Mucosal Immunization, relevance to protection against tuberculosis

Mucosal immunization: relevance to protection against tuberculosis Per Brandtzaeg [email protected]

Laboratory for Immunohistochemistry and Immunopathology (LIIPAT), Department of Pathology, Oslo University Hospital Rikshospitalet, Norway

The mucosae are an enormous battlefield Mucosal effector sites provide secretory IgA (SIgA) antibodies Section through skin Hornified layer Normal human colon IgAIgG Epithelial cells Airways and oral cavity

IgA

Mucus and cilia Epithelial cells Glands Plasma cells

Gastrointestinal mucosa Surface epithelium

Glands (crypts) Plasma cells

Plasma cells At the border of hell! H&E 80% of all plasma cells are located in gut mucosa An adult exports 3 g of SIgA to the gut lumen per day

Local formation and export of mucosal immunoglobulins Lumen

Lamina propria Dimeric Plasma cells IgA (pIgA) IgA+J

Free SC pIgR (mSC)

SIgA Gland Ag ‘The IgA pump’

IgA+J

J chain

SIgM

IgM+J

IgA Pentameric IgM

IgG(±J)

IgG Mucus

IgA-coated bacteria

C o n t a i n m e n t Control, not clearance, provides mutualism

Brandtzaeg Nature & J. Immunol. 1974; Brandtzaeg & Prydz Nature 1984

(SIgA)

Coating of bacteria with SIgA is an important immune exclusion mechanism • SIgA-coated bacteria are

(PRR)

pIgR

IgA-producing cells

less invasive • Less shedding of SIgAcoated bacteria • Less horizontal spread of SIgA-coated pathogens (provides herd protection) Modified from: Natalia Shulzhenko … Polly Matzinger, Nature Med 2011; 17: 1585-93

Trachea and bronchi: Secretory IgA

Bronchioles (< 1 mm): Serum-derived IgG

Defence of lung parenchyma relies largely on serumderived IgG and cellmediated mechanisms

The lung is not a gut that breathes

Defence of lung The lung is Trachea and parenchyma relies not a gut that bronchi: largely on serumbreathes derived IgG and cellSecretory IgA Marcus Gereke (Braunschweig, Germany): mediated mechanisms

Alveolar type II epithelial cells: pneumocytes with regulatory properties, also anti-inflammatory

Type II pneumocyte

Bronchioles (< 1 mm): Serum-derived IgG

ALVEOLUS

Gereke et al., Respir. Res. 2007; 8: 47

Homeostatic function of mucosal vaccines • The goal of mucosal vaccines is to stop the pathogen at the portal of entry • This can best be achieved by induction of secretory IgA (SIgA) antibodies • Protection against invasive mucosal pathogens requires, in addition, systemic immunity (IgG antibodies and cytotoxic T cells)

Regionalization in the integrated mucosal immune system Also Tonsils & adenoids (NALT)

systemic

BALT

Lacrimal, nasal, & salivary glands

Bronchial glands

Small intestinal mucosa Peyer's patches (GALT)

Dichotomy in the integrated mucosal immune system

Also systemic Tonsils (NALT) BALT

Mammary glands

Large Intestinal mucosa Isolated lymphoid follicles (GALT)

Urogenital tract

Peyer’s patches (GALT)

Tonsils and adenoids are well designed for antigen trapping Inductive sites Tonsils & adenoids (NALT)

BALT

Human NALT anlagen: prenatal (19 wks). Nasal ILFs in 40% < 2 yrs (inducible?). Rodent NALT: postnatal organogenesis. Human BALT in 40%-100% at young age (215 yrs); rare in adult normal lungs (>20 yrs), but inducible (also rodent BALT is inducible)

Human palatine tonsil

Reticular crypt

Reticular crypt epithelium epithelium (cytokeratin) (cytokeratin)

BALT

GC

Peyer's patches, appendix Crypt and solitary intestinal lymphoid follicles (GALT)

Scanning electron-microscopy (Owen, 1988)

Inductive mucosa-associated lymphoid tissue (MALT) in human airways Inductive sites Tonsils & adenoids (NALT)

BALT

Human NALT anlagen prenatal (19 wks). Nasal ILFs in 40% < 2 yrs (inducible?). Rodent NALT: postnatal organogenesis Human BALT in 40%-100% at young age (215 yrs); rare in adult normal lungs (>20 yrs), but inducible (also rodent BALT is inducible) Adult lung with chronic infection Human bronchusassocitaed lymphoid tissue (BALT) Submucosal glands

HLA-DR

HLA-DR DC DC

CD3(T)CD20(B)

CD3(T)FoxP3(Treg)

Nasal anatomy and location of regional lymphoid tissue Waldeyer’s ring

Airway mucosa

Organized lymphoid tissue with M cells

Olfactory region

Adenoids Ciliated mucosa

Tubal tonsil Skin

is extremely rich in dendritic cells

HLA-DROlfactory Humanregion nasal RFD-7 mucosa Middle turbinate

Inferior turbinate Palatine tonsil Lingual tonsil

Oral cavity Tounge

150-200 cm2 Epiglottis Jahnsen FL, Gran E, Haye R, Brandtzaeg P. Am J Respir Cell Mol Biol, 2004; 30:31-37

Regional lymph drainage through mesenteric and cervical lymph nodes

Mesenteric lymph nodes Thoracic Right duct lymphatic duct

Cervical lymph nodes

Sublingual vaccination

Regional lymph drainage through mesenteric and cervical lymph nodes

Mesenteric lymph nodes Thoracic Right duct lymphatic duct

Cervical lymph nodes

Immune compartments of the lung From: Holt et al. Nature Rev. Immunol. 2008; 8:142-52

Wolf et al. J. Exp. Med. 2008 205: 105-15

CD4+ T cells only become activated once M. tuberculosis spreads from the lungs to the lymph nodes and starts to produce antigen

Airway luminal T cells: a newcomer on the stage of TB vaccination strategies

Jeyanathan M, Heriazon A, Xing Z. Airway luminal T cells: a newcomer on the stage of TB vaccination strategies. Trends Immunol. 2010; 31: 247-52

pIgR/SC knockout mice lack epithelial IgA transport +/+

IgA IgG

–/–

Johansen et al. J. Exp. Med. 1999; 190: 915-21

Naïve mice infected i.n. with 106 CFUs of BCG

Mice i.n. vaccinated with PstS-1 antigen (plus CT) and then i.n. infected

Effect of mucophilic SIgA and the ciliary conveyer band?

Authors from Cuba, Mexico and Malaysia

Determination of bacterial load (A) and pneumonic area (B) in lungs of mice which were untreated (NT) and those treated with human secretory IgA (hsIgA), after challenge with M. tuberculosis H37Rv by intratracheal route 2 hrs after inoculation.

Another group received M. tuberculosis preincubated with hsIgA (preinc). Well-organized granuloma of preincubated group 2 months after challenge with M. tuberculosis, visualized by H&E staining (25x) (C).

• Such vaccine administration elicits both regional mucosal and systemic immunity

• Future strategy: prime-boost approach, e.g. BCG (prime) followed by mucosal boost, or vice versa

Acknowledgements Laboratory for Immunohistochemistry and Immunopathology (LIIPAT) is part of Centre for Vaccinology and Immunotherapy (CEVI, 2001) and Centre of Excellence for Immune Regulation (CIR, 2007), funded by the Research Council of Norway, University of Oslo and Rikshospitalet University Hospital