Human HR-1 RECEPTOR polypeptides and DNA (RNA) encoding such HR-1 RECEPTOR genes and a procedure for producing such polypeptides by recombinant techniques is disclosed. Also disclosed are methods for utilizing such HR-1 RECEPTORS for the treatment of decreased level of resistance to infection, asthma, various allergic and hematopoietic disorders or a susceptibility to the aforementionel abnormalities. Antagonists against such HR-1 RECEPTOR and their use as a therapeutic to treat decreased level of resistance to infection, asthma, various allergic and hematopoietic disorders or a susceptibility to the aformentioned abnormalities are also disclosed. Also disclosed are diagnostic assays for detecting diseases related to mutations in the nucleic acid sequences and altered concentrations of the polypeptides. Also disclosed are diagnostic assays for detecting mutations in the polynucleotides encoding the HR-1 RECEPTOR and for detecting altered levels of the polypeptide in a host.