Immune Responses to HIV in Blood Cells in HIV-Infected and HIV-Uninfected Volunteers

This study will explore the responses of the immune system to infection with HIV and other pathogens and the changes in these responses over time. Healthy normal volunteers and HIV-infected patients 18 years of age or older may be eligible for this study. Prior to enrollment and yearly thereafter, vital signs, height and weight will be recorded. A medical history will be obtained if relevant to the laboratory research for which the sample will be used. A more extensive history and physical exam is not required but may be performed if deemed necessary by the VRC clinician. A complete blood count will be performed on the day of enrollment and yearly thereafter. Samples will be collected in the following manner: Blood will be drawn from a needle in an arm vein one or more times during the course of the study. From 20 to 150 cc (4 to 30 teaspoonfuls) of blood will be collected at a time. No more than 450 cc (less than 1 pint) of blood will be drawn during any 6-week period. Urine and saliva samples will be collected by the volunteer in private. Swab samples will be collected by a nurse or doctor, using a cotton swab to brush inside the mouth. Samples may be used for the following tests: * Hepatitis and other viral screening-This may include screening for different types of viral liver infections, such as hepatitis A, B, C, D, E, or G; for cytomegalovirus (related to the herpes virus); and for varicella zoster virus (responsible for chicken pox in children and shingles in adults). * Genetic testing-DNA in blood cells may be examined for genetic mutations (physical or chemical changes) or deletions (missing pieces) that affect substances involved in the body's ability to mount an inflammatory immune response. Alterations in the genes for some of these substances have been shown to influence HIV infection. * HLA testing-HLA type is a genetic marker of the immune system. Determining HLA type is necessary in order to do certain research studies. Some HLA types have be