Classical KP Research Articles

Lung infection with classical Klebsiella pneumoniae strains establishes robust macrophage-dependent protection against heterologous reinfection

At present, there is no approved vaccine for prevention of infection by the opportunistic bacterium Klebsiella pneumoniae (Kp); success in treating these infections is increasingly challenged by the spread of antibiotic resistance. Preclinical investigation of adaptive immunity elicited by lung infection with live classical Kp may reveal host mechanisms of protection against this pathogen. Here, we utilize multiple virulent classical Kp strains to demonstrate that following lung infection, surviving wild-type mice develop protective immunity against both homologous and heterologous (heterotypic) reinfection. For Kp strains with low capacity to disseminate from the lung, this immunity is B-cell-independent. We further demonstrate that this immune protection is also effective against subsequent challenge with hypervirulent Kp if the strains share the same capsule type. Systemic inoculation fails to elicit the same protective effect as lung inoculation, revealing a lung-specific immune effector function is responsible for this protection. We therefore utilized clodronate-loaded liposomes to substantially deplete both alveolar macrophages and lung interstitial macrophages, finding that simultaneous depletion of both subsets entirely ablates protection. These findings indicate that following initial lung infection with Kp, lung macrophages mediate protection against ensuing Kp challenge.

Exploring reduced macrophage cell toxicity of hypervirulent Klebsiella pneumoniae compared to classical Klebsiella pneumoniae

Bacterial pneumoniae caused by Klebsiella pneumoniae (Kp) is a major concern due to the prevalence of multiple antibiotic-resistant strains, which limit treatment options and increase mortality rates. Patients with Kp infections often experience an uncontrolled immune response in the lungs, leading to excessive inflammation and elevated levels of proinflammatory cytokines. This study aimed to investigate the cytotoxicity, the inflammatory cytokine response, and the longevity of intracellular bacterial load in RAW 264.7 macrophages, infected with two different Kp strains - cKP (HKU1: Classical Kp) and HvKP (17ZR101: Hypervirulent Kp). This study found that after infecting macrophages with cKP and HvKP, the internalization rate was faster and the intracellular cKP load was higher than that of HvKP. Additionally, the number of intracellular Kp was correlated with the presence of M1 macrophage polarization marker CD86 and expressions of proinflammatory cytokines. Interestingly, the expression of these proinflammatory cytokines was significantly higher in cKP-infected macrophages than in HvKP-infected macrophages. Thus, a higher intracellular cKP load is suggested to play a significant role in causing more proinflammatory cytokines and killing macrophages compared to HvKP infection. This finding highlights the importance of understanding the mechanisms behind Kp infections and developing effective treatment strategies.

(2+1)-dimensional KdV, fifth-order KdV, and Gardner equations derived from the ideal fluid model. Soliton, cnoidal and superposition solutions

We study the problem of gravity surface waves for an ideal fluid model in the (2+1)-dimensional case. We apply a systematic procedure to derive the Boussinesq equations for a given relation between the orders of four expansion parameters, the amplitude parameter α, the long-wavelength parameter β, the transverse wavelength parameter γ, and the bottom variation parameter δ. Such an approach, known in (1+1)-dimensional theory, is extended for the first time for (2+1)-dimensional shallow water waves. Using this procedure, we derived the only possible (2+1)-dimensional extensions of the Korteweg–de Vries equation, the fifth-order KdV equation and the Gardner equation in three cases of the relationship between these parameters. All these equations are non-local. When the bottom is flat, the (2+1)-dimensional KdV equation can be transformed to the Kadomtsev–Petviashvili equation in a fixed reference frame and next to the classical KP equation in a moving frame. Thus, the Kadomtsev–Petviashvili equation gained a derivation from the fundamental laws of hydrodynamics. We have found soliton, cnoidal, and superposition solutions (essentially one-dimensional) to the (2+1)-dimensional Korteweg–de Vries equation and the Kadomtsev–Petviashvili equation.

