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Statewide Cancer Clinical Trial Navigation Service
Moffitt, Karen, Brogan, F. A., Brown, Clarence, Kasper, Michael, Rosenblatt, Joseph D. , Smallridge, Robert C., Kromrey, Jeffrey D., Sullivan, Daniel

Journal of Oncology Practice | May 14, 2010 | Volume: 6 | Issue: 3 | Pages: 127-132

10.1200/jop.200006 | PMID 20808555 Get It

Realizing education and awareness are paramount in making clinical trials available, the authors sought to evaluate a statewide navigation service to identify how it might improve cancer clinical trial accessibility in Florida for physicians and patients.
Blockade of CCL1 Inhibits T Regulatory Cell Suppressive Function Enhancing Tumor Immunity without Affecting T Effector Responses
Hoelzinger, Dominique B. , Smith, Shannon E., Mirza, Noweeda, Manrique, Soraya Zorro, Lustgarten, Joseph, Dominguez, Ana Lucía

The Journal of Immunology | May 7, 2010 | Volume: 184 | Issue: 12 | Pages: 6833-6842

10.4049/jimmunol.0904084 | PMID 20483762 Get It

Abstract Intratumoral accumulation of T regulatory cells (Tregs) creates an immunosuppressive environment that reduces the efficacy of antitumor immunotherapy. The immunosuppressive milieu within tumors is largely brought about by the presence of Tregs, which maintain self-tolerance by directly inhibiting T cells, NK cells, and dendritic cells. Depletion of Tregs enhances antitumor immune responses; however, current depletion therapies also affect the function of CD4 and CD8 T effector cells. Previous studies from our laboratory indicate that intratumoral delivery of CpG-ODN strongly reduces the levels of Tregs within the tumor, which is mainly mediated by IL-6. Because IL-6 promotes growth of some human cancers, alternate pathways to inactivate Tregs were sought through microarray analysis, resulting in gene candidates that can be exploited to modulate the function of Tregs. Analysis of these candidates indicates that neutralization of chemokine (C-C motif) ligand 1 (CCL1) prevented de novo conversion and suppressive function of Tregs without affecting the function of T effector cells. The combination of CpG-ODN and anti-CCL1 treatments induced complete rejection of tumors in BALB-neuT tolerant mice, and result in the generation of long-term protective memory responses. Tumor rejection correlated with changes in the lymphocyte composition within the tumor; we observed decreased Treg numbers and a concomitant accumulation of tumoricidal cells such as CD8+NKG2D+ and NK cells. These studies demonstrate that neutralization of CCL1 can be used as an adjuvant to antitumor immunotherapy, as a means of reversing the immunosuppressive function of Tregs without compromising T cell effector function.
A Single-Institution Review of Portosystemic Shunts in Children: An Ongoing Discussion
Lillegard, Joseph B. , Hanna, Afif, McKenzie, Travis J. , Moir, C., Ishitani, M., Nagorney, David M.

HPB Surgery | May 6, 2010 | Volume: 2010 | Issue: No issue available | Pages: 1-6

10.1155/2010/964597 | PMID 20467465 Get It

Purpose. Review the safety and long-term success with portosystemic shunts in children at a single institution. Methods. An IRB-approved, retrospective chart review of all children ages 19 and undergoing surgical portosystemic shunt from January 1990–September 2008. Results. Ten patients were identified, 8 females and 2 males, with a mean age of 15 years (range 5–19 years). Primary diagnoses were congenital hepatic fibrosis (5), hepatic vein thrombosis (2), portal vein thrombosis (2), and cystic fibrosis (1). Primary indications were repeated variceal bleeding (6), symptomatic hypersplenism (2), and significant liver dysfunction (2). Procedures performed were distal splenorenal bypass (4), side-to-side portocaval shunt (3), proximal splenorenal shunt (2), and an interposition H-graft portocaval shunt (1). There was no perioperative mortality and only minor morbidity. Seventy percent of patients had improvement of their symptoms. Eighty percent of shunts remained patent. Two were occluded at a median follow-up of 50 months (range 0.5–13.16 years). Two patients underwent subsequent liver transplantation. Two patients died at 0.5 and 12.8 years postoperatively, one from multisystem failure with cystic fibrosis and one from post-operative transplant complications. Conclusions. The need for portosystemic shunts in children is rare. However, in the era of liver transplantation, portosystemic shunts in selected patients with well-preserved liver function remains important. We conclude that portosystemic shunts are safe and efficacious in the control of variceal hemorrhage and symptoms related to hypersplenism.
Obesity is associated with an increased risk of monoclonal gammopathy of undetermined significance among black and white women
Rajkumar, S. Vincent , Kyle, Robert A. , Katzmann, Jerry A., Dispenzieri, Angela , Goldin, Lynn R. , Caporaso, Neil E. , Fraumeni, Joseph F., Blot, William J. , Signorello, Lisa B., Landgren, Ola , Pfeiffer, Ruth M. , Cai, Qiuyin , Rajkumar, S Vincent , Dispenzieri, Angela

