Memory T cells possess an innate-like function in local protection from mucosal infection

Mucosal infections pose a significant global health burden. Antigen-specific tissue resident T cells are critical to maintaining barrier immunity. Previous studies in the context of systemic infection suggest that memory CD8 T cells may also provide innate-like protection against antigenically unrelated pathogens independent of TCR engagement. Whether "bystander T cell activation" is also an important defense mechanism in the mucosa is poorly understood. Here, we investigated if innate-like memory CD8 T cells could protect against a model mucosal virus infection, herpes simplex virus 2 (HSV-2). We found that immunization with an irrelevant antigen delayed disease progression from lethal HSV-2 challenge, suggesting that memory CD8 T cells may mediate protection despite the lack of antigen-specificity. Upon HSV-2 infection, we observed an early infiltration, rather than substantial local proliferation, of antigen-non-specific CD8 T cells, which became bystander-activated only within the infected mucosal tissue. Critically, we show that bystander-activated CD8 T cells are sufficient to reduce early viral burden after HSV-2 infection. Finally, local cytokine cues within the tissue microenvironment after infection were sufficient for bystander activation of mucosal tissue memory CD8 T cells from mice and humans. Altogether, our findings suggest that local bystander-activation of CD8 memory T cells contribute a fast and effective innate-like response to infection in mucosal tissue.

HSV-2 Infection Enhances Zika Virus Infection of Primary Genital Epithelial Cells Independently of the Known Zika Virus Receptor AXL

Zika virus (ZIKV) is transmitted to people by bite of an infected mosquito and by sexual contact. ZIKV infects primary genital epithelial cells, the same cells targeted by herpes simplex virus 2 (HSV-2). HSV-2 seroprevalence is high in areas where ZIKV is endemic, but it is unknown whether HSV-2 increases the risk for ZIKV infection. Here, we found that pre-infecting female genital tract epithelial cells with HSV-2 leads to enhanced binding of ZIKV virions. This effect did not require active replication by HSV-2, implying that the effect results from the immune response to HSV-2 exposure or to viral genes expressed early in the HSV-2 lifecycle. Treating cells with toll-like receptor-3 ligand poly-I:C also lead to enhanced binding by ZIKV, which was inhibited by the JAK-STAT pathway inhibitor ruxolitinib. Blocking or knocking down the well-studied ZIKV receptor AXL did not prevent binding of ZIKV to epithelial cells, nor prevent enhanced binding in the presence of HSV-2 infection. Blocking the α5 integrin receptor did not prevent ZIKV binding to cells either. Overall, our results indicate that ZIKV binding to genital epithelial cells is not mediated entirely by a canonical receptor, but likely occurs through redundant pathways that may involve lectin receptors and glycosaminoglycans. Our studies may pave the way to new interventions that interrupt the synergism between herpes and Zika viruses.

Physician attitudes and knowledge on prophylactic salpingectomy in perimenopausal patients

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Cancer risk reduction is of paramount importance when considering salpingectomy.

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Prophylactic salpingectomy performed in more than 75% of patients.

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Patients with preconceived notions of ovarian removal can be difficult to counsel.

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Knowledge gaps persist around the risks and benefits of salpingectomy.

Purpose

Eighty percent of the approximately 500,000 hysterectomies performed annually in the US are for benign indications. There is lack of consensus regarding concurrent removal of fallopian tubes and/or ovaries. Ovarian cancer risk reduction is the principal benefit but the adverse consequences of ovarian removal can include vasomotor disturbance, vaginal dryness, cardiovascular disease, osteoporosis, and cognitive decline. Emerging evidence on the role of fallopian tubes in ovarian carcinogenesis and the consequences of oophorectomy have led the American College of Obstetricians-Gynecologists (ACOG) to recommend bilateral salpingectomy with ovarian conservation during benign hysterectomy for women at population risk for ovarian cancer.

Methods

Five hundred members of the ACOG Collaborative Ambulatory Research Network (CARN) were randomly selected to participate in this survey study.

Results

165 completed the survey (35.3% response rate). Most respondents reported that a family history of breast, ovarian or colon cancer and patient age influence their decision to offer salpingectomy more than 75% of the time. Factors that a majority of respondents reported discussing during counseling included possible ovarian cancer risk reduction, surgical menopause, severity of symptoms, and the effects on bone and cardiovascular health. The respondents mean score for the knowledge-based questions was only 1.7 (±0.92) out of 4 points.

Conclusion

Several factors may affect decision making for prophylactic salpingectomy at the time of hysterectomy however paramount among these is cancer risk reduction. Most physicians found it difficult to discuss and implement a change in care for patients with preconceived notions of ovarian preservation or removal.

Perineal Laceration and Episiotomy Repair Using a Beef Tongue Model

INTRODUCTION

Declining rates of operative vaginal deliveries and routine episiotomy in obstetric practice, along with rising cesarean section rates, have decreased OB/GYN resident experience with episiotomy repair and obstetric anal sphincter injuries (OASIS). Simulation models are valuable educational tools in procedural training. Several models have been reported, each with its own limitations and benefits.

