Mycobacterial 65,000 MW Heat-Shock Protein Shares a Carboxy-Terminal Epitope with Human Epidermal Cytokeratin 1/2

The study demonstrated that monoclonal antibodies Ne5 and Nd4, which target a carboxy-terminal epitope on mycobacterial heat-shock protein (hsp) 65, cross-reacted with suprabasal cytokeratin in normal human skin, specifically cytokeratin 1/2. These antibodies stained the cytoplasm of epidermal keratinocytes but not HeLa cells or fibroblasts, indicating specificity. The cross-reactivity was abolished when preincubated with purified mycobacterial hsp 65, suggesting molecular mimicry. The study concluded that the Ne5/Nd4 epitope on hsp 65 shares similarity with a region on human cytokeratin, potentially implicating it as a target in skin diseases.