Effect of Commensal and Pathogenic Bacteria on Programming of Neonatal Immune Response

Transcription

1 Effect of Commensal and Pathogenic Bacteria on Programming of Neonatal Immune Response Susanna Cunningham- Rundles, PhD 8th ISAPP Meeting Barcelona, Spain August 28th, 21 The immune system is primed at birth Newborns encounter environmental antigens: Food Colonizing commensal bacteria Potential pathogens Exposure can lead to beneficial adaptive changes: Antigen exclusion (IgA and IgM) Suppressor mechanisms Oral tolerance Or exposure can lead to inflammation, translocation, infection, sepsis Newborn immune response to microorganisms/antigens may affect the growth and development of microflora 1

2 The specialized neonatal immune system, is shaped by fetal life, develops postnally Memory T cells are largely absent. CD4+ T cells often have low T cell helper type -1 (Th-1) cytokine response ( IL-2, IFN γ). T cell helper type -2 (Th-2) cytokine response (IL-4) is relatively increased, as in fetal life, favors allergic reactions. Dendritic cells have a different cytokine response pattern: Reduced interferon and IL-12 Increased IL-23 B cell antibody responses are slower, reach lower peak levels, show lower IgG2, have lower average affinity, and reduced heterogeneity. T cells in term and preterm infants 4 35 Percent Posiive Term PreTerm Adult 1 5 CD4 Memory CD8Memory Peoples, Cheung, Nesin, Tatad,, Lin, Hoang, Perlman, Cunningham-Rundle, 29 2

3 Thymic cellularity is reduced in newborns and displays age- related changes A.Total thymocyte numbers per thymic lobe in normal children (black dots) and patients (open symbols) plotted against log age of each child. B. Median total thymocyte numbers of healthy children in 6 age groups. Gray bars show 1th and 9th percentiles. Kruskal- Wallis test: P =.11. Weerkamp, de Haas, Naber, Comans-Bitter, Bogers, van Dongen 25 Preterm infants with respiratory distress syndrome who develop BPD have reduced lymphocyte numbers * * * * * Days post birth * * Controls BPD Ballabh, Simm, Kumari, Krauss,Jain, Auld, Cunningham-Rundles 23 3

4 Response to microbes is critical for host defense throughout life Newborns are vulnerable to microbial infection Normal development of the immune system is compromised by: Pre term birth Low birth weight (<25 gms) SGA (small for gestational age) Can exposure to probiotic bacteria enhance immune development? Neonatal response to bacterial antigens Percent producing cytokine p=.2 CD8 RA CD8 RO Lp299v S. Epi GBBS 4

5 Naïve CD4+T cells are reduced in preterm compared to term infants Percent Positive Term PreTerm Adult Naïve CD4+ T cells are lower in preterm vs term infants or adults (p<.1) Naïve CD4+ T cells become regulatory T cells: CD4+CD25+ Foxp3+T regs CD4+ CD161+ progenitors for Th-17 T cells 5 CD4 Naïve CD8 Naive Peoples, Cheung, Nesin, Tatad, Lin, Hoang, Perlman, Cunningham-Rundles, 29 Regulatory T cell Subset Percent Positive Adults Term Preterm Term & preterm have lower % CD3+CD161+ T cells vs adults (p<.1) Higher in preterm vs term infants (p<.3) Naïve CD4+ CD161+ are progenitors for Th- 17 T cells CD3+ CD161+ Peoples, Cheung, Nesin, Tatad, Lin, Hoang, Perlman, Cunningham-Rundles, 29 5

6 Cytokine patterns determine adaptive immune cell development and function T helper type 1 Interferon gamma Interleukin-2 Tumor necrosis factor T helper type 2 Interleukin 4 Interleukin 5 Interleukin 1 Microbes trigger innate immune responses via Toll- like receptor (TLR) signaling Monocyte/ dendritic cells Interleukin 12 Interleukin 1 Interleukin 6 Interleukin 8 TLR 4 mediated response to bacterial lipopolysaccharide (LPS) Calder 22 6

