Role of intestinal immunization in urinary tract defence

The Human Penis Is a Genuine Immunological Effector Site

The human penis is a main portal of entry for numerous pathogens, and vaccines able to control resulting infections locally are highly desirable. However, in contrast to the gastrointestinal or vaginal mucosa, the penile immune system and mechanisms inducing a penile immune response remain elusive. In this descriptive study, using multiparametric flow cytometry and immunohistochemistry, we characterized mucosal immune cells such as B, T, and natural killer (NK) cells from the urethra, fossa, and glans of human adult penile tissues. We show that memory B lymphocytes and CD138⁺ plasma cells are detected in all penile compartments. CD4⁺ and CD8⁺ T lymphocytes reside in the epithelium and lamina propria of the penile regions and have mostly a resting memory phenotype. All penile regions contain CD56^dim NK cells surface expressing the natural cytotoxicity receptor NKp44 and the antibody-dependent cell cytotoxicity receptor CD16. These cells are also able to spontaneously secrete pro- and anti-inflammatory cytokines, such as IL-17 and IL-22. Finally, CCR10 is the main homing receptor detected in these penile cells although, together with CCR3, CCR6, and CCR9, their expression level differs between penile compartments. Unlike antigen-presenting cells which type differ between penile regions as we reported earlier, urethral, fossa, and glans content in immune B, T, and NK cells is comparable. However, median values per each analysis suggest that the glans, containing higher number and more activated NK cells together with higher number of terminally differentiate effector CD8⁺ T cells, is a superior effector site than the urethra and the fossa. Thus, the human penis is an immunologically active tissue containing the cellular machinery required to induce and produce a specific and effective response against mucosal pathogens. It can therefore be considered as a classic mucosal effector site, a feature that must be taken into account for the elaboration of efficient strategies, including vaccines, against sexually transmitted infections.

Immunisation of the male tammar wallaby (Macropus eugenii) with spermatozoa elicits epididymal antigen-specific antibody secretion and compromised fertilisation rate

Immunocontraception has been proposed as an effective and humane means of controlling overabundant kangaroo populations in Australia. We have examined the feasibility of using a sperm-based vaccine for this purpose using a model macropod species, the tammar wallaby (Macropus eugenii). This study has demonstrated immunocontraception in a marsupial species following immunisation of males with homologous spermatozoa. Serum anti-sperm IgG titres were associated with a significant reduction in fertilisation rates following mating with superovulated female wallabies. Antigen-specific IgG penetrated the reproductive tract at the rete testis and bound spermatozoa in vivo. IgG was detected bound to the acrosome and midpiece regions of both epididymal and ejaculated spermatozoa. The absence of adverse testicular pathology and sperm movement effects suggests that contraception may have been achieved by antibody-mediated blocking of sperm surface antigens essential for fertilisation. This study demonstrates that a contraceptive vaccine targeting sperm antigens has potential for fertility control in male macropods.

Effect of surgical stress on immune function in patients with urologic cancer

BACKGROUND

To determine the immunosuppressive effect of surgery for urologic cancers, multiple variables of immune function were measured serially before and after operation in patients with urologic cancer.

METHODS

Peripheral blood was obtained before operation and at postoperative day 7 and 14 from 20 patients with bladder cancer, renal pelvic, or ureteral cancer, or renal cell carcinoma.

RESULTS

In patients with bladder cancer who were undergoing radical cystectomy with use of intestine for urinary diversion, the serum level of immunosuppressive acidic protein (IAP) increased, and serum levels of immunoglobulin (Ig)A, IgG, and IgM decreased after operation. In contrast, the number of CD25+ lymphocytes significantly increased. Transurethral resection of bladder cancer also resulted in an increase in serum IAP level, however, the number of CD4+ and human leukocyte-associated HLA-DR+ lymphocytes increased. In patients with renal pelvic or ureteral cancer undergoing nephroureterectomy with cuff, the level of serum IAP increased and serum IgG level decreased after operation. By contrast, the number of CD3+ lymphocytes increased. In patients with renal cell carcinoma, radical nephrectomy led to a significant increase in the number of CD8+ lymphocytes.

CONCLUSIONS

These findings suggest that surgical stress in patients with urologic cancer may result in both suppression and stimulation of host immunity.

The importance of mucosal immunology to problems in human reproduction

The field of mucosal immunology is making rapid advances towards establishing the molecular basis of mucosal defense mechanisms and the development of mucosal vaccines. Research on the mucosal immunology of male and female reproductive tract tissues is benefiting from these advances, as well as from current investigations on specialized immunologic features of the reproductive tract. This knowledge may soon be applicable to solutions for many important problems concerning human reproduction, such as fertility regulation and the current epidemic of sexually transmitted diseases, including AIDS.

Effects of sensitization on female guinea pig urinary bladder function: in vivo and in vitro studies

Although bladder inflammation is known clinically to produce a variety of symptoms including urgency, frequency, and pain, there are only a few experimental studies that directly relate bladder inflammation with urodynamic and functional alterations. We have used the sensitized guinea pig model to study the effects of inflammation on micturition parameters, cystometry, and in vitro bladder contractility. This model depends on the allergic response of the bladder mucosa to ovalbumin, an otherwise non-irritative agent, as an antigen. In vivo exposure of the bladder to ovalbumin via urethral catheterization induced a prompt and marked increase in the number of micturitions in antigen-sensitized guinea pigs. Ovalbumin had no effects on the micturition parameters in the control group. Using in vivo cystometry, intravesical exposure to ovalbumin induced a significant decrease in both the pressure at which micturition was induced, and the volume at which micturition was induced. Ovalbumin had no effect on cystometric parameters of the control animals. In vitro exposure of whole-bladder preparations to ovalbumin induced a significant contractile response only in the bladders isolated from the sensitized guinea pigs. The responses of the isolated bladders to field stimulation and bethanechol were identical for bladders from both sensitized and control animals. In conclusion, exposure of the bladder to ovalbumin in the sensitized animal induced an increase in the frequency of micturitions and a decrease in the pressure and volume at which micturition was induced. Thus, intravesical exposure of the bladder mucosa to a substance that the bladder has been sensitized to can induce alterations in micturition that are consistent with the clinical symptoms of "urgency and frequency".

Routes of priming and challenge for IgA antibody-containing cell responses in the intestine

The characteristic unresponsiveness of gut-associated lymphoid tissue (GALT) to orally administered antigen has hampered studies of mucosal immunity and the development of effective vaccines to control diseases of mucosal organs. Our previous studies have shown that priming by the intraperitoneal route can overcome this unresponsiveness and enables a vigorous IgA antibody-containing cell (ACC) response from GALT to subsequent intraduodenal (ID) antigen challenge. However the involvement of a concomitant systemic response arising from intraperitoneal priming complicates the analysis of the mucosal component of this response. The studies reported here indicate that immunization of a single Peyer's patch (PP) by subserosal deposition of antigen adjacent to the patch primes for an equivalent IgA ACC response following ID challenge and immunization of multiple PP generates a substantial IgA ACC response in the gut lamina propria even in the absence of luminal challenge. This response persists for at least 84 days. These techniques provide a means by which the requirements for induction of IgA responses can be studied in the absence of a response in systemic lymphoid tissue.