Pathogenic mechanisms in pulmonary fibrosis: collagen-induced migration inhibition factor production and cytotoxicity mediated by lymphocytes

The universal features of the histopathology of fibrotic lung disease are derangement of parenchymal collagen and infiltration of the parenchyma with chronic inflammatory cells. To determine if this cellular reaction might be associated with autoimmunity to a consitituent of the alveolar interstitium, peripheral blood lymphocytes were exposed to human type I collagen in vitro and evaluated for the production of migration inhibition factor and cytotoxicity. Data from 18 patients with idiopathic pulmonary fibrosis, 8 patients with pulmonary fibrosis other than idiopathic pulmonary fibrosis, 12 patients with nonfibrotic lung disease, and 9 normals demonstrated that circulating lymphocytes from more than 94% of patients with fibrotic lung disease take part in processes where the recognition of collagen results in migration inhibition factor production and lysis of collagen-coated sheep red blood cells. These collagen-induced cell-mediated phenomena are obviated with human T-lymphocyte antiserum. Collagen-induced migration inhibition factor production and cytotoxicity were found in less than 20% of patients with nonfibrotic disease and were not found in normals. Qualitatively, there was no organ (lung, skin) or species (human, rabbit) collagen specificity in these assays, but human lung alpha 2 chains were recognized more often than alpha 1(I) chains. Circulating lymphocytes from patients with fibrotic disease are present in a normal T to B ratio. These lymphocytes did not incorporate [3H]thymidine when exposed to collagen but did when exposed to T-cell mitogens. These in vitro observations suggest that circulating T-lymphocytes and lung collagen may be intimately associated in the pathogenesis of human fibrotic lung disease.

The immunosuppressive mechanism of azathioprine. I. In vitro effect on lymphocyte function in the baboon

The effect of azathioprine on in vitro baboon lymphocyte function tests was evaluated using the mitogen stimulation test, the mixed lymphocyte culture test, the migration inhibition factor test, the cell-mediated lymphocytotoxicity test and the antibody dependent cell-mediated cytotoxicity test. It was found that azathioprine inhibited phytohemagglutinin and Concanavalin A stimulation at lower concentrations than those required to inhibit pokeweed mitogen stimulation. It inhibited the MLC reaction with as little as 0.2 mug/culture in the microculture system. Azathioprine had no effect on (a) the release of migration inhibition factor, (b) the cell-mediated lymphocytotoxicity assay if presensitized cells were used, and (c) the antibody-dependent cell-mediated cytotoxicity assay. However, azathioprine inhibited CML if it was added during in vitro sensitization and induction of killer cells. These in vitro results suggest that azathioprine inhibits those reactions which require cellular division.

THE EFFECT OF GROWTH ENVIRONMENT ON THE PHYSIOLOGY OF ALGAE: LIGHT INTENSITY(1) (2)

Measurements were made of growth, pigmentation, photosynthesis, respiration, quinone Hill reaction, cell morphology, and structure as a function of growth light intensity for various algae. These processes showed varying degrees of dependency upon light intensity and are discussed with reference to algal classification. Eighteen algae, examples from 10 taxonomic divisions, were studied.

Some notes on Purulent Pericarditis

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Fracture of the Femur Occurring at Delivery

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