bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mycobacterium tuberculosis and TLR2 agonists inhibit induction of type I IFN and MHC-I antigen cross processing by TLR9 (37.15)
Authors: Simmons Daimon , Canaday David , Liu Yi , Boom W. Henry , Harding Clifford 
Published: January 2023

Abstract
Dendritic cells (DCs) cross process exogenous antigens and present them by MHC-I molecules to CD8+ T cells specific for antigens from viruses and bacteria such as Mycobacterium tuberculosis (Mtb). Unmethylated CpG DNA signals through TLR9 to induce type I interferon (IFN-α/β), which enhances MHC-I antigen cross processing, but lipoproteins that signal through TLR2 do not induce IFN-α/β. We observed that Mtb, which expresses agonists of both TLR9 and TLR2, did not induce IFN-α/β or cross processing by murine DCs. Furthermore, Mtb and TLR2 agonists inhibited induction of IFN-α/β and DC cross processing by CpG DNA. Exogenous IFN-α/β effectively enhanced cross-processing of Mycobacterium bovis BCG expressing OVA, bypassing the inhibition of induction of endogenous IFN-α/β. Inhibition of the response to one TLR by another may affect the ultimate response to pathogens like Mtb that express agonists of multiple TLRs, including TLR2 and TLR9. This mechanism may contribute to immune evasion and explain why IFN-α/β provides little contribution to host immunity to Mtb. On the other hand, downregulation of certain TLR responses may benefit the host by preventing detrimental excessive inflammation that may occur in the presence of persistent infection.
Critical link between intracellular responses and innate autoimmunity in ischemia-reperfusion injury (37.39)
Authors: Lee Haekyung , Ko Eun Hee , Balroop Javi , Richardson Arlan , Zhang Ming 
Published: January 2023

Abstract
Reperfusion of the ischemic tissue may lead to acute ischemia/reperfusion (I/R) injury. Two theories are suggested for the mechanism of I/R injury. One involves intracellular responses to ischemia (e.g. reactive oxygen species, ROS), while the other involves extrinsic acute inflammation manifested as natural IgM-mediated innate autoimmunity. Whether the ROS-mediated mechanism plays a role in natural IgM-mediated mechanism is still unknown. We studied this important question by using transgenic (tg) mice overexpressing antioxidant enzyme, superoxide dismutase (SOD1) in a murine model of intestinal ischemia. If the intracellular response contributes to the extrinsic inflammation, we predict that inhibiting ROS mechanism will protect animals from natural IgM-mediated I/R injury. Our results showed that SOD1 tg have a significant reduction in intestinal I/R injury compared to wild-type littermates. In addition, the IgM mediated inflammatory response is blocked in SOD1 tg. We further explored whether cell membrane damage is the critical link between the generation of intracellular ROS and exposure of self antigens leading to the innate autoimmune response. A cell membrane stabilizer was applied to WT mice prior to I/R surgery, and mice had a significantly reduced I/R injury with blocked IgM-mediated complement activation. Therefore, our current study identified a critical link between the intracellular response to I/R injury and the first step in the innate autoimmune response.
Conjugation of a TLR5 agonist to the Plasmodium falciparum Circumsporozoite (CS) protein enhances murine and human Dendritic cells (DC) interaction in vitro and increases protective immunity following intranasal immunization in mice (37.4)
Authors: Carapau Daniel , Nacer Adela , Mitchell Robert , Meltzer Abby , Shaw Alan , Frevert Ute , Nardin Elizabeth 
Published: January 2023

