Single amino acid substitutions in melanoma-associated peptides dramatically enhance T-cell cytotoxicity against target cells presenting the modified peptides (often referred to as heteroclitic peptides). The authors tried to determine whether peptide modifications influence other aspects of T-cell immunity toward malignant melanoma. A heteroclitic peptide, E26F, with an E to F substitution in melanoma antigen recognized by T cell 1 (MART-1)26-35, triggers an enhanced tyrosine phosphorylation response when compared with the native- and other-modified MART-1 peptides. Similarly, the E26F peptide enhances the production of mRNA for interleukin (IL)-5, IL-10, IL-13, IL-15, and interferon-gamma and significantly enhances release of IL-13 and IL-10 from anti-MART-1 cytotoxic T cells. Another heteroclitic peptide, 1L, with an A to L substitution in MART-1(27-35), also enhances the tyrosine phosphorylation response in anti-MART-1 cytotoxic CD8+ T cells. Yet, 1L does not enhance the production of T helper cell type 2-like cytokines (IL-10 and IL-13). Together these data show that minor amino acid modifications of immunodominant melanoma peptides profoundly influence the cytokine response in melanoma-specific T cells.

Amino Acid Substitution↗

PubMedDate not supplied

Nystagmus findings in healthy subjects examined with infrared videonystagmoscopy.

The increased use of video systems for the detection of nystagmus is a new diagnostic tool in the diagnosis of patients with vestibular disorders. Small video cameras mounted in a light sealed mask visualize the eyes which are illuminated with infrared light. Compared to the well-established use of Frenzel glasses the patient has no visual references at all. This new technique requires standards for normal limits. Thirty subjects between 20 and 78 years of age with no history of vestibular disorders were examined with infrared video-oculoscopy with the gaze in primary position, after head-shake and in supine position with head torsion and Dix-Hallpike positions backward and forward according to a standardized procedure at our department. Two subjects had spontaneous nystagmus, but nystagmus after head-shake was not found in any. No subject had torsional nystagmus in the Dix-Hallpike positions. In the elderly subjects horizontal nystagmus in head hanging position was a frequent finding.

Adult↗