bims-reprim 2021-05-23 papers

Issue of 2021–05–23
three papers selected by
Iva Filipovic, Karolinska Institutet

Proc Natl Acad Sci U S A. 2021 May 25. pii: e2104407118. [Epub ahead of print]118(21):

Circulating immunity protects the female reproductive tract from Chlamydia infection.

Jasmine C Labuda, Oanh H Pham, Claire E Depew, Kevin D Fong, Bokyung S Lee, Jordan A Rixon, Stephen J McSorley.

Anatomical positioning of memory lymphocytes within barrier tissues accelerates secondary immune responses and is thought to be essential for protection at mucosal surfaces. However, it remains unclear whether resident memory in the female reproductive tract (FRT) is required for Chlamydial immunity. Here, we describe efficient generation of tissue-resident memory CD4 T cells and memory lymphocyte clusters within the FRT after vaginal infection with Chlamydia Despite robust establishment of localized memory lymphocytes within the FRT, naïve mice surgically joined to immune mice, or mice with only circulating immunity following intranasal immunization, were fully capable of resisting Chlamydia infection via the vaginal route. Blocking the rapid mobilization of circulating memory CD4 T cells to the FRT inhibited this protective response. These data demonstrate that secondary protection in the FRT can occur in the complete absence of tissue-resident immune cells. The ability to confer robust protection to barrier tissues via circulating immune memory provides an unexpected opportunity for vaccine development against infections of the FRT.

Keywords: CD4 T cells; Chlamydia; female reproductive tract

DOI: https://doi.org/10.1073/pnas.2104407118

Reprod Biomed Online. 2021 Apr 24. pii: S1472-6483(21)00184-X. [Epub ahead of print]

Endometrial stem/progenitor cells in menstrual blood and peritoneal fluid of women with and without endometriosis.

Hirotaka Masuda, Kjiana E Schwab, C E Filby, Charmaine S C Tan, Jim Tsaltas, Gareth C Weston, Caroline E Gargett.

RESEARCH QUESTION: Are endometrial stem/progenitor cells shed into uterine menstrual blood (UMB) and the peritoneal cavity in women with and without endometriosis during menstruation?
DESIGN: Women with (n = 32) and without endometriosis (n = 29) at laparoscopy (total 61), carried out during the menstrual (n = 41) and non-menstrual phase (n = 20) were recruited. The UMB, peritoneal fluid and peripheral blood were analysed by clonogenicity assay and flow cytometry to quantify the concentrations of endometrial clonogenic cells, SUSD2+ mesenchymal stem cells (eMSC) and N-cadherin+ epithelial progenitor cells (eEPC).
RESULTS: Clonogenic endometrial cells, eMSC and eEPC were found in most UMB samples at similar concentrations in women with and without endometriosis. In contrast, 62.5% of women with endometriosis and 75.0% without (controls) had clonogenic cells in peritoneal fluid samples during menses. The eMSC were present in the peritoneal fluid of 76.9% of women with endometriosis and 44.4% without, and eEPC were found in the peritoneal fluid of 60.0% of women with and 25.0% without endometriosis during menses. Median clonogenic, eMSC and eEPC concentrations in peritoneal fluid were not significantly different between groups. More clonogenic cells persisted beyond the menstrual phase in the peritoneal fluid of women with endometriosis (menstrual 119/ml [0-1360/ml] versus non-menstrual 8.5/ml [0-387/ml]; P = 0.277) compared with controls (menstrual 76.5/ml [1-1378/ml] versus non-menstrual 0/ml [0-14/ml]; P = 0.0362). No clonogenic endometrial cells were found in peripheral blood.
CONCLUSIONS: Clonogenic endometrial cells, SUSD2+ eMSC and N-cadherin+ eEPC are present in UMB and the peritoneal fluid of women with and without endometriosis. Further study of the function of these cells may shed light on the cellular origins of endometriosis.

Keywords: Endometrial stem/progenitor cells; N-cadherin; Peritoneal fluid; Retrograde menstruation; Sushi domain containing 2 (SUSD2)

DOI: https://doi.org/10.1016/j.rbmo.2021.04.008