Contribution of the swine model in the study of human sexually transmitted infections

Abstract

The pig has garnered more and more interest as a model animal to study various conditions in humans. The growing success of the pig as an experimental animal model is explained by its similarities with humans in terms of anatomy, genetics, immunology, and physiology, by their manageable behavior and size, and by the general public acceptance of using pigs for experimental purposes. In addition, the immunological toolbox of pigs has grown substantially in the last decade. This development led to a boost in the use of pigs as a preclinical model for various human infections including sexually transmitted diseases (STIs) like Chlamydia trachomatis. In the current review, we discuss the use of animal models for biomedical research on the major human STIs. We summarize results obtained in the most common animal models and focus on the contributions of the pig model towards the understanding of pathogenesis and the host immune response. In addition, we present the main features of the porcine model that are particularly relevant for the study of pathogens affecting human female and male genital tracts. We also inform on the technological advancements in the porcine toolbox to facilitate new discoveries in this biologically important animal model. There is a continued need for improvements in animal modeling for biomedical research inclusive STI research. With all its advantages and the highly improved toolbox, the porcine model can play a crucial role in STI research and open the door to new exciting discoveries.

Sexual Dimorphism in Immune Development and in Response to Nutritional Intervention in Neonatal Piglets

“…The studies regarding sex differences in immunity in young adults of all species, including humans and pigs, have tended to address the differences which may be present after sexual maturity (23). However, there is a growing body of evidence that immune differences are present very early on, even during the prenatal stages.…”

Animal models for research in human infectious diseases. CMI editorial policy

“…The induced immune response can be assessed to find immune correlates of protection. This preclinical research maximizes the chances that a vaccine candidate will be protective and safe before it is applied to humans [8].…”

“…Besides the thigh model for the study of PK/PD, the mouse is also the predominant animal model for the preclinical study of urinary tract infections [11], different types of pneumonia [12] and sepsis [13]. Differences between animal and human immune systems have on the one hand led to more immunological research in human ex vivo cell systems replacing animals; on the other hand due to immunological differences between humans and mice, swine models have been developed due to their similarities with humans in terms of anatomy, genetics, immunology and physiology, their manageable behaviour and size, and the general public acceptance of using pigs for experimental purposes [8]. As an example, the swine model has been successful in the study of several human sexually transmitted infections [8].…”

“…Differences between animal and human immune systems have on the one hand led to more immunological research in human ex vivo cell systems replacing animals; on the other hand due to immunological differences between humans and mice, swine models have been developed due to their similarities with humans in terms of anatomy, genetics, immunology and physiology, their manageable behaviour and size, and the general public acceptance of using pigs for experimental purposes [8]. As an example, the swine model has been successful in the study of several human sexually transmitted infections [8]. However, the development of so-called 'humanized mice' to correct for immunological differences is more in line with the above-mentioned Refinement principle.…”

Mucosal Vaccination with UV-Inactivated Chlamydia suis in Pre-Exposed Outbred Pigs Decreases Pathogen Load and Induces CD4 T-Cell Maturation into IFN-γ+ Effector Memory Cells

“…The lack of a Ct vaccine can be partially explained by limitations of the currently used animal models ( Figure 1 ). The advantages and disadvantages of different animal models for Ct research has been recently reviewed [ 4 ]. The mouse model has advantages of low cost and a vast toolkit; however, important differences between mice and humans limits its use as a translational animal model.…”