Università  degli  Studi  di  Perugia  Facoltà  di  Medicina  e  Chirurgia  

Lucio  Casali  Mariano  E.  Crapa  

Ca<edra  di  Mala=e  dell’Apparato  Respiratorio  

Storia  naturale  della  Tubercolosi  

Milano,  21  marzo  2014  

Genetic epidemiology of TB The analysis of the epidemic wave of tuberculosis observed in Europe in the XVIII and XIX centuries, have shown mortality frequencies that reach the 2% per year. In particular, in absence of chemotherapy, a spike can be observed in the first 50-100 years, followed by a slow decline in the next 200-250 years.

These data support the hypothesis, developped by E.R.N. Grigg, that in the first phase of the epidemic wave the most susceptible portion of population has been eliminated (rappresenting up to 20% of the whole population).

Grigg ERN. Am Rev Tuberc 1958; 78: 426-53

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The   life   cycle   of   M.   tuberculosis.   The   infecLon   is  iniLated  when  Mtb  bacilli,  present  in  exhaled  droplets   or   nuclei,   are   inhaled   and   phagocytosed   by  resident  alveolar  macrophages.  The  resulLng  proinflammatory  response  triggers   the   infected  cells   to  invade  the  subtending  epithelium.  This  response  also   leads   to   the   recruitment   of   monocytes   from   the  circulaLon,  as  well  as  extensive  neovascularizaLon  of  the   infecLon   site.   The  macrophages   in   the   granulomas  differenLate  to  form  epithelioid  cells,  mulLnucleate  giant  cells,  and  foam  cells  filled  with  lipid  droplets.  The  granuloma  can  become  further  straLfied  by  the  formaLon   of   a   fibrous   cuff   of   extracellular   matrix  material   that   is   laid   down   outside   the   macrophage  layer.  Lymphocytes   appear   to   be   restricted   primarily   to   this  peripheral  area.  Many  of  the  granulomas  persist  in  this   balanced   state,   but   progression   toward   disease   is  characterized  by  the  loss  of  vascularizaLon,  increased  necrosis,   and   the  accumulaLon  of   caseum   in  the  granuloma  center.  UlLmately,  infecLous  bacilli  are   released   into   the   airways   when   the   granuloma  cavitates  and  collapses  into  the  lungs.  

Fact  and  ficLon  in  tuberculosis  vaccine  research:  10  years  later  

Percentage  of  CD4CD25high  T  cells  from  PBMC  of  21  healthy  control  subjects  and  24  paLents  with  acLve  TB.    

Fact  and  ficLon  in  tuberculosis  vaccine  research:  10  years  later  

Targets  and  effectors  of  protecLve  immunity  in  

tuberculosis   T   cells   parLcipate   in   protecLon.  

Cytokines   acLvate   macrophages,   killer  

molecules  lyse  target  cells  and  Mycobacterium  

tuberculosis.   The   role   of   B   cells   is   unknown.  

Th=T   helper,   CTL=cytolyLc   T   lymphocytes,  

TNF=tumour  necrosis  factor.  

Mycobacterium  tuberculosis  evades  host  immunity  by  recruiLng  mesenchymal  stem  cells  

S.  Raghuvanshi  et  Al.www.pnas.org/cgi/doi/10.1073/pnas.1007967107  

Infusion   of   MSCs   converts   a   mouse   strain  resistant   to   M.   tb   infecCon   to   disease  suscepCbility.   TGF-­‐βRIIDN   transgenic   mice  were   infused   with   5   ×   106   MSCs   derived  from  C57BL/6  mice  infected  for  30  d  with  M.  tb,  followed  by  M.  tb  challenge  (∼110  bacilli)  by   the   aerosol   route.   (A)   Bacterial   loads   in  lungs   and   spleens   of  mice   at   different   days  aUer   infecCon.   (B)   Histological   secCons   of  spleens.   (C)   Numbers   of   granuloma-­‐like  structures   per   cross-­‐secCon   evaluated   by  examining   30   slides   of   each   sample.   (D)  Bacterial  loads  in  MSC-­‐treated  C57BL/6  mice  at  different  Cme  points  aUer  M.  tb  infecCon.  (E)   Sorted   CD4+Thy1.2+FoxP3−   cells   from  FoxP3   knock-­‐in   mice   were   adopCvely  transferred   to   Thy1.1+   mice   along   with  MSCs,   followed   by   infecCon   with   H37Rv.  Conversion   to   cells   with   a   Treg   phenotype  was   followed   in   the   spleens   by   analyzing  Thy1.2+CD4+FoxP3+   cells.   Results   presented  here   a re   representaCve   o f   th ree  independent  experiments.  

