Ecological Dynamics of Pro-tumor and Anti-tumorTeams in the Tumor Microenvironment

Tumor growth occurs within a complex tumor microenvironment (TME) composed of many
interacting cell types. However, the signs of tumor-immune interactions in this ecosystem are
not random and possess a structure, the immune cell types in TME tend to organize into two
functional communities: a pro-tumor team and an anti-tumor team, each internally coopera-
tive but mutually antagonistic forming a two-team ecosystem. Quantitatively predicting the
ecological outcomes of such interactions remains challenging due to cellular diversity and in-
teraction variability, and the exact dynamical regimes accessible to such a two-team ecosystem
remain unknown. Here, we model tumor-immune interactions as a structured ecosystem with
two competing teams using a generalized Lotka-Volterra framework and analyze it using the
cavity method. We derive phase diagrams that delineate when these two communities coexist,
when one dominates, and how these outcomes depend on intra-team cooperation, cross-team
inhibition, and ecological heterogeneity. Our work provides a foundation for understanding
tumor-immune dynamics from a community ecology perspective.&#xD.