Blood | April 26, 2010 | Volume: 116 | Issue: 7 | Pages: 1056-1059

10.1182/blood-2010-01-262394 | PMID 20421448 Get It

Abstract Obesity and black race have been associated with excess risk of multiple myeloma. The association of obesity with monoclonal gammopathy of undetermined significance (MGUS) is unknown. Further, it is not known whether the increased risk of multiple myeloma and MGUS in blacks is related to socioeconomic status, genetic susceptibility, or both. We screened 1000 black and 996 white women (range, 40-79 years) of similar socioeconomic status for MGUS; the aim of the study was to assess MGUS risk in relation to obesity and race. A total of 39 (3.9%) blacks and 21 (2.1%) whites had MGUS. On multivariate analysis, obesity (odds ratio [OR] = 1.8; P = .04), black race (OR = 1.8; P = .04), and increasing age (> 55 vs < 43 years; OR = 2.5; P = .03) were independently associated with an excess risk of MGUS. Our findings support the hypothesis that obesity is etiologically linked to myelomagenesis. The 2-fold excess of MGUS among blacks compared with whites of similar socioeconomic status supports a role for susceptibility genes in MGUS.
Once- versus twice-weekly bortezomib induction therapy with CyBorD in newly diagnosed multiple myeloma
Reeder, Craig B. , Reece, Donna , Kukreti, Vishal , Chen, Christine , Trudel, Suzanne , Laumann, Kristina, Hentz, Joseph G. , Pirooz, Nicholas, Píza, J, Tiedemann, Rodger E. , Bergsagel, P. Leif , Leis, José F., Fonseca, Rafaël , Stewart, Alexander K., Mıkhael, Joseph , Bergsagel, P. Leif , Fonseca, Rafael

