participates to homotypic fusion and inhibits endocytic SNARE-mediated membrane fusion. How IncA selectively inhibits or activates membrane fusion remains poorly understood. In this study, we analyzed the spatial and molecular determinants of IncA's fusogenic and inhibitory functions. Using …

Investigating The Role For Il-21 In Rabies Virus Vaccine-Induced Immunity., Corin L Dorfmeier, Evgeni P Tzvetkov, Anthony Gatt, James P Mcgettigan

Department of Microbiology and Immunology Faculty Papers

Over two-thirds of the world's population lives in regions where rabies is endemic, resulting in over 15 million people receiving multi-dose post-exposure prophylaxis (PEP) and over 55,000 deaths per year globally. A major goal in rabies virus (RABV) research is to develop a single-dose PEP that would simplify vaccination protocols, reduce costs associated with RABV prevention, and save lives. Protection against RABV infections requires virus neutralizing antibodies; however, factors influencing the development of protective RABV-specific B cell responses remain to be elucidated. Here we used a mouse model of IL-21 receptor-deficiency (IL-21R-/-) to characterize the role for IL-21 in RABV …

Isolated Laryngeal Leishmaniasis In Immunocompetent Patients: An Underdiagnosed Disease., Salvatore Cocuzza, Alessio Strazzulla, Marilia Rita Pinzone, Stefano Cosentino, Agostino Serra, Rosario Caltabiano, Salvatore Lanzafame, Bruno Cacopardo, Giuseppe Nunnari

Department of Microbiology and Immunology Faculty Papers

We describe a case of isolated primary laryngeal leishmaniasis in an immunocompetent Italian patient with a previous medical history negative for visceral or cutaneous leishmaniasis, presenting with hoarseness. We also summarize the epidemiological, clinical, and diagnostic features and the therapeutic management of other cases of laryngeal leishmaniasis in immunocompetent subjects, described in the literature. Considering the insidious and nonspecific clinical presentation, the increasing number of different forms of mild or underestimated immunosuppressive conditions, and the number of people travelling in endemic zones, along with the ability of Leishmania amastigotes to survive for a long period in the body, we believe …

Toward A Network Model Of Mhc Class Ii-Restricted Antigen Processing., Michael A Miller, Asha Purnima V Ganesan, Laurence C. Eisenlohr

Department of Microbiology and Immunology Faculty Papers

The standard model of Major Histocompatibility Complex class II (MHCII)-restricted antigen processing depicts a straightforward, linear pathway: internalized antigens are converted into peptides that load in a chaperone dependent manner onto nascent MHCII in the late endosome, the complexes subsequently trafficking to the cell surface for recognition by CD4(+) T cells (TCD4+). Several variations on this theme, both moderate and radical, have come to light but these alternatives have remained peripheral, the conventional pathway generally presumed to be the primary driver of TCD4+ responses. Here we continue to press for the conceptual repositioning of these alternatives toward the center while …

Comparison Of Heterologous Prime-Boost Strategies Against Human Immunodeficiency Virus Type 1 Gag Using Negative Stranded Rna Viruses., Tessa M Lawrence, Celestine N Wanjalla, Emily A Gomme, Christoph Wirblich, Anthony Gatt, Elena Carnero, Adolfo García-Sastre, Douglas S Lyles, James P Mcgettigan, Matthias J Schnell

Department of Microbiology and Immunology Faculty Papers

This study analyzed a heterologous prime-boost vaccine approach against HIV-1 using three different antigenically unrelated negative-stranded viruses (NSV) expressing HIV-1 Gag as vaccine vectors: rabies virus (RABV), vesicular stomatitis virus (VSV) and Newcastle disease virus (NDV). We hypothesized that this approach would result in more robust cellular immune responses than those achieved with the use of any of the vaccines alone in a homologous prime-boost regimen. To this end, we primed BALB/c mice with each of the NSV-based vectors. Primed mice were rested for thirty-five days after which we administered a second immunization with the same or heterologous NSV-Gag viruses. …