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M Janusz

Publications and source records attributed to M Janusz.

64 records · Page 4Linked to original sources
PubMedDate not supplied

New analogs of the immunoregulatory PRP-pentapeptide.

To determine the role of consecutive amino acid residues in the immunoreactivity of the shortest active fragment of PRP, a series of analogs substituted by L-alanine in successive positions of the peptide chain was synthesized. The immunological investigations were carried out in several models: the immune response to T-cell dependent antigen, SRBC (in vivo and in vitro) and to T-cell independent antigen, PVP in vitro. The immunotropic action of the peptide was, in addition, verified with respect to thymocytes forming autologous rosettes. The results of these experiments revealed immunotropic activity (in all tests) of the analog containing alanine instead of proline in position 5 of PRP-pentapeptide.

Adjuvants, Immunologic↗
PubMedDate not supplied

Cytokine-inducing activity of a proline-rich polypeptide complex (PRP) from ovine colostrum and its active nonapeptide fragment analogs.

A complex of proline-rich polypeptides (PRP) was isolated from ovine colostrum in our laboratory and was shown to possess immunomodulatory properties and psychotropic activity, including beneficial effects in the treatment of Alzheimer's disease. A nonapeptide fragment (NP): Val-Glu-Ser-Tyr-Val-Pro-Leu-Phe-Pro, isolated from the chymotryptic digestion products of PRP, and its C-terminal fragment, a hexapeptide (HP): Tyr-Val-Pro-Leu-Phe-Pro also exhibited immunoregulatory activity. Although NP and HP expressed activity similar to that of PRP in studies on humoral and cellular immune responses, in other immune processes, e.g. induction of cytokines, they showed markedly lower activity than PRP. In the search for more active peptides, in the present study, we compared the cytokine-inducing ability of PRP, NP, HP, and linear oligomers of NP or HP. For this purpose, the induction of IFN, TNF-alpha, IL-6, and IL-10 in human whole blood cell cultures was measured. NP, HP, and their oligomers showed differential effects in the induction of cytokines, generally lower than that of PRP. Only the PRP complex showed a bell-shaped dose-response dependence suggesting regulatory properties. There were no distinct differences between monomeric forms of NP (NP1) or HP (HP1) and their oligomers in the induction of IFN and TNF-alpha (Th1 cytokines) but such differences were found in the induction of IL-6 and IL-10 (Th2 cytokines). Dimer (NP2) was less active than the monomeric NP1 nonapeptide in the induction of IL-6 and IL-10. On the other hand, oligomers: HP3 and HP4, showed a significantly higher ability to induce Th2 cytokines compared to HP1, HP2 or NP peptides. This was especially evident in the case of IL-10 induction, where the activity of HP4 surpassed the activity of PRP and approached the activity of LPS-PHA. The results obtained showed that some of the peptides studied, when used at higher concentrations (100 microg/ml) may replace the PRP complex as cytokine inducers. Our data also suggest the possibility of using certain oligomers for selective induction of particular cytokines.

Adjuvants, Immunologic↗