A healthy vaginal microbiota is considered to be significant for maintaining vaginal health and preventing infections. However, certain vaginal bacterial commensal species serve an important first line of defense of the body. Any disruption of this microbial barrier might result in a number of urogenital conditions including aerobic vaginitis (AV) and bacterial vaginosis (BV). The health of the vagina is closely associated with inhabitant microbiota. Furthermore, these microbes maintain a low vaginal pH, prevent the acquisition of pathogens, stimulate or moderate the local innate immune system, and further protect against complications during pregnancies. Therefore, this review will focus on vaginal microbial “health” in the lower reproductive tract of women and on the physiological characteristics that determine the well-being of reproductive health. In addition, we explore the distinct versus shared characteristics of BV and AV, which are commonly associated with increased risk for preterm delivery.

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Background: A subset of women who are co-infected with Human Immunodeficiency Virus type 1 (HIV) and Human papillomavirus (HPV), progress rapidly to invasive cervical cancer regardless of antiretroviral therapy (ART) or immune status. We posit that HIV/HPV co-infection along with specific host HLA II -DRB1 and -DQB1 alleles play a major role in cervical cancer development. Methodology: We conducted a hospital-based genetic susceptibility case-control study in Cape Town, South Africa. We recruited 256 women of the same race, from which a total of 624 HLA-DRB1 and -DQB1 class II genotypes were studied. We characterized HLA II candidate genes using PCR based, Luminex intermediate resolution genotyping and confirmed significant associated genotypes at four-digit resolution by high resolution gel typing. We analyzed 160 alleles from cancer, 64 alleles from pre-cancer and 400 alleles from healthy control women. Whole blood was used for HIV antibody test and HLA II typing. Cervical tumor tissue biopsies were used for HPV genotyping. Tests were statistically significant if p<0.05. Results: Women who were co-infected with HIV/HPV had advanced cervical disease compared to women who were HIV negative. HLA class II -DQB1*03:01 and -DQB1*06:02 alleles were associated with cervical cancer in HIV/HPV co-infected women (p=0.001 and p<0.0001, respectively) while HLA class II -DRB1*13:01 and -DQB1*03:19 were rare or absent in women with cervical disease when compared to the control population (p=0.012 and 0.011, respectively). Conclusion: We describe associations between HLA class II genotypes with cervical cancer, or likely protection from cervical cancer disease in HIV/HPV co-infected South African women. Identifying mechanisms that give rise to this likely protective HLA association will provide insight into development of immune-based prevention measures.

Only a small subset of women who are co-infected with Human Immunodeficiency Virus sub-type 1 (HIV) and persistence oncogenic Human papillomavirus (HPV), progress rapidly to invasive cervical cancer by mechanisms that are currently poorly understood. The use of Highly Active Antiretroviral Therapy (HAART), with ensuing immune reconstitution of CD4 T-cells, does not appear to prevent rapidly progressing cervical carcinogenesis. Therefore, to better understand the cervical cancer pathogenesis in HIV/HPV co-infected women, this review focuses on identifying host molecular genetic variations and genetic alterations in cervical cancer progression that may play a role in disease progression. This is an important aspect for individualised genomic profiling and targeted molecular prevention in order to improve the management of the disease in this sub-population.