JMIR Publications

ABSTRACT

Background:

Despite the success of immune checkpoint inhibitors (ICIs) in certain cancers, many late-stage solid tumors remain “immune-cold,” characterized by low T-cell infiltration, dense extracellular matrix (ECM), stromal and vascular barriers, and poor responses to systemic immunotherapy [4,5,6,7,32,33]. Overcoming these resistance mechanisms requires localized and controlled reprogramming of the tumor microenvironment (TME) to permit effective anti-tumor immunity [4,5].

Objective:

Strategy proposes a biomarker-guided, staged, and locally confined immune cascade designed to enable reinfiltration and activation of endogenous or autologous T cells in previously unresponsive solid tumors.

Methods:

“Second Breath” involves a sequential intervention targeting physical and immunologic barriers. Local enzymatic matrix disruption using a collagenase–hyaluronidase mixture combined with lysyl oxidase inhibition reduces ECM density and stromal barriers [31,32]. Transient recruitment and activation of innate immune cells is induced using weakly immunogenic bacteria or localized toll-like receptor agonists to generate local danger signals [18,19,20,34]. Controlled, microdosed intratumoral cytokine pulses (IL-12, IFN-γ, TNF-α) amplify local antigen presentation and effector T-cell priming while minimizing systemic exposure [1,2,9,10,11,21,22,23]. Optional autologous T-cell augmentation can be administered intratumorally or systemically during the window of heightened immune activation [16,17,24,25,26,27]. A recovery or containment phase using local antibiotics or immunomodulators limits excessive inflammation and restores tissue homeostasis after bacteriotherapy [18,19,20,34].

Results:

Target validation identified key proteins and genes involved in immune activation, ECM remodeling, and cytokine signaling. Protein–protein interaction analysis revealed densely interconnected hub nodes, including TNF, TLR4, CTLA4, STAT1, and CD274. Functional enrichment highlighted significant involvement of the Wnt signaling pathway, with hub nodes such as APC, LRP5, CTNNB1, and AXIN1 potentially regulating β-catenin activation and cell proliferation. Gene co-occurrence network analysis demonstrated strong interdependencies among IFNG, TLR4, CD86, TNF, NFKB1, CTLA4, and CD8A, suggesting coordinated regulation of immune activation and checkpoint mechanisms within the proposed cascade.

Conclusions:

Second Breath represents a novel preclinical approach to convert immunologically “cold” tumors into responsive targets for anti-tumor immunity. Its sequential, localized design aims to enhance efficacy while minimizing systemic toxicity. Preclinical network and enrichment analyses provide mechanistic support for its proposed multi-step immune cascade, guiding future in vitro and in vivo validation.