Tracking the Dynamics of Salmonella Specific T Cell Responses

Abstract

Over the last decade, significant advances have been made in the methodology for studying immune responses in vivo. It is now possible to follow almost every aspect of pathogen-specific immunity using in vivo models that incorporate physiological infectious doses and natural routes of infection. This new ability to study immunity in a relevant physiological context will greatly expand our understanding of the dynamic interplay between host and pathogen. Visualizing the resolution of primary infection and the development of long-term immunological memory should also aid the development of new vaccines and therapeutics for infectious diseases. In this review, we will describe the application of in vivo visualization technology to Salmonella infection, describe our current understanding of Salmonella-specific immunity, and discuss some unanswered questions that remain in this model.

Salmonella Serogroup C: Current Status of Vaccines and Why They Are Needed

“…Ultimately, one could combine these live attenuated or conjugate vaccines to protect against serogroups B, D, C1, and C2, therefore preventing the majority of salmonellosis cases (up to 88% of cases in the United States). Vaccines in development should ideally generate both antibody-and cell-mediated immunity, as T cells are required for ultimate resolution of Salmonella infections (62)(63)(64). It was recently reported that cell-mediated immunity might be crucial for protection against NTS in individuals coinfected with malaria, a common comorbidity in parts of Africa and Asia where these pathogens are endemic (65).…”

Protective Host Immune Responses to Salmonella Infection

“…From the initial infection site in the PP, Salmonella can travel via the afferent lymphatics to the draining mesenteric lymph nodes (MLNs), and eventually gain access to the blood and systemic tissues via transit through efferent lymphatic vessels [23]. The transport of Salmonella from PPs to MLNs likely requires CCR7-dependent migration within CD11c + dendritic cells and one study has reported decreased bacterial loads in the MLNs of CCR7-deficient mice [24].…”

Dissemination of Persistent Intestinal Bacteria via the Mesenteric Lymph Nodes Causes Typhoid Relapse

“…Although the susceptible mouse model is often used to examine adaptive immunity to Salmonella, such studies typically use Salmonella strains with significantly reduced virulence (30,34). As an alternative to examining immunity to attenuated bacteria in susceptible mice, we recently reported an antibiotic treatment model that allows examination of the immune response to virulent bacteria in susceptible mice (17).…”