Sordillo RELM Handouts 2017 - For Your Information · enzymes Neutrophil functions ... Pearson...
Transcript of Sordillo RELM Handouts 2017 - For Your Information · enzymes Neutrophil functions ... Pearson...
1/27/17
1
Cow’s Immune Response and Stray Voltage; Overview of Bovine Immunity
Lorraine M. Sordillo College of Veterinary Medicine
Michigan State University
Lameness
Ketosis Mastitis Displaced Abomasum
Milk Fever
Retained Fetal
Membranes
Metritis
Health Disorders of Dairy Cows
Disease resistance is dependent on effective immunity.
§ Several layers of defense • Physical barriers (teat end)
• Innate immune system
• Adaptive immune system
Immune System Overview
1/27/17
2
§ Innate Immunity (minutes to hours)
• Predominant during early infection
• Activated quickly by numerous stimuli
• Not augmented by repeated exposure
• Can eliminate microbes without visible changes to milk or tissues
• Adequacy of inflammatory response
Immune System Overview
Inflammation (Essential Innate Immune Response)
n Purposes of inflammation: • eliminate or neutralize source of injury • assist in repairing damaged tissues to normal function • complex and tightly regulated response • initiated by release of mediators from damaged tissue
� Recognition of Bacteria § Toxin & bacterial factors (i.e. endotoxin)
§ Pathogen associated molecular patterns (PAMPs)
§ Binds receptors on host cells (Toll-like receptors, TLR)
§ Stimulates production of inflammatory mediators (cytokines & oxylipids)
Inflammatory Response
Pathogen
Endotoxin Lipoteichoic Acid
TLR
Cytokines, Leukotrienes, & Prostaglandins
1/27/17
3
� Macrophages & lymphocytes � Various local cell populations
§ Endothelial cells
§ Fibroblasts
§ Epithelial Cells
Sources of Inflammatory Mediators
Migrate to Injury
White Blood Cell Recruitment
Changes in Vascular Permeability
Blood Vessel
Inflammatory mediators: Cytokines, Prostaglandins, & Leukotrienes
Neutrophils
Damaged Tissue
Macrophage
Neutrophils are Essential for Protection
• First cells to accumulate into tissues during inflammation
• Up to 97% of cells found in mastitic milk • Key role in eliminating bacteria
1/27/17
4
Leukocyte Removal of Bacteria
� Neutrophil Antimicrobial Functions • Phagocytosis
• Releases toxic oxidizing agents (H2O2, O., &
HOCl) called ROS • Antibacterial peptides (proteases and
lysozyme) • Neutrophil extracellular traps (NET)
formation
ROS
Vacuole Lysosome containing enzymes
Neutrophil functions dictate the outcome of infection.
Pathogen
Resolution of Inflammation � Return tissues to normal function
• Anti-inflammatory oxylipids and cytokines • Vascular permeability changes • Leukocyte infiltration stops • Local macrophages removes damaged cells • Growth factors help heal tissues
What if innate defenses of the cow fail to eliminate disease-causing
pathogens?
1/27/17
5
§ Adaptive Immunity (> 96 hours) • Important when innate defenses fail
• Recognizes specific antigens
• Heightened reaction upon repeated exposure
• Ability to recognize self and non-self (MHC)
• Basis of vaccination protocols
Immune System Overview
Adaptive Immunity (Pathogen Recognition)
§ Antigen presenting cells • Macrophages and
Dendritic Cells
• Important link with innate immunity
OpenStax College. 2013. Adaptive Immune Response. OpenStax_CNX, June 21, 2013. http://cnx.org/content/m44821/1.6/.
Adaptive Immunity (Effector Phase)
T Helper Cell
Antigen Presentation Cell
T cell receptor
MHC
B cell
Cytokines
Activated Helper T cell
Memory B cells
Plasma cells
Secreted Antibodies
Humoral Immune Response
Pearson Education, Inc., 2011
+
Plasma Cells
Memory
B cell
Recognition of same antigen
T helper cell
Cytokines IFN & IL2
1/27/17
6
Adaptive Immunity (Effector Phase)
OpenStax College. 2013. Adaptive Immune Response. OpenStax_CNX, June 21, 2013. http://cnx.org/content/m44821/1.6/.
§ Re-exposure to pathogen • Circulating memory cells
differentiate
• Response is faster and more robust
• Plasma cells produce 10-100 fold more antibodies
Opsonization Neutralization
Antibody
Pathogen
Pathogen
Neutrophil
Activation of Complement System Complement proteins
Formation of membrane attack complex
Flow of water and ions
Pore
Antigen
Adaptive Immunity (Effector Phase)
Antibody-Mediated Removal of Pathogens
Pearson Education, Inc., 2011
Effective Immune System highly interactive & coordinated
Adaptive Immunity (Later Response)
Innate Immunity (Early Response)
Disease Resistance
Immunity is Important!
