Objective To study the impact of V2 mutations on neutralizing ability of HIV-1-specific neutralizing antibodies. Methods We tested the influence of L175P mutation to the neutralizing ability of V3-specific antibodies by pseudotype virus and the binding affinity of those V3-spesific antibodies to gpl20 monomer by ELISA. Results We found L175P mutation changed the neutralizing ability of V3-specific antibodies. However, L175P mutation showed no effects on the binding affinity of these antibodies to gpl20 monomer. Conclusion Our results revealed the L175P mutation at V2 loop changed the natural trimmer structure of gp120 and enhanced the neutralizing ability of V3-specific antibodies.

Objective To investigate the impact of mutations in the V2 domain of HIV-1 envelop glycoprotein (gp) 120 gene on the recognition of neutralizing antibodies (NAbs) specific to the other domains of gp120.MethodsHIV-1 pseudoviruses (JR-FL) containing wild type or V2-mutant gp120 monomers were constructed,and the neutralization of CD4-binding site-specific and CD4-induced NAbs to the HIV-1 pseudoviruses was observed.Enzyme linked immunosorbent assay(ELISA) was performed to evaluate the binding affinity of CD4-binding site-specific and CD4-induced NAbs to wild type or V2-mutant gp120.Results Neither CD4-binding site-specific nor CD4-induced NAbs could neutralize the wild type JR-FL pseudoviruses,but both of them could neutralize pseudoviruses containg the gp120 V2 mutant at a low concentration.There was no significant difference in the binding affinity to CD4-binding site-specific NAbs between the wild type and mutant gp120,while the ELISA binding curves of wild type and mutant gp120 against CD4-induced NAbs were separate,and the affinity of CD4-induced NAbs to the mutant gp120 (L175P) was notably higher than that to the wild type gp120.Conclusion The mutations in the V2 domain of HIV-1 gp120 may affect the antiviral activity of NAbs.

Objective To study the impact of HIV-1 V2 L175P mutation on the binding capability of anti-V3 neutralizing antibodies to HIV-1.Methods A series of eukaryotic cell expression plasmids were used to concatenate wild type and mutant env gene of HIV-1 and green fluorescent protein(GFP)gene.The recombinant plasmids were transfected into 293T cells to express HIV-1 gp120 protein on the surface of cells.The successfully transfected cells were screened by GFP florescence marker.Immunostaining and dual fluorescence flow cytometry were performed to test the binding affinity of several common V3 region specific neutralizing antibodies to wild type or mutant gp120 proteins.Results The mean fluorescence intensity(MFI)of mutant gp120-expressing 293T cells were significantly higher than that of negative control cells(expressing GFP).Flow cytometry showed that the curve for mutant gp120-expressing 293T cells was obviously different in shape and peak from that for the negative control,while most parts of the curve for the wild type gp120-expressing 293T cells overlapped with those for the negative control.Conclusion The V2 region mutation may increase the sensitivity of HIV-1 to the neutralization by V3 region specific antibodies.

A 55-year-old male patient presented with tense bullae on the extremities and trunk.Histological examination revealed subepidermal vesicles and superficial dermal infiltration of eosinophils and lymphocytes.The patient was primarily diagnosed with bullous pemphigoid.However,serum autoantibodies of the patient bound to the dermal side of salt-split skin,and no serum antibodies against BP180,BP230 or type Ⅶ collagen were detected by enzyme-linked immunosorbent assay.Hence,the diagnoses of bullous pemphigoid and epidermolysis bullosa acquisita were excluded.As Western blot and immunoprecipitation analysis showed,there existed antibodies capable of binding to a dermal antigen with a relative molecular mass of 200 000 in the serum of the patient.Based on the above findings,the patient was diagnosed as anti-laminin γ1 (p200) pemphigoid.

Objective:To summarize clinical characteristics of patients with Aspergillus fumigatus infection in a hospital in Nanjing, to preliminarily assess azole resistance in clinical isolates of Aspergillus fumigatus, and to investigate risk factors for the emergence of azole-resistant Aspergillus fumigatus. Methods:Clinical isolates of Aspergillus fumigatus were collected from inpatients in Department of Laboratory, Nanjing Drum Tower Hospital from March 2017 to February 2021. Clinical data on these infected patients were analyzed, azole sensitivity testing and mutation analysis of the cyp51A gene and its promoter region were performed for these Aspergillus fumigatus isolates. Results:A total of 201 strains of Aspergillus fumigatus were collected, and mainly isolated from sputum specimens. Among the infected patients, there were 131 males and 70 females, and their age were 64.2 ± 15.8 years. The patients were mainly collected from department of respiratory medicine (79 cases), department of intensive medicine (34 cases), department of rheumatology (19 cases), etc. Among these patients, common underlying diseases included interstitial pneumonia (32 cases), malignant tumors (18 cases), pneumonia (13 cases), trauma (12 cases), systemic lupus erythematosus (8 cases), etc. Drug susceptibility testing showed that 6 (2.99%) strains of Aspergillus fumigatus were resistant to itraconazole and posaconazole, and 3 patients infected with azole-resistant Aspergillus fumigatus had used antifungal drugs before testing. Sequencing was performed on the cyp51A gene and its promoter region in the 6 strains of azole-resistant Aspergillus fumigatus, and showed TR34/L98H/S297T/F495I mutation in 5 strains and TR34/L98H mutation in 1 strain. Conclusion:Compared with previously published data about azole resistance in China during 2010 -2015, the resistance of Aspergillus fumigatus to azoles in Nanjing Drum Tower Hospital did not increase from 2017 to 2021, and the mechanism of azole resistance was mostly associated with TR34/L98H/S297T/F495I mutation in the cyp51A gene and its promoter region.