RESUMEN
The liver is among the organs that trap lymphocytes flowing through their blood vasculature. These cells, marginated in sinusoids, participate in the liver's anti-viral and anti-tumor processes. The molecular mechanism of this lymphocyte margination and cooperation with resident sinusoidal cells remains obscure and inadequately studied due to the difficulties in obtaining samples of sinusoidal blood from a living animal. To overcome these shortcomings, we have worked out an in situ rat liver perfusion model in exsanguinated animals that enables quantitative observations of blood lymphocyte trapping in sinusoids. The cell populations trapped by the liver and retained in the perfusing blood were characterized with respect to their phenotypes and cytotoxicity. Perfused livers, previously washed out of sinusoidal lymphocytes, halted leukocytes from normal perfusing blood. The numbers of halted post-perfusion CD5+, CD4+, CD8+, CD56+ (ED1) and MHC class II+ (OX6) subsets did not differ statistically from the pre-perfusion population, which suggests active extraction of leukocytes during perfusion. Moreover, cytotoxicity of post- and preperfusion populations against CC531 and K562 remained at a similar level. The perfused livers with CC531 colon adenocarcinoma metastases halted higher numbers of the CD14 and MHC class II+ and fewer of CD11b+ and CD54+ normal blood leukocytes than normal livers. The phenotypes of cells retrieved from sinusoids after perfusion were almost identical to those obtained prior to perfusion. Interestingly, the post-perfusion populations displayed higher cytotoxic capacity than before perfusion. Taken together, the in situ liver perfusion method allows the study of the specificity and kinetics of recruitment of specific populations of host leukocytes in metastatic tumor tissue and evaluation of their cytotoxicity levels.
Asunto(s)
Adenocarcinoma/secundario , Neoplasias Hepáticas/secundario , Hígado/irrigación sanguínea , Hígado/inmunología , Linfocitos/inmunología , 1,2-Dimetilhidrazina , Adenocarcinoma/inmunología , Análisis de Varianza , Animales , Antígenos CD/inmunología , Carcinógenos , Adhesión Celular/efectos de los fármacos , Neoplasias del Colon/patología , Citotoxicidad Inmunológica , Modelos Animales de Enfermedad , Heparina/farmacología , Hígado/patología , Neoplasias Hepáticas/inmunología , Masculino , Perfusión , Fenotipo , Sistema Porta/inmunología , Ratas , Ratas WistarAsunto(s)
Adenocarcinoma/secundario , Neoplasias del Colon/inmunología , Citotoxicidad Inmunológica , Neoplasias Hepáticas/secundario , Trasplante de Hígado/inmunología , Hígado/inmunología , Linfocitos T/inmunología , Adenocarcinoma/inmunología , Adenocarcinoma/patología , Animales , Neoplasias del Colon/patología , Humanos , Inmunofenotipificación , Hígado/citología , Neoplasias Hepáticas/inmunología , Neoplasias Hepáticas/patología , Trasplante de Hígado/patología , Ratas , Ratas Endogámicas , Ratas Wistar , Linfocitos T/clasificación , Células Tumorales CultivadasRESUMEN
The liver immune function is associated with specific lymphocyte population transiently marginated in the liver sinusoids. These cells are of blood origin, however they are phenotypically and functionally different from peripheral blood lymphocytes. The question arises whether tumor proliferating in the liver can modify cell recruitment and function of marginating sinusoidal lymphocytes. Studies were performed in Wistar rats. Livers of normal and colon cancer (induced by i.v. injection of CC531 cells) metastases bearing rats were perfused for sinusoidal lymphocyte isolation. Our studies showed no difference between the number of lymphocytes retained in sinusoids of tumor bearing and normal rats. T lymphocyte subsets remained in similar proportions in liver with colorectal metastases as in normal rats. Long lasting presence of tumor in the liver was accompanied by decreased cytotoxic activity of liver sinusoidal lymphocytes, whereas it had no influence on cytotoxicity of peripheral blood lymphocytes. Repopulation of tumor liver with peripheral blood cells restored cytotoxic activity of sinusoidal lymphocytes.
Asunto(s)
Neoplasias Hepáticas/etiología , Trasplante de Hígado/inmunología , Hígado/inmunología , Linfocitos/inmunología , Animales , Fenotipo , Ratas , Ratas Wistar , RecurrenciaAsunto(s)
Hígado/inmunología , Transfusión de Linfocitos , Subgrupos de Linfocitos T/inmunología , Animales , Anticuerpos Monoclonales , Células Cultivadas , Citotoxicidad Inmunológica , Inmunofenotipificación , Hígado/citología , Activación de Linfocitos , Transfusión de Linfocitos/métodos , Ratas , Ratas Wistar , Subgrupos de Linfocitos T/citología , Células Tumorales CultivadasRESUMEN
Recent studies strongly suggest that the liver plays an important immunoregulatory role. Evidence of its role in general immune responsiveness originates from observation that, in recipients of liver grafts, the survival of other allografts is significantly prolonged. The question arises as to which blood lymphocyte subsets, most likely to be responsible for this phenomenon, marginate in liver sinusoids. To study this problem, a liver ex vivo perfusion model was designed for rats. In situ W/WAG livers were washed clear of sinusoidal marginating cells prior to and after 1 h perfusion with syngeneic blood. The number of blood cells retained in liver sinusoids, their phenotypes, the responsiveness to mitogen (PHA, 90 micrograms/ ml) and cytotoxicity against YAC-1 tumour cells were examined. Our studies showed that rat liver retains in the sinusoids a population of blood cells, enriched in NK, CD8+ and MHC class II+ cells, displaying a high cytotoxic activity and low responsiveness to mitogen stimulation, with a capacity of about 10(6) cells/g of tissue.