Staphylococcus aureus leukocidins, therapeutic compositions, and uses thereof
AssigneeNew York University
InventorsVictor J. Torres, Ashley L. Dumont
Life of this patent
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Abstract
Disclosed herein are isolated and purified Staphylococcus aureus bi-component leukocidin, referred to herein as LukAB, and its components LukA and LukB, antibodies specific to LukA, antibodies specific to LukB, therapeutic compositions containing LukA and/or LukB, or anti-LukA and/or anti-LukB antibodies, uses of the compositions to treat acute inflammatory conditions or S. aureus infection, methods for identifying inhibitors of LukAB-mediated cytotoxicity of human phagocytes, and methods for using LukAB as a marker to predict severity of S. aureus infection.
Claims20
An active agent useful in inhibiting onset of or treating a Staphyloccocus aureus infection, comprising at least one of:
- a) a therapeutically effective amount of a LukA polypeptide having the amino acid sequence of any of SEQ ID NOS:1-14, or a sequence having at least 70% sequence similarity to any of SEQ ID NOS:1-14 (“LukA”);
- b) a therapeutically effective amount of a LukB polypeptide having the amino acid sequence of any of SEQ ID NOS:15-27, or a sequence having at least 70% sequence similarity to any of SEQ ID NOS:15-27 (“LukB”);
- c) a therapeutically effective amount of an anti-LukA antibody that specifically binds LukA;
- or d) a therapeutically effective amount of an antibody that specifically binds LukB.
A method of identifying inhibitors of LukAB-mediated cytotoxicity, comprising a) contacting in a reaction medium, human phagocytes and at least one concentration of a test compound, followed by LukA and LukB, under conditions that allow intoxication of the phagocytes by LukA and LukB;
- b) contacting the phagocytes of a) with a cell-permeable or a cell-impermeable detectable label;
- and c) measuring amount of the permeable label taken up by the phagocytes as a function of the viability of the phagocytes of b), wherein an increase in the amount of the label, relative to at least one control, indicates increased cell viability and that the test compound inhibits LukAB-mediated cytotoxicity, or c′) measuring damage of the membranes of the phagocytes as a function of amount of the impermeable label, wherein a decrease in amount of the label, relative to at least one control, indicates that the test compound inhibits LukAB cytotoxicity.
A method of identifying inhibitors of LukA binding to human phagocytes, comprising a) contacting in a reaction medium human phagocytes and at least one concentration of a test compound, followed by detectably labeled LukA under conditions that allow binding of LukA to the phagocytes;
- and b) measuring amount of the label as a function of the binding of LukA to the phagocytes, wherein a decrease in the amount of the label, relative to at least one control, indicates that the test compound inhibits binding of LukA to human phagocytes.
A method of identifying inhibitors of LukAB oligomerization, comprising:
- a) contacting in a reaction medium human phagocytes and at least one concentration of a test compound, followed by LukA and detectably labeled LukB under conditions that allow binding of LukA to the phagocytes and oligomerization of LukA and LukB;
- and b) measuring amount of the label as a function of the oligomerization of LukA and LukB, wherein a decrease in the amount of the label, relative to at least one control, indicates that the test compound inhibits oligomerization of LukA and LukB.
A method of identifying inhibitors of LukAB pore formation in membranes of human phagocytes, comprising:
- a) contacting in a reaction medium human phagocytes and at least one concentration of a test compound, followed by LukA and LukB under conditions that allow intoxication of the phagocytes by LukA and LukB;
- b) binding of LukA to the phagocytes and oligomerization of LukA and LukB;
- contacting the phagocytes of a) with a detectable label to which non-intoxicated phagocytes are impermeable;
- and c) measuring amount of the label taken up by the phagocytes as a function of extent of LukAB-mediated pore formation in the membranes of the phagocytes, wherein a decrease in the amount of the label, relative to at least one control, indicates that the test compound inhibits LukAB pore formation in the membranes of the human phagocytes.
A method of predicting severity of an S. aureus infection, comprising:
- a) culturing S. aureus obtained from an infected subject via a fluid or tissue sample from the subject;
- and b) extracting and quantifying LukA and/or LukB from the cultured S. aureus;
- wherein detection of presence or relatively high amounts of LukA and/or LukB from b);
- relative to a control which produces little or undetectable amounts of LukA and/or LukB, is indicative of a severe infection in the subject.
A composition comprising an active agent comprising at least one of:
- a) a therapeutically effective amount of a LukA polypeptide having the amino acid sequence of any of SEQ ID NOS:1-14, or a sequence having at least 70% sequence similarity to any of SEQ ID NOS:1-14 (“LukA”);
- b) a therapeutically effective amount of a LukB polypeptide having the amino acid sequence of any of SEQ ID NOS:15-27, or a sequence having at least 70% sequence similarity to any of SEQ ID NOS:15-27 (“LukB”);
- c) a therapeutically effective amount of an anti-LukA antibody that specifically binds LukA;
- and d) a therapeutically effective amount of an antibody that specifically binds LukB, as a medicament.
Dependencies are inferred from the claim text.