Many events associated with Human Immunodeficiency Virus (HIV) infection/replication occur in and around the germinal centers (GCs) of secondary lymphoid tissues where follicular dendritic cells (FDCs) reside, suggesting that this microenvironment may contribute unique signaling that is important to viral progression. My research focused on characterizing signaling, both positive and negative, contributed by FDCs that affects HIV infection and replication. Specifically, I determined if FDC signals could induce the expression of latent HIV in T cells and if so, to characterize the signaling pathways involved. Moreover, I also examined the ability of FDCs to produce inhibitory signals that might block active virus expression. I approached these problems using FDCs from tonsils and coculturing these with primary CD4+ T cells or latently-infected Jurket cells with a GFP reporter. Results indicated that FDCs dramatically augmented HIV production of these cells. FDC signaling was costimulatory in nature and was mediated by soluble TNFα. However, when ex vivo latently infected T cells were treated with PMA/ionomycin or IL2/IL7, little virus expression was observed until FDCs were added, which greatly increased virus production. The transcription factor NFAT is important for the reactivation of latent HIV. Inhibition studies as well as ELISA suggested that JAK/STAT signaling pathway was involved in virus reactivation. Because FDCs produce prostaglandins (PGs) E2 and I2, I determined the effect of PGE2 and PGI2 analogs on HIV infected T cells. Results indicated that both the PGE2 and PGI2 analogs inhibited proliferation and activation-induced cell death of HIV infected T cells in a dose- and time-dependent manner. Additionally, it was shown that indomethacin and CAY10404, cyclooxygenase and cyclooxygenase-2 inhibitors, partially restored HIV production in the presence of FDCs, suggesting that FDC-produced PGE2 and PGI2 may inhibit virus replication. Thus, FDCs produce PGs that can block virus gene expression in T cells, which may be ideal for viral persistence. Therefore, FDC signaling appears to both promote and inhibit HIV production. A better understanding of FDC signaling and regulation in GCs may suggest new treatment strategies that would be beneficial to infected subjects.

The effects of energy balance on hormonal patterns and recovered oocytes were evaluated in 20 lactating Holstein cows during two trial periods (fall/spring). Cows were randomly selected and assigned to one of two dietary treatments formulated so that cows consumed 3.6% BW (HE- 1.78 mcal/kg; n=6 in fall, n=5 in spring) and 3.2% BW (LE-1.52 mcal/kg; n= 5 in fall, n=4 in spring). Body weight and body condition score (BCS) were recorded prior to parturition and weekly throughout the fall trial. Ultrasound guided transvaginal follicular aspirations were conducted twice weekly between d 30 and 100 of lactation. Follicle size and number were recorded. Follicular fluid (FF) was aspirated from the largest follicle, and serum samples were collected for hormone assay (IGF-1; estradiol (E2); progesterone (P4, serum ); LH and FSH). Oocytes were collected and graded based upon cumulus density and ooplasm homogeneity, then fertilized and cultured in vitro. Milk yield averaged 41.64 ± .3 kg/d (mean ± SE) for HE and 32.8 ± .3 kg/d for LE. There was a significant cubic day postpartum by treatment interaction for milk yield. Dry matter intake and BW treatment by week interactions were significant for the cubic and linear components, respectively. Oocyte numbers increased linearly from d 30 to 100 postpartum. HE cows produced more good + oocytes (1.5 ± .2 ) than LE cows (1.4 ± .1). Follicles less than or equal to 5 mm predominated throughout the study (6.4 ± 3.0). However, greater numbers of follicles 10 to 14 mm and greater than or equal to 15 mm were found in the fall (1.98 ± .08 and .50 ± .06) than spring (1.11 ± .3 and .23 ± .07). Follicular fluid IGF-1 was higher in HE (2.3 ± .2 ng/ml) than in LE cows (1.6 ± .2 ng/ml). Mean basal serum FSH concentration was lower at 28 d postpartum (173 ± 8 pg/ml) compared to later (521 ± 25 at d 60 and 650 ± 25 pg/ml at d 110). Serum P4 peaked at 35 d postpartum, with HE cows having 1 ng/ml higher P4 than LE cows. Low dietary energy reduced milk yield, DMI, BCS, FF IGF-1 and serum P4 and had a negative impact on oocyte quality. / Master of Science

