Vaccine potential of cytosolic proteins loaded fibrin microspheres of Cryptococcus neoformans in BALB/c mice
Authors: Arun Chauhan
Mohammad Owais
Azmat Ali Khan
Mumtaz Jabeen
Journal: Journal of drug targeting (2012)
Discipline: PHARMACOLOGY & TOXICOLOGY
Keywords: Cryptococcosis; vaccine; Cryptococcus neoformans; cytosolic proteins; PLGA microsphere
Affiliations: Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh, India. 

Abstract:  Cryptococcosis is a leading mycological cause of mortality among immunologically compromised individuals. In order to develop an effective vaccine against Cryptococcus neoformans, the cytosolic proteins (Cp) of the pathogen have been used as an antigen in combination with different formulations. In the present study, we have demonstrated that Cp encapsulated poly-lactide co-glycolide (PLGA) microsphere further co-encapsulated into the biocompatible fibrin cross-linked plasma beads (Fib-PLGA-Cp) mediated cytosolic delivery elicited strong immune response in the BALB/c mice. In contrast, other formulations of Cp failed to impart significant level of protection. The immune response, involved with Fib-PLGA-Cp protection, appear to interact with the target cells by both endocytosis as well as membrane fusion mode, thus helping in the activation of both CD4(+) and CD8(+) T-cells. Analysis of cytokine profiles in immunized animals revealed that the protective response was associated with the Th1/Th2 polarization in favor of type-1 cytokine [interferons (IFN)-Œ≥ and interleukin (IL)-2] cells. Furthermore, vaccination with Fib-PLGA-Cp elicited high immunoglobulin (Ig) G(l) and IgG(2a) isotype response; successfully cleared fungal burden in vital organs and also increased the survival rate of immunized animals. Altogether the present study is a clear indicative of the possible use of fibrin microsphere-based targeted delivery of cytosolic proteins to induce protective immune responses against experimental murine cryptococcosis. 

Retracted: No

PubPeer comments:
 Figure 1B shows several fibrin microspheres next to a ruler. The text says that the diameter varied from 1.08 to 1.67 mm. However, all microspheres look exactly the same. Same size, same shape, same blob at the top, same little stripe at the bottom, same reflection. Is this a real photo?  , 
 Figure 7 shows flow cytometry panels from T-cells from mice immunized with various formulations of yeast proteins. There are some unexpected similarities, however, between several panels. In particular, similar constellations of dots are visible across the CD4+ panels in c (Fib-Cp), d (PLGA-Cp), and e (Fib-PLGA-Cp), and in the CD8+ panels of b (Cp) and c (Fib-Cp). Boxes of the same color show similar groups of dots.  , 
 Table 1 appears to have several standard deviations that are identical, while the means are different. All the SDs are also very low (less than 1%), which is unusual in any biological measurements. Boxes of the same color show SDs values that are identical. Could the authors please provide the raw data?  , 
 #3 We did this experiment 12 years back. I scanned my whole system. I am unable to find the raw file of this experiment in my system. I also asked all the coauthors but they also donu2019t have the raw data file. As per my knowledge, there was very close similarity in the triplicate values. #2 Luckily I had the raw images of flow cytometer data. For your convenience I am sending you the raw images that were directly retrieved from the flow cytometer. The pixel similarity might be due to auto-fluorescence.           #1 This is the real photo taken by the phone camera (I think it was of some Nokia model). Because the picture is taken at an angle on the glass slide there is similarity in light reflection. As far as same shape is concerned, Fibrin microspheres were formed with small volume of 3u00b5l using micropipette. All beads are not of same size, and the size variation is within very lesser range of 1 mm. Moreover, the scale has been aligned afterwards. ,