Blood | April 22, 2010 | Volume: 115 | Issue: 16 | Pages: 3416-3417

10.1182/blood-2010-02-271676 | PMID 20413666 Get It

A commonly carried allele of the obesity-related FTO gene is associated with reduced brain volume in the healthy elderly
Ho, April J., Stein, Jason L. , Hua, Xue , Lee, Suh , Hibar, Derrek P., Leow, Alex , Dinov, Ivo D. , Toga, Arthur W. , Saykin, Andrew J. , Shen, Li , Pankratz, Nathan , Huentelman, Matthew J. , Craig, David W. , Gerber, Jill D., Allen, April N., Corneveaux, Jason J., Stephan, Dietrich A. , DeCarli, Charles , Dechairo, Bryan, Jack, Clifford R. , Weiner, Michael W. , Raji, Cyrus A. , Becker, James T. , Carmichael, Owen , Thompson, Paul M. , Initiative, the Alzheimer's Disease Neuroimaging, Thal, Leon J., Petersen, Ronald C., Jagust, William J. , Trojanowki, John Q., Toga, Arthur W., Gamst, Anthony, Potter, William Z., Montine, Tom, Anders, Dale, Felmlee, Joel P. , Schuff, Norbert, Alexander, Gene E. , Bandy, Dan, Foster, Norm, Reiman, Eric M. , Shaw, Les, Korecka, Magdalena , Toga, Arthur W., Crawford, Karen , Neu, Scott, Kornak, John , Kachaturian, Zaven, Frank, Richard , Molchan, Susan, Vorobik, Remi, Schneider, Lon S. , Pawluczyk, Sonia, Spann, Bryan , Fleisher, Adam , Vanderswag, Helen, Heidebrink, Judith L. , Johnson, Kris , Doody, Rachelle S., Villanueva‐Meyer, Javier , Chowdhury, Munir , Bell, Karen L. , Mintun, Mark A., Schneider, Stacy, Marson, Daniel , Griffith, Randall, Badger, Beverly, Grossman, Hillel, deToledo‐Morrell, Leyla, Bach, Julie , Duara, Ranjan , Isaacson, Richard , Strauman, Silvia, Albert, Marilyn S. , Pedroso, Julia, Toroney, Jaimie, Santi, Susan M De, Doraiswamy, P. Murali , Petrella, Jeffrey R. , Aiello, Marilyn, Clark, Christopher M. , Pham, Cassie, Nuñez, Jessica, Smith, Charles D., Given, Curtis A., Hardy, Peter , DeKosky, Steven T. , Oakley, MaryAnn, Simpson, Donna M., Ismail, M. Saleem , McCallum, Colleen, Cramer, Steven C. , Mulnard, Ruth A., Mc-Adams-Ortiz, Catherine, Martin-Cook, Kristen, Devous, Michael D. , Cellar, Janet S., Anderson, Heather S., Laubinger, Mary M., Bartzokis, George, Lu, Po H. , Fletcher, Rita, Parfitt, Francine, Farlow, Martin R. , Herring, Scott, Hake, Ann Marie , Dyck, Christopher H. van , MacAvoy, Martha G., Bifano, Laurel A., Chertkow, Howard, Bergman, Howard , Hosein, Chris, Graham, Simon J. , Caldwell, Curtis, Assaly, Michele, Hsiung, Ging‐Yuek Robin , Kertesz, Andrew , Trost, Dick, Bernick, Charles , Johnson, Nancy , Sadowsky, Carl, Villena, Teresa, Mesner, Scott, Aisen, Paul, Johnson, Kathleen, Behan, Kelly E., Johnson, Keith A. , Rosen, Allyson , Tinklenberg, Jared, Ashford, Wes, Connor, Donald J., Obradov, Sanja, Jayam‐Trouth, Annapurni , Wang, Paul J. , Auchus, Alexander P. , Huang, Juebin , DeCarli, Charles , Kittur, Smita, Mirje, Seema, Borrie, Michael, Lee, T‐Y, Asthana, Sanjay , Carlsson, Cynthia M., Highum, Diane, Preda, Adrian , Tariot, Pierre N. , Hendin, Barry , Kataki, Maria , Zimmerman, Earl A. , Celmins, Dzintra, Brown, Alice D., Gandy, Sam, Marenberg, Marjorie E., Rovner, Barry W. , Blank, Karen, Anderson, Karen, Santulli, Robert B. , Paré, Nadia, Williamson, Jeff D. , Raj, Balebail Ashok, Giordano, Amy T., Ott, Brian R. , Wu, Chuang‐Kuo, Cohen, Ronald A. , Wilks, Kerri, Lee, Ting‐Yim , Foroud, Tatiana , Potkin, Steven G. , López, Oscar L. , Initiative, the Alzheimer's Disease Neuroimaging, Toga, Arthur W., Beckett, Laurel , Green, Robert C. , Bernstein, Matt A. , Fox, Nick C. , Koeppe, Robert A. , Foster, Norm, Chen, Kewei , Lee, Virginia M.‐Y. , Toga, Arthur W., Harvey, Danielle , Snyder, Peter J. , Kaye, Jeffrey , Quinn, Joseph F. , Lord, Joanne L. , Stern, Yaakov , Honig, Lawrence S. , Morris, John C. , Tang, Cheuk Ying , Stern, Jessica A. , Shah, Raj C. , Duara, Ranjan , Rusinek, Henry , Leon, Mony J. de , Porsteinsson, Anton P. , Diaz‐Arrastia, Ramon , Levey, Allan I. , Lah, James J. , Burns, Jeffrey M. , Silverman, Daniel H.S. , Johnson, Heather K. , Black, Sandra E. , Feldman, Howard , ROGERS, John H. , Gitelman, Darren R. , Mesulam, Marsel M. , Sperling, Reisa Anne , Rentz, Dorene M. , Sabbagh, Marwan Noel , Killiany, Ronald , Norbash, Alexander , Obisesan, Thomas O. , Friedland, Robert P. , Fletcher, Evan M. , Johnson, Sterling C. , Nguyen, Dana R. , Scharre, Douglas W. , Beversdorf, David Q. , Gandy, Sam , Pearlson, Godfrey D. , Sink, Kaycee M. , Potter, Huntington , Jack, Clifford R , Saykin, Andrew J , Shen, Li , Preda, Adrian , Toga, Arthur W , Stein, Jason L , Thompson, Paul M , Hsiung, Gink-Yuek , Pankratz, Nathan

Proceedings of the National Academy of Sciences | April 19, 2010 | Volume: 107 | Issue: 18 | Pages: 8404-8409

