Toll-like receptors (TLRs) and common pathogens in the female lower genital tract. The vulva, vagina, and cervix comprises the lower part of the female genital canal. The mucosa of the cervical canal is covered by a single layer of highly columnar epithelium, whereas a complex layer of squamous epithelium covers the vaginal wall. The complex squamous epithelium meets the single columnar epithelium at the ectocervix. The lower region of the female genital tract is often subjected to various pathogenic microorganisms, such as human papillomavirus, herpes simplex virus-2, bacteria, chlamydia trachomatis, treponema pallidum, candida, and trichomonad. Confronted with the invasion of these pathogens, each part plays a unique role in the local immune response mechanism, and the distribution, expression, and response of TLRs within it also display subtle differences. Among the commonly employed in vitro research models for female lower reproductive tract infections, TLRs 2/3/5/6 are highly expressed in primary epithelial cell cultures derived from ectocervix (P-ECTO EC), primary epithelial cell cultures derived from endocervix (P-ENDO EC), and primary epithelial cell cultures derived from vaginal tissue (P-VAG EC). The TLR1/2/3/5/6/7/9 are expressed by immortalized cervical epithelial cell line (End1/E6E7), immortalized ectocervical cell line (Ect1/E6E7), and immortalized vaginal cell line (Vk2/E6E7). Human vagina smooth muscle cells (HvSMCs) express all TLRs, with TLR1/2/3/4 being the most abundant.