1/27/17
7
• Physiological transition from late gestation to early lactation
• Majority of all disease occurs the first weeks of lactation
• 50% of all cows experience disease
• Major reason for culling
Increased Disease Incidence & Severity Periparturient Period
LeBlanc et al., 2006; Nordlund et al., 2006; DeVliegher et al., 2012; Pinedo et al., 2010
Transition Cow Immune Dysfunction
Uncontrolled Inflammation
Cytokines Prostaglandin
Neutrophils Macrophages
Poor Vaccine Response
Antibodies Lymphocyte Function
Innate Immunity
Adaptive Immunity
Inadequate Innate and Adaptive Immunity
Increased Disease Common linkage between metabolic and infectious diseases
Uncontrolled Inflammation in Periparturient Cows
� Inflammatory responses help disease progression ● Inability of local defenses to detect and eliminate pathogen
(inadequate neutrophil function) ● Uncontrolled leukocyte recruitment and activation of
inflammatory response (altered cytokine expression) ● Delicate balance of robust initial response and inflammatory
resolution is lost ● Bystander damage to host tissues ● MASTITIS & METRITIS
1/27/17
8
Sordillo et al., 1997. J. Dairy Sci. 80:1851.
Evidence of Immune Dysfunction Altered Periparturient Cytokine Expression
Impact on Neutrophils & Inflammation
Enhancement/Optimization Suppression/Dysfunction Interferon-γInterleukin-2 Colony Stimulating Factors (granulocyte/macrophage)
Tumor necrosis factor Interleukin-1 Interleukin-4 Interleukin-10
Cytokines in Milk During Mastitis Robust Initial Response
0
1
2
3
4
5
6
TN
F (U
/ml)
or IL
-1 (U
x 1
05 /ml
0
50
100
150
200
IL-8
(pg/
ml)
or IL
-6 (U
/ml)
0 12 24 36 48 60 72 Time Relative to E. coli Challenge (h)
IL-1
TNF α
IL-6
IL-8
Shuster et al, 1995
Cytokine Response in Periparturient Cows Coliform Mastitis Challenge
Sordillo et al. 1992 J. Dairy Sci.75:2119-2125.
0
5
10
15
20
25
30
35
40
0 4 8 12 24 36 48 60
TN
F (n
g/m
l)
Hours Following Challenge
Survived
Excessive cytokine response
Death
*
1/27/17
9
Hoeben et al., 2000. J. Dairy Sci. 67:249
Evidence of Inflammatory Dysfunction Reduced Periparturient Neutrophil Function
Optimal neutrophil function is critical for inflammation
Indicator of bacterial killing capacity
Lee et al., 1998. Am. J. Vet Res. 59:37-43.
Evidence of Immune Dysfunction Reduced Periparturient Neutrophil Function
Indicator of neutrophil migration
Graph courtesy of Marcus Kehrli, USDA, NADC
Neutrophils are Essential for Uterine Health § Retained Placenta
• Decreased immune function contributes to placental retention (Beagley et al. 2010. J. Vet. Intern. Med. 24:261)
• Impaired neutrophil functions leads to development of retained placenta (Gunnink, 1984. Vet Q. 6:49)
§ Metritis • Innate immunity is needed postpartum to prevent
clinical metritis (LeBlanc et al., 2011. Theriogenol. 76:1610)
• Reductions in neutrophil functions are associated with more clinical disease (Hammon et al., 2006. Vet. Immunol. Immunopathol. 113:21-29)
1/27/17
10
Ramification of Immune Dysfunction Reduced Neutrophil Function
Kimura et al., 2002. J. Dairy Sci. 85:544-550.
Retained Placenta Healthy
Indicator of bacterial killing capacity
Ramification of Immune Dysfunction Reduced Neutrophil Function
Kimura et al., 2002. J. Dairy Sci. 85:544-550.
Retained Placenta
Healthy
Indicator of migration from blood to tissue
Ramification of Immune Dysfunction Reduced Neutrophil Function
Endometritis
Healthy
Indicator of bactericidal activity
Kim et al., 2005. J. Reprod Develop. 51:757-764.
