IL-10 Producing B Cells Dampen Protective T Cell Response and Allow Chlamydia muridarum Infection of the Male Genital Tract

A significant proportion of individuals develop chronic, persistent and recurrent genital tract infections with Chlamydia trachomatis, which has been attributed to the numerous strategies that the bacterium uses to subvert host immune responses. Animal chlamydia models have demonstrated that protective immune response is mediated by CD4⁺ Th1 cytokine responses. Herein, we demonstrate that early after infecting the male genital tract, C. muridarum triggers the production of IL-10 by splenic and lymph node cells. In addition, C. muridarum triggers IL-6 and TNFα secretion. Data obtained from in vitro and in vivo experiments revealed B cells as the major IL-10 contributors. Indeed, purified B cells produced high amounts of IL-10 and also exhibited enhanced expression of inhibitory molecules such as CD39, PD-L1 and PD1 after C. muridarum stimulation. In vitro experiments performed with sorted cell subsets revealed that Marginal Zone B cells were the main IL-10 producers. In vitro and in vivo studies using TLR-deficient mice indicated that TLR4 signaling pathway was essential for IL-10 production. In addition, in vivo treatments to neutralize IL-10 or deplete B cells indicated that IL-10 and B cells played a significant role in delaying bacterial clearance ability. Moreover, the latter was confirmed by adoptive cell transfer experiments in which the absence of IL-10-producing B cells conferred the host a greater capability to induce Th1 responses and clear the infection. Interestingly, NOD mice, which were the least efficient in clearing the infection, presented much more Marginal Zone B counts and also enhanced TLR4 expression on Marginal Zone B cells when compared to B6 and BALB/c mice. Besides, treatment with antibodies that selectively deplete Marginal Zone B cells rendered mice more capable of inducing enhanced IFNγ responses and clearing the infection. Our findings suggest that B cells play a detrimental role in C. muridarum infection and that activation by innate receptors like TLR4 and IL-10 production by these cells could be used by Chlamydia spp. as a strategy to modulate the immune response establishing chronic infections in susceptible hosts.

Chronic Infection of the Prostate by Chlamydia muridarum Is Accompanied by Local Inflammation and Pelvic Pain Development

BACKGROUND

Chlamydia trachomatis urogenital infections are the leading cause of sexually transmitted bacterial infections. Although the prevalence of chlamydial infection is similar in men and women, current research is mainly focused on women, neglecting the study of male genital tract infections. We, therefore, investigated Chlamydia infection in the rodent male genital tract.

MATERIALS AND METHODS

Male NOD and C57BL/6 mice were inoculated in the meatus urethra with C. muridarum. Bacterial DNA, leukocyte infiltration of male genital tract tissues, pelvic pain, and Chlamydia-specific immune responses were analyzed at different time points.

RESULTS AND CONCLUSIONS

The inoculation of C. muridarum in the meatus urethra of male mice resulted in an ascending and widely disseminated infection of the male genital tract. C. muridarum remained longer and with the highest bacterial burdens in the prostate, thus showing a special tropism for this organ. Infection caused leukocyte infiltration, mainly composed by neutrophils, and also induced early pelvic pain development that rapidly dropped and resolved as the infection became chronic. Bacterial load and leukocyte infiltration was observed in all prostate lobes, although dorsolateral prostate was the most affected lobe. Interestingly, immune responses induced by both mice strains were characterized by the production of high levels of IL-10 during early stages of the infection, with highest and sustained levels observed in NOD mice, which showed to be less efficient in clearing the infection. Chronic infection of the prostate accompanied by local inflammation and pelvic pain development described herein have important implications for the improvement of the diagnosis and for the design of new efficient therapies. Prostate 77:517-529, 2017. © 2017 Wiley Periodicals, Inc.

Chronic Pelvic Pain Development and Prostate Inflammation in Strains of Mice With Different Susceptibility to Experimental Autoimmune Prostatitis

BACKGROUND

Experimental autoimmune prostatitis (EAP) is an autoimmune inflammatory disease of the prostate characterized by peripheral prostate-specific autoimmune responses associated with prostate inflammation. EAP is induced in rodents upon immunization with prostate antigens (PAg) plus adjuvants and shares important clinical and immunological features with the human disease chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS).

METHODS

EAP was induced in young NOD, C57BL/6, and BALB/c male mice by immunization with PAg plus complete Freund́s adjuvant. Tactile allodynia was assessed using Von Frey fibers as a measure of pelvic pain at baseline and at different time points after immunization. Using conventional histology, immunohistochemistry, FACS analysis, and protein arrays, an interstrain comparative study of prostate cell infiltration and inflammation was performed.

