Drug – bio-affecting and body treating compositions – Antigen – epitope – or other immunospecific immunoeffector – Amino acid sequence disclosed in whole or in part; or...
Reexamination Certificate
2000-11-09
2004-01-27
Chan, Christina (Department: 1644)
Drug, bio-affecting and body treating compositions
Antigen, epitope, or other immunospecific immunoeffector
Amino acid sequence disclosed in whole or in part; or...
C424S278100, C514S012200, C514S013800, C514S014800, C514S015800, C514S016700, C514S017400, C530S324000, C530S325000, C530S326000, C530S327000, C530S328000, C530S329000, C530S330000
Reexamination Certificate
active
06682740
ABSTRACT:
FIELD OF THE INVENTION
The present invention is in the field of allergy and relates to peptides derived from the complement peptide C3a and to their use in the prevention and treatment of allergies.
BACKGROUND OF THE INVENTION
Mast cells and basophils play a central role in inflammatory and immediate hypersensitivity reactions.
Clustering of the type 1 Fc&egr; receptors (Fc&egr;RI) present in their plasma membranes initiates a coupling cascade culminating in the secretion of mediators of immediate-type allergic reactions (Schwartz, 1994). The molecular mechanism of signal transduction initiated by Fc&egr;RI clustering has been studied intensely over the past few years (Ravetch et al, 1991; Holowka et al, 1992; Benhamou et al, 1992; Beaven et al, 1993). The &bgr; and &ggr; subunits of the clustered Fc&egr;RI were found to interact with src family protein tyrosine kinases (PTK) and cause the so far earliest detected biochemical event in their cascade, i.e., their activation. The differential control of these PTK by the &bgr; and &ggr; chains of the receptor has also been described recently (Jouvin et al, 1994). The following steps downstream involve recruitment of PTK of the syk family, activation of phospholipase C&ggr;, which in turn leads to hydrolysis of phosphatidyl inositides and production of inositol triphosphate and diacylglycerol. The former product causes the transient increase in free cytosolic calcium ion concentration while the latter is involved in activation of protein kinase C (Ravetch et al, 1991; Holowka et al, 1992; Benhamou et al, 1992; Beaven et al, 1993).
Two types of mast cells differentiate from a common precursor to produce the so-called serosal (or connective tissue type) and the mucosal type mast cells. Both phenotypes express Fc&egr;RI on their cell membrane; however, they respond differently to secretagogues and inhibitors. For example, only serosal-type mast cells are triggered by cationic peptides (including the complement-derived peptides C3a and C5a; venom-peptides, e.g., mastoparan, mellitin; neuropeptides) or polyamines; mucosal mast cells are non-responsive to these stimuli (Mousli et al, 1994). In comparison to the advanced understanding of the coupling cascade initiated by Fc&egr;RI clustering, the action modes of the complement-derived peptides C3a and C5a are less well understood.
As mentioned above, clustering of the Fc&egr;RI on mast cells and basophils is known to trigger the secretory response of these effector cells central to the allergic reactions. Similarly, the anaphylatoxic activity of the complement-derived peptides C3a and C5a is also well-known, causing activation of serosal type mast cells that results in the release of histamine or serotonin and several other inflammatory mediators including proteases, lipid mediators and several cytokines (Schwartz, 1994).
Cellular events triggered in mast cells and basophils upon Fc&egr;RI clustering or by complement-derived peptides have been investigated so far only as independent physiological processes. However, in vivo, both stimuli might be exerted simultaneously.
In earlier experiments carried out by the inventors of the present application, both the secretory response and biochemical coupling processes initiated by Fc&egr;RI clustering of rat mucosal mast cells of the line RBL-2H3, which is non-responsive to complement-derived peptides, were investigated in the presence of a range of human C3a concentrations. It was found that C3a inhibits dose-dependently antigen-induced degranulation of the mucosal line RBL-2H3 while C5a applied in the same amounts had no effect at all. When added alone, none of the complement-peptides C3a and C5a triggered the secretory response of the rat mucosal-type cells of the line RBL-2H3 (Erdei et al, 1995).
Several steps coupling the Fc&egr;RI-mediated stimulus to the secretory response were tested in order to try and identify at which point of the cascade C3a interferes. It was found that neither antigen binding to IgE-sensitized cells nor the reaction of Fc&egr;RI with IgE were influenced by the complement peptide C3a. However, the tested intracellular events were strongly and dose-dependently inhibited by C3a, i.e., tyrosine phosphorylation of several cellular proteins, the activity of PLC&ggr;, resulting in the inhibition of antigen-induced hydrolysis of phosphatidyl inositides, and elevation of intracellular free Ca
2+
. RBL-2H3 cells proved to be unresponsive to C3a in all these tests.
The fragment C3a, also called anaphylatoxin, is not suitable for use as an anti-allergic drug because it is anaphylatoxic to serosal mast cells, i.e., it is capable of causing mediator release from this type of mast cells.
