Small Molecule TLR9 Antagonists for Autoimmune Inflammation

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Solution Overview

Problem

Current treatments for autoimmune diseases like systemic lupus erythematosus and psoriasis are limited by aberrant activation of toll-like receptors, particularly TLR9, leading to excessive immune responses and inflammation, for which there is a need for effective antagonists that can modulate immune function without significant cytotoxicity.

Innovation Solution

Development of small molecule compounds with specific structures, such as those represented by general formula I, which act as TLR9 antagonists by inhibiting immune stimulation through interaction with TLR9, thereby reducing inflammatory responses and autoreactive inflammation, and are tested for efficacy using human peripheral blood mononuclear cells and plasmacytoid dendritic cells.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If TLR9 antagonists are used to block immune signaling, then inflammatory responses are reduced, but immune function may be suppressed

Engineering Contradiction:
Improveinflammatory responseVSAvoidimmune function
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent applies local quality by designing compounds that selectively target TLR9 signaling pathways specifically involved in autoimmune pathology, rather than broadly suppressing all immune responses. The compounds (I) are structured to interact with TLR9 in a manner that blocks pathogenic signaling while preserving essential immune functions, achieving localized modulation of the immune system's response properties.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent employs parameter changes by optimizing the chemical structure of compounds (I) to achieve differential effects on TLR9 signaling intensity. By modifying molecular parameters such as substituent groups and structural configuration, the compounds can tune the degree of TLR9 blockade to reduce inflammation while maintaining sufficient immune surveillance and response capabilities.

Inventive Principle:
Principle #35Parameter changes

2Ease of operation

If small molecule compounds are developed as TLR9 antagonists, then drug availability and oral bioavailability improve, but selectivity and specificity may decrease

Engineering Contradiction:
Improveoral bioavailabilityVSAvoidtarget specificity
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent applies segmentation by dividing the TLR9 receptor interaction interface into distinct molecular recognition elements. The compounds (I) contain specific structural modules (such as the core scaffold and substituent groups) that independently contribute to binding affinity and selectivity, allowing optimization of both oral bioavailability and target specificity through separate structural modifications.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent uses intermediary principles by designing compounds that act as molecular mediators between the TLR9 receptor and its ligands. The small molecule compounds (I) serve as intermediaries that physically block the interaction between TLR9 and activating ligands, providing selective inhibition while maintaining the natural ligand-binding site integrity, thus preserving specificity.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Productivity

If compounds are tested at higher concentrations for efficacy, then anti-inflammatory effects are enhanced, but cytotoxicity increases

Engineering Contradiction:
Improveanti-inflammatory efficacyVSAvoidcytotoxicity
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The patent applies preliminary anti-action by designing compounds (I) with intrinsic protective features that prevent cytotoxic effects before they can occur. The molecular structure includes elements that confer selective toxicity, allowing the compounds to exert anti-inflammatory effects at therapeutic concentrations while inherently resisting accumulation to cytotoxic levels through controlled metabolism and excretion pathways.

Inventive Principle:
Principle #9Preliminary anti-action

Solution Approach 2:

The patent employs partial action principles by achieving sufficient anti-inflammatory efficacy through moderate TLR9 blockade rather than complete inhibition. The compounds (I) are designed to block pathogenic signaling thresholds while allowing physiological signaling to continue, thereby achieving therapeutic effects at lower concentrations that avoid cytotoxicity associated with complete receptor blockade.

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentEP3433249B1Blocking toll-like receptor 9 signaling with small molecule antagonist
Publication Date: 2022.11.09 COUNCIL OF SCI & IND RES
  • EP3433249B1 patent drawingFigure 1
  • EP3433249B1 patent drawingFigure 2
  • EP3433249B1 patent drawingFigure 3A

AI summary

The present invention relates to small molecule4-(piperazin-1-yl)quinazolin-2-amino compounds with formula (I) useful for inhibiting signalling by certain toll-like receptors (TLRs), especially TLR9. Toll-like receptors (TLRs) are members of the larger family of evolutionarily conserved pattern recognition receptors which are critical first line of defence for self-nonself discrimination by the host immune response. Aberrant TLR9 activation is implicated in autoreactive inflammation in different autoimmune diseases. The invention depicts compounds with formula (I), composition and methods can be used in a number of clinical applications, including as pharmaceutical agents and methods for treating conditions involving unwanted immune activity due to TLR9 activation.