METHODS

We developed a 1-hour workshop to teach novice OB/GYN residents perineal laceration repair skills on a modified beef tongue model. The model required 5-10 minutes to assemble following written and video instruction, and learners had 30-50 minutes to practice using learner instructions. Learners were evaluated using a procedure checklist and global objective structured assessment of technical skills. To evaluate the session, we surveyed current faculty and residents, as well as residency graduates.

RESULTS

Between 2008 and 2017, an estimated 82 OB/GYN residents participated in this activity, and 95 participants and facilitators received the survey. Forty-one (59%) respondents agreed that this model was similar to repairing OASIS in clinical practice. Our trainees reported that the optimal time for simulated OASIS repair was the R2 and R3 years; however, 90% of respondents felt residents should be offered this simulation yearly.

DISCUSSION

Based on our survey of trainees, graduates, and faculty, we created a realistic simulated OASIS repair training, despite the limitation that the model lacked a rectum. Learners reported an interest in repeating the simulation frequently during residency to augment their clinical experience and increase perceived competence in third- and fourth-degree laceration repair by their graduation.

Cryopreservation of Human Mucosal Leukocytes

Background

Understanding how leukocytes in the cervicovaginal and colorectal mucosae respond to pathogens, and how medical interventions affect these responses, is important for developing better tools to prevent HIV and other sexually transmitted infections. An effective cryopreservation protocol for these cells following their isolation will make studying them more feasible.

Methods and Findings

To find an optimal cryopreservation protocol for mucosal mononuclear leukocytes, we compared cryopreservation media and procedures using human vaginal leukocytes and confirmed our results with endocervical and colorectal leukocytes. Specifically, we measured the recovery of viable vaginal T cells and macrophages after cryopreservation with different cryopreservation media and handling procedures. We found several cryopreservation media that led to recoveries above 75%. Limiting the number and volume of washes increased the fraction of cells recovered by 10–15%, possibly due to the small cell numbers in mucosal samples. We confirmed that our cryopreservation protocol also works well for both endocervical and colorectal leukocytes. Cryopreserved leukocytes had slightly increased cytokine responses to antigenic stimulation relative to the same cells tested fresh. Additionally, we tested whether it is better to cryopreserve endocervical cells on the cytobrush or in suspension.

Conclusions

Leukocytes from cervicovaginal and colorectal tissues can be cryopreserved with good recovery of functional, viable cells using several different cryopreservation media. The number and volume of washes has an experimentally meaningful effect on the percentage of cells recovered. We provide a detailed, step-by-step protocol with best practices for cryopreservation of mucosal leukocytes.

Determination of the Membrane Permeability to Water of Human Vaginal Mucosal Immune Cells at Subzero Temperatures Using Differential Scanning Calorimetry

To study mucosal immunity and conduct HIV vaccine trials, it is important to be able to cryopreserve mucosal specimens and recover them in functional viable form. Obtaining a good recovery depends, in part, on cooling the cells at the appropriate rate, which is determined by the rate of water transport across the cell membrane during the cooling process. In this study, the cell membrane permeabilities to water at subzero temperatures of human vaginal mucosal T cells and macrophages were measured using the differential scanning calorimetry method proposed by Devireddy et al. in 1998. Thermal histograms were measured before and after cell lysis using a Slow-Fast-Fast-Slow cooling program. The difference between the thermal histograms of the live intact cells and the dead lysed cells was used to calculate the temperature-dependent cell membrane permeability at subzero temperatures, which was assumed to follow the Arrhenius relationship, [Formula: see text], where Lpg is the permeability to water at the reference temperature (273.15 K). The results showed that Lpg = 0.0209 ± 0.0108 μm/atm/min and Ea = 41.5 ± 11.4 kcal/mol for T cells and Lpg = 0.0198 ± 0.0102 μm/atm/min and Ea = 38.2 ± 10.4 kcal/mol for macrophages, respectively, in the range 0°C to -40°C (mean ± standard deviation). Theoretical simulations predicted that the optimal cooling rate for both T cells and macrophages was about -3°C/min, which was proven by preliminary immune cell cryopreservation experiments.

