Bovine tuberculosis

 CAB International 2018. Bovine Tuberculosis

140 (eds M. Chambers, S. Gordon, F. Olea-Popelka, P. Barrow)

• Email: [email protected]

10.1 Introduction

The innate immune system is the first line of
defense against pathogens, of which some of its
functions include participation in activation and
direction of adaptive immunity, as well as main-
taining the integrity and tissue repair (Kumar
et al., 2011). The innate system is integrated by
macrophages, dendritic cells (DCs), neutrophils
and natural killer (NK) cells. These cells use
pathogen-recognition receptors (PRRs) for their
activity, which are responsible for identifying
the presence of conserved structures between
microorganisms known as pathogen-associated
molecular patterns (PAMPs); similarly, they rec-
ognize molecules from damaged cells known as
damage-associated molecular patterns (DAMs).
During a mycobacterial infection, the innate
immune system is able to recognize bacilli
through PRRs; this allows the activation of
intracellular signalling cascades, the production
of pro-inflammatory cytokines, such as tumor
necrosis factor-alpha (TNF-α), type 1 interferons
(IFNs), interleukin (IL) 1β, IL-18 and IL-12. At
the same time, chemokines and antimicrobial
proteins are also produced, and antigen
presentation is initiated. This inflammatory

microenvironment allows the concentration of

cells of the innate response at the site of infec-

tion, which later allow the activation of the

adaptive immune system that is essential for

restraining the infection. However, virulent

mycobacteria can evade the immune system by

replicating inside macrophages, allowing dis-

ease pathology to develop (Plüddemann et al.,

2011; Yuk and Jo, 2014).

The induced immune response in infection

by Mycobacterium bovis is a complex process, and

its study in cattle has mainly focused on the

adaptive immune response (MacHugh et al.,

2009), therefore comprehension of the innate

immune system in bovine tuberculosis is limited.

Nevertheless, studies in humans and mice have

shown the importance of the innate immune

system in the outcome of mycobacterial infec-

tions, helping to control the bacterial load and

organizing and directing the magnitude of the

adaptive immune response (Magee et al., 2012).

In this chapter we will analyze the components

of the innate immune response involved in

M. bovis infection, such as: PRRs; cells of the

innate immune system; inflammasomes; and

autophagy and apoptosis processes. Further-

more, we will describe the importance of innate

10 Innate Immune Response in

Bovine Tuberculosis

Jacobo Carrisoza-Urbina,^1 Xiangmei Zhou^2 and

José A. Gutiérrez-Pabello1,*

(^1) Departamento de Microbiología e Inmunología, Facultad de Medicina
Veterinaria y Zootecnia, Universidad Nacional Autónoma de México,
México;^2 Veterinary Pathology Department, College of Veterinary Medicine,
China Agricultural University, P. R. China