Macrophage infiltrates play a variety of key roles in the immune defense system, including a central role in innate or natural immunity. We have shown by immunostaining using anti-F4/80 and CD11b antibodies that resident corneal macrophages are not detectable in cornea of uninfected mice. In contrast, following infection of mice with herpes simplex virus type-1 (HSV-1), macrophages appear to be the most dominant infiltrate of the eye. Thus, macrophages may play a central role in both exacerbation and control of acute and chronic HSV-1 infection. In line with our previous studies, our Preliminary studies also suggest that: 1. Injection of mice with macrophage-colony stimulating factor (M-CSF) DNA reduced virus replication in the eye and establishment of latency in trigeminal ganglia (TG) of ocularly infected mice. 2. Similar to M-CSF injection, injection of mice with IL-12p35 DNA also reduced virus replication in the eye and establishment of latency in TGs of latently infected mice. Thus, since macrophages are the most abundant infiltrates in the eye of HSV-1 ocularly infected mice and also appear the fastest in the eye (as early as 4 hours) after ocular infection, we will use macrophage stimulatory factors (i.e., M-CSF and IL-12p35) to reduce virus replication in the eye and establishment of latency in the TGs of ocularly infected mice. We propose to:
Aim : Test the hypothesis that macrophage stimulation by a combination of IL-12p35 and M-CSF DNA as molecular adjuvants will enhance TH1/TC1 responses in the eye and lead to a more rapid clearance of virus from the eye and trigeminal ganglia (TG) during primary ocular HSV-1 infection. This will, lead to a significant reduction in establishment of latency and reactivation in TG of latently infected mice. Our preliminary studies suggest that administration of IL-12p35 and M-CSF DNA improves immunization efficacy as judged by a greater reduction in virus replication in the eye after ocular infection compare with control mice, or mice that are immunized with IL-12p35 or M-CSF alone. This improved efficacy correlated with higher activities of local ocular responses (i.e., IL-2, IFN-a, IFN-, IFN- ?). We propose to test the hypothesis that; (1) a cocktail of IL-12p35 and M-CSF DNA will result in reduction in primary virus replication in the eyes as well as reduction of latency in TGs of infected mice; (2) these reductions are associated with generation of strong and rapid TH1/TC1 responses in addition to IFN-a and IFN- in the eye and TGs of infected mice; and (3) Co-administration of IL-12p35 + M-CSF + 5gP DNA will further reduce latency in immunized mice compared with mice that treated with 5gP alone. Overall, we expect to determine that a combination of IL-12p35 and M-CSF enhances the cytokine secretion and antigen presentation functions of macrophages rather than their phagocytosis function.
HSV-1-induced corneal scarring, also broadly referred to as herpes stromal keratitis (HSK), can lead to blindness; thus, HSV-1 is the leading cause of corneal blindness due to an infectious agent in developed countries. We have shown that macrophages are playing a major role in reducing virus replication in the eye and establishment of latency in trigeminal ganglia of infected mice and inclusion of IL-12p35 and M-CSF enhances immunization efficacy against ocular HSV-1 infection and latency. We now plan to further enhance our immunization efficacy against virus replication in the eye and latency in trigeminal ganglia of infected mice by inclusion of IL-12p35 and M-CSF as molecular adjuvants.