A study of the osmotic characteristics, water permeability, and cryoprotectant permeability of human vaginal immune cells

Cryopreservation of specimens taken from the genital tract of women is important for studying mucosal immunity during HIV prevention trials. However, it is unclear whether the current, empirically developed cryopreservation procedures for peripheral blood cells are also ideal for genital specimens. The optimal cryopreservation protocol depends on the cryobiological features of the cells. Thus, we obtained tissue specimens from vaginal repair surgeries, isolated and flow cytometry-purified immune cells, and determined fundamental cryobiological characteristics of vaginal CD3⁺ T cells and CD14⁺ macrophages using a microfluidic device. The osmotically inactive volumes of the two cell types (V_b) were determined relative to the initial cell volume (V₀) by exposing the cells to hypotonic and hypertonic saline solutions, evaluating the equilibrium volume, and applying the Boyle van't Hoff relationship. The cell membrane permeability to water (L_p) and to four different cryoprotective agent (CPA) solutions (P_s) at room temperature were also measured. Results indicated V_b values of 0.516 V₀ and 0.457 V₀ for mucosal T cells and macrophages, respectively. L_p values at room temperature were 0.196 and 0.295 μm/min/atm for T cells and macrophages, respectively. Both cell types had high P_s values for the three CPAs, dimethyl sulfoxide (DMSO), propylene glycol (PG) and ethylene glycol (EG) (minimum of 0.418 × 10⁻³ cm/min), but transport of the fourth CPA, glycerol, occurred 50–150 times more slowly. Thus, DMSO, PG, and EG are better options than glycerol in avoiding severe cell volume excursion and osmotic injury during CPA addition and removal for cryopreservation of human vaginal immune cells.

Optimizing viable leukocyte sampling from the female genital tract for clinical trials: an international multi-site study

Background

Functional analysis of mononuclear leukocytes in the female genital mucosa is essential for understanding the immunologic effects of HIV vaccines and microbicides at the site of HIV exposure. However, the best female genital tract sampling technique is unclear.

Methods and Findings

We enrolled women from four sites in Africa and the US to compare three genital leukocyte sampling methods: cervicovaginal lavages (CVL), endocervical cytobrushes, and ectocervical biopsies. Absolute yields of mononuclear leukocyte subpopulations were determined by flow cytometric bead-based cell counting. Of the non-invasive sampling types, two combined sequential cytobrushes yielded significantly more viable mononuclear leukocytes than a CVL (p<0.0001). In a subsequent comparison, two cytobrushes yielded as many leukocytes (∼10,000) as one biopsy, with macrophages/monocytes being more prominent in cytobrushes and T lymphocytes in biopsies. Sample yields were consistent between sites. In a subgroup analysis, we observed significant reproducibility between replicate same-day biopsies (r = 0.89, p = 0.0123). Visible red blood cells in cytobrushes increased leukocyte yields more than three-fold (p = 0.0078), but did not change their subpopulation profile, indicating that these leukocytes were still largely derived from the mucosa and not peripheral blood. We also confirmed that many CD4⁺ T cells in the female genital tract express the α4β7 integrin, an HIV envelope-binding mucosal homing receptor.

Conclusions

CVL sampling recovered the lowest number of viable mononuclear leukocytes. Two cervical cytobrushes yielded comparable total numbers of viable leukocytes to one biopsy, but cytobrushes and biopsies were biased toward macrophages and T lymphocytes, respectively. Our study also established the feasibility of obtaining consistent flow cytometric analyses of isolated genital cells from four study sites in the US and Africa. These data represent an important step towards implementing mucosal cell sampling in international clinical trials of HIV prevention.

Reoperation for urinary incontinence

OBJECTIVE(S)

The objective of the study was to describe the rate and associated factors of reoperation for urinary incontinence.

STUDY DESIGN

A cohort study using Washington state hospitalization records from 1987 to 2005 of inpatient urinary incontinence surgeries. The cumulative reoperation rate was estimated for the entire cohort and by procedure. Cox regression was used to estimate the hazard of reoperation.

RESULTS

A total of 41,705 women underwent either a sling or retropubic colposuspension (Burch); 1895 underwent reoperation for urinary incontinence (8.6%; 95% confidence interval, 7.8-9.5%), a rate of 5.5 per 1000 woman-years. Women undergoing Burch had a lower reoperation rate than those undergoing slings (4.2 vs 6.7 per 1000 woman-years; P < .001). Concomitant hysterectomy was associated with a lower reoperation rate for Burch and sling repairs (5.4-2.9 and 7.7-4.2 per 1000 woman-years).

CONCLUSION(S)

Reoperation for urinary incontinence occurs commonly in the general population. The variable reoperation rate observed should be further investigated, given current trends toward increased Sling use.

Initial events in establishing vaginal entry and infection by human immunodeficiency virus type-1

Understanding the initial events in the establishment of vaginal human immunodeficiency virus type-1 (HIV-1) entry and infection has been hampered by the lack of appropriate experimental models. Here, we show in an ex vivo human organ culture system that upon contact in situ, HIV-1 rapidly penetrated both intraepithelial vaginal Langerhans and CD4⁺ T cells. HIV-1 entered CD4⁺ T cells almost exclusively by CD4 and CCR5 receptor-mediated direct fusion, without requiring passage from Langerhans cells, and overt productive infection ensued. By contrast, HIV-1 entered CD1a⁺ Langerhans cells primarily by endocytosis, by means of multiple receptors, and virions persisted intact within the cytoplasm for several days. Our findings shed light on the very earliest steps of mucosal HIV infection in vivo and may guide the design of effective strategies to block local transmission and prevent HIV-1 spread.