10.1073/pnas.0910878107 | PMID 20404173 Get It

A recently identified variant within the fat mass and obesity-associated ( FTO ) gene is carried by 46% of Western Europeans and is associated with an ~1.2 kg higher weight, on average, in adults and an ~1 cm greater waist circumference. With >1 billion overweight and 300 million obese persons worldwide, it is crucial to understand the implications of carrying this very common allele for the health of our aging population. FTO is highly expressed in the brain and elevated body mass index (BMI) is associated with brain atrophy, but it is unknown how the obesity-associated risk allele affects human brain structure. We therefore generated 3D maps of regional brain volume differences in 206 healthy elderly subjects scanned with MRI and genotyped as part of the Alzheimer's Disease Neuroimaging Initiative. We found a pattern of systematic brain volume deficits in carriers of the obesity-associated risk allele versus noncarriers. Relative to structure volumes in the mean template, FTO risk allele carriers versus noncarriers had an average brain volume difference of ~8% in the frontal lobes and 12% in the occipital lobes—these regions also showed significant volume deficits in subjects with higher BMI. These brain differences were not attributable to differences in cholesterol levels, hypertension, or the volume of white matter hyperintensities; which were not detectably higher in FTO risk allele carriers versus noncarriers. These brain maps reveal that a commonly carried susceptibility allele for obesity is associated with structural brain atrophy, with implications for the health of the elderly.
Reoperations After Repair of Partial and Complete Atrioventricular Septal Defect
Stulak, John M., Burkhart, Harold M. , Dearani, Joseph A.

World Journal for Pediatric and Congenital Heart Surgery | April 13, 2010 | Volume: 1 | Issue: 1 | Pages: 97-104