Abstract
A needle-free malaria vaccine has been developed based on intranasal (I.N) immunization with a recombinant P. falciparum circumsporozoite (CS) protein conjugated to the TLR5 agonist flagellin. Mice immunized I.N, but not subcutaneously, with flagellin-modified CS developed sporozoite neutralizing antibodies that protect against challenge with a transgenic rodent parasite expressing P. falciparum CS repeats. To better understand the role of innate immune cells in the induction of protective immunity, we analyzed the interaction of flagellin-modified CS with murine bone marrow-derived dendritic cells (DC) and human monocyte-derived DC in vitro. The fusion protein was rapidly taken up by DC and remained detectable in the cytosol as long as 24 hours post antigen pulse. A murine DC line (D1), and a sub-population of human DC, matured and expressed increased levels of CD40 and CD86 following stimulation with flagellin-modified CS. In I.N. immunized mice, the Nasopharyngeal-associated Lymphoid Tissue (NALT) was enlarged 2-fold over naïve NALT, and increased levels of CD11c+ DC were observed by confocal microscopy and FACS analysis. NALT cell subpopulations exhibited a higher B:T cell ratio than those observed in lymph nodes. A better understanding of innate and adaptive immune responses elicited in NALT by TLR ligand-modified CS protein will help identify critical immune parameters required for the induction of sporozoite specific immunity that protects from malaria infection.
Modulation of pro-inflammatory mediators by IL-10 in mouse J774 macrophages stimulated with rMOMP-498 of Chlamydia trachomatis (37.5)
Authors: Yilma Abebayehu , Singh Shree , Taha Murtada , Dennis Evida , Mishra Manoj , Gunn Karyn , Dennis Vida 
Published: January 2023

Abstract
We have recently constructed several recombinant major outer membrane proteins (rMOMP) of Chlamydia trachomatis, as potential vaccine candidates. In vitro characterization of the rMOMP-498 (gene fragment corresponding to amino acids 187-344) revealed that it stimulated the production of IL-6, IL-12p40, IL-1β, TNF-α and IL-10 in mouse J774 macrophages. Since IL-10 is a modulator of macrophage activities, we hypothesized that IL-10 induced by rMOMP-498 in macrophages may serve to control inflammation during the initial phase of a C. trachomatis infection. To address our hypothesis we added exogenous mouse IL-10 to J774 cells stimulated with rMOMP-498. IL-10 decreased the production of IL-6, IL12p40 and TNF-α in these cells. Removal of endogenous IL-10 with neutralizing anti-IL-10 Ab in cultures stimulated with rMOMP-498 in part increased the levels of inflammatory mediators as compared to the control Ab. Analyses of CD80, TLR2, TLR4, and CD86 receptors on cells stimulated with rMOMP-498 alone or combined with IL-10 showed no differences in receptor expression levels between the stimulants, suggesting that these receptors are not involved in the IL-10 down-regulatory activities in rMOMP-498-stimulated macrophages. Overall, our data show that IL-10 may be important in the innate immune response to rMOMP-498 as a vaccine candidate. Current studies are underway to identify the mechanism of IL-10 control of the inflammatory response in macrophages.
A regulatory double negative - NKT and NK cell cross-talk regulates viral-specific CD4+ T cell responses. (38.9)
Authors: Raynor Jana , Lin Adora , Sholl Allyson , Van Kaer Luc , Mattner Jochen , Hoebe Kasper , Hildeman David 
Published: January 2023

Abstract
Natural killer T cells (NKT) express a T cell receptor, restricted to CD1d molecules, as well as natural killer (NK) cell markers. Two subsets of CD1d restricted NKT cells have been described, type I and type II. Although both subsets of NKTs are transiently activated during viral infection, little is known of their role in controlling virus-specific immune responses. Here, we assessed the role of NKT cells in the CD4+ T cell response to viral infection using a lymphocytic choriomeningitis virus (LCMV) central nervous system (CNS) infection model. We found the virus-specific CD4+ T cell response was significantly decreased in LCMV-infected CD1d-/- mice. Further, virally infected CD1d-/- mice had significantly reduced serum type I IFN and increased NK cells. Interestingly, viral-specific CD4+ T cell responses were normal in mice deficient in type I NKT cells, suggesting that type II NKT cells were critical for promoting CD4+ T cell responses. Finally, depletion of NK cells in CD1d-/- mice completely rescued their CD4+ T cell responses. Together, these results suggest a double negative regulatory circuit whereby NKT cells negatively regulate NK cells, which in turn negatively regulate CNS antiviral CD4+ T cell responses. These data also suggest that innate immune cells exert multilayered control over the magnitude of the CD4+ T cell response.
ICAM-1 deficiency results in enhanced maintenance of effector CD8 T cells following infection (39.3)
Authors: Cox Maureen , Bullard Daniel , Zajac Allan 
Published: January 2023

