Crohn's disease (CD) and Ulcerative Colitis (UC) are inflammatory bowel diseases
(IBD) of unknown etiology. In Italy, the incidence is 3.7-4.2/100.000/year,
the prevalence 50-54/100.000 (x10 in IBD families) and the mortality rate <7%,
with a mean cost/year/patient of 125.404$. No drugs are available to prevent
clinical relapse of CD. Evidences support that in genetically susceptible hosts
an inappropriate mucosal immune response towards luminal antigens, particularly
resident bacterial flora, is involved in the pathogenesis of CD. T-cell and
macrophage activation is a feature of CD, associated to a Th1 immune response
and enhanced IL-12, IFN-gamma and TNF-alpha expression, reproducing "in
vitro" most of the systemic and local alterations of CD. Activated intestinal
mononuclear cells (LPMC) expressing IL-2 receptors (CD25+) and binding IL-2
is a major component of gut inflammation in CD. Scintigraphy using 123I-labelled
IL-2 quantitates CD25+ve LPMC in the gut, showing a higher uptake in CD. In
inactive CD, the degree of gut 123I-IL2 intake and release of TNF-a and IL-1b
correlates with time to relapse, supporting that the persistence of a mucosal
immune activation is a subclinical marker of early relapse in CD. These data
lead to the development of biologic therapies specifically targeting TNF-a and
IL-12, showing a wide range of effectiveness. A persistent "biological
activity" in clinically inactive CD may therefore represent a subclinical
marker of early clinical relapse or responsive to biologic therapies. IL-18
promotes Th1 cell clone development and up-regulates the IL-12Rb2 subunit, being
upregulated in CD gut and inhibited by IL-18 antisense oligonucleotide. Differently
from CD, in UC a humoral immune response predominates, driven by IL-4, IL-5
and IL-10. Serum and mucosal IgG against organ- and non-organ-specific antigens,
as p-ANCA and anti-colon antibodies are shown in UC. Mucosal and serum IgG against
the isoform 5 of the cytoskeletal proteins tropomyosin (hTM5) in colonocytes
are shown in 2/3 of UC and in <5% of CD and C. Serum anti-Saccharomyces mannan
IgG (ASCA) are shown in 62% of ileal CD. The p-ANCA-/ASCA+ phenotype shows a
49% sensitivity, 97% specificity 96% PPV for the diagnosis of CD, while the
p-ANCA+/ASCA- phenotype a 57% sensitivity, 97% specificity, 92.5% PPV for UC.
Both phenotypes may therefore not be used for diagnostic purposes. The usefulness
of combined p-ANCA, ASCA, hTM5 IgG serology for the diagnosis, prediction of
clinical course and responsiveness to biologic therapies in CD is unknown.
In most Western societies, the overall prevalence of Type 2 diabetes mellitus
has reached 4-6% and 10-12% among the 60-70 year old individuals. Annual health
costs caused by diabetes are around 6-12% of the over-all health expenditures.
The major costs of diabetes relate to the long-term complications, the micro-
and macrovascular complications. Since Type 2 diabetes accounts for around 90%
of all diabetes and since the complications of diabetes develop with comparable
frequency in patients with insulin-dependent (Type 1) diabetes and Type 2 diabetes,
it follows that the major health and economic burdens of diabetes are due to
Type 2 diabetes. Furthermore, macrovascular disease is the major problem in
Type 2 diabetes including coronary heart disease, stroke and peripheral atherosclerotic
disease. The etiology of Type 2 diabetes is still unclear. It is generally agreed
that; 1) the disease has both strong genetic and environmental (acquired) components,
2) its inheritance is polygenic, i.e., several genetic abnormalities are necessary
for disease manifestation, 3) impairment of insulin sensitivity (insulin resistance)
and insulin secretion, each of which is regulated by both genetic and environmental
factors, are important elements in its pathogenesis, 4) most patients are obese
and obesity, particularly intra-abdominal obesity, causes insulin resistance
and is under both genetic and environmental regulation. Non-obese, healthy subjects
with at least two first-degree relatives with Type 2 diabetes exhibit both insulin
resistance and impaired insulin secretion as compared to a carefully matched
control group lacking a known genetic predisposition for Type 2 diabetes. Type
2 diabetes is clearly a heterogeneous disease. The central pathogenetic factors
are insulin resistance and secretion abnormalities, but the underlying genetic
defects (with the exception of the rare forms like MODY diabetes) remain to
be identified.
Multiple sclerosis (MS) disease, a progressive disorder of the white matter
of the central nervous system, continuous to challenge investigators trying
to understand the pathogenesis of the disease and to prevent its progression.
