Limits...
CCL5 regulation of mucosal chlamydial immunity and infection.

Sakthivel SK, Singh UP, Singh S, Taub DD, Igietseme JU, Lillard JW - BMC Microbiol. (2008)

Bottom Line: Antigen (Ag)-specific proliferative responses of CD4+ T cells from spleen, ILNs, and genital organs also declined after CCL5 inhibition.The suppression of these responses correlated with delayed clearance of C. muriduram, which indicate chlamydial immunity is mediated by Th1 immune responses driven in part by CCL5.Taken together with other studies, the data show that CCL5 mediates the temporal recruitment and activation of leukocytes to mitigate chlamydial infection through enhancing adaptive mucosal humoral and cellular immunity.

View Article: PubMed Central - HTML - PubMed

Affiliation: Emory University School of Medicine, Department of Pathology, Atlanta GA, USA. ssakthi@emory.edu

ABSTRACT

Background: Following genital chlamydial infection, an early T helper type 1 (Th1)-associated immune response precedes the activation and recruitment of specific Th1 cells bearing distinct chemokine receptors, subsequently leading to the clearance of Chlamydia. We have shown that CCR5, a receptor for CCL5, is crucial for protective chlamydial immunity. Our laboratory and others have also demonstrated that CCL5 deficiencies found in man and animals can increase the susceptibility and progression of infectious diseases by modulating mucosal immunity. These findings suggest the CCR5-CCL5 axis is necessary for optimal chlamydial immunity. We hypothesized CCL5 is required for protective humoral and cellular immunity against Chlamydia.

Results: The present study revealed that CCR5 and CCL5 mRNAs are elevated in the spleen, iliac lymph nodes (ILNs), and genital mucosa following Chlamydia muriduram challenge. Antibody (Ab)-mediated inhibition of CCL5 during genital chlamydial infection suppressed humoral and Th1>Th2 cellular responses by splenic-, ILN-, and genital mucosa-derived lymphocytes. Antigen (Ag)-specific proliferative responses of CD4+ T cells from spleen, ILNs, and genital organs also declined after CCL5 inhibition.

Conclusion: The suppression of these responses correlated with delayed clearance of C. muriduram, which indicate chlamydial immunity is mediated by Th1 immune responses driven in part by CCL5. Taken together with other studies, the data show that CCL5 mediates the temporal recruitment and activation of leukocytes to mitigate chlamydial infection through enhancing adaptive mucosal humoral and cellular immunity.

Show MeSH

Related in: MedlinePlus

T helper cytokine secretion by CD4+ T cells from Chlamydia-infected mice. Groups of naïve or female BALB/c mice challenged with C. muridarum and received 100 μl of control Ab or anti-CCL5 Ab solution every 3 days. Following sacrifice 42 days after challenge, spleen- and ILN-derived CD4+ T cells from these mice were purified and cultured at a density of 5 × 106 cells/ml with 106 cells/ml of γ-irradiated feeder splenocytes for 3 days. Cytokines present in cultured supernatants were determined by ELISA that was capable of detecting < 10 pg of IL-2, IFN-γ, IL-4, IL-6, IL-10, or GM-CSF. The data presented are the mean cytokine (pg/ml) ± SEM of quadruplicate cultures. Asterisks (*) indicate statistically significant differences (p < 0.01) between untreated and control Ab- or anti-CCL5 Ab-treated mice.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC2543025&req=5

Figure 4: T helper cytokine secretion by CD4+ T cells from Chlamydia-infected mice. Groups of naïve or female BALB/c mice challenged with C. muridarum and received 100 μl of control Ab or anti-CCL5 Ab solution every 3 days. Following sacrifice 42 days after challenge, spleen- and ILN-derived CD4+ T cells from these mice were purified and cultured at a density of 5 × 106 cells/ml with 106 cells/ml of γ-irradiated feeder splenocytes for 3 days. Cytokines present in cultured supernatants were determined by ELISA that was capable of detecting < 10 pg of IL-2, IFN-γ, IL-4, IL-6, IL-10, or GM-CSF. The data presented are the mean cytokine (pg/ml) ± SEM of quadruplicate cultures. Asterisks (*) indicate statistically significant differences (p < 0.01) between untreated and control Ab- or anti-CCL5 Ab-treated mice.

