Fig. 2.

Case 1 – Innate Immunity - Photomicrographs from A to D

In photomicrograph A it can be observed FCN3 (arrows) expressed along the thick hyaline membranes (asterisk).

In B, it observed the expression of IL-6 in the alveolar septum (arrow) by lymphocytes, type II pneumocytes, and alveolar macrophages.

In C, it can observe the expression of TNF alpha in the alveolar septum (arrow) by type II pneumocytes and alveolar macrophages.

In D, it observed endothelium (arrow) and pneumocytes (asterisk) expressing ICAM-1. Presence of polymorphonuclear cells permeating the vascular wall (dashed arrow) configuring endotheliitis.

Case 2 – Innate Immunity - Photomicrographs from E to H

In photomicrograph A, there is a scarce expression of FCN3 in a few alveoli still with remaining hyaline membranes (arrow).

In B, it can observe a marked expression of IL-6 in the areas of fibrosis (arrow).

In C, it can observe a discrete expression of TNF alpha (arrow) only in a few alveoli with remaining hyaline membranes (asterisk).

In D, it observed a marked expression of ICAM-1 in endothelial cells (arrow) and pneumocytes (asterisk). Vessels show activation of endothelial cells and endotheliitis (dashed arrow).

Case 1 – Adaptive Immunity - Photomicrographs from A to D

In photomicrograph A, it can be observed scattered (about 2 per medium power field) CD8⁺T lymphocytes (arrows). Vessel with polymorphonuclear cells on its wall (dashed arrow) configuring endotheliitis.

In image B, it observed numerous alveolar macrophages (arrow) expressing SPHINGOSINE, which characterizes the M2 type macrophage.

In C, it can be observed a slight expression of TGF-beta in type II pneumocytes (arrow) and alveolar macrophages.

The photomicrograph D can observe moderate expression of IL-4 in type II pneumocytes (arrow) and alveolar macrophages.

Case 2 – Adaptive Immunity - Photomicrographs from E to H

In photomicrograph A, it can observe numerous (about 20–30 per medium-magnification field) CD8⁺ T lymphocytes (arrow).

In image B, it observed numerous alveolar macrophages (arrow) expressing SPHINGOSINE, which characterizes the M2 type macrophage.

In C, it observed a moderate expression of TGF-beta in macrophages and fibroblasts (arrow).

It can observe moderate to a marked expression of IL-4 (arrow) in macrophages and lymphocytes in photomicrography D.