Local expression of tumor necrosis factor alpha and interleukin-2 correlates with protection against corneal scarring after ocular challenge of vaccinated mice with herpes simplex virus type 1

Abstract

To correlate specific local immune responses with protection from corneal scarring, we examined immune cell infiltrates in the cornea after ocular challenge of vaccinated mice with herpes simplex virus type 1 (HSV-1). This is the first report to examine corneal infiltrates following ocular challenge of a vaccinated mouse rather than following infection of a naive mouse. Mice were vaccinated systemically with vaccines that following ocular challenge with HSV-1 resulted in (i) complete protection against corneal disease (KOS, an avirulent strain of HSV-1); (ii) partial protection, resulting in moderate corneal disease (baculovirus-expressed HSV-1 glycoprotein E [gE]); and (iii) no protection, resulting in severe corneal disease (mock vaccine). Infiltration into the cornea of CD4 ؉ T cells, CD8 ؉ T cells, macrophages, and cells containing various lymphokines was monitored on days 0, 1, 3, 7, and 10 postchallenge by immunocytochemistry of corneal sections. Prior to ocular challenge, no eye disease or corneal infiltrates were detected in any mice. KOS-vaccinated mice developed high HSV-1 neutralizing antibody titers (>1:640) in serum. After ocular challenge, they were completely protected against death, developed no corneal disease, and had no detectable virus in their tear films at any time examined. In response to the ocular challenge, these mice developed high local levels of infiltrating CD4 ؉ T cells and cells containing interleukin-2 (IL-2), IL-4, IL-6, or tumor necrosis factor alpha (TNF-␣). In contrast, only low levels of infiltrating CD8 ؉ T cells were found, and gamma interferon (IFN-␥)-containing cells were not present until day 10. gE-vaccinated mice developed neutralizing antibody titers in serum almost as high as those of the KOS-vaccinated mice (>1:320). After ocular challenge, they were also completely protected against death. However, the gE-vaccinated mice developed low levels of corneal disease and virus was detected in one-third of their eyes. Compared with KOS-vaccinated mice, the gE-vaccinated mice had a similar pattern of IFN-␥, but a delay in the appearance of CD4 ؉ T cells, CD8 ؉ T cells, and IL-4-, IL-6-, and TNF-␣-containing cells. In sharp contrast to those of the KOS-vaccinated mice, no cells containing IL-2 were detected in the eyes of gE-vaccinated mice at any time. Mock-vaccinated mice developed no detectable neutralizing antibody titer and were not protected from lethal HSV-1 challenge. They developed the highest levels of corneal disease, and virus was detected in over 60% of their eyes. The eyes of mock-vaccinated mice had no TNF-␣ response, no IL-2 response, delayed and weaker IL-4 and IL-6 responses, and the strongest CD4 ؉ response on day 10, compared with responses of KOS-vaccinated mice. In contrast to the KOS-and gE-vaccinated mice, the mock-vaccinated mice showed an earlier and stronger CD8 ؉ T-cell response and an early IFN-␥ response. The results of this study show for the first time that in vaccinated mice ocularly challenged with HSV-1, there appears to be a correlation be...

The role of neutralizing antibody and T‐helper subtypes in protection and pathogenesis of vaccinated mice following ocular HSV‐1 challenge

“…Cryostat sections, 8–10‐μm thick, were cut, air dried overnight, and fixed in acetone for 3 min at 25° as we have described. 4,22 …”

“…Immunostaining was performed, as we described previously, on four of the isolated mice eyes using the polyclonal and monoclonal antibodies against CD4, interleukin‐2 (IL‐2), IL‐4, IL‐6 and tumour necrosis factor‐α (TNF‐α). 4 Briefly, frozen sections were incubated for 30 min, at 25° for polyclonal antibodies and 37° for monoclonal antibodies, in a humidified chamber. Subsequently, the appropriate biotin‐labelled secondary antibody was used, either biotin‐conjugated goat anti‐rat immunoglobulin G (IgG), or goat antirabbit IgG (Vector Laboratories Inc., Burlingame, CA).…”

A comparative study of experimental mouse models of central nervous system demyelination

“…Transverse sections of each tissue, 8-10 μm thick, were cut, air-dried overnight and fixed in acetone for 3 min at 25°C. [23][24][25]72 Analysis of demyelination using LFB staining…”

Improved Protection from Primary Ocular HSV-1 Infection and Establishment of Latency Using Multigenic DNA Vaccines

“…Previously, using protein vaccines and live HSV-1 (KOS) immunization, we found that increased expression of IL-2 in the eye correlated with decreased HSV-1 replication in the eye and death. 27,28 More recently, our experiments with IL-2-, IL-4 -, STAT4-, and STAT6-deficient mice revealed a functional relationship, 62,63 in that HSV-1 replicated more in the eyes of IL-2and STAT4-deficient mice than in IL-4 -and STAT6-deficient mice. Similarly, it has been shown that greater efficacy of a gD vaccine against genital herpes in women than in men is due to the higher Th1 (i.e., IL-2, IFN-␥) response in women.…”

“…Herpetic blepharitis is an inflammation of the lid margin after intraocular HSV-1 infection, and in the mouse, increased blepharitis correlates with increased HSV-1 replication. 27,28 There-fore, the eyes of the groups of mice infected with 2 ϫ 10 5 pfu per eye of HSV-1 strain McKrae were examined for blepharitis on day 7 after infection, with disease scored on a scale of 0 to 4. Mice vaccinated with DNA had less blepharitis than any of the other groups ( Fig.…”