Biomedical subjects

J Słoń

Publications and source records attributed to J Słoń.

7 recordsLinked to original sources

PubMed1995

The immunomodulatory diversity of the proteins of the transforming growth factor beta (TGF beta) family.

The examination of immunomodulatory properties of oligopeptides derived from two exposed loops (containing thymopentin-like and tuftsin-like sequences, respectively) of the proteins belonging to TGF beta family suggests that the particular species of the TGF beta family should differ distinctly in their influence on the immune response. According to our results obtained from three TGF beta species of mammals, TGF beta 2 should be a strong immunosuppressor, whereas for TGF beta 3 the immunostimulative potency is more probable. TGF beta 1 species would possess both immunosuppressive and immunostimulative potency, residing in two different loops of the protein. The results obtained also suggest that chicken TGF beta 4 should be associated with immunostimulative effects and xenopus TGF beta 5 with immunosuppressive ones.

Adjuvants, Immunologic↗

PubMed1991

Competition between tuftsin and HIV-1, HIV-2 envelope protein sequences.

Syntheses of tuftsin-like partial sequences of HIV-1 and HIV-2 gp-120 proteins: Thr-Lys-Ala-Lys (I), Thr-Lys-Ala-Lys-Arg (II), Pro-Thr-Lys-Ala-Lys-Arg (III), Thr-Lys-Glu-Lys (IV), Thr-Lys-Glu-Lys-Arg (V), and Pro-Thr-Lys-Glu-Lys-Arg (VI) are described. From HIV-1 partial sequences peptide I inhibited the phagocytosis stimulating activity of tuftsin. The inhibitory potency diminished progressively for peptides II and III, in parallel to the increase of their slight phagocytosis stimulating activity. Similar results were obtained also for the fragments of the HIV-2 gp120 protein. The inhibitory activity, clearly visible for IV, diminished with peptide chain elongation. Peptides IV and VI were devoided of the phagocytosis stimulating activity while peptide V was slightly active.

Amino Acid Sequence↗

PubMed1991

The evidence on the possible interleukin-1 alpha tuftsin competition.

It was demonstrated by the experiments performed in vivo in mice (peripheral blood leukocyte number determination), and in vitro on mouse thymocytes (autologous rosette forming cell number determination) that tuftsin (Thr-Lys-Pro-Arg), a natural phagocytosis-stimulating factor, inhibits the action of interleukin 1 alpha. This effect is interpreted by us in the terms of structural correspondence between tuftsin and "retro-tuftsin"-like sequence 210-213 of the IL-1 alpha peptide chain. The analysis of tertiary structure shows that this sequence is localized in the exposed fragment of the IL-1 alpha molecule, probably responsible for the interaction with the receptor.

Amino Acid Sequence↗

PubMed1990

Immunoregulatory activity of substance P fragments.

The C-terminal SP7-11 pentapeptide (Phe-Phe-Gly-Leu-Met-NH2) was found to suppress in vitro the immune response in a dose of 1-5 micrograms/ml. It produced also a distinct immunosuppression in vivo, by both per os and intraperitoneal, applications. In contrast, the N-terminal SP1-4 fragment (Arg-Pro-Lys-Pro) suppressed the response at a dose of 0.1 microgram/ml, but stimulated it slightly at higher doses (1-5 micrograms/ml). A structural analog of SP1-4 (Gly-Pro-Arg-Pro tetrapeptide) was found to be a strong immunosuppressor at a dose of 5 micrograms/ml, indicating the importance of N-terminal basic residue for the immunoregulatory activity of intact SP.

Amino Acid Sequence↗

PubMed1990

Competition between tuftsin and HBV S-protein sequences.

The syntheses of HBV S-protein partial sequences: Thr-Lys-Pro-Thr (I), Thr-Lys-Pro-Thr-Asp (II), and Thr-Lys-Pro-Thr-Asp-Gly (III) and also of pentapeptide Thr-Lys-Pro-Gly-Arg (IV), are described. For the peptides II and III inhibitory activity against tuftsin was found. Peptide IV (an analogue of tuftsin-inhibitor Thr-Lys-Pro-Pro-Arg) demonstrated a tuftsin-like activity in the phagocytosis experiments.

Amino Acid Sequence↗

PubMedDate not supplied

Antinociceptive action of the SP1-4 tetrapeptide and of some tuftsin analogs.

The N-terminal tetrapeptide of substance P (SP1-4) was found to produce analgesia, after the icv injection to the rat brain, which is lower in its intensity than that produced by tuftsin (Thr-Lys-Pro-Arg tetrapeptide). Among investigated tuftsin analogues Thr-Lys-Pro-Thr and Thr-Lys-Pro-Thr-Asp (partial sequences of S-protein of HB virus) were weakly active, Thr-Arg-Pro-Arg was inactive, and Thr-Lys-Pro-Gly-Arg produced a weak hyperalgesia 30 min after the icv injection. The obtained results were compared with those obtained previously in the phagocytosis stimulation test. In the control experiments the effects of free amino acids of the tuftsin molecule (Thr, Lys, Pro, Arg) were also studied.

Analgesia↗

PubMedDate not supplied

Immunomodulatory activity of disulphide bridged peptides related to lactoferrin immunosuppressive mini-domain.

The following peptides, related to the immunosuppressive loop of lactoferrin (I) and containing the sequence Arg-Lys-Pro-Val-Asp (II) were synthesized [sequence: see text] and their influence on humoral and cellular immune response was evaluated. It was found that all these peptides lack the immunosuppressive activity regarding the humoral immune response, but show quite strong immunosuppressive activity with respect to the cellular immune response. It may suggest, that the peptide conformational requirements for the suppression of the cellular and humoral immune response are different.

Adjuvants, Immunologic↗