Abstract
CD8 T cell responses are critical for the control of intracellular pathogens, and one hallmark of an effective T cell response is the development of a memory T cell pool which can rapidly respond to reinfection. It is known that the presence of polyfunctional pathogen-specific T cells correlates with more effective protection from persistent infections as well as rechallenge; however the factors that lead to the development of these cells are still poorly understood. Interactions mediated by intercellular adhesion molecule 1 (ICAM-1) have been demonstrated to impact the quality of the T cell response, by enhancing both antigenic and cytokine signals. Utilizing mice deficient for ICAM-1, we investigated the effect of this molecule on T cell priming and the response to acute infections. No pronounced differences were observed in the effector T cell response to acute lymphocytic choriomeningitis virus (LCMV)-Armstrong infection in ICAM-1 deficient animals, however greater numbers of virus-specific cells displaying an effector phenotype (KLRG-1hi CD127lo IFNγ+ IL-2-) were maintained in ICAM-1 deficient mice at memory time points. These ICAM-1 deficient mice exhibited reduced expansion of virus-specific CD8 T cells following secondary challenge when compared to wild type mice, potentially due to already elevated numbers in ICAM-1 null mice. These data indicate a critical role for ICAM-1 in the development of immunological responses to viral pathogens.
Pulmonary Orthopoxvirus infection compromises a murine OVA peptide immune response in a dose-dependent manner (39.8)
Authors: Hrusch Cara , Lipscomb Mary , Wilder Julie , Lyons C. 
Published: January 2023

Abstract
Cowpox virus (CPXV), a close relative of variola virus that causes smallpox, can suppress the immune system through a large array of immunosuppressive gene products. We developed a murine model in which DO11.10 T cells specific for an OVA peptide were transferred into BALB/c mice to assess the impact of a pulmonary CPXV infection on DO11.10 T cell proliferation in lung draining lymph nodes following intranasal OVA peptide delivery. High and low-dose CPXV infections were compared. Both doses lead to clinical illness, but the high dose is lethal. A high-dose infection reduced DO11.10 T cell proliferation, but a low-dose infection did not. At the time that proliferation of T cells was assessed (6d),15±1% of lung dendritic cells (DCs) were infected at the high-dose, but only 5±1% of DCs at the low-dose. At both doses, infected and uninfected DCs had decreased expression of co-stimulatory molecules. We speculated that the lung microenvironment created by infection, rather than direct infection of the DCs, suppressed DC immune function. In support, we found that bronchoalveolar lavage fluid and supernatant derived from lung homogenates from infected mice suppressed the function of uninfected lung DCs in vitro. Furthermore, the suppressive activity was more highly concentrated in lungs from high-dose infected mice. These studies strongly suggest that orthopoxvirus infections create an immunosuppressive microenvironment that compromises the host pulmonary immune responses.
How do airborne fungal spores avoid immune recognition? (40.1)
Authors: Bayry Jagadeesh , Aimanianda Vishukumar , Bozza Silvia , Kniemeyer Olaf , Perruccio Katia , Elluru SriRamulu , Clavaud Cecile , Paris Sophie , Brakhage Axel , Kaveri Srini , Romani Luigina , Latgé Jean-Paul 
Published: January 2023

Abstract
Every day we inhale thousands of tiny fungal spores (conidia), originating from many different fungal species such as Aspergillus, Cladosporium, Penicillium and Alternaria. Although these spores are packed with antigens and allergens, yet their inhalation does not continuously activate our innate immune cells or provoke inflammatory responses. By using several fungal inhabitants of the air-borne microflora including the human opportunistic fungal pathogen Aspergillus fumigatus, in vitro assays using human dendritic cells (DC) and alveolar macrophages (AM) and in vivo experiments using a murine model we show that a protein surface-layer called ‘rodlet’ on the dormant conidia masks their recognition by the immune system and hence prevents immune response to conidia. Interestingly, rodlet proteins are found to be immunologically inert and failed to activate either human or mouse DC and AM and did not induce adaptive T responses in vivo upon transfer of rodlet-pulsed DC. Furthermore, dormant conidia that lacked rodlet layer induced strong immune responses in vitro and in vivo despite being dormant in nature. All these results indicate that rodlet layer on dormant conidia masks the immunogenic molecules and prevent immune aggression against inhaled conidia.
Staphylococcus aureus specific memory CD8 T cells in dairy cows (40.12)
Authors: Mullarky Isis , Waithaka Mwangi , Bharathan Mini 
Published: January 2023