T cell immunity to a classical strain of Klebsiella pneumoniae

Abstract Klebsiella pneumoniae (Kp) is a versatile pathogen capable of causing numerous infections that are becoming increasingly difficult to treat due to increasing antibiotic resistance. Kp strains are categorized into two distinct pathotypes: classical and hypervirulent, which exhibit critical differences in pathogenesis. Despite causing the majority of clinical cases, adaptive immunity resulting from classical Kp infections is poorly understood. Our laboratory has recently developed a model of adaptive immunity to live infection with classical Kp in which wild-type mice surviving primary infection are protected from morbidity and mortality upon rechallenge. Passive transfer of convalescent serum from surviving mice to naïve recipients does not confer protection against cKp infection, suggesting antibody responses alone are inadequate to protect against cKp. CD69+CD4+ T cells and γδ T cells expand dramatically in the lung following primary cKp infection and mice deficient in T cells are not protected from reinfection, indicating a requirement for T cells in the protective response. Further analysis of mice deficient in either classical αβ T cells or γδ T cells indicates that either T cell subset is capable of mediating protective immunity against Kp reinfection. Production of IL-17A by both CD4 and γδ T cells is enhanced during secondary infection. Together these data indicate that a natural course of infection with classical Kp elicits populations of classical T cells and γδ T cells that mediate protection against reinfection, likely through the rapid production of IL-17A. These results will ultimately inform rational design of vaccines and immunotherapies to prevent and treat Kp infection. Supported by AAI Careers in Immunology Fellowship

Quantitative estimation of local geomagnetic activity relative to the level of the magnetically quiet period in 2009

A new method for determining geomagnetic activity based on calculation of the hourly amplitudes of geomagnetic field variations at ground-based observatories has been developed. Observations performed in 2009, when unusually low solar and geomagnetic activity was registered, were used as a reference level. The described method was used to estimate the energy of local geomagnetic activity; such energy is estimated for observatories in the Earth’s Northern and Southern hemispheres, and a total estimation is made for both hemispheres and for the entire Earth’s surface during large magnetic storms. These are used to compare characteristics of magnetic storm intensity based on the classical Kp and Dst indices and calculated energy estimate.

The master T-operator for the Gaudin model and the KP hierarchy

Following the approach of [1], we construct the master T-operator for the quantum Gaudin model with twisted boundary conditions and show that it satisfies the bilinear identity and Hirota equations for the classical KP hierarchy. We also characterize the class of solutions to the KP hierarchy that correspond to eigenvalues of the master T-operator and study dynamics of their zeros as functions of the spectral parameter. This implies a remarkable connection between the quantum Gaudin model and the classical Calogero–Moser system of particles.

Quantum Gaudin model and classical KP hierarchy

This short note is a review of the intriguing connection between the quantum Gaudin model and the classical KP hierarchy recently established in [1]. We construct the generating function of integrals of motion for the quantum Gaudin model with twisted boundary conditions (the master T-operator) and show that it satisfies the bilinear identity and Hirota equations for the classical KP hierarchy. This implies that zeros of eigenvalues of the master T-operator in the spectral parameter have the same dynamics as the Calogero-Moser system of particles.

Remarks on the full dispersion Kadomtsev-Petviashvli equation

We consider in this paper the Full Dispersion Kadomtsev-Petviashvili Equation (FDKP) introduced in [19] in order to overcome some shortcomings of the classical KP equation. We investigate its mathematical properties, emphasizing the differences with the Kadomtsev-Petviashvili equation and their relevance to the approximation of water waves. We also present some numerical simulations.

Two dimensional KP systems and their solvability

In this paper we introduce new various generalizations of the classical Kadomtsev-Petviashvili hierarchy in the case of operators in several variables. These generalizations are the candidates for systems that should play the role, analogous to the role of the KP hierarchy in the classical KP theory, in a generalized KP theory. In particular, they should describe flows of some generalized geometric datas, including those described by A.N.Parshin, for certain initial conditions. The unique solvability of the initial value problem for the generalized KP hierarchies is established. The connection of these systems with universal families of isospectral deformations of certain pairs of commuting differential operators is opened. To prove the solvability of the systems we generalize several results from the works of M.Mulase and A.N.Parshin.

Symmetries of the Classical Integrable Systems and 2-Dimensional Quantum Gravity: a `Map'

Abstract We draw attention to the connections recently established by others between the classical integrable KdV and KP hierarchies in 1 + 1 and 2 + 1 dimensions respectively and the matrix models which relate to the partition functions of 2-dimensional (1 + 1 dimensional) quantum gravity. The symmetries of the classical KP hierarchy in 2 + 1 dimensions are fundamental to this connection.

On Soliton Equations of Exceptional Type

The main purpose of this paper is to present an explicit formula for the general hierarchy of soliton equations constructed by Kac-Wakimoto from the basic representation of an arbitrary affine Kac-Moody algebra. The results turn out that the differential operators of the corresponding Hirota bilinear equations can be written explicitly in terms of skew Schur functions for both principal and homogeneous hierarchies. The principal hierarchy includes the classical KP and KdV equations. The homogeneous hierarchy turns out to be related to the classical non-linear Schrodinger equation for type A(1)1 and to the classical 2-dimensional Toda lattice equation for type A(1)2.