Production of HLA class I eluted platelets on a clinical scale using a u-shaped hollow fiber filtration device and citric acid elution

HLA‐Alloimmunization remains a significant problem in platelet transfusion therapy. HLA‐eluted platelet products could aid in the supportive therapy of these patients, because they are readily available in contrast to HLA‐matched platelets. Until now the major drawback of these products were the cumbersome preparation and standardization of such products. Hollow fiber separation systems could be an alternative preparation method because they are based on gravity separation which means there are no centrifugation steps involved. This ensures a very gentle treatment of the platelets with no activation. Single donor platelets were eluted with citric acid and washed three times using a U‐shaped hollow fiber filter device. Products were evaluated for their antigen expression using directly labeled specific monoclonal antibodies for HLA class I (w6/32, FITC labeled) and platelet glycoproteins specific monoclonal antibodies (CD41a PE labeled, CD42 PE labeled) using flow cytometry. Using ten apheresis platelet products and a citric acid elution technique for HLA class I antigen elution we were able to prepare HLA‐eluted platelet products which expressed less then 20% of their initial amount of HLA class I on their surface. The whole procedure took less than three hours. The surface density of platelet specific glycoprotein complexes was unaffected by the procedure. Production of HLA‐eluted platelet products on a clinical scale in a closed system is feasible and can be a good option for the platelet support of HLA class I immunized patients

Carotenoids located in human lymphocyte subpopulations and natural killer cells by Raman microspectroscopy

The presence and subcellular location of carotenoids in human lymphocyte sub-populations (CD4+, CD8+, T-cell receptor-γδ+, and CD19+ ) and natural killer cells (CD16+ ) were studied by means of Raman microspectroscopy. In CD4+ lymphocytes a high concentration (10-3M) of carotenoids was found in the Gall body. In CD8+ lymphocytes, T-cell-receptor-γδ+ lymphocytes and in natural killer cells carotenoids appeared to be concentrated (10-4M) in the Golgi complex. The concentration of carotenoids in CD19+ lymphocytes was found to be below the present detection limit, which is ~10-6 to 10-5 M. The results provide new possibilities to investigate the mechanism(s) behind the suggested protective role of carotenoids against the development of cancers

Interaction of the Cauliflower Mosaic Virus Coat Protein with the Pregenomic RNA Leader

Using the yeast three-hybrid system, the interaction of the Cauliflower mosaic virus (CaMV) pregenomic 35S RNA (pgRNA) leader with the viral coat protein, its precursor, and a series of derivatives was studied. The purine-rich domain in the center of the pgRNA leader was found to specifically interact with the coat protein. The zinc finger motif of the coat protein and the preceding basic domain were essential for this interaction. Removal of the N-terminal portion of the basic domain led to loss of specificity but did not affect the strength of the interaction. Mutations of the zinc finger motif abolished not only the interaction with the RNA but also viral infectivity. In the presence of the very acidic C-terminal domain, which is part of the preprotein but is not present in the mature CP, the interaction with the RNA was undetectable