Abstract
Staphylococcus aureus is a versatile pathogen that causes disease in both humans and animals. An increase in occurrence of nosocomial infections and chronic mastitis caused by antibiotic resistant strains warrants the need for an effective vaccine. This study assessed the presence of S. aureus specific memory T cells (Tm) in previously infected cows using CD14+ monocyte derived dendritic cells (DC). Results indicate that DC are able to uptake and recognize S. aureus antigens through various pattern recognition receptors (PRRs). Blocking of endocytic pathways using inhibitors confirmed S. aureus uptake by DC. S. aureus stimulated DC showed increased cell surface expression of MHC I and II and cytokine production suggesting activation and antigen presentation. An initial screening study for Tm in cows previously infected with S. aureus showed a significant increase in lymphocyte proliferation compared to control animals. To characterize the proliferating population of Tm, CFSE labeled lymphocytes were co-cultured with irradiated or live S. aureus stimulated autologous DC from previously infected cows identified as CD4, CD8 and WC1+ γδ T cells by flow cytometry. Proliferated CD4 and CD8 T cells were further characterized for memory markers, CD45RO and CD62L. Being the first study to show the presence of S. aureus specific CD8 Tm cells, our next step is to identify the S. aureus antigens that initiate T cell clonal expansion.
Immunobiological Signaling in response to S. aureus Extracellular adherence protein (Eap) (40.27)
Authors: Liubchenko Ganna , Ostapchenko Liudmyla 
Published: January 2023

Abstract
Staphylococcus aureus is an important pathogen that affects a significant part of population and presents a major clinical problem. Extracellular adherence protein (Eap) is expressed on the surface of S. aureus and has been implicated in endothelial adhesion and evasion of host immune mechanisms. This study demonstrates several novel signaling properties elicited by Eap in B lymphocytes. Our results indicate the involvement of ICAM-1-mediated signaling pathway(s) that trigger previously uncharacterized rapid intracellular Ca2+ mobilization and protein phosphorylation (pTyr) events in B lymphocytes upon exposure to Eap. Furthermore, combined application of protein A and Eap to intact murine (C57BL/6) B lymphocytes induced co-clustering of the B cell receptor (sIgM) and ICAM-1 in immune synapse-like structures. This effect may be attributed to the previously described ability of protein A to bind sIgM and act as B cell superantigen. Thus, sIgM/ICAM-1 clusters may form in the absence of antigen and Eap may play arole in this process. We hypothesize that the ability of Eap to interfere with B cell receptor signaling regardless of antigen specificity may play a role antigenic mimicry and premature internalization of sIgM signaling complexes in B cells and thus help S. aureus to evade B cell immune responses.
Mannose lipoarabinomannan from Mycobacterium tuberculosis inhibits T cell migration to sphingosine-1-phosphate and promotes trapping of T cells in lung draining lymph nodes. (40.3)
Authors: Richmond Jillian , Lee Jinhee , Green Daniel , Kornfeld Hardy , Cruikshank William 
Published: January 2023

Abstract
Humans and mice that have been infected with Mycobacterium tuberculosis (MTB) develop lymphadenopathy in lung draining lymph nodes. To determine a possible mechanism for this, we examined human and mouse T cell migration to the lymph node chemoattractant CCL21 and to sphingosine-1-phosphate (S1P) following exposure to various TB components. Mannose lipoarabinomannan (ManLAM), a glycolipid from the MTB cell wall, did not alter T cell migration to CCL21; however, ManLAM did significantly inhibit T cell migration to S1P. As S1P is the primary factor required for egress from lymph nodes, this suggested a potential mechanism. To determine whether this effect could be established in vivo ManLAM was administered intratracheally to C57BL/6J mice. Accumulation of T cells was detected in lung-draining lymph nodes within 24 hr with a four to five fold increase in total T cell numbers. Accumulation patterns were similar to mice that had been infected with Erdman TB for 4 weeks, as both groups exhibited a preferential trapping of Th1 cells. Our data provide evidence that ManLAM may be a primary factor for MTB-associated lymphadenopathy during MTB infection. We hypothesize that alteration in T cell homing patterns induced by ManLAM would affect normal host immune responses and thus potentially facilitate infection by the bacterium.
Mannose lipoarabinomannan from Mycobacterium tuberculosis promotes production of soluble TNF Receptors I & II. (40.4)
Authors: Richmond Jillian , Schuller Elizabeth , Lee Jinhee , Remick Daniel , Kornfeld Hardy , Cruikshank William 
Published: January 2023