Mentions: Genital Chlamydia infection up-regulated Ab responses as well as splenic and ILN CD4+ T cell proliferative responses. We next examined whether these effects were mediated in part through T helper cytokine responses. IL-2 secreted by Ag-stimulated splenic CD4+ T cells from infected mice that received control Ab was significantly higher than levels from cells isolated from similar mice that received anti-CCL5 Ab or uninfected mice (Figure 4). The secretion of IFN-γ from splenic, but not ILN, CD4+ T cells from C. muridarum-infected and control Ab-treated were considerably higher than T helper cells isolated from similar mice treated with anti-CCL5 Ab or uninfected animals. Chlamydial infection of mice lead to the development of CD4+ T cells that significantly secreted IL-6, IL-10, and GM-CSF, but not IL-4, in response to C. muridarum re-stimulation. Anti-CCL5 Ab-treated mice infected with C. muridarum resulted in T helper cells with reduced IL-6, IL-10, and GM-CSF secretion following Ag re-stimulation when compared to CD4+ T cells from similar mice treated with control Ab; however, the secretion pattern of Th2 cytokine responses by CD4+ T cells isolated from ILNs did not significantly change. These results indicate that C. muridarum infection invoked splenic, but not ILNs, Chlamydia-specific CD4+ T cells that secreted Th1 cytokines as well as IL-6, IL-10, and GM-CSF, which were reduced by CCL5 blockade. The extent of chlamydial infection, determined by C. muridarum detected in cervico-vaginal swabs, was significantly higher in mice receiving anti-CCL5 Ab treatment than compared to control mice (Figure 5). However, all mice resolved chlamydial infection in < 90 days.


CCL5 regulation of mucosal chlamydial immunity and infection.

Sakthivel SK, Singh UP, Singh S, Taub DD, Igietseme JU, Lillard JW - BMC Microbiol. (2008)

T helper cytokine secretion by CD4+ T cells from Chlamydia-infected mice. Groups of naïve or female BALB/c mice challenged with C. muridarum and received 100 μl of control Ab or anti-CCL5 Ab solution every 3 days. Following sacrifice 42 days after challenge, spleen- and ILN-derived CD4+ T cells from these mice were purified and cultured at a density of 5 × 106 cells/ml with 106 cells/ml of γ-irradiated feeder splenocytes for 3 days. Cytokines present in cultured supernatants were determined by ELISA that was capable of detecting < 10 pg of IL-2, IFN-γ, IL-4, IL-6, IL-10, or GM-CSF. The data presented are the mean cytokine (pg/ml) ± SEM of quadruplicate cultures. Asterisks (*) indicate statistically significant differences (p < 0.01) between untreated and control Ab- or anti-CCL5 Ab-treated mice.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2543025&req=5

