Differential Expression of Toll-like Receptor and NOD-like Receptor in Response to Symptomatic and Asymptomatic Trichomonas vaginalis Infections

Abstract

Background: Trichomonas vaginalis (TV) is the most common non‑viral sexually transmitted protozoan infection globally. A distinctive feature of TV is that a large proportion of infected individuals remain asymptomatic whereas others develop highly symptomatic vaginitis, cervicitis, urethritis, or chronic pelvic irritation. Increasing molecular evidence suggests that these clinical differences are not random but reflect differences in mucosal innate immune activation. Pattern recognition receptors (PRRs) such as Toll‑like receptors (TLRs) and nucleotide‑binding oligomerisation domain‑like receptors (NLRs) represent the first‑line innate recognition modules capable of detecting pathogen‑associated molecular patterns. TLR1/2 heterodimers, TLR4, and NLRP3 inflammasome activation have emerged as major molecular axes in TV recognition. However, the comparative differential expression of these pathways in symptomatic versus asymptomatic infections has not been integrated into a single conceptual framework. The present manuscript synthesises peer‑reviewed evidence to develop a narrative research model that explains how PRRs may drive divergent phenotypes in TV infection and provides an advanced interpretive research narrative suitable for journal publication when raw numeric datasets are not available.