The development of oocytes of differing quality retrieved using transvaginal follicular aspiration (TVFA) and following DNA injection was examined. Eight cows were subjected to twice weekly TVF A for 16 wk. Oocytes retrieved were graded and placed in an in-vitro maturation, fertilization and co-culture (IVMIIVFIIVC) program. Two thirds of oocytes were injected with DNA. Good quality oocytes from slaughtered cows (SH) were obtained once monthly and processed the same way. Good quality TVF A oocytes had a higher mean development score than poor quality oocytes, but not different from that of good quality SH oocytes. Good quality TVF A oocytes produced more viable embryos (31.7% blastocysts) than poor quality oocytes or SH oocytes (12.8% and 20.4% blastocysts, respectively). Embryo development following injection of DNA was the same for oocytes for each source-quality group (TVF A-good, 8.4; TVF A-poor, 5.5; SH-good, 6.3 % blastocysts). Development of good quality TVFA oocytes increased during the last 9 wk of the 16 wk collection period. Poor oocyte development increased slightly to 9 wk and then decreased. Development of TVF A oocytes injected with DNA did not vary during the experiment. However, development of controls increased from a mean score of2.50 at wk 1 to 4.17 at wk 16. Oocytes from TVFA produced more PCR positive blastocysts (95.0%) than SH oocytes (61.5%). More calves were born from the transfer of embryos injected with DNA from TVF A oocytes (3/5) than from SH oocytes (116), although not statistically significant. One calf was PCR positive in bone-marrow, but was negative in other tissues. The use of oocytes obtained by TVF A may improve the efficiency of producing transgenic cattle. / Master of Science

An important obstacle to a functional cure for HIV/AIDS is the persistence of viral reservoirs found throughout the body in various cells and tissues. Reservoirs can be latently infected cells, or in the case of follicular dendritic cells (FDC), non-infected cells that trap infectious virus on their surface through immune complexes (HIV-IC). Although several strategies have been employed to target and eliminate viral reservoirs, they are short-lived and ineffective. In an attempt to provide a long-term approach, chimeric antigen receptor T (CAR-T) cells were designed to eliminate native HIV on FDCs. Although effective at eliminating HIV-infected cells, and halting spreading infection, their ability to eliminate the viral reservoir found on (FDCs) remains unclear. We used a novel second-generation CAR-T cell expressing domains 1 and 2 of CD4 followed by the mannose binding lectin (MBL) to allow recognition of native HIV envelope (Env) to determine the capacity to respond to the viral reservoir found on FDCs. We employed a novel fluorescent lysis assay, the Carboxyfluorescein succinimidyl ester (CFSE) release assay, as well as flow cytometric based assays to detect functional CAR-T activation through IFN-γ production and CD107a (i.e., LAMP1) membrane accumulation to test cytolytic capacity and functional activation of CD4-MBL CAR-T cells, respectively. We demonstrated their efficacy at eliminating HIV-infected cells or cells expressing gp160. However, these CAR-T cells were unable to lyse cells bearing surface bound HIV-IC. We found that failed lysis was not a unique feature of a resistant target, but a limitation in the CAR-T recognition elements. CAR-T cells were inactive in the presence of free HIV or in the presence of concentrated, immobilized virus. Further experiments determined that in addition to gp120 recognition by the CAR-T, the adhesion molecule ICAM-1 was necessary for efficient CAR-T cell killing of HIV-infected cells. CAR-T cell activity and killing were inhibited in the presence of ICAM-1 blocking antibody. These results suggest that other factors, such as adhesion molecules, play a vital role in CAR-T responses to HIV-infected cells. In addition, our findings highlighted the necessity to consider all models of HIV reservoirs, including FDCs, when evaluating therapeutic efficacy.

An important obstacle to a functional cure for HIV/AIDS is the persistence of viral reservoirs found throughout the body in various cells and tissues. Reservoirs can be latently infected cells, or in the case of follicular dendritic cells (FDC), non-infected cells that trap infectious virus on their surface through immune complexes (HIV-IC). Although several strategies have been employed to target and eliminate viral reservoirs, they are short-lived and ineffective. In an attempt to provide a long-term approach, chimeric antigen receptor T (CAR-T) cells were designed to eliminate native HIV on FDCs. Although effective at eliminating HIV-infected cells, and halting spreading infection, their ability to eliminate the viral reservoir found on (FDCs) remains unclear. We used a novel second-generation CAR-T cell expressing domains 1 and 2 of CD4 followed by the mannose binding lectin (MBL) to allow recognition of native HIV envelope (Env) to determine the capacity to respond to the viral reservoir found on FDCs. We employed a novel fluorescent lysis assay, the Carboxyfluorescein succinimidyl ester (CFSE) release assay, as well as flow cytometric based assays to detect functional CAR-T activation through IFN-γ production and CD107a (i.e., LAMP1) membrane accumulation to test cytolytic capacity and functional activation of CD4-MBL CAR-T cells, respectively. We demonstrated their efficacy at eliminating HIV-infected cells or cells expressing gp160. However, these CAR-T cells were unable to lyse cells bearing surface bound HIV-IC. We found that failed lysis was not a unique feature of a resistant target, but a limitation in the CAR-T recognition elements. CAR-T cells were inactive in the presence of free HIV or in the presence of concentrated, immobilized virus. Further experiments determined that in addition to gp120 recognition by the CAR-T, the adhesion molecule ICAM-1 was necessary for efficient CAR-T cell killing of HIV-infected cells. CAR-T cell activity and killing were inhibited in the presence of ICAM-1 blocking antibody. These results suggest that other factors, such as adhesion molecules, play a vital role in CAR-T responses to HIV-infected cells. In addition, our findings highlighted the necessity to consider all models of HIV reservoirs, including FDCs, when evaluating therapeutic efficacy.