RESULTS

Chronic pelvic pain development was similar between immunized NOD and C57BL/6 mice, although the severity of leukocyte infiltration was greater in the first case. Coversely, minimal prostate cell infiltration was observed in immunized BALB/c mice, who showed no pelvic pain development. Increased numbers of mast cells, mostly degranulated, were detected in prostate samples from NOD and C57BL/6 mice, while lower total counts and resting were observed in BALB/c mice. Prostate tissue from NOD mice revealed markedly increased expression levels of inflammatory cytokines, chemokines, adhesion molecules, vascular endothelial growth factor, and metalloproteinases. Similar results, but to a lesser extent, were observed when analyzing prostate tissue from C57BL/6 mice. On the contrary, the expression of the above mediators was very low in prostate tissue from immunized BALB/c mice, showing significantly slight increments only for CXCL1 and IL4.

CONCLUSIONS

Our results provide new evidence indicating that NOD, C57BL/6, and BALB/c mice develop different degrees of chronic pelvic pain, type, and amount of prostate cell infiltration and secretion of inflammatory mediators. Our results corroborate and support the notion that mice with different genetic background have different susceptibility to EAP induction. Prostate 77:94-104, 2017. © 2016 Wiley Periodicals, Inc.

Expression of CXCR3 on specific T cells is essential for homing to the prostate gland in an experimental model of chronic prostatitis/chronic pelvic pain syndrome

Experimental autoimmune prostatitis (EAP) is considered a valid model for the human disease chronic prostatitis/chronic pelvic pain syndrome. In this report, we analyzed phenotypic characteristics of T cells that gain access to the prostate and induce leukocyte recruitment in mice with different susceptibility to EAP. After EAP induction, NOD mice developed a specific cellular response characterized by a mixed Th1/Th17 pattern with specific T cells mainly expressing CXCR3 that infiltrated and damaged the prostate. In contrast, BALB/c mice, as well as NOD-IFN-γ(-/-), exhibited only Th17 cells mainly expressing CCR6 that were not capable of infiltrating the prostate gland. Adoptive transfer experiments of T cells from NOD or NOD-IFN-γ(-/-) mice to NOD-SCID recipients showed that only T cells from NOD mice successfully infiltrated the prostate. However, after "in vitro" or "in vivo" treatment with rIFN-γ, T cells from NOD-IFN-γ(-/-) mice became capable of homing to the prostate and induced leukocyte recruitment. Chemokine levels in prostate tissue from NOD mice showed increased expression levels of CXCR3 ligands. Additional experiments using adoptive transfer of sorted CXCR3(+)CD3(+) T cells or administrating a CXCR3 antagonist treatment confirmed these previous results. Altogether, our results demonstrate that the expression of CXCR3 on effector T cells is essential for their homing to the prostate gland in EAP. CXCR3 emerges as a potential therapeutic target to control chronic prostatitis/chronic pelvic pain syndrome.

Removal of bacterial indicators and pathogens from dairy wastewater by a multi-component treatment system

Microbial removal by a multi-component treatment system for dairy and municipal wastewater is being studied in Arizona, USA. The system consists of paired solids separators, anaerobic lagoons, aerobic ponds and constructed wetlands cells. The organisms under study include: total coliform, fecal coliform, enterovirus, Listeria monocytogenes, Clostridium perfringens, coliphage, Giardia lamblia and Cryptosporidium parvum. Organism removal rates from dairy wastewater varied from 13.2 per cent for fecal coliform to 94.9 per cent for coliphage. It appears that the much higher turbidity of the dairy wastewater, nearly 1,300 NTU, decreased the treatment systems' ability to remove some microbial indicators and pathogens. Information from this study can be used to determine the adequacy of multi-component treatment systems for the control of wastewater-borne pathogens, both in municipal treatment systems as well as in confined animal feeding operations (CAFO). This information also can assist municipalities and the CAFO industry in the implementation of rational and efficient treatment strategies for appropriate reuse of wastewaters.

Primary prevention of neural tube defects with folic acid supplementation: Cuban experience

Folic acid (5 mg) was given daily, for not less than one menstrual period before conception and until the tenth week of pregnancy, to 81 women (FS) with a history of a previous neural tube defect (NTD) birth. There was no NTD recurrence among this group or among the offspring of a further 20 women (PS) whose folic acid supplementation fell short of the full regime. In another 114 women who became pregnant without folic acid supplementation (US), there were four NTD recurrences (3.5 per cent). Our results suggest that folic acid supplementation might be an effective method of primary prevention of neural tube defects.