Biomedical Engineering Reference
In-Depth Information
Figure 3
Role of HSP in peptide handling and presentation. HSP are promiscuous
intracellular chaperones able to bind any peptides. They are only released after cell
lysis and can carry the cell potential antigenic fingerprints. They have the ability to
cross-present antigens using DC receptors MHC Class I-CD8
þ
and MHC II-CD4
þ
T-cells, thus both can be activated simultaneously. Through the toll receptor TLR4,
they can activate the DC to produce the necessary costimulatory molecules for effec-
tive presentation and T-cell activation.
as endogenous signals for DCs maturation and having a role in the regula-
tion of immunity versus tolerance (61,62).
C.
The Adaptive Immune Reaction in COPD
In the early studies investigating the BAL of smokers, T-cells were found to
be increased in the lungs of patients with COPD (6). However, the possible
relevance of that finding was not explored at the time.
The study that initiated the present interest in the T-cell as a possible
important cell in the pathogenesis of COPD was carried out by Finkelstein
et al. in 1995 (7). These authors used immunochemistry, to identify the
inflammatory cells infiltrating the alveolar wall, and morphometry, to define
the extent of emphysema in smokers and nonsmokers undergoing lung
resection. Their findings were surprising at the time, as they reported that
the most prominent inflammatory cell in the lung parenchyma of smokers
was the CD3
þ
T-lymphocyte that increased from a mean of 1546 cells
=
mm
3
in nonsmokers up to 10,000 cells
=
mm
3
in some smokers. Furthermore, a