10.1177/2150135110362453 | PMID 23804729 Get It

The most common cause of reoperation following repair of atrioventricular septal defect (AVSD) is left atrioventricular valve regurgitation. However, reoperation for subaortic obstruction is required in some, especially after initial repair of partial AVSD. Etiology of reoperation and late outcome were evaluated. Between 1962 and 2007, 146 patients (59 male) underwent reoperation at the authors' institution after prior repair of partial (n = 96) and complete (n = 50) AVSD. Median age at reoperation after repair of partial AVSD was 26 years (range, 10 months to 71 years) and 4.5 years (range, 53 days to 38 years) after repair of complete AVSD. The 3 most common indications for reoperation included left atrioventricular (AV) valve regurgitation in 105 patients, subaortic stenosis in 29, and right AV valve regurgitation in 21. The most common procedures performed included left AV valve repair in 59 (40%) patients, left AV valve replacement in 56 (38%), subaortic fibrous resection/myectomy in 24 (16%), and right AV valve surgery in 19 (13%). Freedom from subsequent reoperation at 10 years was 48% after initial repair of complete AVSD and 84% after initial repair of partial AVSD. During late follow-up, 10-year actuarial survival was 91% and 77% after initial repair of complete and partial AVSD, respectively. The most common indication for reoperation after initial repair of partial or complete AVSD is left AV valve pathology; left ventricular outflow tract obstruction was more common in partial AVSD. Although freedom from subsequent reoperations is higher after initial repair of partial AVSD, these patients have reduced long-term survival when compared with complete AVSD.
Genetic variants near TIMP3 and high-density lipoprotein–associated loci influence susceptibility to age-related macular degeneration
Stambolian, Dwight, Edwards, Albert O., Branham, Kari , Othman, Mohammad , Jakobsdóttir, Jóhanna , Tosakulwong, Nirubol , Pericak‐Vance, Margaret A. , Klein, Michael L. , Tan, Perciliz L. , Kanda, Atsuhiro , Kopplin, Laura J. , Li, Yanming , Augustaitis, Katherine J., Karoukis, Athanasios J., Scott, William K. , Agarwal, Anita , Kovach, Jaclyn L. , Postel, Eric A. , Brooks, Matthew, Baratz, Keith H. , Brown, William L. , Brucker, Alexander J., Orlin, Anton, Brown, Gary C. , Ho, Allen C. , Regillo, Carl D. , Donoso, Larry A., Tian, Lifeng , Kaderli, Brian, Hadley, Dexter , Hagstrom, Stephanie A. , Peachey, Neal S. , Klein, Ronald , Klein, Barbara E.K. , Gotoh, Norimoto, Yamashiro, Kenji , Ferris, Frederick L. , Fagerness, Jesen, Reynolds, Robyn, Farrer, Lindsay A. , Kim, Ivana K. , Miller, Joan W. , Cortón, Marta , Carracedo, Ángel , Sánchez‐Salorio, Manuel, Pugh, Elizabeth, Doheny, Kimberly F. , Brión, Marı́a , Weeks, Daniel E. , Zack, Donald J. , Heckenlively, John R., Yoshimura, Nagahisa , Iyengar, Sudha K. , Francis, Peter J. , Katsanis, Nicholas , Seddon, Johanna M. , Haines, Jonathan L. , Abecasis, Gonçalo R. , Swaroop, Anand , Johnson, Robert N., Ai, Everett, McDonald, H. Richard , Stolarczuk, Margaret, Pavan, Peter R., Billiris, Karina K., Iyer, Mohan , Menosky, Matthew M., Pautler, Scott E. , Millard, Sharon M., Hubbard, G. Baker , Aaberg, Thomas , DuBois, Lindy, Lyon, Alice T., Anderson-Nelson, Susan, Jampol, Lee M. , Muñana, Annie, Rozenbajgier, Zuzanna, Orth, David H., Cohen, Jack, MacCumber, Matthew, Figliulo, Celeste, Porcz, Liz, Folk, James C. , Boldt, H. Culver , Russell, Stephen R. , Ivins, Rachel, Hinz, Connie J., Bloom, Steve, Jaegers, Ken, Kritchman, Brian, Whittington, Greg K., Frederick, Albert R., Morley, Michael G., Topping, Trexler M., Davis, Heather L., Bressler, Susan B., Bressler, Neil M. , Doll, W T Jr, Trese, Michael T. , Garretson, Bruce R., Ruby, Alan, Osentoski, Tammy, Ruszczyk, Margaret, Grand, G., Joseph, Daniel P., Shah, Gaurav K. , Nobel, Ginny, Antoszyk, Andrew N., Stallings, Alison H, Singerman, Lawrence J. , Miller, David T. , Novák, Michael, Pendergast, Scott, Zegarra, Hernando, Schura, Stephanie A., Smith-Brewer, Sheila, Davidorf, Frederick H., Chorich, Louis J., Salerno, Jill, Dreyer, Richard F., Ma, Colin, Kopfer, Marcia, Wilson, David J. , Nolte, Susan K., Grunwald, Juan E. , Dunaief, Josh, Fine, Stuart L., Maguire, Albert M. , Stoltz, Robert A., McRay, Monique, Fish, Gary E., Anand, Rajiv, Spencer, Rand , Arnwine, Jean, Chandra, Suresh R., Blodi, Barbara, Gottlieb, Justin L., Ip, Michael S. , Nork, T. Michael , Perry-Raymond, Jennie, Brightwell-Arnold, Mary, Harkins, Sandra, Peskin, Ellen, Ying, Gui‐Shuang , Kurinij, Natalie, Chen, Wei , Campochiaro, Peter A. , Conley, Yvette P. , Schwartz, Stephen G. , DeAngelis, Margaret M. , Chew, Emily Y. , Gorin, Michael B. , Menosky, Matthew M., Weinberg, David V. , Barr, Charles C. , Heier, Jeffrey S. , Capone, A. , Hassan, T. , McCannel, Colin A. , Blinder, Kevin J. , Holekamp, Nancy M. , Browning, David J. , Chambers, Robert , Altaweel, Michael M. , Maguire, Maureen G. , Weeks, Daniel E , Brion, María , Abecasis, Gonçalo

Proceedings of the National Academy of Sciences | April 12, 2010 | Volume: 107 | Issue: 16 | Pages: 7401-7406

10.1073/pnas.0912702107 | PMID 20385819 Get It

We executed a genome-wide association scan for age-related macular degeneration (AMD) in 2,157 cases and 1,150 controls. Our results validate AMD susceptibility loci near CFH ( P < 10 −75 ), ARMS2 ( P < 10 −59 ), C2/CFB ( P < 10 −20 ), C3 ( P < 10 −9 ), and CFI ( P < 10 −6 ). We compared our top findings with the Tufts/Massachusetts General Hospital genome-wide association study of advanced AMD (821 cases, 1,709 controls) and genotyped 30 promising markers in additional individuals (up to 7,749 cases and 4,625 controls). With these data, we identified a susceptibility locus near TIMP3 (overall P = 1.1 × 10 −11 ), a metalloproteinase involved in degradation of the extracellular matrix and previously implicated in early-onset maculopathy. In addition, our data revealed strong association signals with alleles at two loci ( LIPC , P = 1.3 × 10 −7 ; CETP , P = 7.4 × 10 −7 ) that were previously associated with high-density lipoprotein cholesterol (HDL-c) levels in blood. Consistent with the hypothesis that HDL metabolism is associated with AMD pathogenesis, we also observed association with AMD of HDL-c—associated alleles near LPL ( P = 3.0 × 10 −3 ) and ABCA1 ( P = 5.6 × 10 −4 ). Multilocus analysis including all susceptibility loci showed that 329 of 331 individuals (99%) with the highest-risk genotypes were cases, and 85% of these had advanced AMD. Our studies extend the catalog of AMD associated loci, help identify individuals at high risk of disease, and provide clues about underlying cellular pathways that should eventually lead to new therapies.
Carbon monoxide reverses diabetic gastroparesis in NOD mice
Kashyap, Purna , Choi, Kyoung Moo , Dutta, Nirjhar , Szurszewski, Joseph H., Gibbons, Simon J. , Farrugia, Gianrico , Linden, David R. , Gibbons, S J