MS is generally believed to be an immune mediated disorder that occurs in genetically
susceptible people. Although the sequence of event that initiates the disease
remains largely unknown. MS typically begins in early adulthood and has variable
prognosis. Fifty per cent of patients will need help walking within fifteen
year after the onset of disease. The prevalence of MS varies considerable around
the world. Kurtzke classified regions of the world according to prevalence:
a low prevalence was considered less than 5 cases per 100.000 persons an intermediate
prevalence was 5 to 30 per 100.000 persons and a high prevalence was more than
30 per 100.000 persons. The prevalence is highest in North Europe, Shoutern
Australia and the middle part of North America. There has been a trend towards
an increasing prevalence and incidence in Southern Europe. The reasons for the
variation in the prevalence and the incidence of MS worldwide are not understood.
Environmental and genetically explanation have been offered and both factors
probably have a role. Studies that show that the incidence of MS among the adopted
children of patient with MS is not higher than expected seem to argue against
the possibility that a transmissible factor is primarily responsible for the
increased risk of the disease among relatives and instead suggest that genetic
factors may be responsible. The disease typically manifests between the ages
of 20 and 40 and affects women twice as often as man. MS is generally categorised
has been either relapsing-remitting (RR) or primary-progressive (PP) in onset.
The RR form of disease is characterised by series of attacks that risolves in
varying degrees of disability from which the patient recover partly or completely
usually followed by remission period of variable duration before another attack.
The PP forms lack that acute attacks and instead typically involved a gradual
clinical decline.
The emphysema is one of the most dangerous chronic obstructive bronchopneumopathy.
It represents the fourth cause of mortality in the western countries. It is
characterized by a permanent and progressive destruction of the lung architecture.
The aetiology is not known but the relationship with smoke habitude and powder
exposure seems to be important. Some of these patients presents altered serum
levels of Alpha 1 antitrypsin, an antiprotease that provides the major defense
for the lower respiratory tract against the ravages of neutrophil elastase,
a powerful destructive protease. The loss of this protective screen of the fragile
alveolar walls results in emphysema. For several years the therapy consisted
only on bronchodilators and steroids, oxygen administration, respiratory rehabilitation,
smoke abstinence. The progressive pattern of the disease encouraged also surgical
solutions such as the lung volume reduction, which has become an accepted treatment
for selected patients. The procedure shows a wide range of therapeutic response
and, in some patients, with undefined phenotype, is highly effective. A specific
genetic background may be responsible for this differential effect.
To understand the molecular and cellular mechanisms involved in the immuneinflammatory
response in CD in order to elucidate the events leading to the amplification
and perpetuation of the acute inflammatory process of unknown etiology in CD
gut. Aim of the study is also to assess the association between genotypes and
host immune response, to identify genetic and immunologic subclinical markers
of responsiveness to immunomodulatory drugs and biologic therapies in CD.
We propose to perform extensive and unique in-depth phenotypic characterizations
of healthy glucose-tolerant first degree relatives (FDR) of patients with Type
2 diabetes in order to define subgroups as the basis for specific genetic and
molecular studies on tissue samples (fat and muscle), cell cultures (myoblasts/myotubes,
preadipocytes/adipocytes), RNA expression levels and genomic DNA. This study
can be carried out since large populations of Type 2 diabetic subjects and their
relatives are available in our center.
The primary goal of this WP is focused to generate T cells, both ab and gd TCR+,
obtained from the blood of MS patients and from healthy individuals, specific
for lipid antigens isolated from human myelin. We will generate appropriate
antigen presenting cells expressing CD1 molecules to enable presentation of
lipid antigens. We will establish lipid-specific primary T cell lines during
the first 6 months of the project, and from those T cell clones will be generated
and used for further studies in collaboration with the other Units. In addition
we will perform immunophenotyping of the cells present in the CSF of MS patients.
The complexity of the immune system is such that identification of phenotypically
(and functionally) homogeneous subsets requires the simultaneous measurement
of several cell surface antigens. Unless subsets are uniquely identified by
appropriate multiple markers, comparative functional studies between individuals
will be artefactually affected by a differential (and unknown) representation
of unresolved, functionally distinct subsets. Furthermore, we will establish
cells lines and clones from cells present in the CSF in order to study their
functional attributes. Subsets of interest will be sorted and expanded according
to standard procedures. All lines and clones will then be tested for their reactivity
towards relevant CNS antigens. Antigen responsiveness will be evaluated by proliferation
assays and by measurement of cytokines produced following antigen-specific challenge.
The following correlations will be carried out:
- Genotype-phenotype correlation in patients with different grade of emphysema
and plasma levels of alpha-1-antitrypsin;
- Genotype-phenotype correlation in patients with emphysema and SNPs at the
examined loci (see WP2);
- Correlation between genotype and clinical status of patients with emphysema
before and after lung volume reduction surgery.