7 Toll Like Receptor -4 expression in term and pre term infants Expression of TLR-4 on peripheral blood monocytes from preterm infants was reduced compared to term infants or adults Forster- Wadl et al, 25 LPS upregulation of TLR-4 in term infants p<.1 comparing LPS response of neonates and adults by 2- way ANOVA, Bonferroni Hoang, Lin, Perlman, Cunningham-Rundles, in preparation 7

8 Cytokine response to bacteria is species related Gram-positives preferentially induce IL-12 and TNF-alpha Gram-negatives induce more IL-6, and IL-8. Gram-negative species induced more PGE2 than gram-positive bacteria in monocytes Karlsson et al. Inf Immun 22 Cytokine secretion in response to E. coli 12 9 Mean Concentration Ctokine Adults: 2 hrs Adults: 4 hrs Neonates: 2 hrs Neonates: 4 hrs Mean Concentration Cytokine Adults: 2 hrs Adults: 4 hrs Neonates: 2 hrs Neonates: 4 hrs IL6 IL-8 Mohamed, Cunningham-Rundles, Dean, Hammad, Nesin 28 8

9 Detection of multiple cytokine responses in a single cell population CD3 TC Histogram LPS 1mcg/ml=29.9% LPS 1ng/ml=15.5% unstim=6.56% CD14 FITC TNF-a PE Term and preterm monocyte response Tatad, Nesin, Peoples, Cheung, Lin, Sison, Perlman, Cunningham-Rundles 28 9

10 Monocyte response to bacteria in term and preterm infants IL-12 IL-1 Respon Percent positive Unstim LP29v E.coli Adult ControlsTerm InfantsPreTerm Infants Percent Postive Adult ControlsTerm Infants PreTerm Infants Unstim Lp299v E.coli Tatad, Nesin, Peoples, Cheung, Lin, Sison, Perlman, Cunningham-Rundles, 28 Does mode of delivery influence neonatal immune response? Danthanth Hoang, MD Fellow, Division of Newborn Medicine Department of Pediatrics New York Presbyterian Hospital Weill Cornell Medical Center 1

11 Mode of delivery affects IL-1 cytokine response IL-1 Response to LPS significant for NVD (p<.5) but not CS group Hoang, Lin, Perlman, Cunningham-Rundles in preparation Mode of delivery affects IL-12 cytokine response IL-12 Response to LPS significantly higher for CS compared to NVD delivery (p<.1) Hoang, Lin, Perlman, Cunningham-Rundles in preparation 11

12 Mode of delivery affects TNF alpha dose response to LPS Graded TNF alpha response to LPS is evident for NVD but not for CS delivery Hoang, Lin, Perlman, Cunningham-Rundles in preparation Neonates are susceptible to uncontrolled inflammation Chorioamnionitis is associated with increased risk of cerebral palsy and BPD. Pro-inflammatory cytokines are thought to be major mediators of injury. Bronchopulmonary Dysplasia: IL-1 β, IL- 6, IL-8 Cerebral Palsy: TNF-α, IL-1β 12

13 Could omega-3 polyunsaturated fatty acids EPA and DHA reduce proinflammatory cytokine response in the newborn? Michael Espiritu, MD Fellow, Division of Newborn Medicine Department of Pediatrics New York Presbyterian Hospital Weill Cornell Medical Center Background: Omega-3 Fatty Acids Omega-3 and omega-6 PUFAs are not synthesized de novo and must be derived nutritionally. In the typical Western diet, omega-6 fatty acids predominate (by up to 2:1) and may be a cause of increased inflammatory diseases. TPN formulations for infants do not provide a significant source of omega-3 PUFAs. Preterm and critically ill neonates may benefit from omega-3 PUFAs. 13

14 Omega-3 poly unsaturated fatty acids (PUFA)s are potentially anti- inflammatory Incorporation into cellular membranes affects structure and cellular function Modulation of cellular signaling pathways in normal and pathological cells Direct effects on gene expression Galli and Calder, 29 IL-6 response of THP-1 monocytes Espiritu, Lin, Perlman, Cunningham-Rundles in preparation, presented at ESPR and PAS 14