American Journal of Physiology-Gastrointestinal and Liver Physiology | April 9, 2010 | Volume: 298 | Issue: 6 | Pages: G1013-G1019

10.1152/ajpgi.00069.2010 | PMID 20378827 Get It

Diabetic gastroparesis is associated with increased oxidative stress attributable to loss of upregulation of heme oxygenase-1 (HO1), with resultant damage to interstitial cells of Cajal and delayed gastric emptying. These changes can be reversed by induction of HO1. HO1 catalyzes the breakdown of heme into iron, biliverdin and, carbon monoxide (CO). The aim of this study was to determine whether inhalation of CO can mimic the protective effects of HO1. Nonobese diabetic (NOD) mice with delayed gastric emptying were treated with CO inhalation. Serum malondialdehyde was measured as a marker of oxidative stress. Gastric emptying of solids was measured using a [13C]octanoic acid breath test. Kit expression levels were determined in immunoblots of protein extracted from the external muscle layers of the gastric body and antrum. The effect of CO on oxidative stress and gastric emptying was also determined in the presence of HO activity inhibitor chromium mesoporphyrin. CO inhalation reduced oxidative stress, restored Kit expression and reversed delayed gastric emptying in diabetic NOD mice with delayed gastric emptying. CO inhalation maintained this effect in the presence of the HO activity inhibitor, chromium mesoporphyrin, also resulting in restoration of the delay in gastric emptying. CO inhalation mimics the protective effect of upregulation of HO1 and decreased oxidative stress, increased Kit expression, and restored delay in gastric emptying. This effect of CO was independent of HO activity, suggesting that its effects were downstream of HO1. CO represents a potential therapeutic option for treatment of diabetic gastroparesis.
B7-H1 Expression on Old CD8+ T Cells Negatively Regulates the Activation of Immune Responses in Aged Animals
Mirza, Noweeda, Duque‐Correa, Maria A. , Schrum, Adam G. , Lustgarten, Joseph, Dominguez, Ana Lucía , Dong, Haidong , Schrum, Adam G

The Journal of Immunology | April 7, 2010 | Volume: 184 | Issue: 10 | Pages: 5466-5474

10.4049/jimmunol.0903561 | PMID 20375308 Get It

Abstract T cell responses are compromised in the elderly. The B7-CD28 family receptors are critical in the regulation of immune responses. We evaluated whether the B7-family and CD28-family receptors were differentially expressed in dendritic cells, macrophages, and CD4+ and CD8+ T cells from young and old mice, which could contribute to the immune dysfunction in the old. Although most of the receptors were equally expressed in all cells, &gt;85% of the old naive CD8+ T cells expressed B7-H1 compared with 25% in the young. Considering that B7-H1 negatively regulates immune responses, we hypothesized that expression of B7-H1 would downregulate the function of old CD8+ T cells. Old CD8+ T cells showed reduced ability to proliferate, but blockade of B7-H1 restored the proliferative capacity of old CD8+ T cells to a level similar to young CD8+ T cells. In vivo blockade of B7-H1 restored antitumor responses against the B7-H1− BM-185–enhanced GFP tumor, such that old animals responded with the same efficiency as young mice. Our data also indicate that old CD8+ T cells express lower levels of TCR compared with young CD8+ T cells. However, following antigenic stimulation in the presence of B7-H1 blockade, the levels of TCR expression were restored in old CD8+ T cells, which correlated with stronger T cell activation. These studies demonstrated that expression of B7-H1 in old CD8+ T cells impairs the proper activation of these cells and that blockade of B7-H1 could be critical to optimally stimulate a CD8 T cell response in the old.