Effects of 670 Nm and 830 Nm Light on the Immune Response to Borrelia Burgdorferi

Abstract

ABSTRACT EFFECTS OF 670 NM AND 830 NM LIGHT ON THE IMMUNE RESPONSE TO BORRELIA BURGDORFERI by Felice Chen The University of Wisconsin-Milwaukee, 2015 Under the Supervision of Dean T. Nardelli, Ph.D. and Janis T. Eells, Ph.D. Lyme arthritis is a debilitating joint disorder that arises from Lyme disease, which is a result of infection by the spirochete Borrelia burgdorferi. Antibiotics are the traditional treatment for Lyme disease, but chronic arthritis may persist in some patients despite antibiotic treatment. Therefore, other forms of treatment for Lyme arthritis are needed. Photobiomodulation (PBM) using red or near-infrared light, with wavelengths between 630 nm and 900 nm, has been found to be beneficial in alleviating inflammatory symptoms of many disorders. The purpose of this thesis was to determine whether photobiomodulation using either 670 nm or 830 nm light would help alleviate inflammation in a murine Lyme arthritis model. The central hypothesis for this study was that PBM, using 670 nm or 830 nm light, will decrease inflammation in Lyme arthritis. Two specific aims were pursued to test this hypothesis. The first aim was to determine the effect that 670 nm and 830 nm light had on paw swelling and pro-inflammatory cytokine levels in B. burgdorferi-infected mice. The working hypothesis for this specific aim was that 670 nm and 830 nm light would ameliorate swelling and reduce interleukin-17 (IL-17) and interferon-gamma (IFN-γ) production in B. burgdorferi-infected mice. The second aim was to determine the effect of 670 nm or 830 nm light had on production of borreliacidal antibodies in infected mice. The working hypothesis for this specific aim was that neither 670 nm nor 830 nm light would affect borreliacidal antibody production in B. burgdorferi-infected mice. Wild-type or interleukin-10-deficient C57BL/6 mice were infected with B. burgdorferi and treated with either 670 nm light or 830 nm light for six or seven consecutive days. Infected paws were then measured for changes in paw swelling, and IL-17 and IFN-γ production by spleen cells were determined. Sera were used to determine borreliacidal antibody titers. Our hypothesis was partially supported, in that PBM using 670 nm light was capable of significantly decreasing IFN-γ production. Surprisingly, 670 nm light also increased the borreliacidal antibody titer in a model of dysregulated disease. However, it was unable to decrease the paw swelling exhibited in murine Lyme arthritis. Our hypothesis was not supported by the use of 830 nm light. Treatment with 830 nm light did not significantly affect paw swelling, and it significantly increased IL-17 production and reduced borreliacidal antibody titers in the model of dysregulated Lyme arthritis. Our results indicate that different wavelengths may possess varying effects on inflammation in Lyme arthritis.