Abstract
Serum and BAL fluid from mice that had been infected with Erdman Mycobacterium tuberculosis (MTB) for 6 months were analyzed with an in-house multiplex ELISA system. Out of the panel of cytokines tested, the cytokines that exhibited the largest increase in both serum and BAL as compared with uninfected mice were soluble TNF Receptors I & II. This is consistent with current literature demonstrating that soluble TNF Receptors increase over time during TB infection. To determine the potential source of the TNFRs as well to identify the stimulant, murine T cells were treated ex-vivo with a panel of MTB components. It was determined that the MTB cell wall component Mannose lipoarabinomannan (ManLAM) (10 or 100ng/ml) was able to induce a significant increase in sTNFRI & II following treatment overnight. To confirm the ability of ManLAM alone to induce TNFRs, serum and BAL from mice that had received 25ug purified ManLAM intratracheally exhibited elevated sTNFRI & II 24h following instillation. ManLAM was not able to induce increases in TNF alpha in vitro or in vivo, which is consistent with current literature. These data indicate the ability of ManLAM alone to induce elevated soluble TNFR production from T cells, thereby shifting the balance between TNF alpha and TNF soluble receptors. Based on the role of TNF in granuloma formation and maintenance during MTB infection, this could potentially contribute to the inability of mice to form proper granulomas.
Hiding in Plain Site: The Immune System, Tuberculosis, and Antibiotic Resistance (41.6)
Authors: Stephansky Mark 
Published: January 2023

Abstract
This summer I worked in the Cruikshank lab at the Boston University School of Medicine. The Cruikshank research team determined that mannose lipoarabinomannan, (ManLAM), a cell wall component of M. tuberculosis can decrease S1P sensitivity of activated T cells as well as to alter production of selected cytokines. These alterations likely affect the normal immune response by changing T cell homing patterns and decreasing production of response cytokines thereby increasing the mTB’s chances of survival and optimal infection. This research inspired me to create a high school biology unit. This unit is designed to link the study of the immune system with evolution through a closer examination of mTB, particularly, its two main forms: latent TB infection and active TB disease. The unit includes teacher presentations and demonstrations, an internet activity entitled TB in the Media, and laboratory activities. Students are first introduced to the basic functions of the immune system through its defense against Mycobacterium tuberculosis infection. Then, students work through a simulated ELISA to see its importance in diagnosing disease. Finally, we turn to the emergence of multi-drug resistant mTB as students carry out a laboratory exercise on bacterial transformation. Students present a summary of their learning through the creation of a pamphlet/poster where they investigate a specific disease and describe its symptoms, treatments, suggested causes and immune system interactions.
Interferon-γ and Interferon-γ receptor knockout mice are not created equal: examination of cellular signaling and control of alphavirus infection. (42.12)
Authors: Schultz Kimberly , Lee Eun Young , Griffin Diane 
Published: January 2023

Abstract
Interferon-γ (IFN-γ) is a central mediator of the immune response to viral encephalitis. IFN-γ knockout (GKO) and IFN-γ receptor knockout (GRKO) mice have been used interchangeably to examine signaling pathways that control virus infection. GKO mice are unable to produce IFN-γ whereas the alpha chain of the IFN-γ receptor is deleted in GRKO mice. Upon alphavirus infection, both strains of mice succumb to infection with a similar timecourse, however GRKO mice show increased inflammatory cell infiltration and MHC-II-positive cells in the central nervous system compared to GKO mice. Cellular signaling through the mutated receptor was further examined by using mouse embryonic fibroblasts (MEFs). GRKO MEFs were unable to control virus replication in response to IFN-γ treatment. Additionally, signaling through major antiviral IFN-γ receptor pathways (i.e. STAT1) in response to IFN-γ treatment was suppressed in GRKO MEFs as compared to control MEFs. However, inflammatory signaling was intact in GRKO MEFs (i.e. TNFα). These studies indicate that, the mutated IFN-γ receptor can mediate some signaling in response to IFN-γ and therefore, GRKO mice cannot be used interchangeably with GKO mice. This signaling may account for the increased inflammatory cell infiltration in GRKO mice as compared to GKO mice during alphavirus infection.