Curcumin Can Decrease Tissue Inflammation and the Severity of HSV-2 Infection in the Female Reproductive Mucosa

Herpes Simplex Virus Type 2 (HSV-2) is one of the most prevalent sexually transmitted viruses and is a known risk factor for HIV acquisition in the Female Genital Tract (FGT). Previously, we found that curcumin can block HSV-2 infection and abrogate the production of inflammatory cytokines and chemokines by genital epithelial cells in vitro. In this study, we investigated whether curcumin, encapsulated in nanoparticles and delivered by various in vivo routes, could minimize inflammation and prevent or reduce HSV-2 infection in the FGT. Female mice were pre-treated with curcumin nanoparticles through oral, intraperitoneal and intravaginal routes, and then exposed intravaginally to the tissue inflammation stimulant CpG-oligodeoxynucleotide (ODN). Local intravaginal delivery of curcumin nanoparticles, but not intraperitoneal or oral delivery, reduced CpG-mediated inflammatory histopathology and decreased production of pro-inflammatory cytokines Interleukin (IL)-6, Tumor Necrosis Factor Alpha (TNF-α) and Monocyte Chemoattractant Protein-1 (MCP-1) in the FGT. However, curcumin nanoparticles did not demonstrate anti-viral activity nor reduce tissue pathology when administered prior to intravaginal HSV-2 infection. In an alternative approach, intravaginal pre-treatment with crude curcumin or solid dispersion formulations of curcumin demonstrated increased survival and delayed pathology following HSV-2 infection. Our results suggest that curcumin nanoparticle delivery in the vaginal tract could reduce local tissue inflammation. The anti-inflammatory properties of curcumin delivered to the vaginal tract could potentially reduce the severity of HSV-2 infection and decrease the risk of HIV acquisition in the FGT of women.

CXCR3 Signaling Is Required for Restricted Homing of Parenteral Tuberculosis Vaccine-Induced T Cells to Both the Lung Parenchyma and Airway

Although most novel tuberculosis (TB) vaccines are designed for delivery via the muscle or skin for enhanced protection in the lung, it has remained poorly understood whether systemic vaccine-induced memory T cells can readily home to the lung mucosa prior to and shortly after pathogen exposure. We have investigated this issue by using a model of parenteral TB immunization and intravascular immunostaining. We find that systemically induced memory T cells are restricted to the blood vessels in the lung, unable to populate either the lung parenchymal tissue or the airway under homeostatic conditions. We further find that after pulmonary TB infection, it still takes many days before such T cells can enter the lung parenchymal tissue and airway. We have identified the acquisition of CXCR3 expression by circulating T cells to be critical for their entry to these lung mucosal compartments. Our findings offer new insights into mucosal T cell biology and have important implications in vaccine strategies against pulmonary TB and other intracellular infections in the lung.

Role of B Cells in Mucosal Vaccine-Induced Protective CD8+ T Cell Immunity against Pulmonary Tuberculosis

Emerging evidence suggests a role of B cells in host defense against primary pulmonary tuberculosis (TB). However, the role of B cells in TB vaccine-induced protective T cell immunity still remains unknown. Using a viral-vectored model TB vaccine and a number of experimental approaches, we have investigated the role of B cells in respiratory mucosal vaccine-induced T cell responses and protection against pulmonary TB. We found that respiratory mucosal vaccination activated Ag-specific B cell responses. Whereas respiratory mucosal vaccination elicited Ag-specific T cell responses in the airway and lung interstitium of genetic B cell-deficient (Jh(-/-) knockout [KO]) mice, the levels of airway T cell responses were lower than in wild-type hosts, which were associated with suboptimal protection against pulmonary Mycobacterium tuberculosis challenge. However, mucosal vaccination induced T cell responses in the airway and lung interstitium and protection in B cell-depleted wild-type mice to a similar extent as in B cell-competent hosts. Furthermore, by using an adoptive cell transfer approach, reconstitution of B cells in vaccinated Jh(-/-) KO mice did not enhance anti-TB protection. Moreover, respiratory mucosal vaccine-activated T cells alone were able to enhance anti-TB protection in SCID mice, and the transfer of vaccine-primed B cells alongside T cells did not further enhance such protection. Alternatively, adoptively transferring vaccine-primed T cells from Jh(-/-) KO mice into SCID mice only provided suboptimal protection. These data together suggest that B cells play a minimal role, and highlight a central role by T cells, in respiratory mucosal vaccine-induced protective immunity against M. tuberculosis.