Correlation between ultrastructural and histochemical parameters in lymphokine-activated killer (LAK) cells reacting with target cells in vitro

Identification of mRNAs differentially expressed in lymphocytes following interleukin-2 activation

We investigated genes involved in the interleukin-2 activation of cultured lymphocytes using a differential display reverse transcription PCR technique. Three cDNA fragments corresponding to mRNAs differentially amplified in the activated lymphocytes were sequenced and identified. These fragments were identical to the 3' region of the mRNAs encoding for the tumor rejection antigen TRA 1 that is the human homologue of the murine heat shock protein gp96, the DAP12 protein that possesses an immunoreceptor tyrosine-based activation motif, and the human motor protein p87/89 expressed in the heart. These proteins are involved, respectively, in cellular communication, in signal transduction, and in cellular movements. Our findings suggest that the activation of cellular immune response by interleukin-2 is a process analogous to other known phenomena of activation of catabolic reactions of energy transduction for activities which allow adaptation of cells to stress conditions.

Ultrastructural aspect of myocarditis: its relevance for the diagnosis

The Dallas consensus was used to reveal active or borderline inflammatory loci by light microscopy (LM). When lymphocyte-cardiocyte interaction was observed by electron microscopy (EM), the deleterious or dormant pattern of inflammatory process was recognized. The first was determined by lymphocytes that adhered to cardiocytes, next to necrotic cardiocytes or admixed with debris. The second was marked by scattered lymphocytes between preserved cardiocytes and the absence of lymphocytes adhered to cardiocytes and necrotic cardiocytes. The deleterious pattern of the inflammatory process (EM) commonly supplemented the active appearance of inflammatory loci (LM). In contrast, the borderline outlook of the LM completed either the deleterious or dormant pattern of the EM. This discrepancy was related to the restricted resolution of LM, which might hide the actual stage of the disease. The diagnosis of myocarditis was founded on mutual LM and EM observations. The active or borderline appearance of LM of the deleterious pattern (EM) was considered indicative for the active stage of myocarditis. The borderline outlook of the LM of the dormant pattern of the EM was admitted to indicate either the healing phase of the disease with lymphocytes still lagging behind, or a latent phase of the ongoing myocarditis, according to the patient's hemodynamic status.