Figure 4: T helper cytokine secretion by CD4+ T cells from Chlamydia-infected mice. Groups of naïve or female BALB/c mice challenged with C. muridarum and received 100 μl of control Ab or anti-CCL5 Ab solution every 3 days. Following sacrifice 42 days after challenge, spleen- and ILN-derived CD4+ T cells from these mice were purified and cultured at a density of 5 × 106 cells/ml with 106 cells/ml of γ-irradiated feeder splenocytes for 3 days. Cytokines present in cultured supernatants were determined by ELISA that was capable of detecting < 10 pg of IL-2, IFN-γ, IL-4, IL-6, IL-10, or GM-CSF. The data presented are the mean cytokine (pg/ml) ± SEM of quadruplicate cultures. Asterisks (*) indicate statistically significant differences (p < 0.01) between untreated and control Ab- or anti-CCL5 Ab-treated mice.
Mentions: Genital Chlamydia infection up-regulated Ab responses as well as splenic and ILN CD4+ T cell proliferative responses. We next examined whether these effects were mediated in part through T helper cytokine responses. IL-2 secreted by Ag-stimulated splenic CD4+ T cells from infected mice that received control Ab was significantly higher than levels from cells isolated from similar mice that received anti-CCL5 Ab or uninfected mice (Figure 4). The secretion of IFN-γ from splenic, but not ILN, CD4+ T cells from C. muridarum-infected and control Ab-treated were considerably higher than T helper cells isolated from similar mice treated with anti-CCL5 Ab or uninfected animals. Chlamydial infection of mice lead to the development of CD4+ T cells that significantly secreted IL-6, IL-10, and GM-CSF, but not IL-4, in response to C. muridarum re-stimulation. Anti-CCL5 Ab-treated mice infected with C. muridarum resulted in T helper cells with reduced IL-6, IL-10, and GM-CSF secretion following Ag re-stimulation when compared to CD4+ T cells from similar mice treated with control Ab; however, the secretion pattern of Th2 cytokine responses by CD4+ T cells isolated from ILNs did not significantly change. These results indicate that C. muridarum infection invoked splenic, but not ILNs, Chlamydia-specific CD4+ T cells that secreted Th1 cytokines as well as IL-6, IL-10, and GM-CSF, which were reduced by CCL5 blockade. The extent of chlamydial infection, determined by C. muridarum detected in cervico-vaginal swabs, was significantly higher in mice receiving anti-CCL5 Ab treatment than compared to control mice (Figure 5). However, all mice resolved chlamydial infection in < 90 days.

Bottom Line: Antigen (Ag)-specific proliferative responses of CD4+ T cells from spleen, ILNs, and genital organs also declined after CCL5 inhibition.The suppression of these responses correlated with delayed clearance of C. muriduram, which indicate chlamydial immunity is mediated by Th1 immune responses driven in part by CCL5.Taken together with other studies, the data show that CCL5 mediates the temporal recruitment and activation of leukocytes to mitigate chlamydial infection through enhancing adaptive mucosal humoral and cellular immunity.

View Article: PubMed Central - HTML - PubMed

Affiliation: Emory University School of Medicine, Department of Pathology, Atlanta GA, USA. ssakthi@emory.edu

ABSTRACT

Background: Following genital chlamydial infection, an early T helper type 1 (Th1)-associated immune response precedes the activation and recruitment of specific Th1 cells bearing distinct chemokine receptors, subsequently leading to the clearance of Chlamydia. We have shown that CCR5, a receptor for CCL5, is crucial for protective chlamydial immunity. Our laboratory and others have also demonstrated that CCL5 deficiencies found in man and animals can increase the susceptibility and progression of infectious diseases by modulating mucosal immunity. These findings suggest the CCR5-CCL5 axis is necessary for optimal chlamydial immunity. We hypothesized CCL5 is required for protective humoral and cellular immunity against Chlamydia.

Results: The present study revealed that CCR5 and CCL5 mRNAs are elevated in the spleen, iliac lymph nodes (ILNs), and genital mucosa following Chlamydia muriduram challenge. Antibody (Ab)-mediated inhibition of CCL5 during genital chlamydial infection suppressed humoral and Th1>Th2 cellular responses by splenic-, ILN-, and genital mucosa-derived lymphocytes. Antigen (Ag)-specific proliferative responses of CD4+ T cells from spleen, ILNs, and genital organs also declined after CCL5 inhibition.

Conclusion: The suppression of these responses correlated with delayed clearance of C. muriduram, which indicate chlamydial immunity is mediated by Th1 immune responses driven in part by CCL5. Taken together with other studies, the data show that CCL5 mediates the temporal recruitment and activation of leukocytes to mitigate chlamydial infection through enhancing adaptive mucosal humoral and cellular immunity.

Show MeSH
Related in: MedlinePlus