No description available.

Advanced maternal age has been shown to influence follicular and luteal dynamics in bovine ovary resulting in reduced fertility. The overall objective of the four studies presented in this thesis is to identify the maternal age-associated transcriptional changes in granulosa cells of the dominant follicles during follicle development. In the first study, mRNA expression levels of housekeeping genes were measured by real–time quantitative PCR (RT-qPCR) in granulosa cells of dominant follicles and FSH-stimulated follicles to select and validate suitable reference genes for relative gene expression analyses during maternal and follicular aging. Stability of six reference genes (GAPDH, ACTB, EIF2B2, UBE2D2, SF3A1 and RNF20) was analyzed using GeNorm, DeltaCT and NormFinder programs and comprehensive ranking order was determined based on these programs. Geometric mean of multiple genes (UBE2D2, EIF2B2, GAPDH and SF3A1) was more appropriate reference control than individual genes for the comparison of relative gene expression among dominant and FSH-stimulated follicles during maternal and/or follicular aging studies. In the second study, maternal age-associated changes in the transcriptome of granulosa cells recovered at the time of selection of the dominant follicle from aged (n=3) and young cows (n=3) were determined by EmbryoGENE bovine oligo-microarrays (EMBV3, Agilent Technology). The mRNA expression of five transcripts (CYP19A1, PCNA, GJA1, TPM2, and VNN1) was confirmed in a different set of granulosa cell samples by RT-qPCR to validate microarray data. A total of 169 genes/isoforms were differentially expressed (≥ 2-fold-change; P ≤ 0.05) in aged cows vs. young cows. These transcripts revealed inefficient 1) control of gonadotropins, and gonadotropin-induced changes in the cytoskeleton and extracellular matrix, 2) lipid metabolism and steroidogenesis 3) cell proliferation, cell cycle control and intercellular communication, and 4) higher oxidative stress responses in aged cows vs. young cows. In the third study, changes in the transcriptome of granulosa cells of the preovulatory follicle 24 h after LH treatment from aged (n= 3) and young (n=3) were determined. A total of 1340 genes were expressed differentially (≥ 2-fold change; P ≤ 0.05) in aged cows vs. young cows. The mRNA expression of five transcripts (RGS2, PTGS2, TNFAIP6, VNN1, NR5A2 and GADD45B) was confirmed in a different set of granulosa cell samples to validate microarray data. These transcripts were related to delayed 1) response to LH treatment 2) cellular differentiation and luteinization and 3) progesterone synthesis. Intra-follicle levels of progesterone were lower (P < 0.05) in aged cows compared to young and mid-aged cows. The fourth study compared the aged-associated changes in the transcriptome of granulosa cells during follicle development from the time of dominant follicle selection to preovulatory stage (24 h after LH). In comparison to young cows, aged cows expressed fewer differentially expressed genes/isoforms (1206 vs. 2260, respectively) at ≥ 2-fold-change (P ≤ 0.05) in the granulosa cells of the preovulatory (24 h after LH treatment) vs. the dominant follicle at selection. These transcripts in aged cows were related to late and inefficient 1) organization of cytoskeleton and cytoplasm, 2) differentiation, 3) lipid and cholesterol metabolism, 4) proliferation and 5) higher response to oxidative stress and free radical scavenging in the preovulatory follicles vs. the dominant follicle at selection. In conclusion, maternal age-alters the gene expression of granulosa cells of the dominant follicles during follicle development and results in a compromised follicular environment.

