Analysis of the KHRI-3 Antigen in Guinea Pig Inner Ear and Lung Tissues

Abstract

•Mammalian ears are composed of the same basic structures (Figure 1). •How mammals hear •Sound waves ear canal vibrate tympanic membrane (eardrum) vibration to middle ear bones oval window (increase amplitude) standing wave in the endolymph of the organ of corti1. •Sensorineural hearing loss •Results from damage to the organ of corti and the acoustic nerve (i.e. prolonged exposure to loud noises, aging, heredity, meningitis, Meniere’s disease, rubella, etc.) hearing is not easily restored •Autoimmune Sensorineural Hearing Loss (AISNHL) •Western blots of sensorineural hearing loss patient sera showed a 68 kDa band antigen (“KHRI-3 antigen”) (Harris and Sharp, 1990). •Antigen found in other organs (kidney, brain, etc.). •KHRI-3 •A monoclonal, IgG antibody that appears a band with a molecular weight of 68-70 kDa in Western blots (Zajic et. al., 1991). •Mice carrying the KHRI-3 hybridoma had high titers of KHRI-3 antibody and loss of outer hair cells in the basal turn of the cochlea (region responsible for high frequency sounds) (Zajic et. al., 1991). •Has 10 peptides identical to human choline transporter-like protein 2 (CTL2) (Nair et. al., unpublished). •Created polyclonal rabbit anti-CTL2 antibody •Both KHRI-3 and CTL2 can be used to identify the KHRI-3 antigen •Enzymatic digestion of inner ear extracts (Nair et. al., unpublished). •O-glycosidase (removes O-linked sugars) no O-linked sugars on KHRI-3 antigen •PNGaseF (removes N-linked sugars) single band of 62 kDa •Neuraminidase (removes sialic acids)doublet becomes single band •Hypothesis •If the organ and inner ear antigens are the same, there must be differences in glycosylation to account for the different Western blot results. •We hypothesized that sialic acid residues were the glycosylation differences. 1Spiral structure within the cochlea that transmits sound waves to the brain through hair cells that convert sound waves to nerve impulses (Anderson et. al., 1998).