1/27/17
11
Neutrophils are Essential for Mastitis Resistance • First cells to accumulate into mammary tissues
during initial stages of infection (Schalm et al., 1964. AJVR 25:90-96)
• Represents 97% of cells found in mastitic milk (Paape et al., 1963. J. Dairy Sci. 36:1211-1216)
• Key role in eliminating bacteria (Jain et al., 1971. AJVR 32:1929- )
Shuster et al., 1996. AJVR 57:1569-1575
Ramifications of Immune Dysfunction Bacterial Growth During Mastitis
Ramifications of Immune Dysfunction Increased Clinical Mastitis
n Epidemiological Evidence of Coliform Mastitis l 25% cases occur by first 2 weeks lactation
l 45% cases occur by first 4 weeks lactation
l 60% cases occur by first 8 weeks lactation
Smith et al., 1985, J. Dairy Sci. 68:402 Hogan et al., 1989, J. Dairy Sci. 72:1547
1/27/17
12
Factors that Impact Immune Dysfunction
Ø Genetic variation based on heritability estimates (Detilleux et al., J Dairy Sci. 77:2640, 1994)
Ø Stress hormones of parturition (cortisol) (Burton & Kehrli, J Leuk Biol 59:90, 1996)
Ø Nutritional Factors (Sordillo, J Dairy Sci. 99:4967, 2016)
Ø Metabolic Stress (Sordillo & Raphael, Vet Clinics North Am Food Anim 29:267, 2013)
CSIRO PUBLISHING
Animal Production Science, 2014, 54, 1204–1214 Review http://dx.doi.org/10.1071/AN14503 !
The nexus between nutrient metabolism, oxidative stress and inflammation in transition cow
!L. M. Sordillo A,B and V. Mavangira A
Destructive feedback loops that enhance disease susceptibility.
Dysfunctional Inflammation
Oxidative Stress
Altered Nutrient Metabolism
Metabolic Stress Triad
§ Transition from late lactation to dry period § Transition from late gestation to early lactation § Fetal demands § Onset of copious milk production § Linked to changes in nutrient requirements
Increased Need: ü Energy ü Proteins ü Glucose ü Minerals ü Vitamins
Altered Nutrient Metabolism
1/27/17
13
Dry Matter Intake
Nutrient Requirements
Altered Nutrient Metabolism in Periparturient Cows (Negative Energy Balance)
Negative Energy Balance
Ene
rgy
(M
cal N
EI/
day)
24
20
16
12
28
60 120 140 168 196 224 252 280 0 30 Days from Calving
Energy Ingested
Energy Required
Babcock Institute
Altered Nutrient Metabolism
• Lipid and protein mobilization • Alterations in blood lipids • Increased nonesterified fatty
acids (NEFA) • Increased beta-hydroxybutyrate
(BHB)
Metabolic Adaptations to NEB
Suriyasathaporn et al., 2000
Altered Nutrient Metabolism
1/27/17
14
Observed Effect Periparturient Period
● Reduces antibody formation ( van Knegsel , 2007) & neutrophil functions (Hammon et al., 2006)
● Compromised lymphocyte functions (Lacetera et al 2004), impaired cytokine production (Scalia et al 2006), reduced neutrophil function (Ster et al 2012)
● Impairs neutrophil function (Grinberg et al., 2008)
● Alters cytokine production (O’Boyle et al., 2006) and reduces lymphocyte functions (Lacetera et al., 2005)
● Increases disease susceptibility and affects innate and acquired immune parameters (Sordillo & Aitken, 2008)
Elevated NEFA
Body Condition Score
Micronutrient Deficiencies (Vitamins & Minerals)
Negative Energy Balance
Ketosis (BHB levels)
Consequences of Altered Nutrient Metabolism Compromised immunity increases disease susceptibility
Goff and Stabel. 1990 J. Dairy Sci. 73:3195
Decline in Antioxidant Micronutrients During the Periparturient Period
Plasma Vitamin A Plasma Vitamin E
Calving Calving
Observed Effect
Micronutrients and Bovine Immunity Micronutrient
Selenium l improves neutrophil function; decreases severity of mastitis
l increase neutrophil killing; decrease clinical mastitis
l increases killing by phagocytes; increase lymphocyte proliferation
l improves lymphocyte functions; increased antibody responses
l deficiency decreases neutrophil functions & increases susceptibility to disease
Copper & Zinc
β-carotene
Chromium
Vitamin E
Sordillo, J Dairy Sci. 99:4967, 2016; Spears & Weiss, Vet. J. 176:70.
1/27/17
15
Metabolic Adaptations During the Transition Period
NE
FA
Glu
cose
NEFA Release#
Lipase Activity
Blood Insulin
NEFA Release
Lipase Activity
Blood Insulin
NEFA Release
Lipase Activity
Insulin Resistance
Inflammation Metabolic Homeostasis
Sordillo & Raphael (2013) Vet Clin Food Anim 29:267.
Balance is Essential
Practical Considerations • Reduce intense lipid mobilization during the transition period
• Minimize reductions in dry matter intake (DMI) • Design diets to increase energy without affecting DMI • Prevent over-conditioning in the dry period
• Optimize inflammatory responses and oxidant balance • Reduces sources of stress (heat stress, exposure to pathogens) • Micronutrient supplementation (Se, Vitamin E, etc.) • Immunomodulators (vaccines, supplements, etc.)
• Comprehensive Approach to Reduce Metabolic Stress • Monitoring Programs • Inclusive of entire dry period and early lactation • Early intervention