SUMMARY OF THE INVENTION
It has now been found in accordance with the present invention that certain peptides comprised partially or entirely within the sequence of positions 50-77 of the complement-derived peptide C3a, and analogs thereof, are capable of inhibiting the Fc&egr;RI-induced secretory response of mucosal mast cells, without having the anaphylatoxic effect of C3a to mucosal mast cells.
Peptide C3a is a 77-mer peptide of the sequence:
Ser-Val-Gln-Leu-Thr-Glu-Lys-Arg-Met-Asp-Lys-Val-Gly-Lys-Tyr-Pro-Lys-Glu-Leu-Arg-Lys-Cys-Cys-Glu-Asp-Gly-Met-Arg-Glu-Asn-Pro-Met-Arg-Phe-Ser-Cys-Gln-Arg-Arg-Thr-Arg-Phe-Ile-Ser-Leu-Gly-Glu-Ala-Cys-Lys-Lys-Val-Phe-Leu-Asp-Cys-Cys-Asn-Tyr-Ile-Thr-Glu-Leu-Arg-Arg-Gln-His-Ala-Arg-Ala-Ser-His-Leu-Gly-Leu-Ala-Arg (SEQ ID NO:1)
The present invention relates to a peptide corresponding partially or entirely to the 50-77 sequence of the complement-derived peptide C3a and to analogs thereof capable of inhibiting IgE-mediated triggering and/or the Fc&egr;RI-induced secretory response of mucosal mast cells, said peptides being selected from the sequences:
(a) X1-Cys-Asn-R1-Ile-Thr-R2-Leu-R3-R4-Gln-His-R5-R6-R7-R8-R9-R10-Gly-Leu-Ala-R11 (SEQ ID NOs:2-4);
(b) X1-Cys-Asn-R1-X4 (SEQ ID NOs:5-13);
(c) X2-Lys-Val-Phe-Leu-Asp-X3 (SEQ ID NOs:14-17; and
(d) X5-Asp-Ser-Ser-Asn-Tyr-Ile-R11 (SEQ ID NO:18) wherein
X1 is H, lower alkanoyl, Cys, Asp-Cys or Arg-Arg-Cys;
X2 is H, lower alkanoyl or Lys;
X3 is Arg or a sequence selected from
(i) Ala-Ala-Asn-R1-Ile-Thr-R2-Leu-R3-R4 (residues 7-16 of SEQ ID NO:15);
(ii) Cys-Cys-Asn-R1-Ile-Thr-R2-Leu-R3 (residues 7-15 of SEQ ID NO:16); and
(iii) Cys-Cys-Asn-R1-Ile-Thr-R2-Leu-R3-R4-Gln-His-R5-R6 (residues 7-20 of SEQ ID NO:17);
X4 is Gly, (i) Ile-Thr-R2-Leu-R3 (residues 5-9 of ID NO:6); or (ii) Ile-Thr-Arg-R11 (residues 5-8 of SEQ ID 7);
X5 is H, lower alkanoyl or Leu;
R1 is an aromatic amino acid residue;
R2 is Glu or Lys;
R3 is a positively charged amino acid residue;
R4 is Arg or Glu;
R5 is Ala or Arg;
R6 is Arg or Lys;
R7 is Ala or Asp;
R8 is Ser or His;
R9 is His or Val;
R10 is Leu, Ile, Ala or Gly; and
R11 is OH, Arg, Arg-NH
2
, or Agm (agmatine);
and chemical derivatives and pharmaceutically acceptable salts thereof.
The peptide of the invention has preferably at least 5, more preferably 5, 7-8 or 20-21, and at most 28, amino acid residues. According to the invention, R1 is an aromatic amino acid residue preferably selected from Phe, Tyr, His and Trp; and R3 is a positively charged amino acid residue preferably selected from Arg, D-Arg, Har (homoarginine) and Lys. Lower alkanoyl according to the invention has preferably 1-4 carbon atoms, e.g., formyl, acetyl, propanoyl and butyryl.
In one embodiment, the peptide of the invention is the peptide herein identified as peptide C3a2, a 21-mer corresponding to the 57-77 sequence of the human complement peptide C3a, or the amide thereof, of the sequence:
Cys-Asn-Tyr-Ile-Thr-Glu-Leu-Arg-Arg-Gln-His-Ala-Arg-Ala-Ser-His-Leu-Gly-Leu-Ala-Arg (residues 57-77 of SEQ ID NO:1)
In another embodiment, the peptide of the invention is the peptide herein identified as peptide rC3a2, a 21-mer corresponding to the 57-77 sequence of the rat complement peptide C3a, or the amide thereof, of the sequence: Cys-Asn-Tyr-Ile-Thr-Lys-Leu-Arg-Glu-Gln-His-Arg-Arg-Asp-His-Val-Leu-Gly-Leu-Ala-Arg (SEQ ID NO:19)
In a further embodiment, the peptide of the invention i
Erdei Anna
Pecht Israel
Browdy and Neimark , P.L.L.C.
Chan Christina
Vander Vegt F. Pierre
Yeda Research and Development Co. Ltd.
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