The documentation for the format parameter of glTexImage2D states:
The following symbolic values are accepted: GL_COLOR_INDEX, GL_RED, GL_GREEN, GL_BLUE, GL_ALPHA, GL_RGB, GL_BGR, GL_RGBA, GL_BGRA, GL_LUMINANCE, and GL_LUMINANCE_ALPHA.
This doesn't include GL_DEPTH_COMPONENT.
The description section, however lists GL_DEPTH_COMPONENT as a value for format. Also the list of error conditions include a restriction on internalFormat when format is GL_DEPTH_COMPONENT, and a requirement that format is GL_DEPTH_COMPONENT when internalFormat takes certain values.