Hypoxia:  a  window  into  Mycobacterium  tuberculosis  latency  

Tige  R.  et  Al.  Cellular  Microbiology  (2009)  11(8),  1151–1159    

Hypoxic  gene  expression  is  rapidly  dominated  by  the  Enduring  Hypoxic  Response  (EHR).  Each  bar  represents  the  total  number  of  genes  induced  at  that  hypoxic  Cme  point.    The  bars  aredivided  into  the  genes  of  the  DosR  response  (blue),  the  EHR  (red),  and  other  induced  genes  (green)  

The  Mycobacterium  tuberculosis  DosR  Regulon  Assists  in  Metabolic  Homeostasis  and  Enables  Rapid  Recovery  

from  Nonrespiring  Dormancy  

Rachel  L.  et  Al.  J.  Bacteriol.  2010,  192(6):1662.  

Growth  and  survival  during  anaerobic  dormancy  determined  by  recovery  on  solid  and  liquid  media.  Wild-­‐type,  DorKO  mutant,  and  complemented  bacteria  were  grown  in  glass  tubes  with  sCr  bars  and  a  culture-­‐to-­‐headspace  raCo  of  0.65.  Cultures  were  sCrred  with  magneCc  sCrrers.  (A)  CFU  were  counted  at  various  Cmes  by  plaCng  samples  from  tubes  harvested  sacrificially.  Squares,  H37Rv;  triangles,  DorKO;  circles,  DorCO.  

The  Mycobacterium  tuberculosis  DosR  Regulon  Assists  in  Metabolic  Homeostasis  and  Enables  Rapid  Recovery  

from  Nonrespiring  Dormancy  

Rachel  L.  et  Al.  J.  Bacteriol.  2010,  192(6):1662.  

ATP  measurement  during  early  dormancy.  Samples  from  RAD  model  cultures  were  harvested  at  various  Cme  points  in  an  anaerobic  chamber.  ATP  was  extracted  using  a  chloroform  heat-­‐based  method  and  frozen  unCl  measurements  could  be  obtained  using  the  Promega  Enliten  ATP  assay  system.  The  values  are  the  averages  of  three  experiments.  Open  bars,  H37Rv;  black  bars,  DorKO;  gray  bars,  DorCO.  RLUs,  relaCve  light  units.  

No

Anti TNF

Pz  italiano  di  56  aa,  in  tra<amento  con  infliximab  da  2  se=mane,  esordio  con  stato  confusionale,  crisi  epile=che,  tanto  da  portare  a  ricovero  in  

neurologia  per  sospe<a  encefalite.    Successivamente    febbre  e  grave  dispnea.    

Deceduto  in  rianimazione  dopo  3  se=mane  per  shock  se=co.  

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U.  Mack  et  Al.  Eur  Respir  J  2009;  33:  956–973  

Summary  of  the  dynamic  sequence  of  events  governing  the  generaCon,  persistence  

and  reacCvaCon  of  granulomatous  lesions  in  the  

course  of  Mycobacterium  tuberculosis  infecCon.  For  details  of  T-­‐

helper  cell  priming,  triggering  and  effector  molecules,  and  sequenCal  progress  of  lesions  to  latency  and  reacCvaCon,  please  refer  to  secCon  1  of  the  present  arCcle.  IFN:  interferon;  IL:  interleukin;  

TNF:  tumour  necrosis  factor;  ESAT:  early  secreted  anCgenic  target;  CFP:  culture  filtrate  

protein;  ROI:  reacCve  oxygen  

intermediates.