15 TNFα response of THP-1 monocytes Espiritu, Lin, Perlman, and Cunningham-Rundles in preparation, presented at ESPR and PAS IL-12 response of THP-1 monocytes Espiritu, Lin, Perlman, and Cunningham-Rundles in preparation, presented at ESPR and PAS 15

16 IL-1 response of THP-1 monocytes Espiritu, Lin, Perlman, and Cunningham-Rundles in preparation, presented at ESPR and PAS Newborn cord blood cell response to LPS after treatment with EPA and DHA ex vivo Study Population: Healthy term and pre-term (<36 wks gestational age) neonates Exclusion Criteria: genetic syndromes, Apgar scores <5 at 5 min, clinical and/or pathologic evidence of chorioamnionitis, rupture of membranes for more than 24h, confirmed early onset sepsis, HIV or other acquired or genetic immunodeficiency 16

17 IL-12 response of neonatal cord blood monocytes Espiritu, Lin, Perlman, and Cunningham-Rundles in preparation, presented at ESPR and PAS Response to microbes in HIV infection Opportunistic infections in HIV+ children (C. parvum) cause severe diarrhea (Guarino et al 24). Translocation of microbial products (LPS) in chronic (HIV) infection correlates with activation of the immune system (Brenchley et al 26) HIV-positive children are able to mount a mucosal immune response (Silva-Boghossian et al 28) 17

18 HIV infection and mucosal immune system Th17 cells are beneficial in immunity against bacteria and fungi. In SIV(mac251) infection, frequency of Th17 cells at mucosal sites (altered balance between Th17 and Th1 cells) negatively correlates with plasma virus level. Cecchinato et al 28 Commensal microbiota control Th17 differentiation in the gut and are depleted from the gut in HIV-infection individuals leading to microbial translocation, chronic immune activation and disease progression. Ancuta et al 21 Probiotic treatment of HIV+ children Strong rationale for treatment (Reid et al 25) HIV+ children can be colonized with L. plantarum and show systemic immune response (Cunningham-Rundles et al. 2) Randomized double blind placebo controlled trial with (B. bifidum + S. thermophilus showed increase in mean CD4 count in treated children while untreated children showed a loss of CD4+ T cells (Trois et al 28). 18

19 CP M CP M Effect of CD4+ T cell level in vivo on response to Lactobacillus in vitro HIV+ CD4 = 7% HIV+ CD4 = 34% Lp299v PHA Treatment of HIV+ children and growth failure with Lactobacillus plantarum 299v FTT: Chronic condition, stunting, delayed puberty, chronic cytokine activation Height, weight, & head circumference below fifth percentile for age Treatment: Placebo controlled randomized trial for five months following 3 month baseline studies. Lp 299v was prepared as a lyophilized powder in an oatmeal base and given once per day 1(1) CFU 19

20 Trans retinol levels are reduced in children born to HIV+ mothers Cunningham-Rundles, Ahrne, Dnistrian, 29 Effect of Lp 299v on height Responders Non Responders : p=.3 2: p=.24 3: p=.5 4: p=.49 5: p=

21 Effect of Lp299v on weight RESPONDERS NON RESPONDERS * p= * MONTHS ON TREATMENT * Immune response to mitogen after Lp299v treatment 21

22 Collaborators Cellular Immunology Laboratory Hong Lin, PhD S. Cheung, BS Maciej Simm, BS Elizabeth Foley, (Class of 212) John Peoples, MD (CUMC Class of 25) Michael Espiritu, MD (Fellow, Neonatology) Danthanth Hoang, MD (Fellow, Neonatology) AMF Tatad, MD Mohamed Mohamed, MD (Fellow, Neonatology) Praveen Ballabh, MD (Fellow, Neonatology) Division of Newborn Medicine Jeffrey Perlman, MD Alfred Krauss, MD Peter Auld, MD Mirjana Nesin, MD AJ Jain, MD Lund: Microbiology Studies Siv Ahrne, PhD Marie Louise Johansson, PhD 22