In this task, you're given a paragraph from the research paper and your task is to generate a suitable title for the research paper based on the given paper. Under 100 words is a good title length.
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Question: A potent immunosuppressive drug cyclosporin A (CsA) is known to inhibit human cell infection by the pathogenic protozoan parasite Leishmania major both in vitro and in vivo. The proposed mechanism of action involves CsA binding to Leishmania major-expressed cyclophilin and subsequent down-regulation of signaling events necessary for establishing productive infection. Recently, we identified a ubiquitously expressed membrane protein, CD147, as a signaling receptor for extracellular cyclophilins in mammalian cells. Here we demonstrate that, while being enzymatically active, the Leishmania cyclophilin, unlike its human homologue, does not interact with CD147 on the cell surface of target cells. CD147 facilitates neither Leishmania binding nor infection. Primary structure and biochemical analyses revealed that the parasite's cyclophilin is defective in heparan binding, an event required for signaling interaction between CD147 and human cyclophilin. When the heparan-binding motif was reconstituted in Leishmania cyclophilin, it regained the CD147-dependent signaling activity. These results underscore a critical role of cyclophilinheparan interactions in CD147-mediated signaling events and argue against the role of Leishmania cyclophilin in parasite binding to target cells.

Answer: Functional analysis of Leishmania major cyclophilin

Question: publicly funded repositories, such as the WHO COVID database with rights for unrestricted research re-use and analyses in any form or by any means with acknowledgement of the original source. These permissions are granted for free by Elsevier for as long as the COVID-19 resource centre remains active. factors and the gene regulatory network in Escherichia coli. Nucleic Acids Res. 31, 1234-1244 15 Richter, G. et al. (1997 Biosynthesis of riboflavin: characterization of the bifunctional deaminase-reductase of Escherichia coli and Bacillus subtilis.

Answer: Biosynthesis of riboflavin. Lumazine synthase of Escherichia coli

Question: By using peripheral blood samples from 221 cases of severe acute respiratory syndrome (SARS), 34 of Mycoplasma pneumoniae infection, and 44 healthy adults, we measured the total number of natural killer (NK) and CD158b+ NK cells (CD158b+ NK) using flow cytometric analysis and calculated the percentage of CD158b+ NK cells. The total number of NK and CD158b+ NK cells and the percentage of CD158b+ NK cells were significantly lower in patients with SARS than in those with M pneumoniae infection (P < .05 for all) and healthy subjects (P < .01, P < .01, P < .05, respectively); in 72 patients with severe SARS than in 149 with mild SARS (P < .05 for all); and in 174 cases of SARS with anti-SARS coronavirus-specific IgG and/or IgM antibodies than in 47 without antibodies (P < .05, P < .01, P < .01, respectively). There were no significant differences for the 3 values among patients with SARS without anti-SARS coronavirus antibody, patients with M pneumoniae infection, and healthy subjects. The number of NK cells and the expression of CD158b on the surface of NK cells changed in patients with SARS and correlated with disease severity and the presence of anti-SARS coronavirus-specific antibodies; SARS differed from M pneumoniae infection in pathogenesis involving NK cells. Monitoring the total number of NK and CD158b+ NK cells and the percentage of CD158b+ NK cells might aid in differentiating SARS from M pneumoniae infection. Materials and Methods This study included a cohort of 221 patients with SARS who were admitted to hospitals in the Beijing, China, area

Answer:
The Involvement of Natural Killer Cells in the Pathogenesis of Severe Acute Respiratory Syndrome