Indiana University-Purdue University Indianapolis (IUPUI) / Germinal Centers (GCs) are transient lymphoid structures that arise in lymphoid organs in response to T cell-dependent antigen. Within the GC, follicular T helper (TFH) cells promote GC B cell differentiation and in turn the proper antibody production to protect us from invading pathogens. We wished to study the regulation of this process by transcription factors STAT3 and Bcl6. STAT3 is important for both TFH cell differentiation and IL-4 production by Th2 cells. IL-4 is a major functional cytokine produced by TFH cells. To dissect the role of STAT3 in IL-4 production by TFH cells, we generated T cell-specific conditional STAT3 knockout mice (STAT3KO). Compared to WT mice, TFH cell differentiation in STAT3KO mice was partially impaired, both in spleen following sheep red blood cells (SRBC) immunization and in Peyer's patches (PPs). In STAT3KO mice, the numbers of splenic GC B cells were markedly decreased, whereas PP GC B cells developed at normal numbers and IgG1 class switching was greatly increased. Unexpectedly, we found that STAT3 intrinsically suppressed the expression of IL-4 and Bcl6 in TFH cells. Mechanistically, in vitro repression of IL-4 expression in CD4 T cells by Bcl6 required STAT3 function. Apart from TFH cells, the GC reaction is also controlled by regulatory follicular T helper (TFR) cells, a subset of Treg cells. To study the mechanism of how TFR cells regulate the GC reaction, we generated mice specifically lacking TFR cells by specifically deleting Bcl6 in Treg cells. Following immunization, these "Bcl6FC" mice developed normal TFH and GC B cell populations. However, Bcl6FC mice produced altered antigen-specific antibody responses, with reduced titers of IgG and increased IgA. Bcl6FC mice also developed IgG antibodies with significantly decreased avidity to antigen in an HIV-1 gp120 "prime-boost" vaccine model. Additionally, TFH cells from Bcl6FC mice produced higher levels of Interferon-γ, IL-10 and IL-21. Loss of TFR cells therefore leads to highly abnormal TFH and GC B cell responses. Overall, our studies have uncovered unexpected regulatory roles of STAT3 in TFH cell function as well as the novel regulatory roles of TFR cells on cytokine production by TFH cells and on antibody production.

bgbrady@hotmail.com / The primary intestinal follicular lymphoma is a rare disease described in the last classification of lymphomas from WHO. It is a localized disease with excellent prognosis. We describe in this article ,a 64 year-old Peruvian female with abdominal pain and delayed vomiting for the last two years, has undergone a partial intestinal resection due to bowel obstruction. There was a well-circumscribed annular tumor. A diagnosis of non-polypoid primary intestinal follicular lymphoma was made. We report the case and review the literature in this article. / El linfoma folicular primario intestinal es un desorden raro descrito en la última clasificación de linfomas de la WHO. Es una entidad localizada con excelente pronóstico. En el presente artículo, reportamos una mujer peruana de 64 años de edad diagnosticada con linfoma folicular primario intestinal. Ella tuvo dos años con dolor abdominal y vómitos tardíos. Ella desarrolló una obstrucción intestinal y tuvo una resección completa del tumor. Se describe el caso y se realiza una revisión de la literatura de esta entidad.

Antibody responses can be up- or down-regulated by passive administration of specific antibody together with antigen. Depending on the structure of the antigen and the antibody isotype, responses can be completely suppressed or enhanced up to a 1000-fold of what is seen in animals immunized with antigen alone. IgG suppresses primary antibody responses against erythrocytes. Suppression works well in mice lacking Fc-receptors for IgG, C1q, C3, or complement receptor 1 and 2 (CR1/2). Here, we demonstrate that IgG anti-NP given to mice together with NP-conjugated sheep erythrocytes, suppresses the generation of NP-specific extra-follicular antibody-secreting cells, NP-specific germinal center B cells, induction of memory and long-lived plasma cells. IgG increases antigen clearance but this does not explain the suppressed antibody response. It is demonstrated that IgG-mediated suppression of IgG responses is epitope specific, suggesting that epitope masking is the dominant explanation for IgG-mediated suppression of antibody responses. Both IgE and IgG3 can enhance antibody responses against soluble antigens. IgE-antigen complexes bind to recirculating B cells expressing CD23, an Fc-receptor for IgE.  Thirty minutes after intravenous administration, IgE-antigen is found in splenic follicles. Subsequently, germinal center responses, antigen-specific T cell proliferation, and antibody responses are enhanced. We show that also antigen conjugated to anti-CD23 can bind to CD23+ B cells and be transported to splenic follicles. CD11+ spleen cells, rather than CD23+ B cells, present IgE-antigen complexes to T cells. Here, it is demonstrated that CD8α− conventional dendritic cells is the CD11c+ cell population presenting IgE-antigen to T cells. IgG3-mediated enhancement is dependent on CR1/2. We find that IgG3-antigen complexes, administered intravenously to mice, bind to marginal zone B cells via CR1/2. These cells then transport IgG3-antigen into splenic follicles and deposit antigen onto follicular dendritic cells. Mice treated with FTY720, a drug which dislocates marginal zone B cells from the marginal zone, impairs this transport. Studies in bone marrow chimeric mice show that CR1/2 on both B cells and follicular dendritic cells are crucial for IgG3-mediated enhancement. In summary, these observations suggest that antibodies can feedback regulate antibody responses by modulating the access of antigen to the immune system.